Laser Interferometer Gravitational-Wave Observatory

LIGO Caltech 40 meter prototype Upgrade

WEEKLY REPORTS ARCHIVE

May 27, 2004

• Osamu, Bryan, Seiji and Alan have been working to confirm and check the observation that the "sidebands on sidebands" applied by two EOMs in series cause a large contamination of the arm signals (CARM and DARM) onto the short dof double-demod signals (PRC, SEC, MICH), severely complicating lock acquisition and control of the Advanced LIGO optical configuration. This is documented in a set of ppt slides from Osamu, his SPIE paper, and a detailed analysis by Bryan Barr.
• Bryan was able to get reasonably good separation between the arm and short degrees of freedom by careful choice of demod phases, at the expense of large offsets and exceedingly tight demod phase tolerances. Not a practical solution.
• Fortunately, a practical solution is easy to implement: a Mach-Zehnder interferometer on the PSL table, with one EOM in one arm and another in the other. This requires a control system to lock the M-Z via internal modulation (two beamsplitters, an RFPD and demod board, servo filter, pzt mirror actuator), all of which are being acquired now. A very preliminary draft design by Osamu, Bryan, Seiji and Steve is here. It includes an analysis of the frequency and intensity noise introduced by the M-Z; we think it will be negligible. We hope to assemble the system in the next week or 2.
• Osamu will re-measure the PSL frequency noise and intensity noise, before and after implementing the M-Z.
• The PSL, mode cleaner, and FPMI interferometer all continue to lock well and stably. All oplevs and QPDs are centered and the spots come back to where they were before, between locks (we don't leave the FPMI locked routinely).
• Jay reports that the LSC rack cross-connect wiring changes for the double-demod boards are done, all the modules are in hand, and code for the new lsc auxiliary crate 2 will go in next week.
• Rolf is ready to put the new front end LSC software in next week. Rob is working on a first draft of the InputMatrix40m code.
• Rob is also thinking about machine-learning methods for finding the ideal demod phases for double-demod length sensing.
• Ben has been working on the LSC/ASC RF distribution drawings. These drawings are intertwined with Jay's LSC drawings, and usher in a new wiring for the 1x2 rack. This rewiring will be accomplished by Tuesday, along with the cabling of the cross-connects to the modules. This will make the hardware be in place in time for the software's arrival.
• Osamu found a problem with an LSC PD Interface board. Ben took it back to the shop for troubleshooting. He fixed it and it now works fine. There was a bad logic chip that disabled the 1st two PDs.
• Bob has installed heliac cables for all long RF runs.
• Osamu continues to work on the frequency stability servo, implementing some changes that he has planned for a long time.
• Flavio and Peter King have been working on the ISS for the 40m PSL, implementing changes to the servo filter and the current shunt actuator that were developed on the LASTI PSL; the block diagram is here. Preliminary results look very nice. The changes to the current shunt caused the power of the PSL to drop from 10.8 W to 10.4 W.
• The readout board for the TRY QPD is not working; Ben will look at it.
• Ben Olsen and Steve have been diagnosing problems with the STACIS seismic isolators. There is one bad controller (of 4), and at least 3, maybe 4, bad isolators (out of 12). At least one shows evidence that the PZT stacks are burnt out. They will continue to diagnose the problems, before we start sending pieces of the system back to TMC for repair.
• Steve had two Tropel optical spectrum analyzers converted from green light to 1064; they are now back and ready for use. A third Tropel is in continual use monitoring the light transmitted through the mode cleaner.
• Fumiko has implemented a simple servo filter for the oplev P/Y servos, and has taken transfer functions at different gain settings. She finds that the pitch pendulum Q can be reduced from > 10 to < 0.9 before oscillation sets in. The continues to optimize and document the system.
• Shihori continues to work on developing a procedure for diagonalizing the suspensions' output matrix.
• Monica Varvella of Orsay has spent the last few weeks here at Caltech learning how to run e2e, build models, understand the Han2K and SimLIGO models, and thinking about the modifications required for AdvLIGO and the 40m. She will also work on modeling the Mach-Zehnder, as a simple and useful exercise. She leaves tomorrow, but will return for the month of July.
• Bob is busy with many bake jobs for Janeen and the triple pendulum MC crew, and for Larry Jones.
• Bob is baking out and scanning the new squeaky-clean bake oven, in the hopes of achieving the AdvLIGO cleanliness specs.

May 20, 2004

• Osamu and Bryan have uncovered what we believe to be a fundamental design problem in the Advanced LIGO length sensing scheme which the 40meter has been working towards testing. The design calls for two pairs of RF sidebands, f1 and f2 (for AdvLIGO this might be 9 & 180 MHz; for the 40m, it's 33 & 166).
  The CARM and DARM degrees of freedom are sensed at f1 and f2, respectively, while the short dofs (PRC, MICH, SEC) are sensed at f2-f1, f2+f1, or both ("double demod"). The idea is that the short dof sensing is derived only from the sidebands and is undisturbed by the arm-amplified carrier phase shifts.
  We have modeled this scheme using Twiddle and Finesse, and it agrees with the matrix presented by Peter Fritchel in an LSC meeting back in 2000 or so.
  We have implemented these two pairs of sidebands at the 40m using two EOMs in series. This produces "sidebands on sidebands", ie, local oscillators at f2-f1 and f2+f1. These were apparently neglected in all the modeling. They exist, and they can beat with the carrier at f2-f1 and f2+f1. This is not a negligible effect; to the contrary, it completely swamps the signals for the short dofs. Osamu has confirmed this using a modified FINESSE model. Osamu's results are here.
• It turns out that Bryan was unable to lock the Glasgow 10m RSE interferometer for exactly this reason. Bryan's summary of the Glasgow work is here.
• We are considering several possible solutions to this problem:
  • eliminate the sidebands on sidebands by placing the two EOMs in parallel, using a Mach-Zender
  • eliminate the sidebands on sidebands by employing 2 more EOMs to kill f2-f1 and f2+f1
  • Generate f1 and f2 but not f2-f1 or f2+f1 by sending an appropriately tailored RF signal into one broad-band EOM
  • find a different combination of demod phases and other signal processing to allow us to extract clean signals for PRC, MICH, SEC with the existing EOM configuration (it is not clear that this will be successful, but we will try).
  • some more radical solution which might require changes to the interferometer or the length sensing optics and electronics.
• Dave Tanner & Dave Reitze have experience with complex modulation of broadband EOMs, and they say that we can indeed reduce the sidebands on sidebands by, maybe 10 dB. We need more like 20 dB suppression, as well as a system to monitor and actively kill the sidebands.
• Bryan and Osamu have started looking into the finesse model in a bit more depth to see if we can reduce the effect of the arm cavities by tweaking the demod phasing and other such tricks. It looks as if it might be possible if we're not too fussy about offsets (at least initially) but needs some more in depth examination. If it is possible then the diagonalisation of the central part will not be as good and the problem of lock acquisition will still be just as bad due to large signals in the central part signals around the arm cav carrier resonances - only cancels at the operating point as far as I can see. We need to look at this a bit more but it is unlikely to change the conclusion that we need to use a Mach Zender.
• The best course for now seems to be to use a Mach-Zender interferometer because it has no sidebands of sidebands from beginning. Frequency noise by a doppler shift will be considerable, but it should be of the same order as one produced by the other mirrors.
• To control the MZ, Osamu asked Jay to get a PZT driver like PMC which has a fast response up to ~100kHz. Internal modulation using 33MHz should work well to get signal to control the MZ. We will probably put a pick off BS for parallels EOMs just after PMC, so MZ won't change the path length.
• Osamu is writing a proceeding paper on the 40m program for SPIE. The effect of the sidebands of sidebands is already included. A draft can be found here.
• Rolf has prepared new LSC software for the 40m dual-recycling configuration. Some more work is required before it can be installed; Rolf will return to this after his 2 week sojourn to LLO. New MEDM screens and the EPICS sequencer are in progress.
• For lock acq, this code expects to include InputMatrix40m.c; the development of this code is the subject of much active thinking by Rob and everyone else in our group.
• Ben has delivered two 33MHz Wavefront Sensors to the lab, and is getting two boxes for them from the machine shop. These complete the PD requirements, and join the other recently delivered QPD, double demod PDs, and 66MHz LSC PDs at the lab.
• Don has been installing the cross connects for the rewiring of our LSC rack to accommodate the double-demod signals.
• Ben has traced and characterized the PSL fast channel DAQ readback paths. To the design, they are being treated properly by the interface card. The next step is to see if the gain that was dictated by the design is appropriate for the signal levels that we have here.

May 13, 2004

• We did not hold a 40m weekly meeting this week; AJW is out of town. This is an incomplete weekly report.
• Osamu and Bryan have discovered that the length sensing modeling done with both Finesse and Twiddle share a common bug: they don't simulate the sidebands placed on the sidebands by the two EOMs operating at 33 and 166 MHz. These sidebands will change the error signals dramatically. Under intense study.
• All core suspended optics are now well aligned, including the two recycling mirrors.
• Osamu and Steve have used a Tropel optical spectrum analyzer to look at the light tranmitted through the mode cleaner, and then out the asym port. The 33MHz and 166MHz sidebands can be seen clearly at both locations, with expected magnitudes.
• The double-demod (DD) signal at the sym port has about 10mV with maximum modulation index and 15% transmission of SP EOS. The double demod signals generated by 133, 199MHz demod boards are going to whitening filters and they can be seen by dataviewer.
• We expect to see an offset in the DD signal due to imperfect demod phases (from Seiji's and Osamu's calculations) but it is not seen at all. Osamu and Bryan tried to change the phase of 133MHz and 199MHz local oscillators (using different cable lengths; the digital controls are not yet available) to see offset change, but saw no offset. This may be due to the Finesse bug referred to above. Under study.
• Jay has completed drawing up the mods to the length sensing and control (LSC) wiring to accommodate the double-demod LSC photodiodes. He has compiled a list of wiring changes, and work on these is commencing.
• Rolf, Jay, Ben and Alan met to discuss the LSC software required for dual-recycling lock acquisition. New software is in progress and should be ready for initial testing early next week.
• From Rolf, on his new LSC code: Added another Linux kernel module to do linked list DMA on the new VME P4 processor boards. This allowed me to port the present LSC software over. The LSC code under Linux on the new CPU board runs in 28usec (Pentium 3 code at sites runs in 49usec). This LSC code is now being modified for the 40m lab (12 input photodiodes, 8 DOF, and dither locking).
• Alex got the new CPUs to boot Linux over the network (diskless node). Therefore, we no longer require direct connection of a disk drive.
• While Rolf's initial intention was to change over the 40m lab DAQ system to be consistent with the sites at the same time (makes LSC code easier), he is opting to defer that until later.
• Bob has been working on the RF cabling for the LSC photodiodes. All RF signals at 133, 166, and 199 MHz, and also long 33 MHz runs, will be carried by heliax cables. Bob has installed some of these and is ordering the heliax for the remainder; in the meantime, he has installed temporary coax cables.
• Ben is acquiring two WFS photodiodes for the 40m arms. He brought two boxes to the machine shop they should be back soon.
• Ben continues to chase down problems with the PSL fast channel DAQ readback. A connector on the back of the Generic DAQ Interface card was out of position, and has been fixed. This accounts for some signals not lining up with their software names. Now the next step is to do a survey of the incoming signals, to see if they are being treated properly by the interface card.
• Bob cleaned and baked a load of small parts for Janeen.
• Bob bonded and baked (first bake) 10 Hybrid OSEMs, and cleaned and started their hot bake.
• Bob started wrapping the new oven with heating tape and he will switch the SRS RGA from oven B to the new oven.

May 7, 2004

• Bryan Barr has arrived from Glasgow, and Monica Varvella from the Orsay VIRGO group. They will focus on dual recycling lock acquisition strategies at the 40m and, via e2e simulation, AdvLIGO. Please welcome them!
• Commissioning (Miyakawa, Vass, Ward, Kawamura):
  • Osamu locked the power recycling cavity (PRC) along with MICH, for the first time. He used SP 33I for PRC and AP 166Q for MICH. This is a good check that the length control path to the power recycling mirror is working correctly.
  • Osamu is working on establishing signals with the double-demod (DD) photodiode, at 133 and 199 MHz. The signals are very small. He believes that the DD PD amp should be modified by notching out the 33 MHz, which otherwise swamps the DD signals. Jay will look into this.
  • Osamu is measuring the 166 MHz at the AP using an optical spectrum analyzer.
  • Seiji, in Japan, is developing methods to set the double-demod phases correctly for the PRC, MICH, and SRC signals.
  • Rob continues to study and understand the lsc front end code, and is talking with Rolf about how he can help develop it.
• PSL (Miyakawa, Vass, Ward):
  • Osamu found a 10 kHz oscillation on the frequency stability servo (FSS) error signal, and traced it to a back-reflection of 30-40% of the light from the AOM. He adjusted the 1/4 wave plate near the AOM, and eliminated the back-reflection and the 10kHz oscillation.
  • Osamu then found a 100 kHz oscillation on the FSS error signal, and traced it to a bad op-amp which was put on the FSS card to cancel the PMC pole (after we moved the FSS pickoff to be after the PMC). He and Ben replaced the opamp, and the 100 kHz is gone.
  • Osamu then found a 58 kHz oscillation on the FSS error signal, traced to a resonance of the PZT on the new NPRO. The FSS card has a notch at 71 kHz; with the new NPRO, this needs to be moved by changing a capacitor. Osamu and Ben will do that soon.
  • There remains a 500 kHz oscillation on the FSS error signal, whose origin is unknown; it may come from the RFPD amplifier. But, it's small and has a small effect on the performance of the FSS.
  • Osamu thinks that the FSS PZT loop filter has one more pole at 10kHz than it should. He will confirm with Rich Abbott, then remove the extra pole.
  • After all this FSS work, the PSL is very stable and performing as well as ever. The mode cleaner is locking robustly, and staying in lock for many hours at a time.
  • Osamu will remeasure the FSS OLTF and use the MC to re-measure the PSL noise, and compare with what we had 6 months ago.
  • We intend to adjust the PSL slow loop temperature change in the EPICS state code.
• Optical sensing (Kawazoe, Sakata, Ward):
  • Fumiko has installed digital filters on all the oplev servos, and is taking noise spectra with the servos off and on. She sees some significant in-loop noise reduction in the 0.5-1.0 Hz range, but sees little or no change in the OSEM P/Y noise spectra. She's also taking swept-sine transfer functions with one or 2 optics. She's finding several problems, and is not sure whether the problems are with FOTON or something else. Under investigation.
  • Steve is ordering replacement mirrors for two tropel optical spectrum analyzers that were left over from the old green-light 40m days.
  • Steve & Bob set up a video camera to view the area around the MC2 chamber.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran):
  • The group is reviewing Jay's drawings for mods to the LSC rack to accomodate the new double-demod signals.
  • Steve has ordered RF splitters for distributing the RF local oscillators to our long list of LSC demod boards.
  • Steve, Bob, and Rob set up remote controls for the picomotors that dial in beam blocks in front of the four test masses. All 4 beam blocks are visible on the video cameras viewing the test masses.
  • Ben, Jay and Rolf looked at our inability to read out the fast PSL channels correctly into DAQS. They traced it to an ICS110b ADC that was not in synch. They rebooted that crate and it appears to work ok now. Ben will go through the channels to see what gains they need on the DAQ interface board to keep them in range.
  • Rolf says that he will have time in the next couple of weeks to get our new LSC code working. He will run it in a new Pentium IV vme Cpu. Since he doesn't have a VxWorks BSP for this board, he will try to run it on realtime linux.
  • Rolf also plans to upgrade our DAQS system like he did at the sites, including a new frame builder and better handling of channels at different read rates.
  • Undergrad Ben Olson is taking transfer functions of all 12 STACIS systems and is finding that most of them are working well. He's trying to isolate and diagnose the problems.
  • EPICS code to shutter the PSL during vacuum transitions will be implemented soon.
  • Mohana and Shihori continue to work on setting alarm limits on all EPICS channels in the EPICS alarm handler.
• Facility (Vass) and South Annex Bake Ovens (Taylor):
  • Bob is vacuum-prepping OSEM clamps and LASTI MC parts for Janeen.
  • Bob is installing thermocouples on his new super-clean bake oven. He's working with Larry Jones on getting the noise down on RGA scans, etc.

April 30, 2004

• The 40m lab welcomes two visitors on Monday: Bryan Barr from Ken Strain's group in Glasgow, and Monica Varvella from the Orsay VIRGO group. They will focus on dual recycling lock acquisition strategies at the 40m and, via e2e simulation, AdvLIGO. Please welcome them!
• Commissioning (Miyakawa, Vass, Ward, Kawamura):
  • Work on the PSL, and on the LSC electronics, has trumped any experimental progress in dual-recycling lock acquisition this week.
  • Seiji has written a technical note documenting his proposed dual-recycling lock acquisition sequence, which features dither-locking of MICH as a first step. This document is now under review by the 40m group.
  • Rob has been studying the lsc front end code all week, and is starting to feel comfortable with modifying and maintaining it.
• PSL (Miyakawa, Vass, Ward):
  • Osamu has been struggling with the frequency stability servo (FSS) all week. Our new NPRO (SN 238) is much noisier than the old one (SN 332), forcing the FSS to work hard.
  • He re-aligned the entire FSS optical path, but still the FSS was not staying in lock robustly.
  • He found some design flaws in the FSS board, starting from rev D (our board says "rev C" on it, but it looks like it's rev E or F). He has fixed these on our board, and is working with Rich Abbott to generate a new rev (drawing to DCC) for this board.
  • He found saturation in the PC loop for the FSS, and changed some gains to fix it.
  • He sees ~ 10 kHz oscillation and saturation in the PZT loop for the FSS. He changed the dynamic range by a factor 3, which greatly reduced, but did not eliminate this problem.
  • He noted that the FSS EPICS gain sliders don't do what they're supposed to do. It seems to be an EPICS database problem; Ben and Osamu will diagnose and fix it.
  • After all these changes, the FSS is now performing much better, and the FRC and MC lock stably for hours. It's still not perfect: the 10 kHz oscillation still appears sometimes.
  • But just now (Thursday afternoon) Osamu found the source of the oscillation: the AOM QWP was out of adjustment, and much of the light that was supposed to go to the FRC was returning to the laser, introducing noise and optical feedback. He has fixed this, the 10 kHz oscillation is gone, and the FSS appears to be as stable as ever.
  • Osamu will remeasure the FSS OLTF and use the MC to re-measure the PSL noise, and compare with what we had 6 months ago.
  • We would like to get the old NPRO (SN 332) refurbished and made available as a hot spare in the 40m lab.
  • Jay reports that Flavio and Peter King will want to look for a 2.5 MHz peak in the ISS current shunt actuator response function, that has been seen in the LASTI PSL.
  • We intend to adjust the PSL slow loop temperature change in the EPICS state code.
• Optical sensing (Kawazoe, Sakata, Ward):
  • Fumiko continues to study and understand the oplev servo filters employed at the sites, and how to modify them for the 40m. She will talk to oplev servo experts.
  • Bob and Steve are installing the remaining ccd video cameras on beamlines, and cables to the video switch. They checked all cameras using the laser beam and/or flashlights. Mods to the video switch programming and the EPICS screens will be done by Lisa.
  • Steve will attempt to adjust the camera views so that the beam flags (in front of the 4 test masses) can be seen.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran):
  • Ben got the three RFPDs for double-demod from Todd; they are tested and ready for installation. The 66 MHz RFPD for SPOB will be ready by the end of the week.
  • The large fluctuations in the MOPA output power, reported by the EOT photodiode in the MOPA box, are now believed to be due to improper grounding of the photodiode signal to the ADC (VMIC 3123). Ben fixed this, and will do the same for the NPRO power monitor.
  • Ben is working on a switchbox to control all the picomotor beam flags from the control room.
  • Jay reports that drawings and database changes for signal recycling have been started and should be complete by Monday. These are mods required for our existing length sensing (LSC) rack, to accomodate more RFPD signals. It looks like it will be a substantial piece of work, and an additional aux crate is required. We will pursue this work with the highest priority, followed by a serious search for 60 Hz pickup.
  • Bob installed heliac cable for the LSC RFPDs in the POB and AP beamlines.
  • Ben has been in email contact with Vern regarding the RFPD redesign. Things seem to be coming along, and when Vern's design is reviewed, Ben can continue on the production.
  • Ben will check that perennial problems associated with rebooting (XYCOM boards not set right, EOS state not right, polarities for mechanical shutter toggles set right) are now being automatically done right.
  • Steve and Ben Olson are diagnosing the STACIS problems prior to a visit to the 40m lab by TMC reps on Monday.
  • EPICS code to shutter the PSL during vacuum transitions will be implemented soon.
  • Mohana and Shihori continue to work on setting alarm limits on all EPICS channels in the EPICS alarm handler.
• Facility (Vass) and South Annex Bake Ovens (Taylor):
  • Bob is in the middle of the first of a long list of bake jobs for Janeen, for the AdvLIGO MC triple pendulum suspension.
  • Bob is assembling and vacuum-prepping LIGO I osems for Janeen and for the 40m.

April 23, 2004

• Commissioning (Miyakawa, Vass, Ward, Kawamura):
  • Work towards implementing a full LSC system for locking the dual-recycling interferometer is progressing rapidly; see below.
  • The mode cleaner servo is performing less robustly. Osamu thinks that the demod phase has somehow changed (maybe when RF cabling was done in that rack a couple of weeks ago), and will re-tune the demod phase with different-length cables.
  • Rob continues to study the deep complexities of the front-end LSC code, with the aim of modifying it for dual recycling.
  • Seiji is writing a technical note summarizing his studies of dual-recycling lock acquisition, in which he concludes that dither-locking MICH can provide a robust path towards lock of the full IFO.
• PSL (Miyakawa, Vass, Ward):
  • Our MOPA continued to misbehave in new and strange ways. Ever since Steve & Osamu turned down the current on the NPRO (to reduce the overheating), the MOPA power monitor has been fluctuating *upward* from 11 watts up to 13 or 14 watts. When that happens, the mode cleaner falls out of lock.
  • Steve and Rob obtained an NPRO heat sink from the shop (ordered by Peter King weeks ago) and installed it on the NPRO in our MOPA laser. They also removed the cover from the NPRO. The TEC temperature monitor fell to 1 volt, the MOPA power stopped fluctuating, and the mode cleaner held lock for hours. Late last night, there was some more MOPA power fluctuation, but it hasn't happened since.
  • In the next few days, we will close the MOPA cover (it is now propped open a few inches) and declare victory on the heating problem.
  • However, there are still problems with the FSS. There appears to be a big oscillation (3MHz) in the FSS fast PZT loop which is limiting the gain and causing the mode cleaner to fall out of lock. Osamu burned the card out while testing it, by plugging it into a bad extened board. Ben fixed the FSS board this morning, brought over a new extender board, and checked that the FSS board works ok. But it still has the big oscillation. Osamu thinks it is an electronics problem that can be fixed. But he's also checking and tuning up the optical path to the reference cavity.
  • Osamu and Rob found that the EPICS sliders for the FSS common gain and fast gain do not work as they should. They will enlist Ben to help find and fix the problem.
  • We intend to adjust the PSL slow loop temperature change in the EPICS state code.
• Optical sensing (Kawazoe, Sakata, Ward):
  • Fumiko continues to work on implementing an oplev servo filter based on what she found at the sites (modified with FOTON to be more appropriate for our 5" optics).
  • Shihori is documenting her commissioning of the electro-optic shutters.
  • Steve will attempt to adjust the camera views so that the beam flags (in front of the 4 test masses) can be seen.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran):
  • Ben has been accumulating the remaining hardware needed for length sensing for dual recycling, including: two more double-demod RFPDs, another 33 MHz RFPD, a third LSCPD interface board, a fourth whitening board, and a fourth anti-aliasing board.
  • Jay is working on mods to the LSC rack drawings to get the wiring for these additional boards.
  • Ben continues to work on the redesign of the RFPD amplifier for fast RF and low power.
  • The RFM network went down on Wednesday at around 6am for unknown reasons. Rob spent much of the day trying to get it back up (by rebooting the vme cpus) with no success. Jay determined that the problem was that the c1epics linux cpu which connects EPICS with the front-end servos was not performing its task. He restarted the task and everything else could be brought up by the end of the day. Thanks, Jay; this is going into the procedures manual!
  • Ben will check that perennial problems associated with rebooting (XYCOM boards not set right, EOS state not right, polarities for mechanical shutter toggles set right) are now being automatically done right.
  • Steve has had no luck locating our STACIS servo extender board, and TMC wants $1K for a new one. We'll see if we can borrow one, and/or attempt to optimize the servo gains without it.
  • Steve located some old picomotor controls which work with our picomotor-driven in-vacuum beam flags, and he and Bob have run cables so that all beam flags can be controlled from the control room. Ben modified a switch so that it worked with this system.
  • A controller for a uniblitz shutter that was non-functional out of the box will be fixed by the manufacturer at no charge.
  • Bob ordered heliac cables and connectors for the long fast RF runs, and they are on their way.
  • EPICS code to shutter the PSL during vacuum transitions will be implemented soon.
  • We plan to do a careful search for 60 Hz pickup in our LSC crate, which is anomalously large.
  • Mohana and Shihori continue to work on setting alarm limits on all EPICS channels in the EPICS alarm handler.
• Facility (Vass) and South Annex Bake Ovens (Taylor):
  • Bob plans to deliver 8 LIGO-I OSEMs to Janeen (and spares for the 40m) by the middle of next week.
  • Bob is finished plumbing up new "clean" oven C, and is pumping on the RGA line.
  • Bob has decommission "dirty" oven D and surplused it. It is now removed from his lab.
  • Bob is exploring building a new very large bake oven for AdvLIGO.

April 16, 2004

• Commissioning (Miyakawa, Vass, Ward, Kawamura):
  • Osamu is preparing to lock the PRC with double-demodulation (DD) at the SP. A DD RFPD is in place, the DD will be done with a pair of IQ Demod boards, and the LO RF signals are in place (at 166+33 and 166-33 MHz). We need to do some wiring of the LSC rack to get the signals into the LSC system, and are now looking into the needed software changes, if any.
  • Jay, Osamu, and Rob are going over the requirements for LSC hardware and software for the full dual-recycling lock acquisition, and Rolf knows that we're thinking about it.
  • Rolf and Alex are thinking about implementing a general-purpose "math block" in the digital controls software, which we could use for dither-locking the PRC.
  • Locking of the Fabry-Perot-Michelson (FPMI) is currently hampered by a (new) problem with the PSL (see below). It can be done, but there is apparently a problem making the transition between locking of XARM/YARM and CARM/DARM that is not understood and is under investigation.
• PSL (Miyakawa, Vass, Ward):
  • The PSL is starting to misbehave again, in a new way. The frequency reference cavity (FRC) error signal is oscillating in a funny way, suggesting saturation. Osamu suspects the FSS fast (PZT) loop. Under investigation.
  • Steve & Osamu decreased the PSL NPRO #238 power output from 712mW to 504mW by adjusting the doide current potentiometer from 2A to 1.7A. DTEC fell from 1.7 v to 1.25 v (that was the point; the PSL trips off when DTEC exceeds 2 v), and the MOPA power fell from 12.1 W to 11.0 W. The PSL has been performing stably since then. We think we're out of the woods with regard to heating, but we still await an NPRO heat sink from the shop. That will hopefully arrive and be installed next week, at which time we will fully close the MOPA cover and hope that the heat (DTEC voltage) doesn't rise unacceptably.
  • We intend to adjust the PSL slow loop temperature change in the EPICS state code.
• Optical sensing (Kawazoe, Sakata, Ward):
  • Fumiko has tried to implement an oplev servo filter based on what she found at the sites (modified with FOTON to be more appropriate for our 5" optics). She was unable to see a reduction in P/Y noise (as measured by the OSEMs). She will pursue this work systematically.
  • Rob has finished laying out the POB beamline, and is hooking up the electro-optics: a ccd camera, an RFPD, and a QPD.
  • We now have 12 QPDs installed and being read out: IPPOS, IPANG, IOPOS, IOANG, MCR, MCT, TRX, TRY, POX, POY, AP, SP. We need one more, POB, and an additional readout channel. Ben has delivered the QPD itself; we have to either instrument a new readout channel or borrow POY's.
  • Shihori has aligned all the QPDs except for POB, and TRX and TRY. She will do those next.
  • We now have 3 electro-optic shutters (EOS): at MCR, SP, AP. The MCR one has been working for many months. Shihori and Osamu got the SP one working, and Shihori measured the transmittance vs HV; a nice cosine curve. She will document it. There are problems with the one at the AP, which may be due to bugs in the controller. Under investigation.
  • We now have 4 mechanical shutters under EPICS control (PSL, MCR, AP, SP) and 4 under manual control (MCT, POB, POX, POY). One shutter is not functioning and has been returned for repair/replacement.
  • EPICS code to shutter the PSL during vacuum transitions will be implemented soon.
  • Osamu, Steve, Rob and Shihori have cleaned up all the optical tables, removing all excess optical components for storage, and ensuring that all beamlines are fully instrumented and laid out as in the drawings.
  • The PSL table is now grounded to the vacuum enclosure, as are all other optical tables.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran):
  • We now have Marconi signal generators for all required frequencies (29.5 MHz for MCR, and 33, 166, 133, and 199 for the main interferometer, all phase-locked to multiples of 33 MHz).
  • Ben brought over LSC RF distribution boxes for the 133, and 199; not needed for 166, only one IQ demod board needs it. There are heliac cables for the 33 and 166 to the LSC rack, and Bob ran some temporary RG405 for the 133 and 199; more heliac cable is on order.
  • At Osamu's request, Ben removed (and jumpered across) the output attentuators at the end of the RF AM stabilizers that go to the EOMs. Osamu measured the maximum modulation depth for 166 MHz to be 0.3; more than enough, and easily turned down to 0.1 with the EPICS slider. The 33 MHz is probably much deeper, but will also be turned down to 0.1.
  • The 166 MHz and 133,199 MHz RFPDs show oscillation at 500 kHz. This is a known problem for RFPDs with low light level, with a known fix, and Ben will implement it.
  • Ben cured the long-standing problem of the varying monitoring readout of a couple of Thorlabs photodiodes on the PSL (PMC transmitted DCPD and FSS transmitted DCPD), by tying the "Guard" pin to the signal "Lo" pin (discovered after reading the 96 page manual for the 3123 ADC). He will now investigate the PSL DAQ channels, some of which have been railed forever.
  • Ben continues to work on the redesign of the RFPD board, with Vern Sandberg. They are working to incorporate a few new features that would be nice to have. Ben plan to give Dennis a schedule of development by the end of this week.
  • Ben is updating the system wiring schematics for the 40m Auxiliary rack, in order to reflect the as-built condition.
  • We plan to do a careful search for 60 Hz pickup in our LSC crate, which is anomalously large.
  • Mohana and Shihori continue to work on setting alarm limits on all EPICS channels in the EPICS alarm handler.
  • Ben Olson continues to diagnose problems with the STACIS seismic isolators. Two of the 3 isolators in the south end are working well, the NE isolator is behaving badly. Under investigation. Steve will locate the STACIS servo extender board or order a new one.
• Dual-recycling lock acquisition (Kawamura, Miyakawa): Seiji and Osamu have settled on two lock acquisition sequences (using double demod) that they think will work robustly. Seiji's involves dither-locking MICH then locking the PRC and then SRC with double demodulation at the SP and PO, respectively. Osamu's replaces the first step with an alternative scheme for MICH. We will work towards implementing these schemes. This is a perfect thing to test with e2e... new visitors are arriving in May who may want to work on this.
• Facility (Vass) and South Annex Bake Ovens (Taylor):
  • Steve is cleaning up the 40m lab, moving excess optics and equipment to cabinets in the east arm, and getting rid of surplus equipment such as old 40m racks full of obsolete electronics.
  • Bob tied down the monitors in the control room for earthquake safety.
  • Bob is plumbing up new "clean" oven C.
  • Bob will decommission "dirty" oven D, will surplus it, and will recommission old oven C as a new "dirty" oven D.
  • Bob is exploring building a new very large bake oven for AdvLIGO.
  • Bob is building OSEM diodes for Janeen (AdvLIGO MC triple) and for the 40m.

April 9, 2004

• Commissioning (Miyakawa, Vass, Ward, Kawamura):
  • Osamu and Rob locked the Michelson (l-) using the 166 MHz RFPD at the AP. They are now working on locking the PRC (l+) using double demodulation at the SP.
  • Rob and Osamu are studying Matt Evans' thesis and InputMatrix code, in order to generalize it for dual recycling.
  • Fumiko and Osamu have analyzed the MC transmitted beam using the Tropel optical spectrum analyzer. They measure a transmitted modulation depth of 0.13 for the 33 MHz sidebands and 0.06 for the 166 MHz sidebands, with all EPICS sliders set to maximum. they will work on increasing the modulation depth for the 166 MHz.
• PSL (Miyakawa, Vass, Ward):
  • Osamu re-aligned the beam from the (new) NPRO to the power amplifier. The power out of the MOPA is now up to 12.1 watts, and intensity fluctuations are now much reduced. He also re-aligned the beam into the frequency reference cavity and the PMC. The PSL is now performing very well!
  • We are still operating with our MOPA cover off to keep the NPRO from heating up.
  • Steve has ordered a heat sink on the new NPRO and will install it as soon as it arrives.
  • We intend to adjust the PSL slow loop temperature change in the EPICS state code.
• Optical sensing (Kawazoe, Sakata):
  • After tuning up the PSL, Osamu re-optimized the mode cleaner wavefront sensor beamline and digital alignment control system; it is now working well.
  • Shihori and Osamu have installed and aligned electro-optic shutters on the AP, SP, and MCR beamlines. The trigger photodiodes were wired from the auxilliary rack; this proved to be dangerous, and a couple of photodiodes have been fried. We are now running power to these trigger photodiodes using matched power supplies; SP and MCR beamlines have these, and a third will be installed soon on the AP beamline.
  • Shihori and Osamu have checked out 12 of 13 beamline QPDs, from photodetector through the entire electronics chain to EPICS displays. All are working well. One more QPD is required for the POB beamline. Ben is acquiring it (and a spare).
  • Rob is almost finished laying out and aligning the POB beamline. He awaits a QPD and a CCD camera.
  • Osamu and Rob have installed and tested mechanical shutters on the SP, AP, MCR, POX, POY, MCT, and PSL input beamlines. EPICS control of the SP, AP, MCR shutters have been tested; EPICS control of the PSL shutter will be tested soon. EPICS code to shutter the PSL during vacuum transitions will be implemented soon. Mechanical shutters for the other beamlines are controlled manually (as opposed to EPICS).
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran):
  • Jay has generated a block diagram and requirements for the LSC as it relates to signal recycling. There will be 11 LSC RFPDs feeding I&Q demod boards; a 22x8 input matrix; and an 8x8 output matrix (including a path from CM -> MC).
  • Ben continues to check out some varying monitoring readout of a couple (at least) of PSL channels (PMC transmitted DCPD and FSS transmitted DCPD) and now believes that the signals are being pulled down by a weak short to some other signal(s). He has a spare 3123 which he will test during the next PSL down time.
  • Ben helped Rob repair a particularly stubborn oscillation on one of the RFPDs. Adding the 1.5K resistor didn't do any good, so he tried the Inductor-Resistor fix, and it worked very well.
  • Ben received two signal generators (IFR 2024's) that he ordered for the LSC double demodulation, and has brought them to the 40m. Bob Taylor has made shelves to mount them between 1Y2-24, and 1Y2-28. This should make minimal impact on the existing rack drawings.
  • Todd has delivered the four I&Q Demod boards that are needed for double demodulation, and Ben brought those over today. We now have 13 I&Q Demod boards, and much work is required to wire them up for use. Ben will take the lead.
  • Bob has installed heliac cable for some long cable runs from RFPDs to I&Q demod boards, and will order and install heliac cable for all remaining long RF runs.
  • Ben is planning a redesign of the LSC RFPDs for higher frequency operation.
  • We plan to do a careful search for 60 Hz pickup in our LSC crate, which is anomalously large.
  • Mohana and Shihori continue to work on setting alarm limits on all EPICS channels in the EPICS alarm handler.
• Digital suspension controllers (Sakata, B. Abbott, Heefner):
  • The EPICS readback of the coils for ETMX were reading anomalously large values, although the optic was being damped just fine. Ben compared the database for ETMX with the one for ETMY, and found that the ETMX database was wrong (not known how or why) and that a recent reboot (not known when) caused the problem to surface and come to Osamu's attention. Ben fixed the database, rebooted, and all appears to be well.
• Safety (all): A 40m lab safety document T040092 has been completed and submitted to DCC.
• South Annex Bake Ovens (Taylor):
  • Bob continues work on new oven C.
  • Bob is building 40 or 50 OSEM diode boards for Janeen and for the 40m.

April 2, 2004

• Commissioning (Miyakawa, Vass, Ward, Kawamura): With the PSL problems under control (sort-of), Osamu and Rob re-established the Fabry-Perot Michelson interferometer (with misaligned PRM and SRM) and are re-measuring the noise spectrum. They are commissioning the new POB beamline. Rob is increasing the gain on the SP RFPD . Shihori is aligning and commissioning all 12 QPDs on the output beamlines. We are making plans to complete our LSC and Lock Acquisition system in preparation for locking the dual recycled IFO.
• PSL:
  • We are currently running with our replacement PSL NPRO (SN 238), installed 3/11/04, and our old MOPA power supply. The MOPA cover is propped open about an inch to allow it to cool. As far as we can tell, no cooling water is running to the NPRO through the needle valve; it appears to be stuck. In this configuration, the laser is running stably, and the NPRO DTEC voltage is ~ 1.6 volts. If the MOPA cover is not propped open, the DTEC voltage rises to 2 volts, and the NPRO trips off.
  • Steve looked at a history of the DTEC voltage for the last 800 days. About 150 days ago, it rose from 0.6 volts and hovered just below 2 volts while our old NPRO (SN 332) appeared to be dying. It crept closer to 2 v when we replaced it with NPRO SN 238, and the NPRO started tripping off. This indicates a long-standing cooling problem; we are guessing that we were flowing water cooling to the NPRO till the needle valve jammed 150 days ago, and have only now noticed it.
  • We don't have a heat sink on the new NPRO; we have ordered and will install one. Apparently, the sites all have heat sinks on their NPRO, and either have holes punched in their MOPA cover, or have the MOPA cover propped open. We have also ordered and will install a replacement water valve for the NPRO. We are in communication with Lightwave, but the rep there doesn't think that our problem is due to cooling...!
  • Intensity fluctuations out of the MOPA are 10 times larger with the new NPRO. We need to optimize the alignment from NPRO to power amplifier, to maximize power and minimize intensity fluctuations. And, we need to finish commissioning of the ISS!
  • The HV on the frequency reference cavity ion pump has had no failures ever since the 24 v power cable to the ion pump HV was replaced.
  • We intend to adjust the PSL slow loop temperature change in the EPICS state code.
• Optical sensing (Kawazoe, Sakata):
  • Shihori is working with Bob to wire up last EOS, in the AP1 beamline.
  • Rob noticed that the trigger PD for the EOS in the SP beamline was burned out; we have ordered a replacement.
  • Fumiko recentered the ITMY oplev. She is writing up her studies of oplev noise. She will move on to commission the oplev servos, next.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran):
  • Jay has begun generating a block diagram and requirements for the LSC as it relates to signal recycling. There will be 11 LSC RFPDs feeding I&Q demod boards; a 22x8 input matrix; and an 8x8 output matrix (including a path from CM -> MC).
  • Jay and Ben are ordering parts for more high frequency RFPDs and I&Q demod boards and more IFR RF generators.
  • Ben will start work on the design of high frequency (low power) RFPD boards, for double demodulation.
  • Bob is running heliac cables to all the high frequency RFPDs on the optical tables.
  • Ben is getting two more QPDs; one for installation on the new PO beamline, and a spare.
  • We plan to do a careful search for 60 Hz pickup in our LSC crate, which is anomalously large.
  • Mohana and Shihori continue to work on setting alarm limits on all EPICS channels in the EPICS alarm handler.
  • Jay and/or Mohana will implement EPICS code to automatically close the mechanical shutters in the event of a vacuum transition.
  • Ben continues to check out some varying monitoring readout of a couple (at least) of PSL channels (PMC transmitted DCPD and FSS transmitted DCPD) and believes it is due to a bad 3123 ADC.
  • Undergrad Ben Olson is measuring the transfer functions for the STACIS isolators. He has measured the three at ETMY; two work well, providing 22 dB of attenuation at 10 Hz; one is oscillating. He will learn how to adjust the gains on the loops. The STACIS controllers that are supposed to communicate with our EPICS system have many problems...
• Digital suspension controllers (Sakata, B. Abbott, Heefner):
  • Shihori has completed her writeup of the DSC input matrix diagonalization procedure and results and is submitting it to the DCC.
  • She is now preparing to diagonalize the input matrix of the last two suspensions (PRM and SRM) and is preparing the procedure for diagonalizing the output matrices.
• Dual-recycling lock acquisition (Kawamura, Miyakawa):
  • Seiji and Osamu continue to use Finesse to explore how the signals for the short DOFs (PRC, SRC, MICH) change during lock acquisition, in order to develop an efficient lock acquisition procedure. They are making good progress, and are optimistic. Seiji thinks that dither-locking MICH (l-) will work well, allowing us to aquire lock in the other two short degrees of freedom (PRC l+ and SRC ls) more robustly. Osamu is gearing up to test this.
• Safety (all): A follow-up safety audit was held last Monday March 29. All action items were addressed and closed. A 40m lab safety document is nearing completion. Many thanks to the safety audit team for their careful inspection and advice!
• South Annex Bake Ovens (Taylor):
  • Bob is wiring up the temperature controller for new oven C.
  • Bob did some bake jobs for Larry Jones' galling tests.
  • Bob is building 40 or 50 OSEM diode boards for Janeen and for the 40m.

Mar 26, 2004

• Commissioning (Miyakawa, Vass, Ward, Kawamura): There's been a break in commissioning work while repairing the PSL (see below). Now that the PSL is back up and all systems are working, we will re-establish the Fabry-Perot Michelson interferometer (with misaligned PRM and SRM) and remeasure the noise.
• PSL:
  • Our replacement PSL NPRO (SN 238), installed 3/11/04 to replace our old NPRO (SN 332) which was dying after many thousands of hours of service, started to misbehave 4 days after installation. The power drops to zero for around 10 minutes, then comes back up, and repeats every hour or 2.
  • The problem was initially associated with a 580 kHz oscillation seen on the FSS card. Rich Abbott said that this oscillation was also seen on an LLO laser. Jay and Osamu killed the oscillation with a capacitor on the FSS card, but the power problem persisted.
  • The problem did not appear when the stand-alone NPRO power supply was used, only when our MOPA power supply was used. Jay and Peter King swapped MOPA power supplies, but the power problem persisted.
  • We frantically searched for another spare NPRO; neither Peter nor LHO have any to spare.
  • The problem is also associated with raised temperature reported by the NPRO thermoelectric controller (TEC). Yesterday (Wednesday), Steve turned on the water cooling for the NPRO. As of today, the power problem has not reappeared, and the FSS, PMC, and MC remained locked throughout the night. We have switched back to the old MOPA power supply, are keeping the cooling on, and are declaring success.
  • The HV on the frequency reference cavity ion pump occasionally falls to 0. Steve and Bob replaced the 24 v power cable to the ion pump HV, and the problem has not reappeared.
  • These problems uncovered another problem: the PSL slow loop (which changes the temperature of the reference cavity when the FSS PZT signal drifts) changes the temperature by too much. Osamu will adjust this in the EPICS state code.
• Optical sensing (Kawazoe, Sakata):
  • Shihori and Fumiko are preparing to install the last EOS, in the AP1 beamline.
  • Ben is getting two more QPDs; one for installation on the new PO beamline, and a spare.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran):
  • Jay has delivered an RFPD tuned for duoble demodulation (peaks at 133 and 199 MHz, notch at 166 MHz).
  • Jay delivered two 2-omega IQdemod boards (for SPOB), and IQdemod boards for 133 and 199 MHz. Osamu will install and debug these in the LSC system.
  • Mohana and Shihori are establishing the alarm limits on all EPICS channels in the EPICS alarm handler.
  • Jay and/or Mohana will implement EPICS code to automatically close the mechanical shutters in the event of a vacuum transition.
  • Ben is checking out some varying monitoring readout of a couple (at least) of PSL channels (PMC transmitted DCPD and FSS transmitted DCPD) and believes it is due to a bad 3123 ADC. He will look for a replacement.
• Digital suspension controllers (Sakata, B. Abbott, Heefner):
  • Shihori has completed her writeup of the DSC input matrix diagonalization procedure and results; it will be released soon.
• Safety (all): Following through on the remaining action items from the safety inspection of 1/13/04:
  • All crane operators (Steve, Bob, Osamu, Rob) were trained and certified on Tuesday.
  • All 40 Meter personnel attended the lab safety briefing (led by Steve) on Thursday. AJW updated an evolving document summarizing all the material covered in the safety briefing.
  • A follow-up safety audit will be held next Monday March 29.
• South Annex Bake Ovens (Taylor):
  • Bob has recieved a new temperature controller, and 20" oven body, for the new oven C. He's working on wiring up the temperature controller.

Mar 19, 2004

• The 40m Technical Advisory Committee met on Thursday during the LSC meeting in LLO. Osamu presented the status of the project, as well as Seiji's and Osamu's results on strategies for locking the dual-recycled Michelson. Powerpoint slides are here (8 MB).
• Commissioning (Miyakawa, Vass, Ward, Kawamura): There's been a break in commissioning work while repairing the PSL (see below) and while Osamu is at LLO for the LSC meeting.
• PSL:
  • Late last week, Rob and Osamu installed a replacement NPRO (SN 238) in our MOPA laser; our NPRO was showing signs of dying. They aligned it, and tuned up the MOPA by maximizing the output power. They got up to 12.5 watts output.
  • Osamu was then able to lock the frequency stability servo, after readjusting the servo gains. He moved on to the mode cleaner, but ran out of time in optimizing the servo before he had to leave for the LSC meeting.
  • Four days after installing the new NPRO, it has been showing signs of misbehavior: the power drops to zero for around 10 minutes, then comes back up, and repeats every hour or 2. Osamu will diagnose the problem when he returns from the LSC.
  • The HV on the frequency reference cavity ion pump occasionally falls to 0. This is not being monitored by EPICS; Steve noticed it when looking at the controller. Fortunately, the FRC holds vacuum pretty well even when the pump isn't working. Steve and Rob think the problem is with the 24v cable to the HV supply, and Bob will make a replacement.
• Optical sensing (Kawazoe, Sakata):
  • Shihori and Fumiko are preparing to install the last EOS, in the SP beamline.
  • Shihori is preparing to install the remaining QPD, on the new PO beamline, and to cable up and test the MCT QPD.
  • Fumiko is writing up her oplev calibration and noise studies. She is starting to implement and test the oplev servos, and is studying the appropriate filtering.
  • Jay and/or Mohana will implement EPICS code to automatically close the mechanical shutters in the event of a vacuum transition.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran):
  • Mohana and Shihori are establishing the alarm limits on all EPICS channels in the EPICS alarm handler.
  • The monitoring readout of a couple (at least) of PSL channels (PMC transmitted DCPD and FSS transmitted DCPD) has been misbehaving badly for many months. This does not effect the servos. The cause is somewhere in the electronics rack, and Ben continues to investigate it.
• Digital suspension controllers (Sakata, B. Abbott, Heefner):
  • Shihori has measured the damping Q's for the side OSEMS on all of our suspended optics. The poor damping of ITMX side osem servo is clearly observed. Shee will now study the dependence of the Q on the gain, for all OSEM damping servos.
• Dual-recycling lock acquisition (Kawamura, Miyakawa):
  • Seiji and Osamu continue to use Finesse to explore how the signals for the short DOFs (PRC, SRC, MICH) change during lock acquisition, in order to develop an efficient lock acquisition procedure. They think they have a path for locking the PRC (l+) degree of freedom; the other two (SRC or ls, and MICH or l-) are proving to be more problematical. Osamu presented these results at the Advanced Optical Configurations group meeting at the LSC meeting in LLO.
• Safety (all): Following through on the remaining action items from the safety inspection of 1/13/04:
  • The custodian went through the basic LIGO laser training. The Safety Office has requested that they not switch custodians on us so often.
  • All 13 emergency lights in the lab have been tested. Two were not functioning right (the two that were supposedly fixed last month); they have now been fixed properly, and tested.
  • All the fire alarms (including the one newly installed in the South Annex clean room) and extinguishers will be tested on Friday.
  • All rack kill switches have been modified to provide a continuous ground path.
  • All optical tables are being grounded to the vacuum envelope. Not sure whether we should also ground the racks to the vacuum envelope.
  • Bob is setting up lockout / tagout systems for all the relevant vacuum equipment. The racks and power breakers are done.
  • All crane operators (Steve, Bob, Osamu, Rob) will be trained and certified next Tuesday. Signs listing all certified crane operators, with safety reminders, are now posted on all three crane controllers.
  • All 40 Meter personnel will undergo the lab safety briefing (led by Steve) next Thursday. AJW wrote up an evolving document summarizing all the material covered in the safety briefing.
  • A follow-up safety inspection has been scheduled for March 29.
• South Annex Bake Ovens (Taylor):
  • Bob continues to work on rebuilding oven E and building new oven C. Parts are coming in on schedule. He's now working on the temperature controllers and RGA filaments for the new ovens.

Mar 12, 2004

• The 40m Technical Advisory Committee will meet next Tuesday during the LSC meeting in LLO. Osamu will present the status of the project. We hope that there will be time in the AIC working group agenda to present Seiji's and Osamu's results on strategies for locking the dual-recycled Michelson.
• Commissioning (Miyakawa, Vass, Ward, Kawamura):
  • Late last week, Rob increased the gain on the POX RFPD to compensate for the relatively much larger 60 Hz noise that appeared when we installed and mis-aligned the power recycling mirror. The x-arm is locking robustly, with much-reduced relative 60 Hz noise.
  • Increasing the gain on the POY RFPD induced an oscillation; Ben has fixed this with the addition of a resistor.
  • Seiji, Osamu and Rob tried an experiment in which they modified the damping of the ITMX, ITMY, BS optics (comprising the Michelson) to give them lots of DC gain and a UGF at 4 Hz, in effect "tying" them to the optical tables on the seismic stacks. The hope was that, if there isn't much relative motion between the tables, such a scheme could make it easier to obtain lock in the short dual-recycled Michelson. They compared the Michelson error signal and transmitted light power before and after changing the suspended optic damping, and so no significant change. They conclude that there is too much relative motion between the tables to make this a useful approach.
  • On Saturday, the PSL frequency stabilization servo (FSS) lost lock, and we haven't been able to regain robust lock since. After carefully studying the data and performing a variety of checks of the MOPA using the PMC, Osamu, Steve and Rob found no evidence of problems with the FSS, PMC, reference cavity, slow or fast frequency actuation, chiller, cooling water, coolant piping, or the power amplifier. Reviewing the data, it appears that the inability to lock the FSS since last Saturday is due to the failure of the TEC or some other element of the NPRO. The TEC temperature is now back to normal, but the NPRO is not; it appears to have suffered permanent damage. It appears that the 40m NPRO is in its death throes, after 18,000 hours of faithful service. We have now obtained a spare 126 NPRO (SN 238) from Peter King's lab (many thanks, Peter!), and Osamu and Rob installed it into the Lightwave box. They're busy aligning and tuning the output beam. We will return our NPRO (SN 332) to Lightwave for repair.
  • As part of the diagnosis of the PSL problem, Rob, steve and Osamu shut down all electronics and computers in the lab and brought everything back up successfully. Rob is documenting the detailed procedure for doing this.
• Optical sensing (Kawazoe, Sakata):
  • Shihori and Fumiko have installed an electro-optic shutter (EOS) on the SP beamline, and checked out its operation under EPICS control. They had some problem with the trigger photodiode, and a spare one will be installed soon. They are preparing to install the last EOS, in the SP beamline.
  • Shihori has checked out the installed beamline QPDs, and will install the last two (of 12) soon.
  • Fumiko is taking noise spectra of the five oplevs that are currently in service (the ones for the SRM and PRM aren't working because the optics are misaligned). She will start implementing and testing the oplev servos.
  • Bob has cabled up all the beamline mechanical shutters One is installed on the PSL output beam; three others will soon be installed in the MCR, SP, and AP beamlines. Ben and Jay have made them work under EPICS control, although there are some questions about the wiring logic for fail-safe shuttering under loss of power or EPICS cpu reboots.
  • Jay and/or Mohana will implement EPICS code to automatically close the mechanical shutters in the event of a vacuum transition.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran)
  • Rob modified the POY RF photodiode to increase the gain, but it was oscillating. After Ben installed a shunt resistor to ground as advocated a while ago by Mike Zucker, the oscillations have stopped.
  • Ben fixed a flaky LEMO cable reading out the PRM side OSEM.
  • Bob installed some heliac cable for the 33 MHz RF signal from the PSL rack to the LSC rack. The 166 MHz signal is already carried by heliac cable.
  • The kill switches for all the electronics racks have all been modified so that the ground conductor remains connected when power is disconnected.
  • The monitoring readout of a couple (at least) of PSL channels (PMC transmitted DCPD and FSS transmitted DCPD) has been misbehaving badly for many months. This does not effect the servos. The cause is somewhere in the electronics rack, and Ben continues to investigate it.
  • Mohana and Shihori are reviewing the long list of EPICS channels in the EPICS alarm handler, to establish good alarm limits on all channels.
• Digital suspension controllers (Sakata, B. Abbott, Heefner)
  • The DSC system has functioned with no problems this week!
  • Shihori has diagonalized the input matrix for the ETMX suspension, and has re-measured all the cross-couplings for all the other suspensions now that the vent is over (except for the PRM and SRM, which are still misaligned). She has observed some significant changes in the cross-couplings in ITMX. We suspect that the side OSEM in ITMX is not working well. Under investigation.
• Safety (all): We are documenting a response to all of the action items from the safety inspection of 1/13/04, which have all been addressed.
• South Annex Bake Ovens (Taylor):
  • Bob is ordering temperature controllers and RGA filaments for the new oven he's building,

Mar 5, 2004

• Commissioning (Miyakawa, Vass, Ward):
  • We closed up after a successful 4 week vent to install the two suspended recycling mirrors, PRM and SRM. We pumped down last Thursday with no problems, and now are at 9e-6 torr with the maglev turbopump alone.
  • By Thursday evening, the mode cleaner was locked, and by Friday AM the FPMI was locked. Minimal re-alignment was necessary; the mirrors did not move much because of the pump down.
  • All error signals are now much weaker, because only 7% of the light gets through the mis-aligned PRM; and the asymmetric port has an 8% transmitting mis-aligned SRM. As a result, the 60 Hz noise is now relatively much larger, and is a real problem for locking.
  • Osamu hunted for the 60 Hz noise source. It's in the analog LSC crate, and it only goes away when all cables are unplugged and modules pulled out.
  • The band-aid solution is to increase the gains on the RFPDs sensing the FPMI degrees of freedom at the POX, POY, and SP ports.
  • Rob increased the gain on the POX RFPD, but couldn't do the POY; Ben is looking at it. Meanwhile, with this mod, the x-arm is locking robustly, with much-reduced relative 60 Hz noise.
  • Osamu is now modifying the whitening filter gains and re-tuning the LSC servo filters, to optimize the control with these lower light levels.
  • We will then want to recalibrate the FPMI and get a new calibrated noise curve.
  • This past Tuesday, the HV cable(s) to the PZT steering mirror(s) at the end of the PSL table were bumped, and the mirror(s) moved (not sure which one, or both). Before understanding what happened, Osamu re-aligned the MC to the input PSL beam; as a result, the beam to the main IFO was different. Fortunately, we have QPDs monitoring the beam position / angle at the PSL and at the MC -> IFO hand-off. Osamu has now used these to re-establish the correct beam pointing at the PSL, and has brought the MC and and main IFO alignment back to where it was.
• Optical sensing (Kawazoe, Sakata):
  • All 7 oplevs are working well after pumpdown.
  • Shihori is checking out the installed beamline QPDs, and will install the last few (of 12). Then she'll calibrate them all.
  • Fumiko did some more measurements to determine how well the oplevs sense the suspended optic pitch and yaw, above the noise. We remain unsure about how useful the oplev servos would be for us, whether we should bother to commission them, and over what frequency range they should act.
  • Because of the large amount of light reflected from the PRM to the SP when it is aligned, we need to finally install and commission the electro-optic shutter (EOS) at the SP and AP ports. Fumiko and Shihori are working on this, and Bob is helping with the wiring.
  • Bob is checking all the wiring for the remote control of the mechanical shutters for the PSL, SP, AP, MCR beamlines. We still need to complete the EPICS control software for these.
  • All camera views are established for all 7 core optics and all 8 output beams, and all signals are going into the video switch. We still need a few more camera power supplies to make use of all cameras. Steve has them on order.
  • All chamber illuminators are working and under EPICS control.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran)
  • The monitoring readout of a couple (at least) of PSL channels (PMC transmitted DCPD and FSS transmitted DCPD) has been misbehaving badly for many months. This does not effect the servos. The cause is somewhere in the electronics rack, and Rob and Ben are searching for the problem.
  • Jay reports that the PD needed for double demodulation has been tuned up and is ready for installation.The response has a notch at 166MHZ and peaks at 133 and 199MHz. The is ~30dB of suppression of the 166MHz. Better suppression will require a re-layout/redesign of the board.
  • Mohana and Shihori are reviewing the long list of EPICS channels in the EPICS alarm handler, to establish good alarm limits on all channels.
  • Steve and Bob spent some time cleaning up the PSL cable plant.
  • We continue to think about the necessary mods to the LSC software to implement lock acquisition code.
• Digital suspension controllers (Sakata, B. Abbott, Heefner)
  • On Wednesday, the DSC sensor ADCs (ICS 110b's) started to channel hop, and all the vertex suspension watchdogs tripped off. We rebooted the DSCs, and several suspensions came back, but not all. The DSC filtering computer c1suslinuxpc2, which services MC1, MC2, MC3 and SRM, wouldn't re-start; when manually restarted, it segfaulted (as if it was getting corrupted data from the sensors). Jay found a bad cable from the PRM side OSEM sensor; Ben fixed it; Alex restarted the DSC system. By the end of the day, all the DSC system is back up with all suspensions damping nicely.
  • Shihori is diagonalizing the input matrices for the ETMX, PRM and SRM suspensions.
• Safety (all): We still need to document a satisfactory response to all of the action items from the safety inspection of 1/13/04. All the action items have been addressed, we just need to assemble documentation. Steve gave a safety lecture to new undergrad student Ben Olson who is looking at the STACIS system.
• South Annex Bake Ovens (Taylor):
  • Bob continues to work with Larry and Dennis on rebuilding ovens C and F, aimed at achieving AdvLIGO cleanliness specs. He has placed orders for all parts for oven C.
  • Bob is building hybrid OSEMs or Janeen, as well as spare OSEMs for the 40m suspensions.

Feb 27, 2004

• Installation (Miyakawa, Vass, Ward):
  • We are closing up after a 4 week vent to install the two suspended recycling mirrors, PRM and SRM.
  • The installation went very smoothly and successfully. The installation crew (Steve, Osamu, Rob) installed both new suspended optics, got them damping well in the middle of the OSEM ranges, balanced the chamber optical table, established good alignment of all optics, centered the beams on the in-vac PZT steering mirrors with the PZTs in the middle of their mechanical and electrical range, established all output beams (AP, SP, PO, POX, POY, initial pointing), observed aligned spots and michelson fringes at the AP and SP beams, established all oplev beamlines, installed glass dishes to isolate the OSEM cables from the chamber walls and checked for any contact, established good camera views of all optics, checked everything, and took lots of pictures. A complete list of tasks is here. Terrific job, installation crew!
  • On Wednesday, all access connectors and doors were replaced, and pumping on the annuli commenced. On Thursday, pumpdown commenced and has been proceeding smoothly. As of Thursday 5pm, the maglev turbopump is pumping on the main volume at about 3e-5 torr. We should be ready to recommission the interferometer on Monday.
• Optical sensing (Kawazoe, Sakata):
  • All 7 oplevs are working well. The two new ones (for SRM and PRM) were set up by Rob. They require several in-vac mirrors each, and the resulting beams on the QPDs are dim, but adequate for sensing.
  • Fumiko has completed her calibration of the first 5 oplev qpds, and is measuring the pitch and yaw motion spectra in units of radians/rtHz, and rms motion in radians.
  • Fumiko is determining what changes are required to Mike ACad optical layout drawings in light of the recent installation work.
  • Shihori will be working with Fumiko to commission the electro-optic shutters for the AP and SP beamlines.
  • Shihori will commission and calibrate all 12 beamline QPD monitors.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran)
  • Jay reports that the 2 Omega I&Q demod board for SPOB is fabricated and in test.
  • Jay has a working "double resonant" photodetector circuit for testing, but it is clear that a new design is required to make it work well.
  • Mohana has completed implementing a long list of EPICS channels into the EPICS alarm handler. She and Shihori will establish good alarm limits on all channels.
  • We continue to think about the necessary mods to the LSC software to implement lock acquisition code.
• Digital suspension controllers (Sakata, B. Abbott, Heefner)
  • Several more problems with corrupted entries in the SUS AUX databases were found, and Jay fixed them. It's hard to check everything; problems will be fixed as they reveal themselves. We're not sure how or why these databases got corrupted, but care will be taken to ensure it doesn't happen again.
  • Ben fixed a flaky cable on carrying the BS LL OSEM SENSOR into the ISC patch panel.
  • Shihori is working on a final draft document describing her diagonalization of the suspension controller input (OSEM) matrix. She will diagonalize the input matrices for the ETMX, PRM and SRM suspensions next week. She is also developing her plan for diagonalization of the output (coil) matrix.
• Dual-recycling lock acquisition (Kawamura):
  • Seiji was in Aspen last week and gave a talk on dual recycling at the 40m. After highlighting the progress at the 40m, he described the challenge of finding a clean path to lock acquisition of the dual-recycled Michelson with the current readout scheme. He got lots of interesting suggestions, and quickly tried many of them with Finesse; none worked well. The path to lock acquisition will be a challenging one! We hope that expert members of the e2e team will contribute.
• Safety (all): We hope to complete a satisfactory response to all of the action items from the safety inspection of 1/13/04, next week. Meanwhile, all crane work at the 40m in the last two weeks (there was a lot of it) was performed by operators wearing steel-toed safety shoes.
• South Annex Bake Ovens (Taylor):
  • Bob continues to work on rebuilding ovens C and F, aimed at achieving AdvLIGO cleanliness specs.
  • Bob expects all ovens to be back up and running by the end of March.

Feb 20, 2004

• Installation (Miyakawa, Vass, Ward):
  • We are vented for the installation of the two suspended recycling mirrors, PRM and SRM.
  • Steve used the de-ionizing N2 gun to attempt to clean the dust off of the PRM, but it didn't do much. Then he tried the CO2 snow gun; it got some of the dust off, not all. Steve talked with Stan, Helena and Betsy; apparently, the sites have the same problem, and they live with it. So will we; we will NOT attempt to drag-wipe the optics to get the remaining dust off.
  • The installation crew installed the signal recycling mirror last week, and the power recycling mirror this week. They are both positioned within 1 mm (or so) of specifications.
  • The OSEM pigtail bracket had to be moved in order for the pigtails to reach it. Steve moved it without any problems.
  • In-vac mirrors for the oplevs have been placed on the BS optical table, and the table was leveled using counterweights.
  • Both newly installed suspended optics are now damping well, with all OSEMs nicely centered both electronically and mechanically.
  • The two in-vac PZT steering mirrors were adjusted so that they are in the center of their dynamic range, both mechanically and electronically. The settings are being auto-burted.
  • Alignment of all five vertex suspended optics is in progress, and the SP, AP, and PO beams are being established. Currently, the main beam is flashing through the mode cleaner, through the faraday isolator and MMT, through the PRM, beam-splitter, to ITMX, and back through to the asymmetric port. Work is in progress to re-establish the symmetric port beam.
  • We had been using the PRM oplev to monitor the BS table, and last week we observed a significant drift of this signal. Rob traced this to a bad oplev laser mount, and this has been fixed. The PRM and SRM oplev systems are now being aligned onto the newly-installed optics.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran)
  • Jay reports that the 2 Omega I&Q demod board for SPOB is fabricated and in test. It should be available by Monday.
  • Jay reports that work on the "double resonant" photodetector continues.
  • We continue to think about the necessary mods to the LSC software to implement lock acquisition code.
  • Jay suggests that we run the high frequency (33, 166, 199) MHz LSC RFPD signals to the I&Q demod boards using heliac cable. Bob will get the cable and connectors.
  • Alex Ivanov has developed an x-y display of digital signals using a modified dataviewer. Osamu and Seiji find the display of error-signal versus transmitted power to be a powerful diagnostic tool.
  • Mohana continues to work on the EPICS alarm handler to make it useful.
  • Caltech undergrad Ben Olsen is beginning to look at the STACIS system, to resolve problems with it.
• Digital suspension controllers (Sakata, B. Abbott, Heefner)
  • There was an earthquake last Saturday, 4.3 in central CA. All suspensions got shaken. Watchdogs tripped off for ETMX and ETMY, but for none of the others. This has been seen before. Jay looked at it, but couldn't figure out why the watchdogs for the vertex optics weren't working. Finally, he rebooted the AUX cpu that runs the vertex watchdogs, and then verified that they are now working correctly. This remains a mystery.
  • After rebooting the AUX cpu, some of the optics were not damping well, and some OSEMs were not being read out. Jay discovered and cleared up a few problems with database records caused by inadvertant replacement of files in the target area. We will be implementing procedures to minimize the risk of this happening in the future.
  • Shihori has completed a second draft document describing her diagonalization of the suspension controller input (OSEM) matrix. She is also developing her plan for diagonalization of the output (coil) matrix.
• Dual-recycling lock acquisition (Kawamura):
  • Seiji is in Aspen this week and will give a talk on dual recycling at the 40m.
• Safety (all): Almost all of the action items from the safety inspection of 1/13/04 have been followed up on, and a response report is being prepared. Now that the two suspended optics are no longer on the South Annex flow bench, work on installing a fire alarm in the South Annex will be scheduled.
• South Annex Bake Ovens (Taylor):
  • Bob is cleaning and baking a reworked SOS suspension for our BS, which has a notch cut out of it to allow the POB beam to exit without clipping.
  • Bob rebuilt oven F, and is now doing an RGA scan to assess its cleanliness.
  • Bob is doing bake jobs for Larry Jones in support of HEPI and AdvLIGO.
  • Bob continues to work with Larry Jones and Dennis Coyne on the design of new 12" bake ovens for the lab, aimed at achieving AdvLIGO cleanliness specs.

Feb 13, 2004

• Installation (Miyakawa, Vass, Ward):
  • We are vented for the installation of the two suspended recycling mirrors.
  • The installation crew replaced a Brewster prism mirror on the SP beamline with a 2" mirror, and re-established the SP beam through to the photodetector.
  • Steve set up a ccd camera on the SP for installation / monitoring.
  • The installation crew placed two in-vac mirrors to steer a pickoff beam (from BS to ITMY) onto the optical table near ITMY, and established this PO beam on that optical table.
  • The installation crew carefully measured the distances between the ITMs and the BS. Osamu and Rob carefully calculated the optical path length for the power and signal recycling cavities and the Schnupp asymmetry to an accuracy of 1 mm (Seiji established the tolerance on this to be within a few mm of the design values for the two recycling cavities, and several cm for the asymmetry).
  • Steve used the di-inonizing N2 gun on the SRM. Then, the installation crew moved the SRM suspension and installed it in the chamber, positioning it precisely within 1 mm.
  • They connected the cables, and it damped well, immediately. Well, the side damping was a bit noisy until the OSEM was adjusted and the table balanced; then all 5 OSEMs damped the optic nicely.
  • The table was balanced using counterweights, and the OSEMs were adjusted to read around 1 V each (the middle of their range). Visual inspection of the magnets in the OSEMs remains to be done.
  • Osamu and Rob noticed discrepancies between their two calculations, and when it was resolved, it was realized that the SRM was placed 2 mm off from design. The suspension was moved by that amount.
  • After a bit more table balancing, PSL flashes were seen in the initial point beams, in reflections from ITMX back to the symmetric and asymmetric ports, and at ETMX. After some touch-ups, the reflections from ITMX and the SRM were made to overlap with each other, and the incoming beam, at the symmetric port. Additional alignment of suspended optics and output beams are in progress.
  • Plan to install the suspended power recycling mirror on Friday.
• Electronics (B. Abbott, Heefner, Taylor, Mageswaran)
  • Jay reports that The 2 omega I&Q demod board needed for SPOB should be stuffed and tested by 2/13/04.
  • Jay reports that work on a "double resonant" photodetector is proceeding. Right now we can get a PD that has peaks at roughly 133 and 199MHz with a notch at 166MHz. A PD should be ready for installation and test by 2/20.
  • The signal from the PSL frequency reference cavity transmitted light photodiode is fluctuating wildly. The problem appears to be downstream of the photodiode, eg, in the cable to the 3113 ADC, the ADC, or beyond. Under investigation.
  • The PRM oplev signals are fluctuating; under investigation. We have requested a spare oplev QPD from the controls group, and we have spare oplev lasers. This oplev is currently monitoring the levelness of the BS chamber optical table, NOT the PRM, which has not yet been installed.
  • Ben notes that the Minco temperature controller on the PSL frequency reference cavity is oscillating. He and Bob will look at the filtering in that controller.
  • Mohana installed a first draft of the EPICS alarm handler. Much work is needed to make it useful.
  • Caltech undergrad Ben Olsen is beginning to look at the STACIS system, to resolve problems with it.
• Digital suspension controllers (Sakata, B. Abbott, Heefner)
  • The DSC watchdogs to not do their thing. When the rms motion exceeds the set limit, they should disable the coils; they do not. Under investigation.
  • Shihori has completed a first draft document describing her diagonalization of the suspension controller input (OSEM) matrix. She is also planning her diagonalization of the output (coil) matrix.
• Dual-recycling lock acquisition (Kawamura):
  • Seiji continues to use Finesse to explore how the signals for the short DOFs (PRC, SRC, MICH) change during lock acquisition, in order to develop an efficient lock acquisition procedure. He spoke at some length with Hartmut Grote of GEO about how they lock their dual-recycled IFO. He is trying some of the techniques they use, but it is not clear that they will be helpful to us.
  • Seiji will be in Aspen next week and will give a talk on dual recycling at the 40m.
• South Annex Bake Ovens (Taylor):
  • Bob is cleaning and baking a reworked SOS suspension for our BS, which has a notch cut out of it to allow the POB beam to exit without clipping.
  • Bob is doing bake jobs for Larry Jones in support of HEPI and AdvLIGO.
  • Bob continues to work with Larry Jones and Dennis Coyne on the design of new 12" bake ovens for the lab, aimed at achieving AdvLIGO cleanliness specs.

Feb 6, 2004

• Commissioning (Miyakawa, Kawamura, Sakata):
  • We are vented for the installation of the two suspended recycling mirrors.
  • We are carefully monitoring all oplev and OSEM signals as we work. Everything appears to be pretty stable.
  • The PSL beam (low power) is flashing through the mode cleaner, to the ITMs and back to the SP and AP ports. This beam is being used to align all optics.
  • Steve, Osamu and Robert replaced an in-vac prism mirror with a regular 2" mirror, and will use the prism mirror to correct for the astigmatism in the SP beam in air, where it can be more easily aligned.
  • Then they installed two mirrors to bring the beam from BS -> ITMY out to a nearby optical table.
  • The distances between vertex suspended optics are being measured with a ruler. We aim to install the power- and signal-recycling mirror suspensions with a tolerance of a couple of mm with respect to the ITMs.
  • Next is to install the PRM and SRM suspended optics and oplev beamlines, and align everything.
  • We decided to not center the beam better on ITMX. It is a bout 1cm from the center of the optic. Since it's not really a problem, and would be a big chore to correct, we decided not to bother.
  • After we pump down, we will re-establish the Fabry-Perot Michelson (FPMI), with misaligned power- and signal-recycling mirrors. Our original plan was to first commission a LIGO-1-like power-recycled FPMI. But we decided that we would not learn anything valuable from that exercise, and that it would be more efficient to go straight to a dual-recycled Michelson (without Fabry-Perot arms, at first). Opinions on this are welcome.
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • The 2 Omega I&Q demod boards needed for the SPOB signal should be ready within the week.
  • Mohana is working on the EPICS alarms and vacuum interlock.
  • AJW, Jay and Alex have been looking at the LSC front end code (Rolf) and lock acquisition code (Matt), and are discussing the mods needed for the dual-recycling experiment.
  • A considerable amount of additional electronics (LSC RFPD's, double-demod boards, and associated wiring) still need to be specified, designed, and built.
  • The STACIS system still is down, awaiting some attention.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori is documenting her diagonalization of the suspension controller input (OSEM) matrix. She is also planning her diagonalization of the output (coil) matrix.
• Simulations:
  • Seiji has released a note on Signal Extraction Matrix of the 40m Detuned RSE Prototype, T040010-00-R.pdf. This note explores different variations on the 5x5 signal extraction matrix for Detuned RSE: comparison of differential demodulation and double demodulation, dependence of each DOF on demod phases, allocation of ports for optimal signals, comparison of different PO ports, and cavity length tolerances.
  • Seiji continues to use Finesse to explore how the signals for the short DOFs (PRC, SRC, MICH) change during lock acquisition, in order to develop an efficient lock acquisition procedure.
• Safety (all): Following up on the action items from the safety inspection of 1/13/04:
  • Bob ordered steel-toed safety boot covers for crane operation, but they're too small, so they will be returned for larger sizes.
  • Steve installed drip trays under the vacuum roughing pumps.
• South Annex Bake Ovens (Taylor):
  • Bob continues to work with Larry Jones and Dennis Coyne on the design of a new 12" bake oven for the lab, aimed at achieving AdvLIGO cleanliness specs.

Jan 30, 2004

• Commissioning (Miyakawa, Kawamura, Sakata):
  • We vented on Wednesday, for the installation of the two suspended recycling mirrors, with no problems or incidents.
  • As noted below, we had many problems with the suspension controllers on Monday. By Wed morning, things had been stable for more than 24 hours. All oplev, OSEM, PZT, etc signals and servo settings were recorded before the vent.
  • During the vent, the drifts in the oplev and osem readings were carefully monitored. There was considerable motion in the oplev signals, much less on the OSEMS: consistent with the motion being due to the table motion (in yaw, mainly) as the seismic stacks respond to the vent. There is clearly a daily drift in the oplev readings, correlated with temperature, but it isn't very big (~ 0.2 volts, while deviations of ~ 1 volt are tolerable for maintaining alignment). After the vent, the P/Y biases on the OSEMS were changed to recover the pre-vent oplev readings.
  • Osamu completed the mode-matching into the IFO last week, by maximizing the ratio of the x-arm transmitted power to input power. He needed to make only one turn of the MMT adjustment screw, which means the original MMT alignment and adjustment was done very well (thanks, Koji!). The MMT did not steer the beam very much; the spots did not move visibly on the PZT steering mirrors, and only moved by around 1 cm 40 meters away. The PZT steering mirrors easily corrected for this.
  • We are now at atmosphere, and the access connectors have been removed. Osamu re-established the PSL beam through the mode cleaner, and flashes were seen through the faraday isolator. Remarkably, no steering of the PSL launch was required!
  • Now, Rob is establishing a pair of optical levers to monitor the levelness of the BS optical table, where all the installation action will be. Next is to replace an in-vac prism mirror with a regular 2" mirror, and will use the prism mirror to correct for the astigmatism in the SP beam in air, where it can be more easily aligned. Then install the pickoff beamline, and then intall the PRM and SRM suspended optics and oplev beamlines, and align everything.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Last week, the digital suspension controllers for the PRM and SRM were fully tested by having them damp the BS. This week, Steve & Rob used them to damp the PRM and SRM, on the South Annex flow bench. Now, everything's been tested except for the in-vac cables, which were tested when they were installed, and one satellite amplifier, which is at Wilson House for full checkout.
  • On Monday night, the c1suslinuxpc1 computer which filters the suspension controller signals for the BS, ITMX, ITMY suspensions went crazy: the cpu maxed out, the three suspensions were shaking all night long, and the watchdogs (on a separate aux computer) failed to shut them down. Rebooting all the relevant computers in the morning recovered the system, but the cause of it remains a mystery.
  • The shaking might have messed up the suspension alignment; the OSEM readings were different after damping was re-established.
  • It appears that the oplev signals are a better (short-term) reference than the OSEMs. After the shaking, Osamu found that the Michelson error signal was better when the P/Y biases were adjusted to recover the old oplev readings, rather than the old OSEM readings.
  • Shihori has re-measured the pos/pit/yaw frequencies and couplings on all the optics whose input matrices she has diagonalized in the last few weeks. She finds that the frequencies are unchanged, but that the pos/pit/yaw coplings have degraded a bit. A document is in progress.
• Optical sensing:
  • The oplev QPD readout for the PRM and SRM have been tested and seem to work well.
  • Fumiko recentered all oplevs prior to venting. She continues to work on calibrating the oplev response.
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • The computer that does the filtering for the mode cleaner WFS system, c1asclinux, loses time synch regularly (every day or so). Sometimes it recovers upon reboot, sometimes not. On Monday, when it would not recover, it was power-cycled, which interrupted the RFM network, bringing down the DSC (digital suspension controllers) system. To avoid this, Alex Ivanov gave this computer its own slot in the RFM bypass switch.
  • Jay and Alex fixed the code that was reading out the QPDX signals incorrectly. Now, QPDX appears to be working well.
  • The 2 Omega I&Q demod boards needed for the SPOB signal are being fabricated.
  • Mohana is working on the EPICS alarms and vacuum interlock.
  • In the process of mode matching (see above), the PZT steering mirrors were turned on and off many times, and they always come back very close to where they were.
  • The new EPICS controls of the PZT steering mirrors work well. Osamu will adjust the biases to allow the desiring setting to be mid-range on the sliders, while ensuring that the voltage applied to the PZTs are always within the 0-10 volt spec.
  • We are startingf to look at the lock acquisition code. We will need Rolf's help, but it is unlikely that we will get it soon, since he is saturated with HEPI.
  • The STACIS system still is down, awaiting some attention.
• Simulations:
  Seiji is using Finesse to address several questions regarding the length sensing matrix:
  • The baseline for the 40m is to use fouble-demodulation at f2xf1 (f1 = 33 MHz, f2 = 166 MHz) to sense MICH and f2-f1 to sense PRC and SRC. Seiji finds that double-demodulation makes noticable improvements for PRC and SRC as well, so we tentatively plan on using double demod for all three length sensings.
  • Seiji is exploring the demod phases required for double demodulation: one has to find a pair of demod phases that produces no DC offset to the error signal while maximizing the error dignal for the desired length degree of freedom. He can find workable phases (in principle).
  • Seiji explored the relative merits of different pickoff ports for length sensing, and finds them all to be roughly equivalent in terms of error signal strength. We will instrument the pickoff of the light from the BS to ITMY, for convenience.
  • Seiji explored the sensitivity of the length sensing matrix to deviations from the ideal macroscopic cavity lengths. He finds length tolerances of 6 cm for MICH, 3 mm for PRC, and 3 mm for SRC. It may be difficult to position the PRM and SRM sufficiently accurately in air, which may require us to iterate (vent, reposition, pump down).
• Safety (all):
  Following up on the action items from the safety inspection of 1/13/04:
  • Bob and Steve continue to set up the lockout-tagout system.
  • Steve is getting a quote on the installation of a fire alarm in the South Annex clean room.
  • Steve asked the electricians to identify a main breaker for the south annex which is outside the lab and which thus could be accessed in case of a fire in the lab.
  • Steve asked the electricians modify the rack power kill switches so that the ground is not broken (as they currently do).
  • Steve will ask the electricians to ground all the optical tables to the 40m vacuum envelope (basically, anything but the racks).
  • Steve arranged for routine fire alarm maintenance, which was done this week.
  • Steve and Bob are getting info on formal crane operation certification from the safety office.
  • Bob ordered steel-toed safety boot covers for crane operation.
  • Steve will install drip trays under the vacuum roughing pumps.
  • All 40m personnel will get an update on lab safety from Steve in the next couple of weeks.
• South Annex Bake Ovens (Taylor):
  • Bob is working with Larry Jones and Dennis Coyne on the design of a new 12" bake oven for the lab, aimed at achieving AdvLIGO cleanliness specs.
  • The SRS RGA has been repaired and is being shipped back to us.

Jan 23, 2004

• Rob Ward has joined the 40 meter team as a graduate research assistant. Welcome!
• Commissioning (Miyakawa, Kawamura, Sakata):
  • We plan to vent for the installation of the two suspended recycling mirrors, early next next week.
  • Osamu remeasured the Michelson asymmetry using the 33 MHz RF sidebants, and obtained 0.462 +- 0.028 m, or 0.012+-0.028 m larger than design. It is hard to reduce the error on this measurement as it is currently being done.
  • Seiji used Finesse to determine that the length sensing matrix is not too sensitive to the Michelson asymmetry, and can tolerate a few cm difference from design.
  • However, Seiji also found that the lengths of the power and signal recycling cavities must be within a couple of mm of design, or the length sensing matrix will be significantly degraded. We're not sure how we can place the optics to that level of accuracy in air! We will try our best, and iterate (requiring vents) if necessary.
  • Osamu looked at the optical axis of the 29 MHz and 33 MHz pockels cells, and found they differed by 18 degrees! But, then he found that a HPW placed before the 29 MHz pockels cell in the PSL IOO path during the re-layout was actually a quarter wave plate! He has replaced it, and remeasured the optical axes of the 2 pockels cells; they are within 3 degrees, quite tolerable. He has realigned the beam through all 3 pockels cells (including 166 MHz), minimized the AM for the 33 MHz, and found that the AM on the other two frequencies was small and tolerable.
  • He then re-established the mode cleaner lock with the correct polarization and modulation depth for all 3 RF frequencies.
  • Osamu is testing the use of the in-vac mode matching telescope and in-vac PZT steering mirrors, in preparation for mode matching into the main IFO after installation of the recycling mirrors. We are relieved to see that moving the mode matching telescope focus steers the beam only slightly, and the spot doesn't move off the small PZT steering mirror downstream. Current plan is to mode match by maximizing the light transmitted through the arm cavities; not very sensitive, but good enough for us.
  • Before vent, we will recenter all oplevs, and document all the readbacks and settings for all servos, OSEMS, oplevs, PZT steering mirrors, etc.
  • Rob Ward has built a small Michelson interferometer for use as a hands-on demo. It works great!
  • Seiji has been looking at uses for double demodulation to improve the diagonality of the length sensing matrix, and finds that it can be used to improve the matrix for the PRC, SRC, and MICH degrees of freedom (l+, ls, l-), *if* the demod phases can be chosen and optimized well. We are not sure how to do that!
  • Bob has returned the dycor RGA head to Steve, and Steve has reinstalled it on the 40m main volume and calibrated it. The electron multiplier on this head doesn't work, but it isn't a big problem right now.
  • Steve has all the 2" mirrors and mounts needed to install a BS pickoff beam. He has all the in-vac oplev mirrors. he has all the weights for balancing the BS table (cleaned and baked). He has all the clean air for the vent.
  • Bob is getting replacement bulbs for the chamber illuminators (plus spares).
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • Jay and Peter Fritschel discussed the prototyping of the sensing beamline centering/stabilization servo at the 40m. Peter will send us some steering mirrors. Rob Ward will take responsibility for commissioning and characterizing the servo.
  • Jay has 133 MHz and 199 MHz resonant circuits working for the LSC RFPDs.
  • Jay has 2omega I&Q demod boards for SPOB signal ordered and are due by 1/29. They will then be stuffed and tested.
  • Mohana is working on the EPICS controls of the PZT steering mirrors, the mechanical shutters, and the vacuum interlock (ensure that the PSL shutter is closed, and the PZT mirrors are not energized, when making transition from vent to high vacuum and vice versa).
  • Rob and Steve discovered a 2 hz comb on the ETMY UL OSEM noise spectrum. Jay determined that it was due to ICS110b channel hopping, and he cold-booted the crate (power down crate; count to 60; power back up; restart processor) and it went away. A day later, it was ETMX LL, again fixed by cold booting.
  • The c1asclinux processor (for MC WFS ASC control) has been falling out of time-synch; the servo works fine, but the DAQ data is probably screwed up. Rebooting fixes it. Sigh.
  • Lisa Bogue has instructed us on how to back up the data on our main CDS computer (op140m), and we will do it weekly.
  • Work on ASC readout (especially the QPDs) is in progress.
  • The STACIS system still is down, awaiting some attention. Rob Ward is starting to look at it.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • We have checked out the PRM and SRM digital suspension controllers (DSC's) by using them to damp the BS. Next, we will damp the actual suspensions with them (they are in the South Annex flow bench). Thus, everything will be well tested prior to installation, except for the in-vac cables (which were tested when they were installed last year).
  • Shihori has completed the diagonalization of the input matrix for all suspended optics except for ETMX (which has a badly-positioned OSEM which will be fixed during the upcoming vent). She obtains satisfactory decoupling of POS, PIT, YAW; the worst cases in the small optics are ~ 8% cross-coupling; in the ITMs and ETMs, ~ 3%. She is documenting the procedures and results, and will move on to the output (coil) matrix.
• Optical sensing:
  • We should have 12 QPDs looking at the main beam (as well as 7 oplev QPDs). Most are in place, have light on them, are being read out, and being logged to frames (16 Hz). Steve and Jay are getting two very important ones (initial pointing position and angle) all checked out. A few more will be completed after the vent. (Done: IOPOS, IOANG, TRX, TRY, POX, POY. In progress: IPPOS, IPANG. Later: SP, AP, MCR, MCT).
• Safety (all):
  Following up on the action items from the safety inspection of 1/13/04:
  • Bob has installed a lockout-tagout kit, and he and Steve are setting up the system. We will all be trained on it in a week or 2.
  • Steve and Bob are getting info on formal crane operation certification from the safety office.
  • Steve & Bob are getting steel-toed safety boots for all crane operators (Steve, Bob, Osamu).
  • Steve will install drip trays under the vacuum roughing pumps.
  • Bob has modified and reposted the emergency procedure for the South Annex bake-out facility.
  • An audible fire alarm will be installed in the back room of the South Annex.
  • Steve has removed obstructions in the areas around the electrical panels and the emergency exits.
  • All 40m personnel will get an update on lab safety from Steve in the next couple of weeks.
• South Annex Bake Ovens (Taylor):
  • Bob is baking glass dishes to hold the in-vac cables, to keep the ground braid isolated from the chamber walls.
  • Bob continues to work with Larry Jones and Dennis Coyne on getting the bake ovens clean enough for AdvLIGO specs. He's building a new super-clean oven, and is replacing the temperature controller for another.

Jan 16, 2004

• Safety (all):
  • There was a safety inspection of the 40m lab on Tuesday, January 13. Several items that were called out last year had not been addressed; All of these issues are now being addressed, aggressively, belatedly.
  • Bob has ordered a lockout-tagout kit, and will set up the system. All personnel will be trained in its use.
  • Steve and Bob are investigating more formal crane operation certification.
  • Bob is ordering steel-toed safety boots for all crane operators (Steve, Bob, Osamu).
  • Steve is ordering, and will install, drip trays under vacuum roughing pumps.
  • Bob is modifying the emergency procedure for the South Annex bake-out facility in case of fire, equipment overheating/failure or loss of electrical power, based on comments from the safety inspectors.
  • Bob had the South Annex fume hoods calibrated, and they are within specs.
  • An audible fire alarm will be installed in the back room of the South Annex.
• Commissioning (Miyakawa, Kawamura, Sakata):
  • We are planning to vent for the installation of the two suspended recycling mirrors, next week. More detail below. The current work is all preparation for this installation.
  • Steve is completing the installation and commissioning of all the QPDs for beam monitoring, especially the ones that monitor the initial pointing of the beam just before it hits the PRM.
  • A mechanical shutter has, at long last, been installed on the PSL periscope. EPICS control of this shutter, including an interlock to the vacuum state, will be implemented by Jay soon. Steve and Osamu will install three more mechanical shutters in the API table, for the MCR, SP, and AP beamlines.
  • The 166 MHz pockels cell has been installed on the PSL table. All wiring is in place, the pockels cell has been energized; modulation depth checked with a scope; signals appear at the 166 MHz I&Q demod board (at the SP beamline); and into the digital LSC system. The signal generator has been phase-locked to be exactly 5x the 33 MHz signal.
  • Osamu used the 166 MHz sidebands to measure the Michelson Schnupp asymmetry. He put a HWP before the 166 MHz pockels cell to induce AM as well as PM onto the light, and measured the transmission of the AM at the dark port. From this he calculated the Schnupp asymmetry to be (0.39+-0.05) meters, or (6+-5) cm lower than design (the design will tolerate a difference of up to 10 cm). The large errors are due to difficulty in measuring the AM in the presence of beats at lower frequencies. Osamu is working on a different, more sensitive method.
  • However, the 166 MHz RF PD seems to have sustained some damage, and Osamu is working on getting a replacement PD.
  • Osamu has developed a procedure for aligning the PSL beam into the Mode Cleaner (in vacuum or in air) using the MC error signal as a guide. This should make it much easier to use the PSL beam, in air, to align the interferometer during installation.
  • Osamu checked that we are able to robustly lock the arms (using POX and POY) even at 8% of our usual input power, thereby simulating the situation when the PRM is installed (but misaligned so that the power recycling cavity is not in resonance). Indeed, we can; however, the DC output is very low, and is in the digitization noise. Jay will look into increasing the gain on the PD board.
  • We will check out the damping of the PRM and SRM on the bench in the South Annex, using the real satellite amplifiers and digital suspension controllers; only the in-situ cables will remain to be tested during installation.
  • Steve has assembled all of the vacuum mirrors needed for installation (Lee Cardenas will assemple a few more in the next few days), for the pickoff beam, the oplevs, and the video views. He has also ordered more laser diodes for the oplevs. He has all the clean air tanks for the vent.
  • Steve and Bob will prepare clean glass dishes to hold the in-vac cables, so that the ground braids aren't electrically shorted to the chamber.
  • Osamu has assembled a detailed installation procedure / checklist.
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • Jay retuned an LSC PD and I&Q demod board for operation at 166MHz. The higher frequency required us to use a smaller active area PD. The PD and demod board are installed and operational in the SPD2 position. (But see above; it is already damaged).
  • Jay installed 2 more power supplies in parallel with the +/-15V supplies to raise the maximum current to 8 amps. Requested sorenson power supplies from LLO to be used to handle future power supply needs.
  • Jay is fabricating another 2 Omega I&Q demod board for SPOB.
  • Work on ASC readout (especially the QPDs) is in progress.
  • Mohana is implementing the EPICS control of the in-vac steering mirrors. These will help us to re-establish correct initial pointing, during and after the installation.
  • Mohana is also implementing the EPICS control of the mechanical shutters, and the interlock with the vacuum.
  • Most of the VME cpus went down over last weekend for some unknown reason. After a few failed attempts, Jay and Alex got them all back up.
  • DTT has not been working well. Alex and Daniel Sigg have found bugs in the code (related to timing); they fixed one and are working on another.
  • The STACIS system still is down, awaiting some attention. Rob Ward is starting to look at it.
• South Annex Bake Ovens (Taylor):
  • Bob obtained a new RGA for his bake ovens.
  • The SRS RGA was removed from the 40m and is now in Bob's lab.
  • Bob has reviewed the draft specs on vacuum cleanliness for Advanced LIGO, from Dennis Coyne.
  • Bob continues to work with Larry Jones on making the mods to his ovens to mean the Advanced LIGO cleanliness specs; looks do-able.
  • See safety issues, above.

Jan 8, 2004

• Commissioning (Miyakawa, Kawamura, Sakata):
  • We are now routinely locking our Fabry-Perot-Michelson (FPMI).
  • During the long break, Osamu worked on filters and whitening/dewhitening to reduce the noise in the FPMI; the resulting spectrum can be seen here.
  • Seiji and Osamu tried getting a Michelson control signal using the 2nd harmonic of the 33 MHz RF; unfortunately, they could not turn up the modulation depth sufficiently, and thus a signal at 99 MHz (3rd harmonic demodulation) could not be cleanly seen.
  • Osamu, Steve, and Bob are installing the 166 MHz Pockels cell and associated cabling, for HF RF sensing of the dual-recycling length (and angular) degrees of freedom. Jay is preparing the 166 MHz LSC RFPD and I&Q demod board.
  • Osamu and Seiji are making plans to measure the Michelson asymmetry. One approach is to amplitude-modulate the 166 MHz RF sidebands, and measure the reflection to the SP. Another approach is to lock the arms one at a time using the SP RFPD, and measure the difference in demod phase required to zero the signal at resonance (as Peter Fritchel explained to us).
  • We are making plans to install the power recycling mirror (PRM) and signal recycling mirror (SRM) in the next week or 2. In consultation with Mike Smith, we outlined a tentative alignment procedure for aligning the recycling mirrors, using an autocollimator beam brought in from outside (so as to not have to use the PSL beam through the mode cleaner, while in air; this requires too much re-steering of the PSL, which then has to be undone after we pump back down).
  • We plan to vent in the next week: install the two suspended recycling mirrors; install mirrors for oplevs for those suspended optics; install mirrors for camera views for those suspended optics; fix a badly-positioned UR OSEM on ETMX; adjust the in-vac PZT steering mirrors; commission the PRC PO port; and align the beam through the DR IFO. We hope that we can complete all these tasks in 2 weeks.
  • We also need to replace an in-vac Brewster prism mirror (used to correct the astigmatism placed on the SP beam) with a regular mirror; we'll use the Brewster prism mirror in air, where we can fine tune its position.
  • During this time, we will continuously monitor the positions of the suspended optics with our optical levers. Fumiko is making sure that all the oplev beams are centered on their QPDs, and reliably sensing the optic P&Y.
  • We will then re-establish the FPMI with mis-aligned PRM and SRM. Before the installation, we will verify that we can control the FPMI with the expected loss of incident power through a mis-aligned 7% transmissive PRM.
  • We will postpone the cleaning of the optics (we know their surfaces are dusty and reducing the visibility of the high-finesse arms) for a later vent.
  • We will postpone fine-tuning the mode matching into the IFO until after we install the recycling mirrors. However, we will go through the mode-matching procedure (changing the MMT focus, and compensating for beam steering with the the in-vac PZT steering mirrors) before venting, in order to determine whether / how much to move the PZT steering mirrors positions.
  • Steve is working on the commissioning of the remaining QPDs for the initial pointing position, and then the QPDs and cameras at the SP and AP.
  • We are working on the commissioning of the LA code for power recycling and then dual recycling. currently, we use a fixed sensing matrix for lock acquisition of the FPMI.
  • Jay is working on the readout of the ASC QPDS, which we need for linearization of the sensing signals for lock acquisition.
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • Jay delivered to us an LSC RFPD tuned to 99 MHz and associated I&Q demod board for the 3rd harmonic demodulation experiment referred to above.
  • Jay is now in the process of converting the LSC RFPD and I&Q demod board for 166 MHz. The PD will likely require that we use the smaller active area PDs that we have, to control parasitic capacitances.
  • Several of the chamber illuminators are not working. Bob will check; they may just be blown bulbs!
  • Jay will set up EPICS controls for the mechanical shutters, including an interlock to shutter the PSL beam if the vacuum pressure goes up.
  • The STACIS system still is down, awaiting some attention.
• There will be a safety inspection of the 40m lab on Tuesday, January 13. An update was made to our 40m PSL SOP (Standard Operating Procedure) document, as recommended by the safety inspectors last year.

Dec 19, 2003

• Commissioning (Miyakawa, Kawamura, Sakata):
  • After some effort, Osamu and Seiji have managed to get the ETMX and ETMY coil dewhitening filters turned on after aquiring lock, without losing lock. This required several changes: (a) when turning on the hardware dewhitening, the software inverse dewhitening gets turned on at the same time. That software (digital) filter was being turned on with "Zero history" instead of "always on", so there was an initial impulse which would kick the mirror, causing lock loss. They changed it to "always on", fixing that problem. (b) The feedback signal has large peaks at 3-5 kHz and 300-500 Hz, origin unknown. (They will trace these upstream to see where they come from). The 3-5 kHz oscillation was saturating the coil driver DACs. To reduce the effect of these peaks, they adjusted the filters, reducing the UGF from 300 Hz to ~100 Hz, adding more phase margin at 300 Hz, and reducing the LPF corner frequency. (c) They put in notch filters to eliminate the feedback at the peaks at 300-500 Hz.
  • After all this, they were able to switch on the ETM coil dewhitening filters (and digital inverse filters) without losing lock. They saw 30 dB of noise reduction in AS_Q from 40-300 Hz.
  • Next big effort is to mode match the beam into the arms. Our in-vac mode matching telescope uses fixed mirrors with a stepping motor for focus. When we adjust the MMT, the beam is steered. So, we need to complete the setup of the QPDs that monitor the initial pointing position and angle of the beam (after the MMT but before the IFO) to correct for this using the in-vac PZT steering mirrors. And, we are setting up remote control of these PZT steering mirrors. Osamu and Seiji are working out methods for sensing mode mismatch using reflected light through an iris to sense the TEM00 mode, as the MMT is stepped through its range. Osamu's first attempt to make this work failed, presumably due to the ringing of the reflected light power due to doppler effects. Seiji is developing another scheme using the Michelson which should be immune to this effect.
  • Seiji and Shihori checked one aspect of the displacement calibration: is the BW reported by dtt right? It is.
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • Jay has been debugging the electronics readout of the QPDs that were set up by Steve. He found a bad 3113 and has replaced it.
  • Jay began the tuning of an LSC PD for 99MHz operation. I t is proving to be difficult due to parasitics in the circuitry. An I&Q demod board is also being tuned for 99MHz operation.
  • Bob is running cables for the remote control of the mechanical shutters for the input beam from the PSL and the output beams for MCR, SP, and AP.
  • Jay will set up an EPICS channel that can be used to shut the mechanical shutter at the PSL periscope if the vacuum pressure rises above some level.
  • Bob is running cables for slow EPICS control of the PZT steering mirrors.
  • Steve set up a ccd camera to provide a wide view of the entire PSL table.
  • Bob has run the last of the cables for the ccd cameras that view all the optics and all the beams (and the PSL table).
  • We are following with interest the discussions in the CDS group about (a) placing multiple RF sidebands with one EOM. (b) Progress with the PSL ISS at LLO. (c) The ASI servo at LHO. (d) Servoing the beams onto the photodiodes on the ISC tables.
  • The STACIS system still is down, awaiting some attention.
• PSL (Miyakawa, Kawamura, Abbott, Nocera):
  • The power from the PSL was observed to drop by a factor of 2 on 12/4. After much investigation, Osamu discovered that it was mode-hopping. He adjusted the FSS slow loop (temperature servo) DC offset until the laser re-locked onto the correct mode, and the power came back up.
  • The PSL ISS system is disabled until Flavio investigates the dynamic range problem.
• Optical sensing (Smith, Kawazoe):
  • Steve completed the instumentation of the POX and POY beamlines as well as the TRX and TRY, and is now turning to the initial pointing position QPD, and then the QPDs and cameras at the SP and AP.
  • Fumiko has made great progress in establishing the sensitivity of the oplevs to the motion of the suspended optics, and also the laser pointing jitter noise. She will soon be able to turn to implementing the oplev damping servos.
• South Annex Bake Ovens (Taylor):
  • Bob continues to work on cleaning the bake ovens and attempting to each the cleanliness levels required for AdvLIGO.
  • Several of Bob's bake ovens have RGA heads that are 15-20 years old and are starting to fail. He will purchase a new one.
  • There was a fire alarm test at the lab, and the alarm could not be heard in the south cleanroom in the south annex. Steve will follow up.

Dec 12, 2003

• Commissioning (Miyakawa, Kawamura, Sakata):
  • Osamu has been out with the flu, so there hasn't been much commissioning work.
  • Seiji wrote up a document describing the calibration procedure of the Fabry-Perot Michelson, resulting in a noise spectrum that bottoms out at ~ 2e-16 m/rtHz above 2 kHz.
  • Osamu and Seiji found that the demod phase required to lock the Michelson if only one arm was locked was different, depending on which arm it was. Seiji determined that this is due to contamination of a large ASI signal into ASQ when the demod phase is not tuned precisely correctly, to better than 1degree. This isn't really a problem, because one normally doesn't bother to lock the Michelson with only one arm locked. I suppose we will eventually need an ASI_CORR servo.
  • Our original plan was to attempt to lock the michelson using beats between the 33 and 166 MHz sidebands (ie, not using the carrier, and thus insensitive to the arms). However, Seiji realized that this could not work, because both sidebands are phase modulations, and no Michelson signal can be obtained using phase modulation only. He suggests using the 2nd-order sideband at 66 MHz, which is amplitude modulation; beating that against the 166 MHz will yield a signal at 99 MHz, sensitive to the Michelson. Seiji verified this with Finesse. Jay will see about getting an LSC RFPD and demod board for 99 MHz.
  • Osamu is documenting all the 40m procedures and the performance of the various components (PSL, MC, IFO). It's already a very substantial document, but still in progress.
  • Steve is working on installing the last of the beamline cameras and QPDs.
  • Next big step is to implement 166 MHz RF sidebands and demod boards at 166, 99, 133, and 199 MHz.
  • And, tune mode-matching into the main IFO.
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • Medm screens for the beamline QPDs have been made, and the QPD channels have been added to DAQS.
  • From Jay: Researching various ways to produce the 133MHz and 199MHz that the 40M double demod system will require. Our fall back is to use phase locked IFRs. I am also looking into how to make an LSC PD with resonant peaks at 133 and 199MHz and a notch at 166MHz. Theoretically it is possible, but practically it may be difficult.
  • Bob is running RF heliac cables for these new RF signals.
  • There are plans brewing to add steering servos to the sensing beamlines, as a prototype for the sites. It would be relatively easy to add these to the existing controls.
  • Bob continues to clean up and label the cable plant throughout the lab.
  • Osamu is preparing to install the 166 MHz EOM on the PSL table.
  • The STACIS system still is down, awaiting some attention.
• PSL (Miyakawa, Kawamura, Abbott, Nocera):
  • The PSL ISS system is disabled until Flavio investigates the dynamic range problem.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori now has a suspension diagonalization procedure that seems to work well, and has completed the input matrix for ITMY.
  • She will move on to the other 9 optics, then work on the output matrices, and then optimize the damping.
• Optical sensing (Smith, Kawazoe):
  • Fumiko continues to work on understanding the oplev signals, to establish the calibrated rms motion of the sensed optics and distinguish it from oplev sensing noise.
• South Annex Bake Ovens (Taylor):
  • Bob continues to work on cleaning the bake ovens; some are so dirty that they have to be rebuilt. He's making progress, and the oven cleanup is improving the RGA scans.
  • At the moment, the ovens in the south annex (and at the sites) are not clean enough to meet the AdvLIGO specs. Bob is working with Dennis Coyne and Larry Jones to see what can be done.

Dec 5, 2003

• Commissioning (Miyakawa, Kawamura, Sakata):
  • Osamu, Seiji, and Shihori have been working on tuning the filters for length control of the Fabry-Perot-Michelson to achieve low-noise operation.
  • They did a careful calibration (documentation in progress) and a displacement noise spectrum. To reduce the noise, they are working on implementing whitening and dewhitening filters in hardware, with appropriate software compensation.
  • They succeeded in reducing the noise above 2KHz (to around 1e-16 m/rtHz) using the hardware LSC whitening filter, after adjusting offsets and gains.
  • They had trouble employing the dewhitening to the coil drivers; there was a large 100 Hz oscillation. They traced it to the MC servo cross-over (between MCL and VCO). They reduced the MCL gain, but MC locking became less stable; they suspect VCO saturation.
  • But, with the modified MCL/VCO gains, the noise in the 30-300 Hz region is now 2x better than before.
  • Another problem with the hardware dewhiting filter is that the board is RevB2; should be B5. This has been fixed; now, the dewhitening filter transfer function is according to design.
  • There's also some 4kHz oscillation in the coil driver. All under investigation.
  • The symmetric port beam seems to be clipping at an in-vac Brewster prism mirror. This might improve once we properly mode-match into the IFO (not yet done).
  • IFO auto-locking scripts have been developed and tested.
  • QPDs and cameras have been installed and aligned at the ends (TRX and TRY). Still need to install the remaining optics in POX and POY, and complete the sym port (SP) beamline, including electro-optic shutter.
  • Next big step is to implement 166 MHz RF sidebands and demod boards at 166, 133, and 199 MHz.
  • And, tune mode-matching into the main IFO.
  • Osamu is documenting all the IFO locking, tuning, and calibration procedures that he and Seiji are developing.
• Computing:
  • Our main "online" computer, op140m, crashed last week, bringing all commissioning to a halt.
  • Lisa Bogue came to our rescue, and with Jay, they took the opportunity to finally bring up our Sun E450's and completely re-arrange the computers in our control room. Bob, Steve, and Osamu all helped rearrange and recable all the computers there.
  • One E450 is now the new op140m, and has all the controls software (targets, dataviewer, dtt, etc). One of the old Blade 100's now has 2 screens in "cinematic" mode.
  • Finally, dataviewer and dtt now seem to run reliably on the E450. These essential commissioning tools were all but useless when running on our Blade 100's; they now seem to work!
  • Lisa is rearranging all the data and accounts in our martian network, cleaning up a very sloppy and barely functional system.
  • Many thanks to Lisa and Jay for getting our control room back in shape!!
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • From Jay: ASC aux crate testing is ~90% complete.
  • Ben has installed balancing pots on the last three Universal Dewhitening boards needed for the IFO. These and others that he had done previously, are now installed on: ITMX, ITMY, BS, PRM, SRM, ETMX, ETMY, and MC2. These optics are now finished on this issue except the four newly installed ones (ITMX, ITMY, PRM and SRM) which need to have their digital gains balanced by Osamu.
  • Jay continues to develop plans to form double demod signals (at the sum and difference of 33 and 166 MHz) for LSC. He suggests first using the sums and differences, then move to genuine double demod in a second step.
  • So, we'll form 133 MHz and 199 MHz by phase-locking the signal generators, then bring those signals over to the LSC crate demod boards.
  • Bob is running RF heliac cables for these new RF signals.
  • Osamu is preparing to install the 166 MHz EOM on the PSL table.
  • The STACIS system still is down, awaiting some attention.
• PSL (Miyakawa, Kawamura, Abbott, Nocera):
  • The PSL ISS system is disabled until Flavio investigates the dynamic range problem.
  • Osamu is working on completing technical notes on the performance of the PSL post-re-layout.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori continues to work on improving the input matrix for ITMY and the remaining suspended optics.
• Optical sensing (Smith, Kawazoe):
  • Fumiko continues to work on understanding the oplev signals, to establish the calibrated rms motion of the sensed optics and distinguish it from oplev sensing noise.
• South Annex Bake Ovens (Taylor):
  • A mistake in the bake oven RGA calibration was found, and it is now realized that some of Bob's bake ovens are dirtier than was thought. Bob is working with Larry Jones and Steve to diagnose and correct the problem.
  • He is in the process of rebuilding bake oven C, and has found a large deposity of gunk close to the turbopump manifold. Under investigation.
  • He's also been baking the other ovens to recondition them.
• AJW compiled an equipment budget for the 40m for FY04, with input from Jay, Steve, and Bob. There has been some re-alignment of the budget in order to relieve the pressure on the overall LIGO budget...

Nov 21, 2003

• Commissioning (Miyakawa, Kawamura):
  • Osamu and Seiji now routinely lock MICH, CARM, and DARM quickly and reliably; locks hold for more than 30 minutes.
  • They have been tuning demod phases, gains, filters, etc. They have added filters to compensate for the cavity pole, and for notching the violin modes, to avoid ringing them up.
  • They calibrated the response of ITMX using Michelson fringes, measured the OLG, and applied a calibration signal at 100 Hz on ITMx. Using this info, they took the first calibrated displacement sensitivity curve on the 14th, tweaked the alignment and gains, and a second on the 18th: 40m displacement sensitivity. It's about 5e-16 m.rtHz at 3 kHz, with lots of excess noise below that.
  • Since then, they were able to minimize LSC error signal offsets, turn on whitening and dewhitening filters without losing lock, and saw improved noise above 3 kHz.
  • We still need to lock the arms separately before engaging CARM and DARM, because we don't yet have lock acquisition code for a dynamic control matrix to allow direct acquisition via MICH, CARM, DARM.
  • Steve and Shihori have been commissioning the TRX and TRY transmitted ports. The ASC photodiodes and CCD cameras there are needed for continued progress.
  • Commissioning is *severely* hobbled by the unreliability of dataviewer and DTT; they often hang or crash or simply fail to run on our underpowered Suns. We continue to await help from the computer group to get our new E450's up and running. Meanwhile, much of the problem is a beleagered test point manager; it will need to be rebooted.
  • Steve and Shihori are in the process of installing QPDs at SP, AP, POX, POB, POY, TRX, TRY, and InitialPointing postition and angle.
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • Mohana and Ben have installed and are testing the EPICS crate software and MEDM screens for all the ASC signals (QPDs and WFSs) at the vertex. Problems with wiring, databases, and screens are being found and fixed.
  • The ASC QPD modules are now being read out correctly. The QPDs themselves are still being installed and aligned.
  • One LSC photodiode spontaneously had it's power turned off, and we couldn't get it back on. Ben traced the problem to an error in the EPICS control database for that LSCPD, and fixed it.
  • Jay is developing plans to form double demod signals (at the sum and difference of 33 and 166 MHz) for LSC. He suggests first using the sums and differences, then move to genuine double demod in a second step.
  • The STACIS system still is down. Ben got a PC-based program to help diagnose the problems, but it wasn't very helpful.
  • Bob and Art laid down heliac cable to run the RF signals from the RF signal generator rack to the distribution box in the LSC/ASC rack.
  • Bob ran video cables for CCD cameras at SP, AP, POX, POB, POY, TRX, TRY.
  • Bob is building spare OSEMS for the 40m and for Janeen.
• PSL (Miyakawa, Kawamura, Abbott, Nocera):
  • The PSL ISS system seems to run up against dynamic range and slowly push down the beam power. Flavio is investigating to see if this is the same problem as has been seen and addressed at LLO.
  • We need a way to quickly diagnose whether the ISS is working. Flavio will look into forming ISS_error_rms EPICS channels.
  • Conor is visiting, and has drawn up a nice picture of the new layout of the PSL, as part of his final writeup of the new system and its performance.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori continues to work on improving the input matrix for ITMY and the remaining suspended optics.
  • Ben finished modifying all of our Universal Dewhite Boards to allow the nulling, or at least equalization, of offsets when switching in and out hardware dewhitening.
• Optical sensing (Smith, Kawazoe):
  • Fumiko continues to work on understanding the oplev signals, to establish the calibrated rms motion of the sensed optics and distinguish it from oplev sensing noise.
  • The oplev signal scanning frequency will be increased from 2 to 16 Hz to allow us to study the noise spectrum up to 8 Hz Nyquist.
• Modeling (Miyakawa, Kawamura):
  • Seiji is continuing to study error signals with Finesse while sweeping through (l+,l-,ls) space. He's making "movies" that show how error signals in one DOF are lost when sweeping through the other two DOFs.
  • Matt Evans kindly gave us a tutotial on his lock acquisition algorithm and code, walking us through all the gory details.
• South Annex Bake Ovens (Taylor):
  • Bob and Steve were doing RGA scans for Larry Jones (AdvLIGO SEI system), and discovered that the bake oven heaters had failed. Bob has been rebuilding the heater tape on oven B, and revamping the temperature controllers. He's gearing up for many more bakes for Larry.

Nov 14, 2003

• Commissioning (Miyakawa, Kawamura):
  • Michelson, X-arm, Y-arm all locked simultaneously in CARM, DARM, MICH degrees of freedom.
    Osamu and Seiji accomplished this by first locking XARM, YARM, MICH, then moving slowly to CARM, DARM, MICH without losing lock. Longest lock time so far in this mode is 1.5 minutes.
  • Before this, they tuned up the FPMI in XARM,YARM,MICH mode, measuring the noise power spectrum in the XARM and YARM as they went along.
    • Aligned for both cavities.
    • Conpensating filter for cavity pole with zero at 1.6kHz, pole 3kHz.
    • Adjusting SP1Q demodulation phase for Michelson to minimize L+ signal at SP1Q.
    • FPMI lock with POX, POY and SP1Q signal.
    • Low noise FPMI with A.A filter, whitening filter.
    • Gain distribution for Michelson servo to remove satiration at feedback signal to BS.
    • Filter to remove the violin mode, notch at 884Hz, Q=100, Gain=10.
• Computing:
  • Our main "online" disk, op140m:/cvs/cds , died on Monday. Lisa Bogue did some emergeny repairs, and recovered it, backed it up, and copied it to a new partition, on Wednesday. Thanks, Lisa!
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • Ben is installing the last EO shutter controller in the 40m lab. There is a slight problem in the power, but that should be an easy fix.
  • Ben got the Labview exacutable program for the STACIS controllers at the 40m. So far, the program seems to not be very useful, but a newer version may be available. He is waiting for a call back from TMC.
  • Ben put balancing potentiometers on 6 more Universal Dewhite boards, and balanced their regular and bypassed paths for each channel.
  • Upon installation, the LR channel for ETMY looked bad. Ben finally traced the problem to a bad connector on the Pentek.
  • Ben has been working with Mohana to install her ASC auxillary code and screens. There are some white fields in the WFS screens that will probably be fixed once we figure out what is wrong with two of our 4116 modules.
  • Ben, Osamu and Seiji installed filters into one of our digital filter banks with help from Rolf and Alex.
• More progress will be reported in the next weekly report.

Nov 7, 2003

• Commissioning (Miyakawa, Kawamura):
  • Michelson, X-arm, Y-arm all locked simultaneously.
    
  • Using three LSC RFPD (POX, POY, and AP), Osamu and Seiji have succeeded in locking these 3 degrees of freedom at the same time, robustly, last Monday. We celebrated with a lunch party, today (Thursday).
  • The Y arm gain has a sign flip with respect to the X arm, probably due to flipped magnets on ETMX.
  • The Michelson signal was very noisy at first. This was traced to ADC digitization noise from the error signal readout with low gain on the whitening boards. They adjusted the gains and software filtering for the LSC channels, Now, all 3 loops have software gain around 1, and exhibit robust, low-noise locking and relatively high UGF's.
  • Osamu and Seiji continue to tune and improve the lock acquisition and in-lock servos optimization, including better tuning of the Michelson demod phase, to reduce the influence of the arm signals on the Michelson.
  • The Michelson contrast is very good; to be measured carefully, soon. We still need to adjust the mode matching into the arms.
  • We need to re-measure the arm reflectivity; but it sure looks like the mirror surfaces have lots of dust. We plan to vent soon, to clean them (and fix a misplaced OSEM on ETMX).
  • Next step is to move to the common-mode and diff-mode control topology, and implement a common mode servo (based on the LLO incarnation).
  • Then, characterize, measure response, calibrate, noise spectrum, etc.
  • The longer-term plan proposed by Seiji and Osamu is to vent, clean mirrors, fix osems, but don't install the recycling mirrors yet. Then, re-establish operation, with clean mirrors. Then, commission 166 MHz sidebands, and see how robust the Michelson signal is in the (166-33) MHz demodulation, where the carrier light is not used. This is a key element of the AdvLIGO control scheme, allowing us to control the short degrees of freedom (Michelson, PRC, SRC) without being sensitive to the locking and control of the long arms. We need to build 133 MHz frequency distribution system and demod boards.
  • The mode cleaner and its ASC WFS system are working well. Remaining low-frequency intensity fluctuations in the MC transmitted beam are from upstream of the MC, so Flavio is now commissioning the Intensity Stabilization servo for the PSL, to address this.
  • Osamu and Seiji are optimizing all the control loops with the help of 6 scopes, including three fast (100 MHz or higher, with high sampling rate) 4-channel digital scopes. We need more scopes, more shutter controllers, more SR560's. (Basically, we need more money!).
  • We also need to learn how to use the EZCA scripts for autolocking, calibration, etc.
• Electronics (B. Abbott, Heefner, Taylor, Nocera, Mageswaran)
  • Jay found some problems with signals from one of the LSC PD interface boards. He and Ben trouble shot the problem, and found two independant causes. One was a low voltage problem on the +/- 5V supplies, and another was an ungrounded LEMO connector. Both have been corrected, and the signals are fine now. Ben will survey all the cables.
  • Ben and Sander are getting parts for two more EO shutter controllers. All the cables for three EO shutters are in place.
  • The PCB for the LSC PD tester board arrived Wednesday, and Ben will stuff and test it today.
  • Mohana is completing the code, databases, and screens for the ASC auxiliary crate, and we hope it will go in today, so that we can read out all the QPDs in the vertex and the ends.
  • We have a long list of new signals (ISS, ASC QPDs, etc) that need to go into master.config.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori applied her iterative procedure to better diagonalize the input matrix, to ITMY and BS (ITMX is already much better diagonalized).
  • She is now working with Osamu to diagonalize the output (coil) matrix of the BS to help with michelson lock stability.
  • Her work is severely hampered by the inability to run DTT with bandwidths smaller than 0.05 Hz; we hope that this is due to the slowness of the Sun Blade 100, and will be remedied when we get the new Sun E450's online.
  • Ben is modifying six of our Universal Dewhite Boards to allow the nulling, or at least equalization, of offsets when switching in and out hardware dewhitening.
• Optical levers (Kawazoe, Heefner, Abbott):
  • Fumiko has analyzed her oplev response calibration data; all 6 oplev sensors have similar slopes (response in volts versus pitch and yaw) near their operating point.
  • She will use this information to calibrate the pitch/yaw bias controls, measure the rms noise (in radians) with the mirrors (a) undamped; (b) damped; (c) under IFO lock.
  • Next step is to import the oplev servo filters from the sites, make any necessary mods, and commission the servos.
• Optical sensing (Smith, Kawazoe):
  • Fumiko aligned the optical, photodetector, and electronics chains for the POX and POY beams. Osamu and Steve did the SP beamline. Still to be done: TRX, TRY, POB.
  • Fumiko is installing all the QPDs on all the beamlines, and awaits the installation of the ASC auxiliary readout software that Mohana will install soon.
  • Fumiko will commision the EO shutters on the SP and AP.
  • She and Lisa will put in all the ccd cameras.
• Computing:
  • We desperately need to bring our new Sun E450 online so that we can (hope to) run dataviewer and dtt reliably (we've had no end of problems with these programs, running on an under-powered Sun Blade 100). We will need help from the computing group, and Alex Ivanov.
• Modeling (Miyakawa, Kawamura):
  • Seiji is continuing to study error signals with Finesse while sweeping through (l+,l-,ls) space.
  • Per his request, Andreas Freise quickly implemented the ability to sweep 3 DOF simultaneously, into Finesse. Seiji now writing scripts to explore the 3D space.
• Facilities and vacuum envelope (Vass):
  • Flavio and Ben are beginning to look at the STACIS controllers at the 40m. They are having a colorful array of problems, and we will characterize them as we find them. Ben has ordered another copy of the control software that we can use to better understand the fault conditions.
  • Steve has been ordering commissioning equipment (scopes, sensor cards, camera cables, etc). He sent back the metone particle counter for repair. It has been reading zero on the South Annex flow bench, but it was a lie. He checked with our other (working) particle counter; it's 10-15, still quite low (but not 0).
  • The turbopump and scroll pump that failed during the last pumpdown has been repaired and returned.
• South Annex Bake Ovens (Taylor):
  • Bob has been on vacation for the last 2 weeks.
  • Larry Jones needed some RGA scans for AdvLIGO SEI parts. Steve ran some scans on coils, which failed. Steve later discovered it was due to a blown fuse on the heater strips on the bake oven. He's now doing a magnet bake/scan for Larry.

Oct 31, 2003

• Commissioning (Miyakawa, Kawamura):
  • Michelson, X-arm, Y-arm all locked (one at a time).
    Using one LSC RFPD (at the asymmetric port), Osamu, Seiji, Jay and Ben have succeeded in locking these 3 degrees of freedom, one at a time, robustly. The high-finesse arms typically take 20 seconds to acquire lock, and have remained in lock for over an hour at a time.
  • They observed a strong oscillation at ~ 330 Hz, attributed to the dewhitening filter. They bypassed the hardware dewhitening filter and the software compensation filter, in order to make it easier to lock. They measured the OLTF, and designed appropriate filters to achieve robust lock, with UGF around 300 Hz. The violin resonances ar 451 Hz are seen, as well as its first harmonic (approximate) at 880 Hz. The AA filter also seems to produce an oscillation near the UGF, presumably due to insufficient phase margin near the UGF.
  • To lock the y arm, they used the same filters, and only a sign flip in the gain (consistent with the sign flip needed for damping - the magnets must be reversed for ETMY compared with ETMX).
  • They estimated the cavity reflectivity; it was ~ 50%. Osamu refocused the retuning beam on the PD, and it went up to 85%.
  • The 50% reflectivity implies that the loss per mirror is 90 ppm instead of the 37 ppm design (and a finesse of 1200 instead of 1270, and a PRC gain of 6 instead of 14). And indeed, a lot of dust cattering can be seen on all mirror surfaces when viewed with an IR viewer through the viewport (the ccd camerase are too saturated to see this). We need to vent and clean each mirror.
  • All of the above is with poor mode matching into the arms. In order to tune the mode matching telescope, Osamu is trying to maximize the arm transmitted light. He saw large (5-10%) intensity fluctuations in the arm transmitted light, which is likely due to (a) aperture limits in the transmitted light beamline; (b) angular fluctuations from the MC; (c) real intensity fluctuations from the MC (~ 1-2%).
  • He then re-commissioned the MC ASC (WFS) system to stabilize the MC transmitted light. He installed a control matrix to feed back onto MC2 and MC3, and a simple feedback filter. It now works very well, stabilizing the intensity fluctuations in the ~ 1 Hz region quite effectively.
  • Remaining MC transmitted light intensity fluctuations are all at lower frequency, and Osamu has determined that they originate in the PSL. MOPA or PMC? Under investigation.
  • Meanwhile, Flavio will commission the ISS, sensing the light transmitted through the MC, which should fix the problem, whatever the source.
  • The mode cleaner now locks quickly and robustly, even in low noise mode (with dewhitening filter on), now that Osamu has applied a limiter in the MCL feedback path.
  • Osamu balanced the MC2 coil outputs in the digital filters, so now the MC dewhitening (and software compensation) can be turned on and off without disturbing the MC lock.
  • Fumiko is in the process of aligning the optical, photodetector, and electronics chains for the POX and POY beams. After that: SP, POB, TRX, TRY.
• LSC Electronics (B. Abbott, Heefner, Taylor)
  • Ben has reverse engineered the Common Mode Servo board so that Todd could reconcile the fully stuffed board that he had with the marked up schematics and pictures given to him from LLO.
  • Ben then redrew the schematics for the CM servo board, and made a test procedure for Todd. The new schematics are going to be sent to Livingston for review.
  • Ben tested a spare CM servo board for Livingston using the new test procedure.
  • Ben made a milled prototype of the LSC PD tester board that could not be used as the milled board had many shorts on it. He has sent a board to PCB express, and will test that when it arrives.
  • Ben checked the QPD wiring in the vertex, and concluded that it is all there ready for the ASC auxillary code to come from Mohana, when we can test the wiring using tester boards and actual QPDs. Should happen in the next week.
  • Ben ordered 50 Ohm SMA terminators for our frequency distribution box.
  • Jay reports that ASC code from Rolf is in progress, and will be a prototype for a new system at the sites.
  • We have a long list of new signals (ISS, ASC QPDs, etc) that need to go into master.config.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori continues to develop and document an iterative procedure to better diagonalize the input matrix, to distinguish POS/PIT/YAW. She has improved the ITMX input matrix, and is now applying the procedure to ITMY.
• Optical levers (Kawazoe, Heefner, Abbott):
  • Fumiko has taken oplev response calibration data and is analyzing it. She will work with Jay to begin to commission the oplev servos.
• Optical sensing (Smith):
  • All parts for optical sensing are in hand except for one 67% BS, on back order.
  • We have finally received one last q-switch E/O shutter from Fast Pulse which we have been waiting for for at least 6 months.
  • Ben ordered some cable connectors for the EO shutters that should be in next week.
  • We have heard that the sites are moving away from the EO shutters, and switching to fast mechanical shutters and simpler methods for limiting the power to the photodiodes. Our MC EO shutter works well; we wonder why these changes are necessary, or desirable at the 40m, where time constants are shorter than at the sites.
  • Steve ordered power supplies and cables for the ccd cameras that view the sensing beams.
• Computing:
  • Alex Ivanov plans to commission one of our new Sun Ultra E450's to run GDS software (dtt, dmt, dataviewer).
• Modeling (Miyakawa, Kawamura):
  • Seiji is continuing to study error signals with Finesse while sweeping through (l+,l-,ls) space. He is finding it difficult to use matlab to do this by interfacing with Finesse. Hiro suggests modifying Finesse instead; Seiji is trying to contact Andreas Freise.
• Facilities and vacuum envelope (Vass):
  • Ben and Flavio are diagnosing the staus of our STACIS system.
  • Steve is straightening up the lab and reducing earthquake hazards (like using the shelf above the PSL table to store spare optics).

Oct 24, 2003

• An informal review of the 40 Meter experimental plan, scope, staffing and budget was conducted on Tuesday (Shoemaker, Wilkinson, Strain, Fritschel, Weinstein, Miyakawa, Kawamura, Vass). Minutes.
• Commissioning (Miyakawa, Kawamura):
  • Michelson locked.
    The Length sensing and control (LSC) system wiring & cabling is just about done, and Rolf and Alex installed new software on Wednesday afternoon. Within a couple of hours, Osamu, Seiji, Jay and Ben used the LSC system to lock the Michelson (after blocking the ETMs). They then used DTT to take a transfer function, hastily designed some filters with FOTON, and made the lock robust.
  • The Michelson contrast is better than 99.8%. However, the beam is not well mode-matched into the IFO (the MMT was set for the case where the PRM is in place, which it isn't). So, the beam is significantly larger than it should be, making it easier to obtain high contrast.
  • They are now working on locking the x arm, using the AP sensing train.
  • We still need to commission the optical, photodetector, and electronics chains for the SP, POX, POY, POB, TRX, TRY; but almost all the parts are in.
  • We continue to see the alignment of the input beam (after the mode cleaner but before the ifo) changing significantly, from time to time, usually overnight. The QPD monitoring of the beam alignment is still not yet in place, but we're working on it. We continue to suspect that the problem is with the PZT steering mirrors (after the mode cleaner but before the ifo) which were never fully checked out before installation, since they were the last item to arrive. The beam is now nicely aligned, and is centered on the PZT1 mirror, but still off to one side of the PZT2 mirror.
  • Anyway, Osamu and Seiji re-aligned the input beam with the PZTs. They had to tweak the beam launch at the PSL table to eliminate some clipping that they saw on both the SP and AP beams; likely, this clipping is at the Faraday isolator.
  • Osamu noted that the resonant frequency of the MC, 33.207 MHz, changed by 60 Hz from day to night. He also notes that there's some excess noise in the detection of the 33 MHz signal transmitted from the MC. To be investigated.
  • Osamu continues to commission the mode cleaner wavefront sensors. He sees good error signals, but needs to calibrate the control matrix between WFS1/WFS2 and the MC mirrors. In progress.
  • The MC transmitted intensity fluctuations are at the 1% level, good enough for Flavio to commission the PSL ISS.
• LSC Electronics (B. Abbott, Heefner, Taylor)
  • From Rolf: Modified the LSC software to run the 40m lab system; code installed today.
  • From Jay: The LSC software and 90% of the electronics are now installed and operational. As a test of the system we locked the Michelson. In the process of locking the mich. we found several signals and test points that were not available to DAQ or DTT. These will be corrected.
  • Osamu and Ben checked the four RF PD heads (for AP1, SP, POX, POY) and all seemed to be functioning fine.
  • Ben installed the refurbished PZT mirror driver in its slot, and Osamu and Seiji aligned the beam using all four controls (PZT1X, 1Y, 2X, 2Y).
  • Ben mailed off two RAID disks to get replaced. One of these was already sent to us as a replacement. This is the only replacement that has gone bad so far, and it has been in place for over a year.
  • Ben is in the process of laying out an LSC PD tester board that will help in debugging LSC PD and wiring problems.
  • Ben was was having problems with the enable/disable on the LSC PD screens. He traced the problem to the LSC PD interface, where the logic chips had been damaged due to a bad cable. He fixed the bad chips, and one damaged PD head. This sort of problem can be averted in the future using the tester board that he is laying out.
  • Bob and Art continue to wire and cable up the LSC and ASC racks. The cabling for the vertex QPDs are going in now. Cabling for the electro-optic shutters are next.
  • Ben got 2 more Kepco power supplies for the ASC rack DC power.
  • We have a long list of new signals (ISS, ASC QPDs, etc) that need to go into master.config.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori is developing an iterative procedure to better diagonalize the input matrix, to distinguish POS/PIT/YAW. She has improved the ITMX input matrix, reducing the POS motion in the PIT channel by a factor of more than 10.
  • As we commission the IFO, we really need to better diagonalize the input and output matrices for all 10 optics. In progress, progressing slowly.
• PSL (Miyakawa, Kawamura, Abbott, Nocera):
  • Osamu has final results on the improvement in the PSL frequency noise (as measured by the MC) due to (a) reducing the number of folding mirrors on the PSL table from 6 to 3 (several large peaks between 300 and 800 Hz have disappeared), and (b) moving the FSS pickoff to after the PMC (much improved noise spectrum in 1 kHz to 10 kHz region). These two changes helped a lot, and make it possible to run with low noise even when the HEPA filters in the PSL enclosure are on.
  • The intensity fluctuations in the MC transmitted beam have been reduced to ~ 1%. Flavio can resume commissioning of the ISS servo.
• Optical levers (Kawazoe, Heefner, Abbott):
  • Ben has changed the resistors on all the oplev QPD preamps from 10K to 100K. They are now all back in place and reading out the oplev beam positions.
  • Fumiko still needs to center the beams, zero the response when the beam is blocked, re-measure the response, characterize the pitch/yaw motion of all the monitored optics, and begin to commission the oplev servos.
• Optical sensing (Smith):
  • PZT1 STEERING MIRROR: PZT1 pitch amplifier was received from Piezojena and is now re-installed.
  • QPD MOUNTS: Mounts were received, and QPDs are mounted on all sensing trains (not yet aligned).
  • POX and POY: 40%, 50%, and 67% BS are on back order.
  • INITIAL POINTING: The mount for the 10 X telescope initial pointing ANG beam is being fabricated.
• Computing:
  • We look forward to Lisa and Larry setting up our two new "cast-off" Sun Ultra E450's, which we desperately need for commissioning. Our Blade 100's are "dogs": a typical dataviewer display lags by 20 seconds; dtt only runs (verrry slowly) one one computer).
• Modeling (Miyakawa, Kawamura):
  • Seiji is working on interfacing Finesse with Matlab to facilitate exploring lock acquisition strategies.
• South Annex Bake Ovens (Taylor):
  • Bob continues to spend most of his time cabling the LSC/ASC racks.
• Facilities and vacuum envelope (Vass):
  • Steve is back from vacation and checked out the vacuum system; all seems fine.
  • Steve is working on the documentation of the last pump-down.

Oct 17, 2003

• Commissioning (Miyakawa, Kawamura):
  • Osamu and Seiji measured the 33 MHz sidebands being transmitted through the mode cleaner. The new measurement yields 33.194871 MHz (L_MC = 13.547 m). This is a change of 50 Hz from last year, and 162 Hz from 3 months ago (before the vent).
  • Does a change that large require one to re-tune the transmission frequency, in order to avoid excess noise? To evaluate this, they measured the noise spectrum of the demodulated signal from the transmitted beam, and compared it with a noise spectrum taken with the frequency deliberately mis-tuned by some amount. They found that the frequency had to be off by more than 500 Hz before any excess noise was noticed.
  • The MC is now being operated in low-noise mode. If lock is lost, it does not re-aquire easily in low-noise mode; the gains need to be turned down and the dewhitening filter on MCL needs to be turned off for robust lock acquisition. We need to automate this procedure with ezca.
  • Osamu and Seiji have been searching for the source of a ~ 5% intensity fluctuation in both the MCR and MCT beams, which made it impossible to commission the PSL intensity servo. The MCR beam was drifting at the RFPD, causing clipping. They introduced a lens to make the beam size smaller. They traced the beam wander to an oscillation in the MC suspension controller damping, associated with a Cheb filter. Turning off these filters on all 3 MC optics reduced the transmitted beam intensity fluctuations from ~5% to 1.2%. This should be enough to commission the ISS.
  • Meanwhile, they will begin to re-commision the MC WFS system.
• LSC Electronics (B. Abbott, Heefner, Taylor)
  • Ben and Jay have completed the checkout of the LSC auxiliary controls database, operator screens and wiring. They are now ready for operation.
  • They are now checking out the front end controls, and found a variety of problems with the signal mapping, mainly because the 40m has different RFPD wiring than the sites. They will go over this with Rolf on Monday to settle on the required changes to the software and/or wiring, and screens.
  • Ben fixed the three LSC Whitening boards so that they incorporate the fixes in Flavio's DCN #E030506.
  • Todd fixed the two blown LSC PD interface boards and they are now back in the rack and are no longer blowing up.
  • Ben and Art have almost completely finished the wiring and cabling for the LSC part of the new racks. They have run long cables to the four LSC RFPDs and five ASC QPDs. Ben and Osamu will begin plugging them in (including the three ASC QPDs at the ends) and verify signals, using light from the PSL flashing in the main IFO.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Ben has balanced the electronic offsets on the MC2 coil dewhite board, but it didn't cure problems associated with switching from mode cleaner lock acquisition mode (dewhitening turned off to increase dynamic range at the expense of noise, to make lock acquisition robust) to low noise mode. Osamu will try to fix this by balancing the gains in the digital dewhite compensation filter.
  • ETMX is not damping at nominal gain (ever since tuesday 8pm); don't know why. But it's damping ok at 5 times nominal gain. Ben and Jay will investigate.
  • Shihori looked at the couplings between POS, PIT, and YAW in ITMX, *after* input matrix diagonalizing. There's still plenty of cross-coupling in the sensing input matrix; the diagonalizing procedure needs refinement. She will look at the other 7 optics, next.
• PSL:
  • Osamu noticed that the PSL beam steering into the frequency reference cavity was not optimal; he will tune it.
  • The intensity fluctuations in the MC transmitted beam have been reduced by a factor 4. Flavio can resume commissioning of the ISS servo.
  • Rolf has a list of all the ISS DAQ channels, and will need to modify the code running in the c1iovme processor to read them in and make them available to DAQ, etc.
  • Mike has the info he needs to update the PSL table layout with the locations of the ISS photodiodes.
• Optical levers (Kawazoe, Heefner, Abbott):
  • Ben re-fixed the Oplev photodiodes. What he thought was a regularly unlabeled 2.2nF capacitor (as it was found in a drawer labelling it as such), turned out to be an unusually un-labled 1K resistor. This made the Oplevs act crazy, and Jay discovered the part was to blame. It has now been finally fixed.
  • Fumiko continues work on centering the oplev beams on the QPDs and zeroing the offsets. She's also continuing work on characterizing the calibrated angular motion spectra, and system noise.
• Optical sensing (Smith):
  • PZT1 STEERING MIRROR: PZT1 pitch amplifier was received from Piezojena.
  • QPD MOUNTS: Mounts were received.
  • POX and POY: An ACAD optical layout for the POX and POY beams was completed. The design of the focusing lenses for the QPD, video camera, LSC, WFS, and power meter paths were completed and an updated parts list was generated. Additional required parts were ordered.
  • INITIAL POINTING: The mount for the 10 X telescope initial pointing ANG beam is being fabricated.
• Computing:
  • We have acquired two "cast-off" Sun Ultra E450's from Stuart Anderson. These will replace our very underpowered Blade 100 online computers, and hopefully reduce the problems we are having with DTT, dataviewer, and medm. Lisa and Larry will get the machines up and running at the 40m, soon.
• Modeling (Miyakawa, Kawamura):
• South Annex Bake Ovens (Taylor):
  • Bob continues to spend most of his time cabling the LSC/ASC racks.

Oct 10, 2003

• Commissioning (Miyakawa, Kawamura):
  • Osamu and Seiji re-measured the PSL frequency noise using the mode cleaner, and the new procedure outlined in T030239.pdf. After some time trying to reconcile a difference in normalization between the old procedure and the new, they determined that the new procedure is more reliable, and the old method had a couple of mistakes in the normalization; the old noise curves were underestimated by a factor of around 2.8. With the new normalization, the frequency noise still meets specs above 50 Hz, except for a set of acoustic spikes in the 200-1000 Hz range; the re-layout of the PSL (reducing the number of folding mirrors and placing the FSS pickoff after the PMC) has improved things considerably areound 800 Hz and above 1 kHz. The noise around 100Hz is lower due to the dewhitening filter in the MC2 suspension controller. The peak at 180 Hz noticed last week is now gone.
  • Osamu and Seiji used the transmission of the 33.2MHz sidebands to re-measure the length of the MC, and found it had changed by 5 Hz (out of 33.2MHz) during the vent; ie, not at all. They also find that the detection of the 33.2MHz sidebands is shot-noise limited, even if the MC length varies by the equivalent of 40 Hz.
  • Osamu and Seiji are now working to understand the origin of the large (as much as 8%) intensity variation in the MC transmitted beam. The PSL intensity servo cannot be commissioned until this anomalous intensity variation is eliminated.
• LSC Electronics (B. Abbott, Heefner, Taylor)
  • Mohana installed the LSC auxiliary controls target code (c1iscaux), operator screens and databases. The lsc aux database has been loaded on the processor and everything appears to be OK. The XY212, VMIC 3113A and VMIC 4116s addresses were set. Jay and Ben checked all auxilary controls for the LSC system, and they are operational.
  • The next step will be to inject signals into the LSC front end ADCs and propogate them through the code. If all goes well and all field cabling is completed, the system should be ready operation by the end of next week.
  • In the process of checking out the LSC analog boards through the auxiliary controls, Ben smoked two LSC PD Interface boards. The problem was found to be a bad cable on the XY212 that was connected to both boards. Replacements are being obtained from Todd.
  • The processor for the LSC front end was replaced and the system appears to be a bit more stable, but still crashes every once in a while.
  • Ben moved the PZT Drivers to 1X3 to get them away from the analog crate where they were originally placed.
  • Bob and Art continue to work on cross connect and internal rack cabling for the LSC and ASC, as well as the cables to the photodetectors. They can get 5000 ft folls of SpectraStrip multi-conductor twisted-pair cable, for the long runs. They are making great progress.
  • Bob and Art powered up the LSC/ASC analog rack (1X2) with the Kepco linear power supplies, and discovered that the WFS demod boards are power hogs. We'll need to buy more power supplies to keep those boards happy, but we won't need them for a while.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Ben has balanced the electronic offsets on the MC2 coil dewhite board. So, switching from mode cleaner lock acquisition mode (dewhitening turned off to increase dynamic range at the expense of noise, to make lock acquisition robust) to low noise mode will not disturb the optic.
  • Jay and Ben have checked out all the whitening / dewhitening switches on the XYCOM screens for all the suspension controllers. Finally, they all work as they should.
  • Ben redrew the schematics for the end station wiring to reflect recent changes to the layout. They are now a current representation of the as-built condition.
  • Shihori continues to make DTT spectra of all the core optics OSEM sensors, to find and diagnose problems. Most of the problems she is encountering are in DTT!
  • Lisa and Shirori (with help from Ben) re-did the input sensing matrix for the MC optics, in an attempt to fix the intensity variation problem in the MC transmitted beam. But, it didn't help. Now she's re-doing the output coil matrix for MC2. Lisa is documenting the diagonalization procedure that we have been using.
• PSL:
  • Flavio cannot commission the ISS servo until the large intensity fluctuation mentioned above is fixed.
  • Meanwhile, he finished installing all the permanent cables and DAQ channels.
  • Rolf has a list of all the ISS DAQ channels, and will need to modify the code running in the c1iovme processor to read them in and make them available to DAQ, etc.
  • Mike has the info he needs to update the PSL table layout with the locations of the ISS photodiodes.
• Optical levers (Kawazoe, Heefner, Abbott):
  • Jay used DTT to measure the transfer function from The OLYAW_EXC input to the OLYAW_IN1 TP for ETMY. The transfer function was as expected, flat to a peak at ~0.6Hz and then falling as f^-2. Foton was then used to generate filters for a DC coupled OL servo. The servo was engaged and appears to work. The same filters were installed on PIT and the optic damped in PIT and YAW using only the optical levers. The filters used had poles at 0.1, 100, 100 and zeros at 0.5, 0.5.
  • Fumiko continues to refine her calibration of all the oplev QPDs in terms of angular displacement of the optic, in radians. She is now working on getting calibrated angular motion spectra, and comparing with the detector system noise and dynamic range.
  • Ben increased the gain in the Oplev photodiodes by a factor of 10 as is called for on Note 2 on its schematics.
• Optical sensing (Smith):
  • PZT1 STEERING MIRROR: Awaiting repair by Piezojena of the PZT1 pitch amplifier.
  • ELECTROOPTIC SHUTTER: Awaiting delivery of 3rd EOS.
  • QPD MOUNTS: Awaiting delivery of mounts.
  • POX and POY: A preliminary ACAD optical layout for the POX and POY beams was completed. The design of the focussing lenses for the QPD, video camera, LSC, WFS, and power meter paths is in process. The final choice of lenses will require a slight change of the path lengths and component locations.
  • INITIAL POINTING: A mount for the 10 X telescope in the initial pointing ANG beam was designed; working drawings were completed and will be released to the DCC.
  • Mike is updating the ACad drawing with the as-modified PSL table.
• Computing:
  • We continue to have lots of problems with DTT. It only runs on one computer (op140m), but not on op240m or dmt140m. With Peter Shawhan's help, we suspect that the problem is with the way op140m NFS-mounts the disk that has the DTT executable libraries.
  • Even on op140m, it often freezes, gets out of synch with the data, or fails to access test points. Alex Ivanov is trying to figure it out, and in the meantime, showed us how to release and set test points manually.
  • Alex also changed the GPS IRIG B slave in the AWG, which helped with the synch problems.
  • Meanwhile, it is clear that our online computers, which are Blade 100's, are not up to the task of running DTT, Dataviewer, many copies of medm, etc. We are trying to get one or two surplus Sun 450's to replace these machines.
• Modeling (Miyakawa, Kawamura):
  • Seiji continues to use his Finesse model of the 40m to study lock acquisition. He tried to use the scheme employed at the Garching 30m, using non-resonant sidebands to robustly lock the PRC (l+). He found, again, that the desired locking point has much sensitivity to the position of the SRM and Michelson degrees of freedom (ls and l-). However, it may be possible to lock l+, and keep it locked while acquiring lock on ls and l- in a second step. He is investigating.
• South Annex Bake Ovens (Taylor):
  • Bob continues to keep an eye on the 40m vacuum system while Steve is on vacation.
  • Bob continues to spend most of his time cabling the LSC/ASC racks.

Oct 3, 2003

• Commissioning (Miyakawa, Kawamura):
  • Osamu and Seiji measured the PSL frequency noise using the mode cleaner. The raw error signal spectrum looks as good or better than we have ever achieved before, at all frequencies ... except for a new peak at 180 Hz.
  • The MC2 coil dewhitening filters make it hard to acquire lock robustly, but are necessary to achieve low noise operation of the MC. Switching the dewhitening filters on after acquiring lock will kick the MC out of lock due to offsets that are believed to be in the dewhitening board. Ben is re-balancing these offsets now.
  • Osamu and Seiji see an offset in the MC error signal after locking, always in the same direction. Its origin is not understood.
  • The MC transmitted beam is experiencing significant (~ 1%) intensity fluctuations at ~ 1 Hz. Osamu believes that it is due to wobbling mirrors. Lisa Goggin is re-doing the diagonalization of the input sensing matrices for all 3 MC mirrors, to address this problem.
  • They are now measuring the noise using the feedback signal, and using a measured transfer function to express it as PSL frequency noise (see writeup by Seiji, T030239.pdf). The shape agrees with the method using the error signal, but the normalization is off by a factor around 8; they are trying to understand this.
• LSC Electronics (B. Abbott, Heefner, Taylor)
  • All the boards needed for our LSC system are now in. We're still waiting for filter modules for the AA boards.
  • Bob and Art are wiring up all the cables, and running power from Kepco linear power supplies in a satellite rack. They have all of the multi-connector cable they need. They're making great progress, but it's still days of work to completion.
  • Rolf, Alex, and Jay are installing the LSC front end cpu, reflective memory, software, epics screens, etc. They ran into some timing snags, and are working on it.
  • Mohana is almost ready to install the LSC auxilliary crate software and database. Hopefully, by the end of the week. Then, Ben can test out all the controls with tester boards.
  • Ben has modified the GPS clock driver board for the LSC crate per Flavio's DCN. He'll do the other clock driver boards as time permits.
  • Ben and Jay diagnosed a problem with the MC servo board; the ADC on the board which decodes the gain slider settings was latched up (a problem which is known at the sites). To reset it, must pull out the board, count to 30, put it back in.
  • Jay continues to develop the design for LSC double-demod boards.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori continues to make DTT spectra of all the core optics OSEM sensors, to find and diagnose problems. The test masses all seem to damp the pendulum resonances well, but some of the optics are noisy at higher frequencies, presumably due to wrong dewhitening filtering.
  • Ben and Jay are working to make sure all the XYCOM switches are set up right for the dewhitening filters for all the DSCs.
  • Ben replaced a whitening board for MC2 whose connections were flaky. Todd has the old one, and will analyze it in his spare time.
  • The ETMX UR sensor is not reading out right. Ben discovered that the satellite amplifier was not putting out enough current to the LED: the added resistors that boost the LED drive current for one of the optics were not properly soldered on one side, and therefore, that OSEM was dimmer than the others. This caused the OSEM to be misaligned during the process of balancing the OSEMS, and it means that it must be adjusted the next time we vent.
  • Shihori would like to determine the coil output matrix for all optics. This is most easily done by exciting the optic test points with DTT. However, DTT doesn't work most of the time; there's some weird timing problem. Alex Ivanov will try to figure it out.
  • Lisa and Shirori will re-do the input sensing matrix for the MC optics, in an attempt to fix the intensity variation problem in the MC transmitted beam. Lisa is documenting the diagonalization procedure that we have been using.
• PSL:
  • Flavio cannot commission the ISS servo until the large intensity fluctuation mentioned above is fixed.
  • Meanwhile, he will finish installing all the permanent cables and DAQ channels.
• Optical levers (Kawazoe):
  • Fumiko has calibrated all the oplev QPDs in terms of angular displacement of the optic, in radians. She is now working on getting calibrated angular motion spectra, and comparing with the detector system noise and dynamic range.
  • Jay is installing digital filters in the oplev servo system, in preparation for turning the servos on.
  • However, there is a strange offset in the oplev servo system. Jay will ask Rolf to look at it when he gets a chance.
  • Ben will change the resistors on the BS and ITMY oplev QPDs; the signal on these QPDs is very weak.
• Optical sensing (Smith):
  • PZT1 STEERING MIRROR: Awaiting repair by Piezojena of the PZT1 pitch amplifier.
  • QPD MOUNTS: Awaiting delivery of mounts.
  • INITIAL POINTING SENSORS: The optical system was designed and a parts list was created for the initial pointing position and initial pointing angle sensing system. There is negligible cross-coupling between the position and angle sensing measurements. The 40 m optical table ACAD drawing was updated. A purchase req was generated to purchase the components.
  • ETM TRANSMISSION SENSING: The optical system was designed and a parts list was created for the ETM transmission sensing systems (TRX and TRY). The 40 m optical table ACAD drawing was updated. A purchase req was generated to purchase the components.
  • Mike is drawing up the temporary layout of the POX/POY sensing beamlines, for independent arm locking.
  • Mike is updating the ACad drawing with the as-modified PSL table.
• Modeling (Miyakawa, Kawamura):
  • Seiji continues to use his Finesse model of the 40m to study lock acquisition.
  • Osamu continues to come back up to speed with E2E/Alfi.
• South Annex Bake Ovens (Taylor):
  • Bob sent the TP2 turbo pump and scroll pump back for repair; the spares are performing well.
  • Bob is doing some solder joints for Helena, and an inventory of OSEM boards for Janeen.

Sep 26, 2003

• Commissioning (Miyakawa, Kawamura):
  • As reported last week, we have PSL light through the mode cleaner the input optics, and the main IFO. The MC is locked, and we see Michelson fringes at AP and SP, and Fabry-Perot flashes in both arms.
  • Our current big effort is to wire up the LSC rack and set up and align all the sensing beamlines.
  • In preparation for this, Osamu and Seiji are tuning up the PSL and mode cleaner.
  • They optimized the gains of the PSL PMC and FSS servos.
  • They then turned to the mode cleaner, to measure the frequency noise and compare it to what we had before the vent and the re-layout of the PSL path. They adjusted the EOS to put more light on the MCR RFPD, to minimize the noise.
  • They then measured the noise in the MCR VCO feeback signal and compared it with pre-vent version. In almost the entire frequency range, it is as good or better than before. AND, they took the measurement with the PSL enclosure HEPA filter *on*. Previously, noise was *much* worse with the HEPA filter on; now, noise with HEPA on is as good or better as pre-vent noise with HEPA off!
  • Many peaks in the 300-1000 Hz region, which were due to PMC and mirror vibrations downstream of the old FSS pickoff are gone, now that the FSS pickoff is after the PMC. Mysterious peaks at 25, 32, and 50 Hz are now gone.
  • The region from 120-500 Hz was worse than before. Osamu traced it to the absence of dewhitening on MC2. When Jay fixed this, the excess noise in that region went away. The noise spectrum is now better than before at all frequencies.
  • The re-layout of the PSL required re-optimization of the mode matching into the MC. Osamu and Seiji measured the visibility of the MC to be 75%; should be > 95%. They used a translation stage to fix the mode matching; visibility is now around 98%.
  • They will now re-establish the transmitted sidebands and re-measure the MC length.
• Installation (Vass, Miyakawa, Smith, everyone):
  • Steve and Bob covered up all vacuum viewports.
  • We need one more camera mount for viewing the BS optic. Larry Jones ordered two more camera mounts. And, Bob will put extensions on existing camera mounts for cameras with long lenses.
• Electronics (B. Abbott, Heefner, Taylor)
  • The LSC rack is the focus of much attention. Most of the modules are in place, all of the cross-connection wiring is done. Art, Bob, and Ben are beginning the cabling of modules to cross-connects. Ben is ready with tester boards.
  • Unfortunately, we *don't* have enough multi-conductor cable for the runs from optical table to rack! Bob, Jay, and Ben are scrambling to get suppliers.
  • Ben installed all of the components needed for the LSC part of the LSC AUX crate (c1lscaux). It is now ready for Mohana to install code, databases, screens.
  • Rolf is working on the front end LSC code. The electronics and software are all just about ready.
  • Ben will make mods to the GPS clock drivers.
  • Lisa sent back the PC projector for repair under warrantee.
• Digital suspension controllers (Sakata, Goggin, B. Abbott, Heefner)
  • Shihori made DTT spectra of all the core optics OSEM sensors, with and without damping on. Three sensor channels looked dead. Ben traced it to the LEMO cables from the whitening boards, and replaced them; this fixed those problems. It's clear from the spectra that work is required to optimize the damping of the test mass optics.
  • One OSEM still looks like its not working right: ETMX UR. Ben will check the satellite amplifier.
  • Lisa G and Shihori used Mark Barton's method to diagonalize the input matrices for the 5 new core optics. The numbers are all within 25% of 1, and are reproducible from three separate trials. The numbers are now in the screens, and damping works fine. They are now working on the output matrix, using DTT to excite position and watching dataviewer to decouple position, pitch & yaw. They will use DTT to study the couplings of pos,pit,yaw as a function of frequency across the pendulum resonances.
• PSL:
  • Osamu and Seiji re-optimized the PMC and FSS gains, now that the FSS pickoff is after the PMC.
  • Ben made up and tested two ISS PD boxes and three PD heads.
  • Flavio and Ben installed the ISS PDs and electronics in the 40m. The installation is almost done; they need some longer cables for permanent routing. The EPICS crate, database and screens seem to be working. The commissioning of the servo will begin soon.
• Optical levers (Kawazoe):
  • Fumiko has zeroed the offsets on all oplev quadrants.
  • Fumiko has re-checked her calibration of the oplev response of the 5 IFO optics. She will express it in terms of radians at the optic. She's measuring the optic motion (with damping on and off), as well as detection noise, and comparing it to the region of sensing linearity.
  • Next, she will obtain the oplev digital servo filter design used at the sites, implement it here, and commission the oplev servos.
  • Ben will change the resistors on the BS and ITMX oplev QPDs.
• Optical sensing (Smith):
  • PZT1 STEERING MIRROR: Awaiting repair by Piezojena of the PZT1 pitch amplifier.
  • QPD MOUNTS: The QPD boxes were modified and mounted to the rigid electrically isolated table mounts; 2 sets of mounts were missing. Replacement mounts will be ordered.
  • Fumiko is beginning to assemble electro-optic shutters for the SP and AP beamlines. We still await one more EOS Q-switch.
  • Mike is drawing up the temporary layout of the POX/POY sensing beamlines, for independent arm locking.
  • Mike is updating the ACad drawing with the as-modified PSL table.
• Modeling (Miyakawa, Kawamura):
  • Seiji is using a Finesse model of the 40m to study lock acquisition. He is studying how the error signals for each of the short length degrees of freedom (PRC/l+, Michelson/l-, SRC/ls) change when other degrees of freedom change (ignoring the arms, for now). He finds that in some cases, there is no decent error signal unless the other degrees of freedom are very close to their in-lock positions. This will make locking the full DRM hard ... as expected. He's thinking about ways to make it work.
  • Osamu continues to come back up to speed with E2E/Alfi.
• South Annex Bake Ovens (Taylor):
  • While Steve is on vacation (4 weeks!), Bob is doing all of Steve's daily duties: checking the vacuum system and controls, N2 level for the vacuum valves, ion pump V's and I's, and PSL chiller level.
  • Bob is doing some bake jobs for Larry Jones.
  • Bob is working with Caltech electricians to fix the AC to the flow benches.

Sep 19, 2003

• Commissioning (Miyakawa, Kawamura): Osamu and Seiji have re-established the alignment of all suspended optics (no recycling mirrors) in the 40m after pumpdown. We have Michelson fringes at the SP and AP ports, and Fabry-Perot fringes on the X and Y arms!
• Installation (Vass, Miyakawa, Smith, everyone):
  • Installation, alignment, and full checkout of the IO and main IFO was completed last Wednesday. Steve et all secured all chamber doors and access connectors.
  • The only known problem is that the driver amp for in-vac PZT2-pitch is broken; Mike has sent it back to Piezojena for repair under warranty.
  • Pumpdown began last Thursday at 9am. TP2 failed! Bearings need replacement. And, and its backing scroll-pump is not pumping up to spec. Fortunately, Steve has replacements for both. They were replaced within an hour, and pump-down recommenced. It all proceeded smoothly, and a week later, all looks ok; no sign of any leaks or failures.
  • Steve turned on the cryopump on Monday. RGA scan sees the usual dominance of H2O, with little evidence of hydrocarbon contamination. By this Thursday, CC1 was reading ~ 1e-6 torr. Steve turned off the cryopump this Thursday AM, and the pressure went up to ~1e-5 torr. Steve will leave only TP1, TP2, and TP3 running during the 4 weeks that he's away on vacation.
  • During pumpdown roughing, we observe the OSEMs on all suspended optics moving; and oplevs on core optics. They didn't all go back to where they were before pump-down, not sure why.
  • And sure enough, Osamu and Seiji find that they have to completely re-align MC1,MC2,MC3 and the initial launch beam from the PSL, in order to get everything back. First attempt to align the MC to the incoming PSL beam produced a MCT beam which was ~ 1 cm away from the Faraday isolator aperture. This suggests that the initial launch beam from the PSL has moved; presumably, the fixed folding mirror from the PSL to MC1 has moved; not sure how or why.
  • Osamu and Seiji have now re-aligned the MC to the FI, and the PSL input beam to the MC.
  • They went on and established Michelson fringes by aligning ITMX and ITMY. Then, aligning ETMX, they saw Fabry-Perot fringes on our high-finesse arms.
  • Meanwhile, Steve will install all remaining beam tubes and viewport covers before he leaves.
• Electronics (B. Abbott, Heefner, Taylor)
  • The LSC front end crate is now installed and ready for Rolf to install code. The fiber, timing, and ethernet cables are in.
  • From Rolf: Modified the LSC code to run on the CIT 40m system. Main change was to move DAQ from the VME DAQ network card (used at the sites) to the new PCI network card used in the 40m system. Making use of the PCI card DMA engine, able to move data onto the DAQ network at ~120MByte/sec.
  • Mohana is working on generating database records and screens for the ISC aux crate (c1iscaux) up and running.
  • Ben has completed the latest version of the inventory needed for LSC completion. This list includes cables and approximate lengths so that cables can be ordered in good time. Everything else seems to be coming along fine, and all of the LSC should be ready to go the first full week in October.
  • Bob and Ben will begin LSC wiring with the cables that we have here, and continue as more cable arrives from the vendors.
  • Bob and Ben will set up the Kepco power supplies for the ISC analog rack. These power supplies will live in a small rack nearby; no power supplies, or AC of any kind, in the analog rack!
  • Ben brought over 8 QPDs and 4RFPDs to the 40m yesterday. They need mounting hardware to be supplied by Mike Smith, then they can be placed on the tables, ready for use.
  • Flavio is releasing a DCN for the GPS Clock Driver boards that will necessitate a bit of work to the boards that Ben will do when time and ongoing work permit.
  • Jay is beginning the design of a double-demod board for 40m/AdvLIGO LSC.
  • Jay has been cleaning up and re-arranging the target directories and startup files for the 40 meter processors.
  • The DAQS controller c1daqsctrl has synch-faulted several times in the last few days. It's now clear that this is due to Shirori's attempts to use DTT to plot noise spectra for 40 OSEM sensor test points. Rolf suggested that she instead use the regular sensor channels (2048), not the 16K test point channels. This seems to work; she can take 40 spectra simultaneously, without a synch fault.
  • Shihori's work is paying off: we found one disconneced OSEM (MC2 UL; it appears to have lost its signal after the pump-down. Jay reseated the cable, it's now working fine). Shihori will next take spectra with the damping off.
  • Lisa G and Shihori are continuing to learn how to diagonalize the IFO suspensions. First attempt didn't work; they will talk with Stan about how it was done at the sites.
  • Flavio is looking at our STACIS system, and assessing the problems. It looks like at least one controller is bad, and maybe also one isolator.
  • Ben is now familiar with the LLO common mode servo board, which will be helpful when we go to implement ours.
  • The PC projector that displays our beam spots on the wall has died. Lisa is sending it back for repair under warrantee.
• PSL is performing well. Osamu plans to re-optimize all the servos, and measure the frequency noise with the MC. Flavio intends to install the ISS next week.
• Optical levers (Kawazoe, Mow-Lowry):
  • Fumiko has calibrated the oplev response of the 5 IFO optics. She has shifted the QPDs to center the signal; but she'll have to do it again after Osamu and Seiji finish their alignment.
  • Ben will replace the resistors on the BS and ITMY oplev QPDs from 10K to 100K, to increase the gain on their oplev readout.
  • Fumiko will zero the offsets on all oplev quadrants.
  • Nergis educated us on the oplev servo compensation filters used at the sites; we'll try to get ahold of them.
• Modeling (Miyakawa, Kawamura, Eichenfield):
  • Seiji is using a Finesse model of the 40m to study the length sensing matrix. He is refining the procedure for establishing the demod phases for double-demod of the Michelson signal. He's now beginning to think about establishing a lock acquisition procedure.
  • Osamu has been trying to run E2E/Alfi.
• South Annex Bake Ovens (Taylor):
  • Bob needs to upgrade the clean bake oven E; 2 heating elements went bad, causing some of the insulation to burn. He plans to replace the heating elements, insulation, and put on a new, better, heater controller.
  • We have no OSEM spares; Bob will build a set of SOS and MOS OSEMs.
  • Bob is still working on a batch of baffles for LHO.
  • Bob plans to completely clean up and re-organize the south annex clean room. This includes fixing the AC to the flow benches; right now, if we try to run both flow benches, the breaker trips.

Sep 12, 2003

• Installation (Vass, Miyakawa, Smith, everyone):
  • All in-vacuum installation is complete.
  • All components have been aligned: the suspended optics; input optics (mode cleaner, faraday isolator, MMT, PZT steering mirrors); all output beams (SP, AP, POX, POY, TRX, TRY); shutter flags in front of all four test masses, all oplev beams.
  • All suspended optics check out ok. Jay checked all the OSEM cables last week and found two OSEMs to be bad; Steve replaced them and Bob will do a post-mortem on them.
  • The beam at the X-end was observed to move by as much as inches, overnight, several nights in the last week or 2. The problem was isolated to be downstream of the mode cleaner and upstream of the main IFO, and the only reasonable suspects are the two in-vac PZT mirrors which steer from the IO to the main IFO. Due to a series of delays, the PZTs and their controllers were *not* thoroughly tested before they were installed! And then...
  • The IFO PZT2 steering mirror pitch control amplifier announced its culpability by spontaneously failing. The PZT1 pitch control was used to temporarily correct the resulting pointing error. We are waiting for directions from Piezojena to repair the unit under warranty. Meanwhile, we will begin to commission the IFO without the PZT2 pitch control; we should be able to work around it, and install a repaired control amp without having to vent. No beam motion at the X-end has been observed since PZT2-pitch was disconnected.
  • The POB beam could not be accessed because of a physical interference with the BS SOS structure; a modification of the structure will be required in the future.
  • Conor and Fumiko did a full independent checkout of the installation. Steve, Osamu, and Mike did a full checkout of the alignment. Michelson fringes were again observed, and PSL flashes were seen at both ETMs.
  • Steve et al removed the HWP in front of the Faraday isolator, and had to move the Faraday isolator a bit to get the beam centered on its aperture.
  • Steve et al sealed up all doors and access connectors on Wednesday.
  • Steve and Osamu began pump-down on Thursday morning. (The vent lasted from 7/8/03 to 9/11/03). TP2 (which backs the maglev turbopump TP1 which pumps on the main volume) promptly failed. They promptly replaced it with a spare, and proceeded with the pumpdown. As of 4pm Thursday, the main volume is at ~ 1 mTorr and falling.
• Optical levers (Kawazoe, Mow-Lowry):
  • Fumiko and Conor checked out all oplev beams. They made some changes to the beams: they now strike the ETMs from the back, eliminating the need for the in-vac oplev mirrors (which nonetheless remain in place in the chambers), increasing the light returning to the QPDs by an order of magnitude. All oplevs now have adequate light on the QPDs.
  • They recommend that we nonetheless increase the gains on the QPDs for ITMY and BS (replacing 10K resistors with 100K) to improve the signal for those oplevs. Ben will pursue.
  • Oplev signals are still not making their way into frames, and many signals (pitch, yaw, sum) are not in Dataviewer or DTT. Jay will pursue.
  • Fumiko is working on calibrating the oplev responses, and will work with Jay on implementing the servos and with Mike on testing Mike's oplev telescope.
• PSL: Conor is completing his documentation of: his mods to the FSS servo board and its improved performance; his measurements of the PSL PMC finesse; and his re-layout of the PSL beamlines, and its performance. This is Conor's last week at the 40m; his 5 month visit has been tremendously productive, and fun for all of us - thanks, Conor, we'll miss you, come back soon!
• Electronics (B. Abbott, Heefner, Taylor)
  • With fixes and adjustments to various OSEMs, all suspended optics and DSCs are operating well.
  • As noted above, one of the in-vac PZT controller boards died, and the manufacturer has been contacted.
  • Shihori continues to learn about the digital suspension controllers. She and Lisa are gearing up to diagonalize the core optics suspensions.
  • Lisa G found several problems with the long-neglected STACIS system; we will get some help from CDS to get them fixed.
  • Lisa G continues to construct lots of nice MEDM screens to help us keep track of all the 40m systems.
  • Next big push is to get the LSC/ASC racks completed.
• Modeling (Miyakawa, Kawamura, Eichenfield):
  • Seiji is using a Finesse model of the 40m to study the length sensing matrix. His matrix is very similar to the one predicted by Twiddle; AJW and Seiji will compare details to see if they can be made to agree exactly. Seiji is also exploring the use of double demodulation, with carefully chosen demod phases, to improve the signals. He is developing a method for setting the double demodulation phases.
• South Annex Bake Ovens (Taylor):
  • Bob took a few days off; now back.
  • Bob is continuing to service last-minute installation needs.

Sep 5, 2003

• Installation (Vass, Miyakawa, Smith, everyone):
  • Steve and Bob installed the last of the optical windows, and established camera views for the BS and the FI.
  • Ben made final control cables for both in-vac PZT steering mirrors, and the system is now in, in closed loop, and apparently operational.
  • Mike and Steve installed mirrors to pick off the light reflected from both arms (POX and POY), and aligned these output beams.
  • Mike and Steve re-established the alignment of the main IFO, including the SP and AP beams and the two Initial Pointing beams (at the BS and at ETMX).
  • 40 M IFO PRE-ALIGNMENT (Smith): All IFO mirrors are aligned. Bright port and Dark port beams are directed out the viewports onto the ISC table. The POXprime and POYprime pickoff beams are directed out the viewport onto the ISC tables. The POB prime beam cannot be picked off because of interference with the BS SOS structure; a modification to the structure will be required in the future. The PZT IFO steering mirrors were adjusted to mid range. Optlev beams for the BS, ITMs and ETMs are aligned and active. The initial pointing position and angle beams are directed out the viewports, awaiting installation of the QPD readouts. Video camera viewing of the Faraday isolator input is aligned and operating.
  • All the picomotor controls of the shutter flags and the MMT have been tested. However, the shutter flags need to be adjusted to ensure that the beam passes through their apertures. This will hopefully be done today.
  • Conor and Fumiko have checked out all of the oplevs. They re-arranged three of the oplev beam paths to bounce the beam off of the back, AR-coated side of the test mass. This increased the light power returning to the QPD substantially, to well over 100 uW in most cases.
  • Final installation and alignment is just about complete. The MC is flashing as it goes through resonance (we are not attempting to lock the MC in air), and the flashes have been seen at the ITMs and ETMs. We have seen Michelson fringes at the SP and the AP ports. Cause for celebration, including champagne.
  • However, we are plagued by several persistent problems. The beam appears to be moving occasionally, by significant amounts; it is consistent with some pathology in the PZT mirrors that steer from the MC to the IFO.
  • Also, ITMX keeps acting up. Jay can calm it down by flipping the sign of the gain on the side osem damping loop (!!). Very strange.
  • There are periods when both these problems give way to stability. During those times, we are doing the final leveling and alignment tweaks.
  • AJW wrote up a detailed checkout procedure for all installed in-vac components, alignment, suspended optics, and oplevs.
  • Tomorrow (Friday), we'll do a final checkout, seal everything up, and then monitor the situation throughout the weekend. If things are stable, we'll proceed with the pumpdown on Monday.
• Electronics (B. Abbott, Heefner, Taylor)
  • As noted above, the DSC for ITMX is acting very strange.
  • The PZT interface board for the ASC PZT mirrors arrived on Tuesday. Ben stuffed the boards, milled some front panels for them from the aluminum panels already on the controllers, and set them in place. With the help of Steve, Ben swapped the cables from their temporary FLKM blocks, to the new patch panels, and realigned the PZTs one by one.
  • The EPICS servers running in the linux box (c1epics) were running multiple "IOCs", and were not communicating to the EDCU, so EPICS channels were not available to DAQs or dataviewer. Jay and Alex are working on a fix which combines all channels onto one IOC, and will test it tomorrow.
  • Jay and Alex will get the EPICS timeserver going on the EDCU, and test it tomorrow.
  • Ben has been helping Aidan with his photon actuator experiment. Aidan finished testing a filter that Ben made for him, and he found that it has the shape that he wanted, so he is now attempting to put it into a control circuit. He is having problems getting his 5W or 0.5W lasers to work with Mohana's driver board, but Ben will help iron that out.
  • Ben is in the process of testing some ISS PD boards that he and Flavio will take to Livingston on Monday.
  • Shihori is learning about the digital suspension controllers, and is taking DTT spectra as an aid to optimizing gains and diagnosing problems. Lisa and Shihori are learning how to diagonalize suspensions.
  • Lisa G is trying to diagnose problems with the long-neglected STACIS system.
  • Lisa G has been constructing lots of nice MEDM screens to help us keep track of all the 40m systems.
• Modeling (Miyakawa, Kawamura, Eichenfield):
  • Seiji continues to develop a model of the 40m and AdvLIGO with Finesse, and comparing with Twiddle calculations.
• Computing (Ivanov, Bork, Goggin, Wallace, Bogue, Pedraza):
  • We are able to run medm on our wireless laptop PCs on the martian network, mounting the our online software disk (containing all the .adl files) via samba. Unfortunately, various display pathologies appear on the medm screens, making some of them useless.
  • However, we continue to have intermittent wireless and network problems. Lisa Bogue has been helping.
• South Annex Bake Ovens (Taylor):
  • Bob is continuing to service last-minute installation needs.

Aug 29, 2003

• Installation (Vass, Miyakawa, Smith, everyone):
  • Osamu has re-established the alignment of the PSL -> IOO -> ITMx and ITMy, and back out the SP and AP. Michelson fringes have been observed!!
  • Steve & Mike have installed all the components in the vacuum chambers, and Mike is doing the last alignments (of the Initial Pointing beam position and angle beams to QPDs).
  • Well, a few more components remain: Bob is installing the last mirrors for camera views. Camera views for ITMx, ITMy, ETMx, ETMy are in place; the one for the beam input to the faraday isolator is going in today, and and one for BS/PRM/SRM will go in last (next Tuesday). One or two more optical viewports need to be installed.
  • The two in-vac PZT steering mirrors were tested successfully by Ben. However, he only had enough cable to test one of them at a time. He's made a 2nd cable, but encountering problems. We need to have both PZT's powered for the final alignment. Fortunately, these PZTs have strain-gauge readbacks and feedback loops, so we can be optimistic that they will return to their proper places when they get powered on again.
  • Mike's autocollimator was finding that the ETMx yaw was changing from day to day, even though the OSEMs showed no indication of movement. Fortunately, there's bee no evidence of movement in the last ~ 5 days. An oplev is monitoring it.
  • Picomotor controls for the MMT and the in-vac shutter flags all check out.
  • All the oplevs were set up and aligned by Naman before she left, but they all need to be re-aligned.
  • Mike & Steve eliminated a potential clipping of the AP beam on the faraday isolator, by moving things slightly.
  • We hope to complete this installation and alignment, check everything out, and pump down early next week.
• Electronics (B. Abbott, Heefner, Taylor)
  • PZT controls for in-vac steering mirrors: Ben finished testing the PZT chain; as of last Friday, everything checked out fine. Ben made and routed a second cable so that both PZT could be actuated simultaneously. When this was done, the old PZT controller didn't work properly. Ben's out of town till next Tuesday, will check it out then.
  • The interface board for the PZT controls should be in tomorrow, and in place next week.
  • Aidan's photon actuator experiment design came back from the boardhouse on Friday. Aidan stuffed it and is still in the process of testing it ready for use early next week.
  • Ben has made up and finished two of the the ISS PD boxes and six PD heads for Flavio so that he can test his ISS boards with the PDs in place.
  • Art and Bob are continuing to work on the LSC and ASC rack cross-connects. They have been wired, mounted, and grounded.
  • Ben has compiled a list of components that we will need to finish the ASC and LSC systems, and is taking steps to get everything we need.
  • Lisa G finished wiring up all of the video monitors in the control room, and spiffed up the video switch control screen.
  • Jay and Ben will assemble the equipment they need to move all the front end timing signals to a separate "pizza box" crate, independent of the DAQS crate.
  • Jay and Ben are thinking about 166 RFPDs and demodulation, and double demod.
• Optical levers (Bhatt, Goggin, Smith, Vass, Taylor):
  • Just before Naman left, we turned on the oplev servos and used them to control the pitch and yaw of the suspended optics at DC. It worked reasonably well for ETMy and BS. The beams were blocked at ITMy and ETMx for various reasons. The ITMx oplev sorta worked, but the response was consistent with the beam moving off of the QPD.
  • With Naman gone, Fumiko will take over the development of this system.
  • The oplev beams (red) are attenuated to only a few microwatts by the time they get to the QPDs. Most of the loss appears to be at the suspended optics. More reflectivity can be obtained by moving the beams off of the coated part of the optic surface. We will attempt to maximize the light on the QPDs as part of the final checkout next week.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor is documenting all of the changes he made to the PSL table, and the changes he and Ben and Rich made to the FSS board.
  • Ben accidentally blew the PA85 on the FFS board, then promptly fixed it.
  • Ben made the HVamp daughter board on the FSS card into a permanent mod.
  • Osamu found that the PSL beam was getting clipped slightly at one of the IOO pockels cells. This explained the ellipticity Conor had noted before. Osamu re-aligned it and eliminated the clipping.
  • Conor then re-aligned the two IOO monitoring QPDs near the periscope. He is all set to re-commissioni the MCR and MCT monitoring QPDs as soon as the MC is back up.
  • Conor cleaned up the PSL table, removing all unused components.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: Spherical collection mirror from Rolyn for the BRDF meter.
  • 40 M IFO PRE-ALIGNMENT: The symmetric (bright) port was aligned by centering the PSL input beam with a target at the ITMx and then retroreflecting from the ITMx to produce the bright port beam. The overlappig reflection from ITMy produced visible fringes at the bright port. The initial pointing beam splitters were aligned by using modecleaner flashes to produce an observable initial pointing beam. The initial pointing position beam was aligned out through the viewport. The initial pointing angle beam remains to be directed out the the x-end viewport. Spacers need to be placed to raise the x and y end optical tables to the designed 4 inch beam height. The IFO PZT steering mirrors change their pointing direction when energized; however, the pointing direction can be adjusted electronically and when the PZT feedback loop is activated, the mirrors appear to reproduce their pointing when the voltage is turned on and off. One of the steering mirrors was not functioning electronically. The video image mirrors in the BSC chamber and input chamber for observing the Faraday isolator input aperture were installed and aligned. Beam dumps were placed in the BSC chamber to catch the reflected beams from the x and y spoiling flags in front of the ITMx and ITMy mirrors. The POX pickoff mirror was installed and aligned. The ETMx and ETMy output optical trains have not been aligned. All optical lever beams are functioning, but may require final alignment. The video turning mirror for viewing the BS from the input chamber is assembled and awaiting installation.
  • PHOTON DRIVE R&D: The test of the photon actuation control of the mode cleaner is awaiting the pump down and commissioning of the mode cleaner. Aidan Crook is staying an extra week and will test the photon actuation control of the mode cleaner after it is locked. He has boards from Ben and from Jay to test his servo, which is designed to notch out a line in the MC error signal at 153 Hz (a mechanical resonance of the MC suspensions).
• Modeling (Miyakawa, Kawamura, Eichenfield):
  • Seiji continues to develop a model of the 40m and AdvLIGO with Finesse, and comparing with Twiddle calculations. He's exploring the use of double demodulation in all degrees of freedom to improve the LSC matrix.
• Computing (Ivanov, Bork, Goggin, Wallace, Bogue, Pedraza):
  • Lisa Bogue set up samba to serve the our online software disk (op140m:/cvs/cds/caltech) to PCs on our martian network. Jay installed EPICS on our PC laptops. Now we can run EPICS and medm screens on PCs, with no extra load on op140m!
  • Jay and Alex think they know why many of the new EPICS channels (for oplevs and QPDs) are not being read out correctly for logging to frames or display with dataviewer. They will need to reboot DAQS (and just about everything else) to implement the fix. They'll do that early next week.
  • Lisa G has constructed a new "40m checklist" medm screen with most all important EPICS channels, so that the status of all active systems can be seen at a glance.
  • Jay is working on getting the epics timeserver going so that epics will finally know what time it is!
  • Lisa was able to reboot zuben, the Sun blade 100 on Dennis' desk.
• South Annex Bake Ovens (Taylor):
  • Bob is shipping baffles for LHO to the heat treaters.
  • Bob is cleaning some parts for Larry Jones.
  • Bob is cleaning up the South Annex clean room, and re-organizing the cabinets so that less time is spent looking for parts.

Aug 22, 2003

• The 40 Meter Technical Review Board (chair: Ken Strain, kstrain@physics.gla.ac.uk) met on Wed, Aug 20, at the LSC meeting, Hannover. Osamu Miyakawa presented the 40m status report.
• Installation (Vass, Miyakawa, Smith, everyone):
  • The PSL -> IOO -> IFO is now completely aligned in air, including all output beams, all oplev beams, and with all suspended optics' OSEMs at mid-range.
  • Mike is trying different places to put the autocollimator for a final, out-of-vacuum alignment.
  • It's not final, yet: the last oplev mirrors, camera view mirrors, shutter flags, will be installed today. This should have negligible effect, but the full alignment will be re-established afterwards.
  • But, there's a problem: a few suspended optics have been observed to drift significantly in their alignment, overnight. The obvious suspect is the settling of the seismic isolation stacks (with viton springs); but it seems too big an effect. Mike and Steve continue to investigate this.
  • If the alignment does not continue to drift, we hope to complete this installation and pump down early next week.
  • Also, Mike discovered that the BS suspension clips the AP beam. He and steve will construct a jig to move the BS suspension to get rid of this.
  • Steve is reviewing the placement of all optical-quality viewports, and re-arranging as necessary.
  • The interface board for the in-vac PZT mirrors is finished, and was sent to the boardhouse on Tuesday; should be back by Monday. But we hope to seal up on Monday; so in the meantime, Ben is testing the system with a cross-connect block in place of the interface board.
• Electronics (B. Abbott, Heefner, Taylor)
  • ITMx was damping poorly. Steve discovered that it was banging on an EQ stop. He backed it out; now all suspended optics are damping well at nominal gains.
  • The DAQS was crashing last week, but has not crashed once this week. Not sure why; there may have been a loose ethernet cable that was inserted more firmly.
  • Ben had some simulation problems with Aidan's photon actuator experiment filter designs. He finally fixed the problem on Monday, and the design went to the boardhouse on Tuesday. When it arrives, it will be stuffed and tested ready for use early next week.
  • Ben has assembled an inventory of all the parts we need to finish the ASC and LSC systems, and is taking steps to get everything we need.
  • Lisa G is running more video monitor cables from the video switch to the monitors in the control room.
• Optical levers (Bhatt, Goggin, Smith, Vass, Taylor):
  • Naman, with help from Jay, Ben, Steve, and Mike, has oplev beams on all 5 optics: BS, ITMx, ITMy, ETMx, ETMy; all work fine, through to EPICS screens and dataviewer.
  • Except, the beam for ITMx is severely attenuated by the time it gets to the oplev QPD. She is investigating.
  • Ben changed the gains on the oplev QPD circuit by 10x to see if that would help with the weak ITMx signal, but the problem seems to be due to too many mirror bounces.
  • Alex and Jay installed and verified new code for the optical levers in the vertex. The segments on the optical lever servo screen now match the segment definitions for the aux crate, i.e. segment 1 is segment 1, etc. This is the same definition used for the ends.
  • As part of the new code installation in the vertex, Jay tested the optical lever signals in dataviewer. We observed the 4 segment signals for the BS in dataviewer and verified that we could see them. They all work.
  • Next step is to set up and turn on the digital servo and see if it damps.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor measured the OLTF of the FSS with the pickoff after the PMC and before the PMC. They look exactly the same (and the same as before the re-layout) at 100 kHz and below, with +16.5db of gain at 100 kHz (LIGO spec is +12db at 100 kHz).
  • The PMC pole rolloff is clearly seen above 200 kHz. We can easily switch between having the pickoff before and after the PMC, with no change in gain at 100 kHz; this will allow us to easily evaluate the effect of the change on the frequency noise spectrum measured by the mode cleaner, as soon as we get the mode cleaner back up.
  • This good performance at 100 kHz means that there's no need to make further mods to the FSS to increase the UGF. In particular, no PMC pole compensation is needed.
  • Conor and Ben will make the HVamp daughter board on the FSS card into a permanent mod.
  • Conor is re-commissioning the 4 QPDs that monitor the PSL beam position, PSL beam angle, MCT beam position, and MCR beam position.
  • Conor is investigating some beam ellipticity in the vicinity of the PSL periscope.
  • There was a slight delay on the ISS PDs boxes silkscreening. They are now ready, and I will go and pick them up tomorrow. The head enclosures are finished, and just need some screws to finish them off.
  • One set of ISS boards and PD's is earmarked for our PSL.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: Spherical collection mirror from Rolyn for the BRDF meter.
  • 40 M IFO PRE-ALIGNMENT: Both arms have been aligned. The antisymmetric (dark) port has been aligned. We are in the process of aligning the symmetric port with the autocollimator.
  • PHOTON DRIVE R&D: Tom Essinger-Hileman has aligned an optical system with 4 bounces from the MC2 mirror. He presented his SURF talk, and has completed his SURF program.
    Aidan Crook is staying an extra week and will test the photon actuation control of the mode cleaner after it is locked.
• Modeling (Miyakawa, Kawamura, Eichenfield):
  • SURF Keiko Kokeyama presented her results on testing (in MATLAB) the approximate solution for the dual-recycled summation cavity for E2E. It looks good! Implementation in E2E can now begin.
  • Seiji continues to develop a model of the 40m and AdvLIGO with Finesse, and comparing with Twiddle calculations.
  • Matt continues to develop his Simulink model of the MC WFS system. He talked to Luca at LHO about how they do the servoing there.
• Computing (Ivanov, Bork, Goggin, Wallace, Bogue, Pedraza):
  • Lisa Goggin assembled a database of all the computers and their target directories in /cvs/cds/caltech/target, and labelled all the embedded computers. She updated the network status medm screen.
  • Lisa Bogue set up cron jobs on all the online Suns to synch their system clock with our gateway computer, which synchs to a GPS server on campus. We hope that will reduce the time synch problems that prevent us from running DTT.
  • Jay looked at the problems with running dataviewer on op140m, "The problem was with the number of queues. I did an ipcs -q and found 9. I then used ipcrm -q to remove each one. Dataviewer now appears to work. I started it with 8 different optical lever signals from different optics and they all display. The updates are very slow since op140m is such a dog. We should get a fatser machine to run dataviewer on."
  • We use PC laptops to display medm screens, off of op140m. We can lessen the load on op140m considerably by running medm directly on the PCs, if they can mount the op140m disk. Jay suggests getting Samba to run on op140m, to serve the disk to the laptops. We'll ask Lisa B.
  • The Sun blade 100 on Dennis' desk won't boot; Lisa B has been alerted.
• South Annex Bake Ovens (Taylor):
  • Bob is working on yet more baffles for LHO.
  • Bob is baking more misc parts for installation, including remachined shutter flags.
  • Bob has prepared optical viewport assemblies for Steve.

Aug 15, 2003

• The 40 Meter Technical Review Board (chair: Ken Strain, kstrain@physics.gla.ac.uk) meets on Wed, Aug 20, at the LSC meeting, Hannover. Osamu Miyakawa will present the status report.
• Installation (Vass, Miyakawa, Smith, everyone):
  • Steve, Mike, and Osamu continue to align the main IFO (BS, ITMs, ETMs; the PRM and SRM will be installed after we learn how to lock the Fabry-Perot Michelson).
  • The path from PSL -> MC -> FaradayIsolator -> MMT -> BS -> ITMx and then back through FaradayIsolator to symmetric port beam has been completed.
  • The path from autocollimator BS -> ITMx -> ETMx and the path from autocollimator BS -> ITMy -> ETMy have been completed.
  • Next, the dark port beams and pickoff beams will be established.
  • Then, we'll screw it all up by adding oplev mirrors, camera mirrors, shutter flags. And screw it up even more by balancing all the OSEMS on all suspended optics. Then re-do all the alignment again!
  • Hope to complete this and pump down by end of next week.
• Electronics (B. Abbott, Heefner, Taylor)
  • Ben changed the power on all DSC satellite amplifiers from 24 to 20 volts.
  • All 10 digital suspension controllers are functioning and 8 are in continual use (SRM and PRM are still on the bench).
  • ITMx continues to damp poorly; suspect a mechanical problem (wire out of standoff groove); will be investigated.
  • The DAQS crashed several times this week, and wouldn't reboot with a cpu reset to c1daqscntrl. Powering down the DAQS crate, reseating the GPS board, powering back up, and restarting all the front end CPUs did the trick, but it crashed again 22 hours later. Ben and Jay got it back up. It may be a dying GPS board. Fortunately we have a spare.
  • Each time we try to reboot the DAQS, the DSC's go crazy. Don't know if it's because of the timing or the RFM. We'll need to put a separate timing GPS system into a separate crate ("pizza box"), and make sure the RFM network bypass switch is working. Rolf will investigate when he returns next week.
  • Ben is getting QPDs and LSC RFPDs for the SP, AP, pickoff, and end transmitted sensing beams.
  • Art is finishing up the LSC rack cross-connects. All LSC modules are being fabricated and/or purchased; Jay and Ben will inventory them.
  • There is a bad VME crate in the LSC rack; it was pulled out of the ETMx rack because the cpu would hang. Ben will see if it can be fixed; else, replaced.
  • Ben is setting up the drivers for the in-vac PZT steering mirrors. He is designing an interface board that will go between the PZT driver cables in the ASC rack, and the flange feedthroughs. It's almost done. It should go out to the board house today.
  • Ben has been helping Aidan with his photon actuator experiment filter designs. Aidan gave Ben a transfer function that I have made into a hardware design. It should go to the boardhouse tomorrow.
• Optical levers (Bhatt, Goggin, Smith, Vass, Taylor):
  • Naman has calibrated the response of the 7 oplev PD's, in terms of volts on the EPICS screen versus x/y of beam on QPD face.
  • She measured the RMS noise spectrum in pitch and yaw (in Vrms) with the laser pointing directly at the QPD, both for short lever arms (laser and QPD on same table) and 40m lever arms. She's working on the conversion to meters-rms.
  • Naman and Jay chased down the differences between the two ETM electronics chains and the other 5. All 7 QPDs are the same, but the ETM screens display the 4 quadrants differently than the other 5. It looks like the problem is in the readout software. Alex will be notified.
  • Naman and Steve will install the remaining in-vac oplev mirrors by the end of this week.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • The PSL has been operating robustly in its new configuration (fewer mirrors between PSL and periscope, FRC pickoff after the PMC).
  • Mike is updating the ACad optical layout to reflect the changes in the PSL table.
  • Conor noted that the beam near the periscope was elliptical; he'll re-adjust the optics between the PMC and the periscope to fix it.
  • The new layout puts less optical power into the FRC; the electronics gain is maxed out. Conor increased the power into the PMC from 1w to 2w, and observed the FSS going unstable. He turned down the electronics (common) gain, and it is now stable, with headroom to spare in the electronics.
  • Conor is re-commissioning the diagnostic devices (QPD, camera, OSA) at the periscope pickoff and at the MCT beamline.
  • Conor and Ben will continue to work on the mods to the FSS card which increase the UGF too 800 kHz: making the HVamp daughter board permanent, adding a zero to compensate for the PMC pole, and maybe a pole to roll off the gain above 1 MHz.
  • The stands and boxes for the ISS PDs are finished being fabricated, anodized and silkscreened. Ben will go and pick them up on Friday.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: Spherical collection mirror from Rolyn for the BRDF meter.
  • OPTICAL LEVER ASSY: Naman is installing all of the external and in-vacuum components. She is in the process of testing the 40m long focal length lens for the optlev receiver.
  • 40 M IFO PRE-ALIGNMENT: The IR autocollimator was used to establish the y-arm cavity centerline and to align the BS and the ITMy. The ETMy is recalcitrant and has yet to be aligned.
  • POX and POY: Mike is designing cantilevered mirror mounts to catch the pickoff beams reflected off the two arms.
  • PHOTON DRIVE R&D: Tom Essinger-Hileman has aligned an optical system with 4 bounces from the MC2 mirror, with the addition of 8 bounces if necessary, and is awaiting the locking of the mode cleaner to complete his photon acuation of the mode cleaner cavity. He has acheived around 10 dB of intensity noise suppression, bringing the intensity noise to around -140 dB, in the LIGO band.
    Aidan Crook has designed the filter for the additional photon actuation servo loop (focussing on suppressing a suspension mechanical resonance at 154 Hz). Ben is making a hardware filter. Aidan and Tom will test the photon actuation control of the mode cleaner after it is locked.
• Modeling (Miyakawa, Kawamura, Eichenfield):
  • Osamu, with SURF Keiko Kokeyama, is testing out (in MATLAB) the approximate solution for the dual-recycled summation cavity for E2E.
  • Seiji is developing a model of the 40m and AdvLIGO with Finesse.
  • Matt continues to develop his Simulink model of the MC WFS system.
• Computing (Ivanov, Bork, Goggin, Wallace, Bogue, Pedraza):
  • With all the changes to the embedded computers in the lab (front-end pentiums, EPICS mvme162s, linux PCs for front-end filtering, linux PCs for EPICS access, general computing, ...), Lisa Goggin is inventorying all the computers and their target directories in /cvs/cds/caltech/target.
  • Both dataviewer and DTT are cranky, extremely slow, and often hang or give errors. We hope Rolf and/or Alex can help with this when they get back from MIT.
  • Can't plot or excite test points with DTT.
  • DTT requires the host Sun to be synched to GPS time within one second. We need to make this happen, somehow...
• South Annex Bake Ovens (Taylor):
  • Bob assembled and vac-prepped the picomotors for the shutter flags and the camera mirror mounts.
  • Bob is working on more baffles for LHO.
  • Bob is building more OSEMs for Janeen/Calum, GinGin, and Glasgow.
  • Bob is baking more misc parts for installation, including camera mirror mounts.

Aug 8, 2003

• Installation (Vass, Miyakawa, Smith, everyone):
  • The in-vac PZT steering mirrors were installed, as well as most of the remaining in-vac mirrors needed for the IO system.
  • Matt and Naman installed in-vac oplev mirrors on ETMy. The other 6 sets of in-vac oplev mirrors are ready for installation but not yet in.
  • More counterweights were needed, and Betsy sent us some from LHO. Thanks, Betsy!
  • Steve, Mike and Osamu have been aligning all the components of the main IFO (except for the PRM and SRM, which will be installed at a later stage).
  • Osamu has sent the PSL beam through the mode cleaner mirrors, the fraraday isolator, the mode matching telescope, the beam splitter, and ITMx. The beam reflects off of ITMx and back through the faraday isolator, exiting the vacuum enclosure as the SP beam.
  • Meanwhile, Mike and Steve used the autocollimator beam entering at ETMx, aligning ETMx and ITMx and the BS, back towards the mode matching telescope.
  • Mike and Steve moved on to the y (south) arm, and noticed that the beamsplitter is in wrong. They rotated it by 180degrees, and are now in the process of re-establishing the above 2 steps before moving on to the y arm alignment.
  • Mike modified his optical layout drawing so that POX and POY carry the light *reflected* from the two arms, not incident on them.
  • Steve has installed optical-quality (BK7), 1/2 degree wedge, 1064 AR coated viewport windows on the input from the PSL, the output for SP and AP beams, and TRX. He will also do TRY and POX. The remaining BK7 windows are broad-band AR coated; one will go on the POB beam.
  • Bob has completed in-vac cables for the PZT steering mirrors, and picomotors for the shutter flags and MMT.
  • Matt has checked out the picomotor controller and tested it on the 4 shutter flag picomotors prior to their installation. He will check the picomotor on the mode matching telescope as soon as alignment work in that chamber is complete.
  • Four shutter flags, and a few in-vac camera view mirrors remain to be installed. Teflon flags for the shutter flags are being re-worked and vac-prepped.
• Electronics (B. Abbott, Heefner, Taylor)
  • Last week, Ben and Jay fixed the xycom screens for the ETMx and ETMy DSC's, they are now fully functional and switching the End Station Whitening and Dewhitening.
  • Last week, Ben changed the power to the ETM satellite amplifiers from 24v to 20v. He will do the same for the vertex satAmps.
  • Last week, Ben and Jay got the ETM DSCs all working and damping the ETMs. However, they require high gains (~ 25 instead of 1); being investigated.
  • A few days ago, ETMy was discovered to be not damping. Ben found a couple of minor electronics errors. Then Matt noted that ETMy seemed to be resting on an EQ stop (probably after the oplev mirrors were installed; se below). After this was backed off, ETMy damps just fine.
  • However, ITMx damping is not very good; under investigation.
  • Matt has taken DTT spectra of all 7*5 OSEM sensors (ETMx is still EQ-stopped for alignment, and SRM and PRM are not yet installed). There are several anomalies, under investigation. This is the beginning of a systematic characterization of the performance of all 10 DSCs / suspended optics.
  • Ben is setting up the driver electronics and cabling for the in-vac PZT steering mirrors. Ben is designing an interface board that will go between the PZT driver cables in the ASC rack, and the flange feedthroughs. There are no spare flange feedthroughs on the BS chamber!
• Optical levers (Bhatt, Goggin, Smith, Vass, Taylor):
  • Naman has checked out all 7 oplev electronics chains and all 7 oplev QPDs. All look ok.
  • Except, that both ETM oplevs get mapped onto the EPICS screen differently than the other 5. Will investigate whether this is a cabling, electronics, or software problem.
  • Naman has measured the reflectivity of the old (pre-upgrade) in-vac oplev mirrors; they seem to be fine for the job.
  • Naman and Matt have installed in-vac oplev mirrors on ETMy and have used them to diagnose a problem with ETMy damping.
  • Naman is calibrating the position response of the oplevs / electronics chains.
  • As suggested by Seiji, Naman will measure the oplev signal noise without any suspended optic, to see how it compares with the signal expected from the damped optics.
  • Naman is trying to get the oplev beam into Mike's prototype oplev telescope; it's not easy to align it.
  • Naman plans to model the oplev system and design optimal filters.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor, Ben and Rich finished the testing of the FSS board mods; the servo is now operating with the extended bandwidth circuit, and we are seeing bandwidths approaching 800 KHz. The implementation is still temporary, and is missing two potentially important pieces: compensation for the FSS pickoff being taken after the PMC, and a roll-off beyond 1 MHz.
  • Conor has completed the re-layout of the PSL optical paths; it looks great! And the stray light in the PSL enclosure is under control.
  • The PMC and FRC both have > 80% transmission.
  • Osamu measured the error signal spectra for both the PMC and FSS loops; they are essentially unchanged with respect to the re-re-layout configuration, except for a peak in the FSS spectrum at 25 kHz which is no longer present. This is presumably due to mods to the FSS card, not the re-layout of the optical paths.
  • However, the optical gain in the FSS path is reduced with the new layout, and the electronic gain has been raised to maximum, to compensate. This needs to be remedied.
  • Seiji has analyzed the predicted noise performance of the PSL with the FSS pickoff moved to after the PMC. This technical note T030149 concludes that the move should be advantageous.
  • But the true test will come when we finish installation, pump down, and analyze the frequency noise with the mode cleaner. Conor has made it easy to switch the pickoff between pre-PMC and post-PMC locations.
  • The ISS PDs for the sites have almost finished being fabricated in the back shop. Testing will begin soon.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 1 q-switch E/O shutter from Fast Pulse. Spherical collection mirror from Rolyn for the BRDF meter.
  • OPTICAL LEVER ASSY: Naman is installing all of the external and in-vacuum components. She is in the process of testing the 40m long focal length lens for the optlev receiver.
  • IFO STEERING MIRRORS: The PZT steering mirrors have been installed and aligned in the vacuum chamber.
  • SPS BREWSTER PRISM MIRROR: Installed and aligned in vacuum chamber.
  • IN-VACUUM MIRRORs: In-vacuum mirrors for the IO path have been installed and aligned in the chambers.
  • 40 M IFO PRE-ALIGNMENT: The entire optical path from the PSL laser through the x-arm has been aligned. The IR autocollimator was used to establish the arm cavity centerline and to align the ETMx and ITMx, and to initially align the IO mirrors back to the MMT. The PSL laser was used to align the Faraday isolator, the MMT, and to make a final alignment of the PZT1 and PZT2 steering mirrors to obtain a retroreflection from the ITMx. The retroreflected beam was aligned with the Brewster mirror and was sent out the bright port viewport on the output chamber.
  • PHOTON DRIVE R&D: Tom Essinger-Hileman has closed the loop of his 0.5 watt intensity stabilized laser servo system. A relative intensity noise close to 1E-7 was measured. The initial result was obtained with PDA 55 photodetector, and subsequently Ben found the problem with the intensity stabilization PD and similar results were also obtained. Tom had spacers made to raise the height of the external optical table to be compatible with the optical table in the mode cleaner chamber. He has designed an optical system which will allow initially 4 bounces from the MC2 mirror, with the addition of 8 bounces if necessary.
    Aidan Crook has calculated the bandwidth of the photon acuator for the mode cleaner based on the available effective laser power (which is proportional to the number of bounces). He is in the process of designing the filter functions for the additional photon actuation servo loop.
• Mode Cleaner (Miyakawa)
  • Matt continues to develop his model of the MC WFS system. He has completed a detailed model of the optical plant, and is now adding the sensing, actuation, and feedback modules.
• South Annex Bake Ovens (Taylor):
  • Bob is completing paperwork for all the bake jobs he's been doing for Janeen and the site baffles.
  • Bob is building more OSEMs for Janeen/Calum, GinGin, and Glasgow.
  • Bob is baking more misc parts for installation, including camera mirror mounts.

July 25, 2003

• This is Dennis' last week before moving to San Antonio. So, there are more parties than usual. Dennis has completed the PSL and Networking chapters of the 40m Procedures Manual.
• Installation (Vass, Ugolini, Miyakawa, Smith, everyone):
  • Steve and Helena commissioned the CO2 snow blower to clean off the ETMs before installation.
  • Dennis and Steve installed ETMy and ETMx in their chambers. Matt carefully positioned the suspensions in their correct location. The tables were levelled with counterweights. The EQ stops are currently in.
  • Osamu and Seiji have aligned all the input optics, using the PSL beam with the wrong polarization to get through MC1 and MC3 better: PSL -> MC1 -> MC3 -> MCT pickoff -> temporary HWP -> faraday isolator -> alignment iris -> mode matching telescope -> first IFO steering mirror in BS chamber. All optics in the Input Optic Chamber (IOC) have been installed, and the SP and AP paths are clear.
  • MCT pickoff beam is aligned onto a camera on the MCT sensing table (the PSL table).
  • According to Mike's alignment procedure T030141-00.pdf, we no longer need the PSL beam. So, Conor is now performing the PSL re-layout (see below).
  • With more weight in the IOC, we needed more counterweights. Steve & Bob are hastily making up a bunch more, with help from the machine shop.
  • Currently, we have pickoffs of the light incident on the arms (POX and POY). Osamu and Seiji believe that we should instead have pickoffs of the light reflected from the arms (call them POX' and POY') to help in lock acquisition. Mike Smith will work out how to change the pickoff mirrors and beam stops to get these paths out.
  • Steve and Bob are preparing the in-vacuum cabling for the two PZT steering mirrors, and for the pico-motors used by the MMT and the shutter flags.
  • Next step: Steve will put new optical-quality viewports at the ends (and everywhere else where they are not yet in). Then, continue with Mike's alignment procedure, using the autocollimator from the ETMx end, on in.
  • Steve is continuing to assemble and prepare all the misc things that must be installed, including: optical-quality viewports, in-vac oplev mirrors, cameras, beam dumps, shutter flags, cables for the MMT picomotor, shutter flag picomotors, and PZT steering mirrors.
• Electronics (B. Abbott, Heefner, Taylor)
  • Ben continues to work through the subtleties of setting up the Xycom switches for hardware and software whitening and dewhitening in the DSCs, especially the ends, with help from Osamu and Jay.
  • ETMy has been wired to its suspension controller. Ben checked it out; after fixing some problems (with Bob's help), he sees all the sensors.
  • Steve has backed out the earthquake stops, and Ben is now damping the optic. The gain settings are little wierd, Ben will investigate.
  • The DSC sattelite amplifiers are all being powered with +-15 v, and they should be more like +-18 or 20v. Ben and Bob will investigate and make the needed changes.
  • The ETMx DSC crate was locking up repeatedly after boot-up. Jay discovered that the problem was with the crate; switching in another crate fixed the problem, reproducibly. Jay & Ben will find a permanent crate for that location so that the ETMx DSC can be commissioned next.
  • Jay reports that the rest of the parts for the LSC/ASC racks cross-connects are in, and Art and Bob are finishing them up.
  • Linear power supplies for the LSC system are in. They will go in a small rack near the LSC/ASC racks.
  • Jay ordered Penteks for the LSC/ASC system, and will ask Rolf about the Pentiums, RM boards, and other modules.
• Optical levers (Bhatt, Goggin, Smith, Vass, Taylor):
  • Naman has checked out all 5 vertex oplev electronics chains from the QPD to the EPICS screens, with help from Ben. Two end oplev chains remain to be checked out.
  • Naman checked out 7 oplev QPDs. Two are bad, and Ben brought them over to Art to be diagnosed & fixed.
  • Naman is working on understanding Mike's oplev telescope design, and has reproduced many of the numbers with a Mathematica model.
  • Naman is working with Steve to prepare the in-vac mirrors for all 7 oplevs.
  • Naman and Steve Beam-scanned a couple of the oplev laser diodes, and found that their profile is rectangular. Shouldn't be a problem, we think.
  • Naman is calibrating the response of the QPDs and electronics chains, by scanning an oplev laser beam across the face of the QPD and reading out the response on the EPICS screens.
  • Naman identified some unintuitive aspects of the EPICS screens that display the oplev position information; but, if that's what they live with at the sites, I guess we can live with it as well. Jay will check whether that's really how it's done at the sites.
  • Naman and Jay are thinking about the filters needed for the oplev servos, and will start a model of the system.
  • Bob is making more cables for the optical levers at the ends.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor, Ben and Rich have been implementing changes to the FSS board: replacing a slow HVamp with a new faster one on a daughter board, and adding an additional LV amp. They have increased the FSS UGF from 200 kHz to 700 KHz, and the servo is locking robustly. The gain curve is rather flat beyond 700 kHz; they will consider adding a notch filter for a ~4 MHz EOM resonance peak, and maybe something to roll off the gain faster beyong 700 kHz.
  • To do this measurement, they had to borrow an HP 4195 from Wilson House, since ours seems to be malfunctioning. The loaner was promptly returned! We will need to get ours repaired.
  • Conor and Matt have begun to re-layout the PSL, and are proceeding quickly. They've already laid down the new main beam path, have mode-matched into the PMC in its new location, and are ready to test the PMC servo.
  • Seiji is developing a noise model to understand the potential advantage of moving the FSS pickoff from upstream of the PMC to downstream. He's derived all the transfer functions from each noise source to the frequency noise of the PMC-transmitted beam.
  • Mike is evaluating the consequences of having the PSL->MC PZT steering mirrors only 20 cm apart instead of ~ 1.5 meters (as required for the re-layout). Doesn't seem to be a big problem.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 1 q-switch E/O shutter from Fast Pulse. Spherical collection mirror from Rolyn for the BRDF meter.
  • FARADAY ISOLATOR: Faraday isolator was installed and aligned.
  • OPTICAL LEVER ASSY: Naman is staging all of the external and in-vacuum components. She has independently checked the design of the 40m long focal length lens for the optlev receiver, and has verified the design by Mike Smith.
  • IFO STEERING MIRRORS: The PZT steering mirrors are awaiting installation in the vacuum chamber.
  • SPS BREWSTER PRISM MIRROR: In process of being installed in vacuum chamber.
  • IMMT: The input MMT was installed and aligned.
  • IN-VACUUM MIRRORS: In-vacuum mirrors are in the process of being assembled with the appropriate mirrors and beam splitters.
  • 40 M IFO PRE-ALIGNMENT: Alignment apertures are in place before the MMT. Alignment targets for the IR autocollimator beam were cleaned and ready for installation. The IR autocollimation equipment has been staged in preparation for the pre-alignment.
  • PHOTON DRIVE R&D: Tom Essinger-Hileman has re-designed the 40m photon drive optical layout so that we can provide four bounces onto the same spot on the MC2 mirror. He has wired up and tested the 0.500 mw 1047nm laser and the photdetectors. He is in the process of setting up the SR 560 servoamp with Osamu's help to stabilize the laser's intensity. Aidan Crook received valuable information from working with Peter Fritschel at MIT. He has completed a simulink model of the 40m PSL/mode cleaner system with the addition of a photon actuation loop. He is in the process of determining the suitable frequency range over which the photon actuator loop will be able to perform length control of the mode cleaner.
• Mode Cleaner (Miyakawa)
  • During installation, the PSL beam has been going through MC1 and MC3 (with the "wrong" polarization to increase transmission), with no attempt to lock the MC in air.
  • Matt continues to develop his model of the MC WFS system. He has validated his Simulink model of the optical plant with independent Matlab and Mathematica models.
• South Annex Bake Ovens (Taylor):
  • Bob coimpleted a set of baffles for LLO and shipped them out on Monday.
  • Work on the LHO baffles is in progress.
  • Bob continues to do quick clean and bake jobs of misc components for the 40m installation (irises, counterweights, pigtail cables, etc).
  • Bob continues to re-supply the South Annex lab with consumables such as cleaning chamicals, wipes, clean bags, etc.

July 18, 2003

• Installation (Vass, Ugolini, Miyakawa, Smith, everyone):
  • The 40m was vented on Tuesday 7/8 without incident. We did notice, however, that the ion pump currents rose somewhat after the pumpdown even with their gate valves closed. One has since begun to decrease, and John Worden has told us the rest will probably follow suit.
  • Steve moved the MC2 feedthroughs to the east side of the MC end chamber, and put a window on the back of the chamber for Mike Smith's photon actuation experiment. A 4'x3' table has been placed next to the window as well, for Mike/Tom's laser.
  • Several irises have been cleaned by Bob, and were installed on Friday 7/11 to lock down the laser alignment.
  • The old steering mirrors for PSL->MC, MC->MCR, and MC->MCT are being replaced by mirrors with better (DLC) mounts, with due attention to polarization (unlike before).
  • The PSL beam was observed to flash through the MC (in air), verifying the correct alignment of all the above changes.
  • The remaining input optics (Faraday Isolator, mode matching telescope, various steering mirrors and pickoffs, PZT steering mirrors, etc) are installed and are being aligned to the PSL beam.
  • A procedure for pre-aligning the 40M IFO was developed by Mike Smith and described in the document T030141-00, which is in the process of being finalized. Alignment targets were designed and manufactured and are in process of being cleaned and baked. The IR autocollimation equipment has been staged in preparation for the pre-alignment.
  • The first step of the procedure is to use the PSL beam to align the IO train through the Faraday isolator, and lay down defining irises. This step is nearing completion, and the PSL beam will no longer be needed for alignment. The 2nd step uses the IR autocollimator to align from the ETMs back through to the Faraday Isolator, for the hand-off. We are beginning this phase now.
  • We hope to install both ETMs by the end of this week, so as to pursue the alignment 2nd phase, and to facilitate debugging of the ETM DSC's.
  • We have decided to NOT install the PRM and SRM during this vent, to make the commissioning of the FabryPerot Michelson easier. We'll have to shedule another vent, some months from now, to install the recycling mirrors and re-align everything. Meanwhile, the mirrors will sit in the clean flowbench in the south annex.
  • Steve is continuing to assemble and prepare all the misc things that must be installed, including: optical-quality viewports, in-vac oplev mirrors, cameras, beam dumps, shutter flags, cables for the MMT picomotor, shutter flag picomotors, and PZT steering mirrors.
• Electronics (B. Abbott, Heefner, Taylor)
  • Ben has been testing the ETMY suspension rack 1Y9. The auxiliary crate readbacks appear to be working fine, but the front end crate is not. Ben figures that we still need a Xycom controller screen for the dewhitening switches; Jay cranked one out yesterday. Ben is now beginning the remainder of the ETMY testing, and will move on to ETMX.
  • We plan to install the ETMs in the next few days, so Ben can try to damp them.
  • All of the remaining electronics racks were anchored to the floor last week.
  • Ben continues to populate the LSC/ASC racks 1X2 and 1X3.
  • Art is waiting for FLKM 64s to arrive from the sites so that he can finish the LSC wiring in 1X3.
  • Jay, Ian, and Calloway successfully prototyped their new digital demodulation board using the PMC at the 40m PSL.
• Optical levers (Bhatt, Goggin, Smith, Vass, Taylor):
  • Naman and Lisa have looked at the signals from one oplev QPD through the electronics chain to the EPICS screen.
  • They found some channel assignment problems, with help from Ben. It turned out to be a code problem which Alex quickly fixed. There seems to be another problem in the EPICS display, a flipping of the sign of pitch or yaw; being debugged.
  • Mike and Naman went over the oplev parts list. All the parts for all 7 oplevs are in hand, and Naman is assembling them on their proper tables, and beginning the job of checking out the readout chain for each.
  • Naman is thinking about what lens to put in front of the QPDs, ie, what the optimal spot size should be. We have a 10mm dia QPD, we figure a beam with beam radius w = 3 mm should be about right. Naman will use the beam scan to measure the beam size and divergence.
  • Mike has to update the telescope design. He designed it for 960 nm light, but we're using read 670 nm laser diodes.
  • Naman continues to learn about the oplev system and Mike's telescope design. She'll assemble and test the prototype.
  • Bob is making more cables for the optical levers.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor continues to refine his plan to re-layout the PSL. Seiji has been thinking about, and plans to help with, these mods.
  • Reducing the number of mirrors in the main beam path by 2 requires us to put both PZT steering mirrors on the periscope, 20 cm apart. Conor figures this is sufficient lever arm to displace the beam at the MC input by a sufficient amount to servo it effectively (should we choose to implement the MC ASC this way, which we currently don't plan to do, anyway).
  • Conor and Rich and Ben are modifying the frequency servo board to bypass a slow slew-rate op amp with a faster one. This should allow us to increase the UGF of the PSL FSS from ~ 200 kHz to the neighborhood of 1 MHz.
  • Conor has a clean way to switch the optical path of the FSS pickoff from pre-PMC to post-PMC, easily, and requiring no changes to the mode-matching lenses.
  • Moving the FSS pickoff to post-PMC *may* require us to compensate for the PMC pole in the frequency servo board. This change is easy to do and undo, to easily compare the noise performance in both configurations.
  • Ben has put together and tested an ISS PD for Mike Smith so that he can use it in his Photon Actuation tests. Now he has to make a pile more, for the sites.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Received parts: Aluminum coated mirrors for optlev mirrors and additional mirror posts and clamps were received. The mirrors for the PZT steering assemblies were received.
  • Orders pending: 1 q-switch E/O shutter from Fast Pulse. Spherical collection mirror from Rolyn for the BRDF meter.
  • FARADAY ISOLATOR: Faraday isolator was placed inside the input chamber and is process of final alignment.
  • OPTICAL LEVER ASSY: Naman is staging all of the external and in-vacuum components.
  • IFO STEERING MIRRORS: A revised layout was done to simplify the path between the two PZT steering mirrors. The change reduced the path length between the IMMT and the ITM. This effects the mode-matching slightly, but the mode-matching of the IMMT can be re-optimized to < 10E-6 by changing the defocusing of the telescope from the pre-focused value of 1.2 mm to 1.1 mm; the correction is less than the uncertainty in the pre-focus of the telescope, and this change will be made with the Pico motor once the IFO is locked. The new placement of the displacement steering mirror still provides a range of displacement of the IFO beam at the PRM of +/- 1mm. The PZT steering mirrors are awaiting installation in the vacuum chamber.
  • SPS BREWSTER PRISM MIRROR: Installed in vacuum chamber.
  • IMMT: The input MMT was placed inside the input chamber and is process of final alignment.
  • IN-VACUUM MIRRORS: In-vacuum mirrors are in the process of being assembled with the appropriate mirrors and beam splitters.
  • PHOTON DRIVE R&D: Tom Essinger-Hileman has designed the optical system using the ABCD matrix formulation with Mathematica, and has established three congugal image points: the laser spot, the spot on the mirror, and the spot on the ISS PD. He has made a layout of the 40m photon drive experiment using ACAD. All of the parts have been received for the apparatus. Tom and Steve installed a 3ft x 4ft optical table at the end of the MC chamber for mounting the apparatus, and Steve moved the OSEM wiring to the side viewport and installed a new viewport in the end of the MC chamber. Tom completed an analysis of the change in photocurrent as a result of beam displacement jitter and spot size on the surface of the QPD. He is working on a new layout in which the laser beam is sampled before hitting the mirror, rather than the present design which samples the returned beam. Aidan Crook is at MIT working with Peter Fritschel.
• Mode Cleaner (Miyakawa)
  • Osamu recentered the MC beam on MC2 before the vent, and realigned all of the MC optics.
  • Osamu found that the dewhitening filters for the MC1,2,3 DSC's, which have had repeated switching problems, were still off. He jumpered back in a filter that had been bypassed, and will work with Ben and Jay to make sure these switches work in the future.
  • With that change, the mode cleaner noise is now as good or better than it ever was! It is dominated by seismic noise below 30 Hz. From 30 Hz on up, it is as good or better than specs, except for a forest of peaks near 200 Hz which is associated with acoustic noise on the PSL table. Conor's mods (see above) should reduce this.
  • Osamu still thinks there's excess electronics noise which can be improved. The mods to the FSS to increase its UGF (see above) should help at higher frequencies. Osamu plans to replace the resistors in the DSC coil drivers, which should reduce the electronics noise in the 100 Hz region.
  • Osamu had reduced the gain of the position, pitch and yaw damping in all 3 MC DSC's, from 1.0 to 0.1, so that the Q's of the pendulum modes went from ~4 to ~ 40. He found that this was helping reduce the noise. Now, with the above changes and fixes, he no longer needs to do this; gains are back up at 1.0.
  Mode Cleaner WFS system (Ourjoumtsev, Abbott, Eichenfield):
  • Alexei had a very productive July 4 weekend before leaving us. He has commissioned the MC WFS system and ASC feedback to MC2 and MC3 P/Y (four feedback loops). He has used it to demonstrate:
    • If you misalign the mode cleaner "by hand" (changing the offsets on MC2 and MC3 P/Y), the MC transmitted power falls. Switch on the ASC, and the alignment and transmitted power quickly go back to their optimal points, and the transmitted power becomes more stable.
    • Transmitted power is observed to decline by a factor ~ 2 overnight, presumably due to thermal variations. With the ASC system on, transmitted power remains stable for many hours.
    • The noise spectrum of the transmitted power was measured with ASC off and on. With ASC off, there is a large peak at microseim and at the various pendulum frequencies ~ 0.85 Hz. With ASC on, that peak disappears, but new (smaller) peaks at ~2-3 Hz appear. Presumably, this is an artifact of un-optimized feedback filtering, and can be eliminated.
  • This is a tremendous acheivement! Alexei has documented these measurements, along with a first-draft "User manual": Preliminary report on Mode Cleaner WFS alignment system commissioning.
  • Conor and Matt absorbed the final core dump from Alexei on both the WFS and EO shutter systems, before he returned to France. They will pursue the optimization and full characterization of the system, over the summer (once our vent is over and the MC is back in operation).
  • Matt is also working on his WFS Simulink model and making great progress. He and Conor have found some errors in some of the WFS documentation. He is emailing lots of questions to Daniel Sigg and Nergis.
• South Annex Bake Ovens (Taylor):
  • Bob is working on the baffles for LLO. Since this is high priority, it preempts all his 40m work.
  • Bob continues to do baking and scanning for the Gingin hybrid OSEMs and associated parts, for Janeen.
  • His small sonic cleaner has broken again, but the larger one is still fine.
  • Bob continues to work with Steve and Mike to get all the parts to be installed in the vacuum prepped and ready.

July 4, 2003

• Alexei leaves next week. In his six months at the 40m, he has made major contributions to all aspects of the project, often working for 14 hours a day. Amongst his more major contributions: He laid out most of the sensing beamlines. He helped assemble and commission the Faraday Isolator. He developed a powerful and easy-to-use Gaussian beam propagation analysis tool. He assembled, installed, and fully commissioned the EOS system. He has assembled and commissioned the MC ASC system, almost single-handedly; a tremendous acheivement. We are immensely grateful to Alexei, and hope he comes back soon!
• Core digital suspension controllers (DSC), LSC, ASC, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • The vertex DSC's have been running fine since Rolf's changes.
  • The end DSC's are still being commissioned by Rolf and Ben.
  • Ben has been testing the auxiliary (EPICS) controls in the ETMY rack. He found and fixed problems with switching the dewhitening filter (the XY220 outputs need to be re-set via an epics screen after reboot). Aside from this, ETMY looks ok, and Ben is moving on to ETMX.
  • Bob replaced the fiber link to ETMX. Rolf is now working on getting the ETMX and ETMY front end code running.
  • From Rolf: Continued installation of 40m lab ETM controls. We were having problems with ETMY controls, as the 110B ADC was only reading zeros, and, after a few hours, the reflected memory would lock some bits. We replaced the RFM card, and now everything seems fine. Don't have a clue what this had to do with the ADC readings.
  • Ben has stuffed the ASC & LSC racks as much as can be done for now. All of the VME and Eurocard crates are in, and are stuffed with the modules that we have so far. Todd is keeping Ben appraised when the new modules will be complete.
  • The cross connect lists for the ASC and LSC have been generated by Jay. The 1X3 rack was put into place last week. Art is busy making up the cross connects for the LSC/ASC racks. 1X2 is now complete, and 1X3 is coming along nicely. Ben will be helping Jay and Rolf install and commission these systems in the coming weeks.
  • From Jay: The QPD to ICS110 interface module layout has been completed and the board was sent out for fab by 6/27. Boards should be received back in two weeks.
  • Lisa has more-or-less completed the cabling of the video cameras to the switch and the monitors; she needs a bunch more ables to complete it. Her EPICS-based controls work well.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu adjusted the MC gains, and it is now locking quite robustly. It didn't even lose lock when holes were drilled into the concrete floor to secure the LSC and ASC racks.
  • Osamu measured the OLTF and the the frequency noise of the MC servo, and comparing it to what it was before the DSC re-wiring (2 months ago, when it met specs over almost the entire frequency range). At first, it was 100 times worse, in the 20-700 Hz range; due, presumably, to changes in the MCL actuation path. He added a low-pass filter for MC2, which improved the noise but it was still 15 dB higher than before. He and Dennis searched through all the changes, and found problems with the control that switches between software and analog dewhitening. Ben fixed that. Software dewhitening contributes to the noise, so we are using analog dewhitening.
  • Still, changes to the analog and software filtering that no longer adequately filter DAC noise appear to be causing the excess noise.
  • Osamu found that a resistor in the coil driver was not the right value; changing it would reduce this DAC noise, but also reduce the dynamic range of the coils. He will consult with Jay about what to do.
  • Osamu measured the OLTF of the DSC loops for the MC2. With a gain of 1, he measured a Q of 4. Then he turned down the damping gain to 0.1 (Q ~ 40), and found reduced noise in the MC servo. We don't understand this, but for now, we're keeping it that way.
• Mode Cleaner WFS system (Ourjoumtsev, Abbott, Eichenfield):
  • Alexei has been working like mad; he's leaving next week. Conor and Matt have been helping and learning about the MC WFS system from him.
  • Alexei found a 3 MHz oscillation on one WFS head, and traced it to a wrong component on the board; he fixed the board and eliminated the oscillation.
  • He changed some capacitors on WFS head 1; Ben will do the same for WFS2.
  • Now, Alexei give a clean bill of health to all the WFS hardware (modulo the point above).
  • Alexei checked and tuned the gains and RF phases on all 2x4 WFS quadrants, to give zero readings for aligned MC mirrors and maximal signals for misaligned mirrors. The gains on all the demod boards are within 20% of each other.
  • He adjusted the Guoy telescope lens for WFS1 to provide maximal signal from a misaligned MC2, and is now in the process of doing the same for WFS2 -> MC3.
  • If we intend to feed back on the PZT input beam steering mirrors, we'd set the relative Guoy phases of WFS1 and WFS2 to be 90degrees apart. But, instead, we think we'll beed back to MC2 and MC3. MC3 is 60degrees of Guoy phase away from MC2. So, the Guoy phase for WFS2 will be set accordingly.
  • Alexei saw some pitch/yaw coupling from MC2 -> WFS1. He developed a simple alignment procedure to minimize / eliminate this, by adjusting the height of the Guoy telescope lens.
  • Alexei chose some default digital filters and gains, and closed the WFS1->MC2 loop. First he misaligned MC2; when he closed the loop, it brought MC2 back to the right spot, maximizing the transmitted beam intensity. He observed a marked reduction in fluctuations in the transmitted beam intensity with the loop on. ie, it works!
  • Then, he measured the 2x2 DC transfer matrix from MC2,MC3 -> WFS1,WFS2. He inverted this and input it into the servo matrix. Then he turned on the full 2x2 loops in both pitch and yaw. Again, it worked quite nicely, taking out misalignments and reducing the transmitted beam intensity jitter.
  • Much more tuning is necessary to optimize the MC ASC servos, including better filtering and calibration and Guoy telescope optimization; this work will be continued by Matt.
  • Matt is developing a Simulink model of the full WFS alignment system for the Mode Cleaner. He's making good progress, with help from Hiro, and papers by Mavalvala and Sigg.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor is ready to re-layout the PSL, to (a) reduce the number of mirrors in the main beam path by 2, and (b) pick off the FSS beam after the PMC, rather than before.
  • A problem with (a) is that mode-matching lenses will have to be placed after the first PZT steering mirror. Since this doesn't sound like a good idea, Conor is evaluating how much worse the beam steering will be if the two steering mirrors are both on the periscope, close to each other.
  • A problem with (b) is that it didn't seem to help at LLO or at LASTI. Conor will talk with Nergis and Peter Fritschel to see if they think it is a bad idea or not. Meanwhile, Conor is prepared to do only (a), and (b) later if desired.
  • The box panels for the ISS PD boxes are now complete. Their PCBs are being stuffed, and a few should be available next week, as Mike Smith wanted me to make a set for him, and then we will have more for the ISS testing.
  • Jay and SURF Ian plan to test out their Digital Demod board, which operates out to 207MHz, on our PSL PMC servo loop. Tentative plan is to do this on Monday Jul 7.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa, Arai):
  • OPTICS PARTS LIST, Orders pending: 1 q-switch E/O shutter from Fast Pulse.
  • MODE MATCHING TELESCOPE: Assembly is complete, awaiting installation.
  • FARADAY ISOLATOR: Assembly is complete, awaiting installation. Mike and Alexei measured a transmission of 97% and extinction ratio of 4e-4, better than specs.
  • OPTICAL LEVER ASSY: Updated parts list was given to Naman. Aluminum coated mirrors and additional mirror posts and clamps were ordered.
  • IFO STEERING MIRRORS: Steering mirrors mounts with PZT platforms were assembled. The mirrors were ordered (off the shelf).
  • SPS BREWSTER PRISM MIRROR: Assembly is complete, awaiting installation.
  • MISSING PARTS: All is well that ends well; the 10 DLC mounts were found in the 40m optics lab, and are ready for installation.
  • IN-VACUUM MIRROR: A list of in-vacuum mirrors was made and the mirrors are in the process of being assembled with the appropriate mirrors and beam splitters.
  • A camera for looking at the beam entering the Faraday Isolator, and associated telescopic lens and in-vac mirrors, is being prepared for installation.
  • PHOTON DRIVE R&D: Tom Essinger-Hileman is designing the optical system using the ABCD matrix formulation with Mathematica. He has made a preliminary layout of the 40m photon drive experiment using ACAD. Most of the parts have been received for the apparatus. Steve Vass will place a 3ft x 4ft optical table at the end of the MC chamber for mounting the apparatus and will move the OSEM wiring to the side viewport; the actuation beam will enter through a new viewport in the end of the MC chamber and will reflect from the back side of MC2 mirror. No steering mirrors will be needed on the MC2 optical table inside the chamber. Tom has written a progress report. Aidan Crook has made a Simulink model of an SOS mirror suspension having displacement and pitch motion with photon force actuation on the mirror; the model includes velocity damping for both motions. He has written a progress report.
• Optical levers (Bhatt, Goggin, Smith, Vass, Taylor):
  • SURF Naman Bhatt and Bob are working on completing the remaining cabling for the oplev photodiodes for all 7 core optics. Most of the vertex optical levers are cabled; the ends will be done soon.
  • Naman is learning about the oplev system and pursuing some relevant calculations. She's playing with the oplevs that are already set up near the beamsplitter chamber. She's working on getting the signals into EPICS and the DSC front end, and calibrating the response.
• Electro-optic shutters (Smith, Ourjoumtsev):
  • Alexei completed the installation and tuning of the EOS on the MCR beam line, and has documented the system and tuning procedure. We will complete the other two EOS's (for the SP and AP beamlines) later; we're still waiting for delivery of a 3rd Q-switch.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • We plan to vent for installation next Tuesday, Jul 8. Dennis has written an installation plan. Over three weeks, we will install and damp the remaining core optics (ETMx, ETMy, PRM, and SRM). We are debating whether the PRM and SRM will be installed in their correct location, or temporarily in another chamber. We'll install the Faraday isolator, mode matching telescope, PZT steering mirrors, input and output beam folding mirrors and pickoffs, shutter flags, irises, baffling. We'll install optical quality output port mirrors, including one on the MC2 chamber for photon actuation.
  • Then we'll align everything. Mike Smith is writing up an alignment procedure using his autocollimator. We hope to re-commission, with the PSL in air, by the 3rd week in July. So, this is a very major installation!
  • After the first few days of vent, when the PSL beam path is fully defined via irises and initial pointing spots, Conor will re-layout the PSL.
  • Dennis, Conor, and Matt calculated the effect of refraction on the (IR) beam over 40m of air and estimates it to be displaced by 28 microns (28 cm for 4km). Negligible for us!
  • Steve is completing an inventory of all the things that will be installed. He's getting the remaining items: cameras, oplev mirrors, beam dumps, and cables for the MMT picomotor, shutter flag picomotors, and PZT steering mirrors.
  • Steve has received all the remaining cameras and lenses we need.
  • Racks 1X1, 1X2, 1X3, 1X4, and 1Y9 are being bolted to the concrete floor.
• Modeling (Miyakawa, Goggin): Lisa continues to learn about Finesse and develop a model of the 40m and AdvLIGO with that tool.
• South Annex Bake Ovens (Taylor):
  • Bob lost then found the DLC in-vac mirror mounts.
  • Bob continues to work with Steve to get all the parts to be installed in the vacuum prepped and ready, including the cables for the shutter flags and PZT steering mirrors.
  • Bob is assembling 11 more hybrid OSEMs for Janeen & Calum.
  • Bob is preparing several big bake jobs for Gingin suspensions.

June 20, 2003

• Core digital suspension controllers (DSC), LSC, ASC, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Status of DSC system:
    Over the last 2 weeks, Rolf and Alex Ivanov have consolidated the two reflective memory (RM) networks, fast controls and DAQ, into one 2Gbit network. After some struggle, it is back up as a single network, and the DSC system and DAQ are running fine.
  • Art and Bob have completed the wiring and cabling of the end racks. However, one fiber run is bad, and the second is suspect. Both will be replaced when new fiber arrives in the next week.
  • The DSC system software for the ETMs is mostly in place but is currently not operating. Ben is back from vacation and is waiting for Rolf to come back and get the ends processors up and running, so that he can check out the auxillary and front end wiring and code.
  • However, timing issues still prevent the operation of the AWG (arbitrary Waveform Generator, which must be synched with the DAQS). Currently, the AWG is disconnected.
  • Status of LSC/ASC electronics, from Jay:
    - Art has started cross connect wiring and assembly for the LSC.
    - The 1X3 rack will be put in place, in the next week. The Sorenson power supplies will be put in a separate rack nearby, to minimize EMI.
    - An inventory of required modules has been generated. Modules that are not on hand will be procurred or fabricated.
    - Layout of the QPD to ICS interface board has not been started due to other higher priority tasks.
    
  • Jay found an error in the wiring drawing for the 1X1 auxiliary rack. He fixed the wiring, and now Ben is fixing the drawing.
  • Lisa continues to complete the cabling of the many video cameras and refine tyhe EPICS controls. Quad splitters are in place, and monitors are in place in the control room.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • The DSC and MC electronics are back up, and the MC suspensions are damped.
  • Osamu worked on re-acquiring MC lock. Since several things had changed in the last few weeks, this was not an easy task:
    - the modulation index was modified as discussed below;
    - an offset in the MCS error signal was traced to AM modulation due to imperfectly aligned polarization after the changes to the pockels cell path. This was fixed, as discussed below;
    - The MCL signal was not getting to the DSC system. The C1IOOVME processor was rebooted, and that fixed it.
    - The EOS was fully commisionied in the MCR path, and its setting optimized, as discussed below.
  • The MC is now locked robustly. Visibility is now ~ 97%, better than it's ever been.
  • However, the error signal is observed to drift over hours. This is likely due to changed MCL gain.
  • Osamu is now measuring the OLTF and noise spectrum, and is optimizing the gains, cross-over frequency, and other parameters, to improve lock stability and minimize the frequency noise.
  • After tuning gains, the MC lock is extremely stable. However, the noise is much higher in the 30-1000 Hz range than before. Prime suspect is electronic noise due to the new MCL signal path. Under investigation.
• Mode Cleaner WFS system (Ourjoumtsev, Abbott, Eichenfield):
  • Alexei and Matt are recommencing work on commissioning the IO WFS system now that the MC is back in lock and the EOS is in place. They need the AWG, which is not currently working, so this is hampering their progress.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Matt, Conor, Osamu et al measured the modulation depth of the MCR sidebands with an OSA and found it to be quite small. Matt traced the full electronics path for the modulation depth setting from EPICS to the pockels cell.
  • Conor and Stan realized that the wrong polarization was being sent through the pockels cell: it was P (as in the site drawings) but should be S. (One wonders how the PSLs could be working at the sites, but we guess this is yet another example of changes made at the sites that are not documented sufficiently well for us to find them).
  • Conor inserted a HWP to rotate the polarization, and he and Osamu tuned it's orientation, re-aligned the Pockels cells, and re-measured the modulation depth. It was a healthy 0.1.
  • Conor and Dennis set up a standard set of power levels on the PSL table. It's now ~ 8.3 watts out of the MOPA. It is now being attenuated to 1.0 W into the PMC, ~ 0.6 W out of the PMC, 0.5 W at the periscope. It can be attenuated further at the periscope if desired. Changing the power level upstream of the PMC will require changes to the FSS gain, PMC servo gain, etc; so we won't do that unless we need to.
  • Conor's plan to re-layout the PSL is finalized. We will begin this work during the installation vent, which is tentatively scheduled for June 30.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa, Arai):
  • OPTICS PARTS LIST, Orders pending: 1 q-switch E/O shutter from Fast Pulse.
  • FARADAY ISOLATOR: Assembly is expected the week of 6/16.
  • IFO STEERING MIRRORS: Parts are cleaned and baked. Assembly is expected the week of 6/16.
  • SPS BREWSTER PRISM MIRROR: Parts are cleaned and baked. Assembly is expected the week of 616.
  • MODE MATCHING TELESCOPE: Telescope is aligned and is awaiting installation.
  • OPTICAL LEVER ASSY: SURF student Naman Bhatt has begun working on the optical lever telescope assembly.
  • PHOTON DRIVE R&D: A SURF student, Tom Essinger-Hileman, has begun working on the photon drive experiment at the 40m IFO at CIT. A second SURF student, Aidan Crook, will arrive the week of 6/23 to begin work on modeling the advanced LIGO photon drive system.
• Electro-optic shutters (Smith, Ourjoumtsev):
  • Bob and Alexei have completed the EOS EPICS wiring.
  • Alexei has completed the commissioning of the EOS on the MCR beamline. It works well, including all the EPICS controls. It was tested with the MC: when the MC lock was broken, the EOS closed, allowing in a small amount of light to re-acquire lock. MC lock was quickly required, and 100 msec later, the EOS opened; the MC remained locked.
  • Alexei has established correct settings of the EOS for different power parameters. He has documented the system, including some nice transparencies.
  • He is now moving on to fully instrumenting the remaining two EOSs (on SP and AP). We still await delivery of a 3rd Q-switch; most everything else is in place.
  • Electricians will bring bAC power to the small racks containing the EOS equipment, by the end of the week.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • We tentatively plan to vent for installation on June 30. If WFS commissioning requires it, we can delay this for a week.
  • Steve is getting together all the things that will be installed: the suspended ETMx, ETMy, PRM, SRM; the mode matching telescope, Faraday isolator, PZT stering mirrors, main laser folding mirrors, oplev mirrors, shutter flags.
  • Steve found some problems with the shutter flags, and had the shop re-machine them. Bob vacuum-prepped them.
  • Steve and Bob will arrange for in-vac "pigtail" cables for the MMT picomotor, shutter flag picomotors, and PZT steering mirrors.
  • Steve is ordering more cameras, and a wide-angle lens for the PSL table.
  • The portable A/C is now working in the control room.
• South Annex Bake Ovens (Taylor):
  • Bob sent the vac-prepped errant beam baffle parts to LHO, and they have been received.
  • Bob finished the vac-prepping of the picomotors used to drive the shutter flags, and is now vac-prepping the remaining shutter parts.
  • Bob is preparing 10 more hybrid OSEMs for Janeen.

June 13, 2003

• Koji Arai helped Mike Smith and Alexei Ourjoumtsev re-assemble and align the vacuum-prepped mode-matching telescope and Faraday isolator before he left, and is preparing a writeup of the procedure.
• Lisa G and SURF students Matt and Naman are going through daily lab checklists, using EPICS, dataviewer and the iLog.
• Osamu returned from Japan, where he helped Kentaro lock his 4-meter signal-recycled Michelson, detuned. They moved on to the signal-recycled Fabry-Perot Michelson, in broad-band RSE. After much tuning and aligning, they were successful in both configurations. He modeled the error signals and power outputs with Finesse, and saw good agreement with the experiment.
• Core digital suspension controllers (DSC), LSC, ASC, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • From Rolf:
    - Primary goals for this week are to get the ETM controls installed and running the the 40m lab and, now that we have enough high speed (2Gbit/sec) network interface boards, to remove the slower network completely from the 40m lab and go with the single fast network.
    - The first objective is almost complete. The ETM control PC and ETMY VME systems are installed and running. There is about a day of testing remaining, primarily DAQ and GDS connections. The ETMX VME is a direct copy, so should come up quickly after ETMY testing.
    - The move to the single network is complete, but there was a snag. The Arbitrary Waveform Generator (AWG) software was written to run on the older MIPS processors, but the new network cards do not work on these CPU boards (don't even get power indications on the cards). So, we have had to port the AWG code to Pentium processors. While this seemed straight forward and compiled fine, it did not work properly. It looks like Alex got it running last night though, so we'll test it more thoroughly today.
  • From Jay:
    - The databases, processors and VME modules for the ends are installed and operational. Medm screens need to be generated. Checkout of the racks will begin next week.
  • From Jay:
    - All rack drawings and wiring diagrams for the ASC and LSC are now complete.
    - Cross connect fabrication will begin next week and should take about 2 weeks. Rack assembly will begin after the cross connects are complete.
    - The schematics for the new QPD to ICS interface moduel are complete. Board layout will begin next week.
  • Art and Bob have been completing the remaining cabling to/from the ETM racks; just a bit more to do. Dennis set up ethernet hubs at the ends.
  • Dennis set up memory dipswitches on 1X1 VME boards with Alexei.
  • Lisa has got the video EPICS controls working, and succeeded in getting signals to the control room projector and monitor. So right now we can see ITMX, ITMY, MC13 & MC2. She's running cables from the PSL and IMCR & SPS beamline cameras to the switch, with help from Bob. She has added illuminator buttons to the video EPICS screen, and is refining the layout.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • The DSC and MC electronics are down, while Rolf and Alex make big changes.
  • Osamu is back, and preparing to optimize the gains, cross-over frequency, and other parameters, to minimize the frequency noise.
• Mode Cleaner WFS system (Ourjoumtsev, Abbott, Eichenfield):
  • Due to the DSC and PSL activities, WFS commissioning has been less productive than last week.
  • Alexei tuned the second WFS demod board
  • Alexei measured DC gains on both WFS heads.
  • As soon as the MC is back up, Alex will measure the RF gains and match the overall phases on the WFS. Then he'll move the PZT mirrors with dtt. Then he can finally start taking transfer functions and commission the servo loop.
  • Matt is helping Alexei with the WFS work and is learning all about it, to continue that work when Alexei leaves.
  • Matt is working through Eric Black's paper on PDH locking, w hich led him to working out the FP arm reflected beam properties when it is not in equilibrium with the cavity (found a good paper by Benno Wilke and Robert Byer)
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Plan to re-layout the PSL sometime in the next two weeks.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa, Arai):
  • OPTICS PARTS LIST, Orders pending: 1 q-switch E/O shutter from Fast Pulse.
  • FARADAY ISOLATOR: Assembly is expected the week of 6/16.
  • OPTICAL LEVER ASSY: Assembly on hold.
  • IFO STEERING MIRRORS: Parts are cleaned and baked. Assembly is expected the week of 6/16.
  • MODE MATCHING TELESCOPE: Telescope is aligned and is awaiting installation.
  • SPS BREWSTER PRISM MIRROR: Parts are cleaned and baked. Assembly is expected the week of 616.
• Electro-optic shutters (Smith, Ourjoumtsev):
  • Alexei realigned the EOS after modifications on the PSL table. Transmission goes from 0.025% to 98%, half-wave voltage is 3.79V.
  • Alexei is commissioning the EPICS control of the EOS's. Bob did some of the cabling for it.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Steve Regenerated cryo. Maglev is still noisy a bit.
  • Steve ordered quad splitters for video monitors.
  • Steve helped Koji with mode-matching telescope alignment.
  • Steve measured 670nm transmittance of 40m safety glasses.
• South Annex Bake Ovens (Taylor):
  • Bob is doing a bake job on some more of the LHO baffle parts for Ken Mailand, they are in the oven now.
  • Bob is doing the clean and bake of the Pico Motors used to drive the shutter flags.
  • Bob has received the spare MOS and SOS suspensions to be baked when he gets a chance.

June 6, 2003

• Koji Arai is visiting from TAMA, and is helping Mike Smith and Alexei Ourjoumtsev re-assemble and align the vacuum-prepped mode-matching telescope and Faraday isolator. Thanks, Koji!
• Core digital suspension controllers (DSC), LSC, ASC, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Dennis and Jay debugged and fixed some problems with a dewhitening board for the DSC.
  • Ben and Art are populated the two end racks (ETM DSC's, oplevs, QPD's, etc), and wiring is close to completion, including 40m runs of fibers. Almost all of the hardware is there; Rolf will install the Pentiums, linux box, RM fiber loops, etc, on Monday.
  • From Rolf: Primary work this week is to complete end station software for 40m lab. The PC side is complete. The VME is 95% complete, with only the GDS EXC/TP function to add.
    We will install and start testing the system at the 40m lab on Monday. At this time, we will also remove the present separate DAQ network and move all traffic onto the new high speed network. The DAQ controller, TP manager, and Arbitary Waveform Generator (AWG) code has been modified to accomadate this move. The AWG code has also been ported to move onto a Pentium CPU instead of the MIPS CPU, as used at the sites.
  • From Jay: first draft rack and wiring diagrams for the ASC and LSC are complete and under review. These include a new board for interfacing the beam line QPDs to an ICS110B for beamline servoing. Hope to get started on these racks in the next couple of weeks.
  • Lisa is making progress on adopting the Hanford video switch control state code, EPICS database, and PICS screens, for the 40m. Steve ordered monitors for the control room, they are expected in the next week.
  • We have been unable to use dtt to take transfer functions, because the computer clock was not synch'ed to GPS to less han 1 second. Lisa Bogue, Dennis and Rolf debugged the problem and determined that the Sun's clocks drift by 0.7 secs every 10 minutes! Lisa set up a cron job to resynch with ntp (network time) every 10 minutes.
  • Dennis has reorganized and rationalized the /cvs/cds/caltech file directory, putting medm screens in sensible places, etc.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • The mode cleaner has been locking reliably and robustly, despite intensive work on the MCR beamline.
  • We still have to optimize the gains, cross-over frequency, and other parameters, to minimize the frequency noise. This can wait till Osamu returns next Tuesday.
  • Conor noticed that the RFAM photodiode in the MC transmitted path wasn't working, and will look into it.
• Mode Cleaner WFS system (Ourjoumtsev, Abbott, Eichenfield):
  • Alexei and Ben have made much progress debugging the WFS sensing electronics and PZT mirror actuation path. They've actuated on the PZT mirrors, and observed hysteresis.
  • Alexei has tuned all the WFS phases and offsets, for WFS1, and will do WFS2 next.
  • Now that we can use dtt, Alexei will begin taking transfer functions for the open loop of the alignment servo.
  • Matt is learning about the system to develop a simulink model of the servo, includin actuation on both the PZT mirrors and the suspended optics.
• Suspended optics:
  • Steve and Lisa re-hung the SRM optic after baking, damped it, and prepared it for installation. All core optics are now either installed or ready for installation, on the bench with their EQ stops engaged.
  • When we install in the next month, we'll probably put the PRM and SRM off to a side, to begin commissioning a "simple" Fabry-Perot Michelson.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor & Stan realized that the PSL beam was going through the 3 pockels cells with the wrong polarizations. Conor inserted half-wave plates to correct it.
  • Conor has completed a detailed layout of the PSL which reduces the number of turning mirrors and picks of the FSS beam after the PMC. He has passed it on to Mike for updating the detailed AutoCAD layout.
  • He and SURF Matt Eichenfield finished calculating all the mode matching lenses that are required for the new layout (mode matching into the PMC, the FRC, the suspended mode cleaner, and through the AOM and the EOMs). They used Alexei's snazzy beam optics GUI, as well as mode matching code by Matt.
  • Alexei continues to develop his beam optics GUI.
  • Plan to perform this re-layout while we install all our in-vac components, sometime in the next few weeks.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa, Arai):
  • OPTICS PARTS LIST, Orders pending: 1 q-switch E/O shutter from Fast Pulse. It had fallen off their list; Mike put it back on.
  • FARADAY ISOLATOR: Final assembly and alignment is expected the week of 6/9.
  • OPTICAL LEVER ASSY: Assembly on hold.
  • IFO STEERING MIRRORS: Parts are cleaned and baked. Final assembly and is expected the week of 6/9.
  • MODE MATCHING TELESCOPE: Telescope is assembled. Final alignment is expected by 6/6.
  • SPS BREWSTER PRISM MIRROR: Parts are cleaned and baked. Assembly is expected the week of 6/9.
  • SURF Naman Bhatt will implement the optical levers and their use in local alignment sensing and control.
• Electro-optic shutters (Smith, Ourjoumtsev):
  • Alexei installed one EOS on MCR, and it is operating under manual control; work to get EPICS control is progressing.
  • He has set the "open" and "closed" HV on the EOS so that the light on the WFS's never gets too big during loss and re-aquisition of lock, and so that there's sufficient light on the LSC PD to re-acquire lock and not lose it when the EOS opens up. He's working out how to change the settings if the light power into the IFO changes.
  • however, the EOS leads have gotten damaged, and it may be serious. Under investigation.
  • Electricians will get AC power to the small racks that hold EOS electronics, from rack 1X1, next week.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The STACIS active pre-isolation system has one or more problems (faulted electronics?) that needs attention...
  • Power has been installed for a portable A/C unit for the control room.
• South Annex Bake Ovens (Taylor):
  • Bob completed the vacuum-prepping of the parts for the Mode Matching Telescope, Faraday isolator, PZT steering mirrors, etc. Bob is preparing all the traveller paperwork.
  • Bob completed the bake of the SRM optic and gave it to Steve to be re-hung.
  • The ultrasonic cleaning bath crapped out. Bob repaired it, cleaned it out, and it is ready for use again.
  • Bob tuned up the Dycor RGA's, they now have very good AMU resolution.

May 30, 2003

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Dennis and company diagnosed and fixed a set of problems associated with the new MCL electronics path, and the mode cleaner is now locking robustly.
  • He measured the transfer functions from the MC servo board to the coil driver. He discovered a filter on the Pentek Interface Board that apparently was implemented at LLO; we don't know why it's there, but it didn't exist in our old path; Dennis bypassed it. He found a gain 10 stage in the digital PZ filter, which is not a good place for it (it amplifies any offsets); he took it out. He found that the software filter that compensates for the hardware dewhitening was not set correctly, and fixed it Finally, he found that the RF local oscillator cable was 180degrees out of phase with what was needed (don't know why!). He shortened it. After all that, the MC locked immediately and robustly!
  • We still have to optimize the gains, cross-over frequency, and other parameters, to minimize the frequency noise. This can wait till Osamu returns.
• Core digital suspension controllers (DSC), LSC, ASC, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • All 6 installed optics are damping well. There is an issue with the Universal Dewhite board which is the wrong Rev for the MC2 optic, however. Dennis and Ben are fixing this.
  • Ben and Art are populating the two end racks (ETM DSC's, oplevs, QPD's, etc). They are progressing rapidly and hope to complete the wiring by Monday.
  • Rolf is working on the software required for the end DSC's. He reported last week that the work required to prepare the end DSC software should only take a few days. Rolf hopefully has the Pentiums, Penteks, RM cards and fiber cables that are required.
  • We will bring the GPS time signals from the vertex area to both ends via long (40m) cables. We hope this will work; if the signals degrade too much, Jay and Ben are thinking about building an optical driver for the signals.
  • Jay reports that work on the rack and wiring diagrams for the ASC and LSC has resumed and should be complete by the end of the week.
  • From Jay: A new board for interfacing the beam line QPDs to an ICS110B has been designed. After the wiring diagrams and cross connects ahve been designed this board will be layed out and sent out for fab.
  • Lisa continues to develop the EPICS controls (screens, state code, and wiring and cabling) for the video switch, and Steve is ordering monitors for the control room.
• Mode Cleaner WFS system (Ourjoumtsev, Abbott, Eichenfield):
  • Alexei has checked out all the IQ demod boards for the WFS system. He is tuning the boards so that there's exactly 90degrees RF phase difference between I&Q. He's preparing to determine the overall phase to maximize the misalignment signal.
  • Alexei and Ben will continue to debug and commission the photodetectors, electronics, and actuators (PZT mirrors on the PSL table) for the WFS system.
  • We will pursue feedback to these PZT steering mirrors and to the MC suspended optics; so we are following the work done by Joe Kovalik and Valery Frolov at LLO.
  • Alexei continues to prepare the EPICS screens and databases that control the WFS system.
  • It would be really nice to be able to use dtt to produce a transfer function for the MC ASC. However, dtt can't operate in real-time (for transfer functions) unless the computer it runs on is synch'ed with the data (GPS time) to within 1 second (accd to Daniel Sigg). This requires NTP to be running on the machine, to get the network time from our gateway computer, which hopefully can get the time from some accurate clock on the campus net. It's not clear whether this will be possible; we have asked Larry & Lisa to help. We may have to purchase a GPS-based NTP server for the lab.
  • SURF Matt Eichenfield is learning Matlab/simulink to model the MC WFS system properly.
• Suspended optics:
  • Bob will be baking the SRM optic this weekend. Early next week, Steve will rehang it, and prepare it for installation. That's the last of the core optics to be prepared.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor wants to measure the cavity pole of the pre-mode cleaner, but it is too high to measure by conventional means. Nergis suggested that we obtain a broadband AOM, and Conor will see if we can scare one up.
  • Conor continues to develop a detailed layout of the PSL which reduces the number of turning mirrors and picks of the FSS beam after the PMC. He and SURF Matt Eichenfield are calculating all the mode matching lenses that are required for the new layout.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Received parts: 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC; New mirror holders for PZT steering mirror.
  • Orders pending: 1 q-switch E/O shutter from Fast Pulse.
  • FARADAY ISOLATOR: Parts are baked and ready for assembly.
  • OPTICAL LEVER ASSY: Assembly on hold
  • IFO STEERING MIRRORS: All parts are on hand, ready to be cleaned and baked.
  • MODE MATCHING TELESCOPE: Parts are baked and ready for assembly.
  • SPS BREWSTER PRISM MIRROR: All parts, except for the Brewster prism are baked and ready for assembly. The Brewster prism is on hand ready to be cleaned and baked.
  • Mike will work with visitor Koji Arai to assemble, align, and prepare for installation, the Faraday isolator and mode matching telescope. They hope to begin the work by the end of this week.
  • Mike is working on designing an AdvLIGO R&D experiment with a SURF student this summer to study photon-force induced movement of a locked cavity mirror. The 40m mode cleaner cavity curved mirror will be pushed with an external photon beam and the loop response will be measured (photon calibrator). It may be possible to actively control the mirror position with the photon beam within a narrow frequency band (photon actuator).
  • Alexei installed one EOS on MCR. It is not yet powered, so a half-wave plate is in place to permit the beam to get to the MCR LSC photodiode and WFS's. Unfortunately, the EOS controller box is dying on him; he will work with Sander to debug it.
  • Alexei continues to prepare the EPICS screens and databases that control the electro-optic shutters. Dennis has booted up the the EPICS cpu (c1aux) in 1X1 which will control these devices. He and Bob will get the remaining cables in place.
  • AC power is being run to the small racks that hold EOS electronics, from rack 1X1.
  • Steve ordered picomotors and one controller for our shutter flags (one goes in front of every test mass, to block or attenuate the beam if desired). Bob has vac-prepped the shutter flag parts.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Steve got the cranes inspected. The vertex crane did not work (again!). The crane repair guy fixed it today.
  • Steve has arranged for power to be installed for a portable A/C unit for the control room.
• South Annex Bake Ovens (Taylor):
  • Cleaned and baked the parts for the Mode Matching Telescope.
  • Cleaned, baked and shipped the Baffle parts for LHO.
  • Cleaned and baked the Faraday Isolator parts.
  • Cleaned and baked the Brewster Mirror ASSY.
  • cleaned and baked the special fix in vacuum 1.5 Mirror Mount.
  • Helped Art with wiring the So. End 1Y9.
  • Cleaned calcite Prisms for Faraday Isolator.
  • Finished Hybrid OSEMs for Janeen.
  • Will finish cleaning and start bake job on silver mirrors tomorrow.
  • will start bake job on ETM optic tomorrow.

May 23, 2003

• SURF Matt Eichenfield from UNLV has begun work at the 40m. He's starting by working with Alexei on the MC WFS system. Welcome, Matt!
• Core digital suspension controllers (DSC), LSC, ASC, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • All installed optics (MC1, MC2, MC3, BS, ITMX, ITMY) are damping well with the new DSC system.
  • Dennis and Conor completed the diagonalization of the sensor readings for MC1, MC2, MC3, starting with the P/Y biases they obtained from their recent alignment work. The results were reproducible, and close to what they were before we tore apart the DSC system. They will move on to diagonalizing the outputs (coils). They will then move on to diagonalize the core optics DSCs, and optimize the damping gains.
  • Ben rearranged the end rack drawings to reduce the number of needed VME crates by one per end. The drawings have been reviewed by AJW and Jay, and Ben has begun to assemble all the hardware for the end racks (all of which should be in hand).
  • Rolf reported last week that the work required to prepare the end DSC software should only take a few days. We are aiming towards completion of the system before Ben leaves for vacation in less than 2 weeks!
  • Ben matched the gains and filters in the Generic DAQ Intfc Board in 1Y2 (new read-out for fast PSL and MC signals) to the requirements.
  • Jay reports that the drawings for the core IFO LSC system, and for much of the ASC system, are almost complete; he just needs to add in some QPDs. He is contemplating designing a new board to interface QPD signals into an ICS110B for DAQ. He thinks that an LSC system can be assembled by July.
  • Ben has updated the drawings for the 1X1 auxiliary rack (EOS's, mech shutters, video switch, illuminators), and has implemented the changes in the 1X1 wiring. Lisa is cabling up the cameras to the video switch. Dennis and Steve will order some monitors. Dennis and Lisa are preparing the EPICS code to control all these devices (c1aux).
  • Alexei is preparing the EOS EPICS screens. We aim to complete this system in the next week or 2.
  • We need to run AC power to the small racks that hold EOS electronics. Steve & Ben will pursue.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • The MC1, MC2, and MC3 optics are all damping well, and the DSC's have been diagonalized.
  • Dennis and Conor improved the alignment of the mirrors (looking at TEM00 fringes on the cameras) in preparation for acquiring lock with the new system.
  • Lock acquisition has been problematical. The MC_F path to the PSL appears to be behaving normally, but the MCL path is not. Which makes sense, because only this path had changes made: Signal digitized by Pentek rather than ICS110B; New suspension code (one error in this code has already been fixed); Pole-zero module moved from a VME board to a digital filter; Dewhitening filter is now in use. Thus, the gain is substantially different, and it's not clear if all the filtering is appropriate. Dennis is taking transfer functions and trying to compare with ones made by Osamu before the DSC changes (unfortunately, Osamu is in Japan). Work in progress.
• Mode Cleaner WFS system (Ourjoumtsev, Abbott, Eichenfield):
  • Alexei and Ben have been finding and fixing problems in the MC WFS heads (bad op amps replaced) and MC WFS demod boards in 1Y2 (bad op amps replaced).
  • Alexei is fixing small problems in the (new, digital) WFS EPICS screens, and bringing over missing databases and screens from the sites so that the attenuators on the WFS heads can be switched. He's adding the DC WFS quad signal monitoring.
  • Alexei now sees good RF signals on all 2*4 channels, as well as DC signals in EPICS. He continues to await good MC locking.
  • SURF Matt Eichenfield is learning Matlab/simulink to model the MC WFS system properly.
  • The output to the PZT steering mirrors on the PSL table are being debugged. We will pursue feedback to these PZT steering mirrors and to the MC suspended optics; so we are following the work done by Joe Kovalik and Valery Frolov at LLO.
• Suspended optics:
  • Steve & Conor balanced and re-hung the PRM. It damps well, and is ready for installation.
  • Steve & Conor, with help from Matt, balanced and glued the SRM. Bob is baking it, and it will be re-hung and prepared for installation by the end of this week. That's the last of the core optics to be prepared.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry): Working well. Development work on hold.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Orders pending: 1 q-switch E/O shutter from Fast Pulse; 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC; New mirror holders for PZT steering mirror.
  • FARADAY ISOLATOR: Parts are in process of cleaning and baking by Bob. Vacuum-ready parts expected by 5/28.
  • OPTICAL LEVER ASSY: Assembly on hold.
  • IFO STEERING MIRRORS: The mirror holders were manufactured incorrectly and are being remade by the vendor. New parts are expected by 5/23. All other parts are in process of cleaning and baking by Bob. Vacuum-ready parts expected by 5/28.
  • MODE MATCHING TELESCOPE: Parts are in process of cleaning and baking by Bob. Vacuum-ready parts expected by 5/28.
  • SPS BREWSTER PRISM MIRROR: All parts, except for the Brewster prism, which is expected the week of 5/19 are in process of cleaning and baking by Bob. Vacuum-ready parts expected by 5/28; prism to follow.
  • AUXILIARY VAC WIRING: Completed a spread-sheet detailing the in-vacuum wiring for auxiliary components inside the chambers: MMT focus motor, PZT steering mirrors, motorized beam flags. Gave information to Jay H. regarding the IFO ISC signal interface with the PZT mirror drivers. Bob has OSEM pigtails, vacuum-ready, for the MMT focus motor and motorized beam flags. The PZT steering mirror cables need to be RGA scanned, and a 25-pin connector added.
  • Steve proposes that we move the mechanical shutters for MCR and SPS beamlines to the first table that they go through after exiting the vacuum envelope (AP1) instead of the table that they are sensed on; for safety purposes. Mike will look at re-layout of the drawing.
  • Alexei is ready to install EOS's on MCR and SPS beamlines as soon as the 1X1 software is ready and AC power is run to the small racks that hold EOS electronics.
  • Steve has almost all the parts that were designed by Larry Jones for our shutter flags (one goes in front of every test mass, to block or attenuate the beam if desired). Bob is vac-prepping the parts this weekend. Steve is ordering picomotor controllers for them. Mike will design beam dumps for them.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • We plan to install almost all the remaining in-vac equipment for the first round of experiments, in the next month: PRM, SRM, ETMx, ETMy, Faraday Isolator, MMT, PZT sterring mirrors, all other steering mirrors, shutter flags, camera mirrors, optical viewports, etc. Mike will develop an initial alignment procedure. We hope to have this complete, sometime in July (Seiji arrives July 1 to help).
  • Steve has LOTS of surplus vacuum equipment (including high-quality VAT right-angle manual valves) available to any interested LIGOn. Ed Chargois will ship some of it to the sites.
  • Two PC's had virus warnings. They were decontaminated by Mike Pedraza.
  • Steve ordered an A/C unit for the control room (which is starting to really warm up), and will call in electricians to wire it up.
  • AJW ordered two new PCs for the hoardes of summer visitors.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is currently baking the last optic (SRM) before final hanging.
  • Bob has lots of clean/bake jobs from Mike (MMT, FI, etc); all six vacuum bake ovens, and the air bake oven, in the South Annex will be in use, this weekend!
  • Bob will be building hybrid OSEMs for Janeen next week.

May 16, 2003

• Core digital suspension controllers (DSC), MC WFS, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • All installed optics (MC1, MC2, MC3, BS, ITMX, ITMY) are damping well with the new DSC system. The electronics for PRM and SRM seem to operate fine, but are having trouble damping because the optics are not installed yet.
  • From Rolf: Code had to be fixed this week to get the all the suspension signals into DAQ properly and the MCL signal properly sent to EPICS from the suspension PCs.
  • Rolf: The GDS signals from the suspension PCs are late by 1/16 second. This should be an easy fix in the DAQ router software.
  • Rolf: Added the capability of the IOO VME system to acquire 16KHz channels to the DAQ as well as 2KHz channels. This allows the IOO VME system to acquire all IOO/PSL DAQ channels, thereby removing the previous long DAQ cable runs from the PSL area down to the DAQ analog data collection unit (ADCU).
  • Ben made a list of DAQ channels for Rolf, and learned that the Generic DAQ Interface Board needs modification to condition all of the channels correctly with regards to gain and filtration, and to reorder one of the channels to limit them to 16.
  • Rolf: Signals to IOO M1/M2 are comming off the wrong (3rd) pentek. This is corrected and needs a reboot to move the outputs back to the first Pentek.
  • Rolf: Work will start next week on the 40m end station controllers, which should only take a few days (very minor mods to existing software).
  • Ben is rearranging the end rack drawings to reduce the number of needed VME crates by one per end.
  • Dennis et al are preparing to re-diagonalize any optics that need it.
  • The servo gains will be tweaked to optimize x_rms. From dtt displacement spectra it looks like the ITMs will need higher gain.
  • Bob continues to wire the auxiliary rack (1X1), which holds the electro-optics shutter signals, video switch, and other misc stuff. He had to shift all the crates back several inches so that the rack door would close. Dennis will set up to boot the cpu; He and Alexei will work on the database for EOS channels.
  • Ben is updating the rack drawing for 1X1 to incorporate recent changes.
  • We need to run AC power to the small racks that hold EOS electronics. Steve & Ben will pursue.
  • We have enumerated all the places, in vacuum, which need wiring to auxiliary components (PZT steering mirrors and picomotors for shutters, flags, MMT). We will prepare pigtail-like in-vac cables for these devices.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • The DSC system, and MCL path, now all work.
  • Dennis restored Autoburt biases to the mirror pitch & yaw, and saw flashes on MC2 and light on the photodiodes; so alignment hasn't changed much.
  • Dennis & Conor are re-aligning the MC mirrors, and attempting to re-lock.
  • Alexei is working on the MC WFS system: Ben helped Alexei troubleshoot a bad WFS Demod board and replaced the bad chips. It now operates fine. 2 of 4 quads on the WFS2 head appear to have large offsets. The output to the PZT steering mirrors on the PSL table are being debugged. Signals from dtt excitation are seen on test points. Rolf and Alexei are checking out the path to the mirrors themselves. IO WFS medm screens are being refined.
• Suspended optics:
  • Bob cleaned and baked the new part to hold the OSEMs on our SOSs which have the PRM and SRM, and which have 2.5degree wedges, necessitating the changes. Steve et al will re-hang these optics and prepare them for installation, in the next week.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor is planning a re-layout of the PSL beam, to (1) reduce the number of turns from the MOPA to the periscope by two mirrors; (2) pick off the FSS beam after the PMC, as is done at LLO, to stabilize against PMC displacement noise.
  • Conor has measured and modeled the frequency reference cavity pole, and is doing the same for the PMC cavity pole, in case it needs compensation in the FSS servo.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Orders pending: 1 q-switch E/O shutter from Fast Pulse; 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC;
  • FARADAY ISOLATOR: Updated the parts list and released the final assembly drawing. Parts will be disassembled for cleaning and baking. Prepared traveller.
  • OPTICAL LEVER ASSY: Assembly on hold.
  • IFO STEERING MIRRORS: Updated the parts list and released the final assembly drawing. Parts are on hand, awaiting assembly for fit checking. Prepared traveller.
  • MODE MATCHING TELESCOPE: Alternate MMT with spherical mirrors was assembled and tested with the COS IR autocollimator. The astigmatism is so bad that with a double pass test through the autocollimator, only the on-axis portion of the reticle pattern could be focussed. By comparison, the off-axis parabolic mirror telescope causes negligible distortion of the double pass reticle pattern. Updated the parts list for the parabolic mirror version and released the final assembly drawing. Parts will be disassembled for cleaning and baking. Prepared traveller.
  • SPS BREWSTER PRISM MIRROR: Updated the parts list and released the final assembly drawing. Prepared traveller. All parts are on hand except for the Brewster prism, which is expected the week of 5/19.
  • Alexei discovered that all the beamsplitter mirrors on the MCR beamline downstream of where the EOS will go (to the LSCPD and WFSs) were for S-polarization, not P-polarization; he replaced them with the correct mirrors. He continues to evaluate how much power the WFSs need.
  • Alexei received three 6KV DEI pulsers for the EOS system. He continues to work on getting EPICS control of the EOS systems, and AC power to the EOS control racks, with help from Dennis and Bob.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Steve and Bob cleaned and removed a bunch of cabinets to make room for desks for summer students. There's LOTS of surplus vacuum equipment (including high-quality VAT right-angle manual valves) available to any interested LIGOn; check it out!
  • Steve is getting a portable air conditioning unit for the control room, before the summer students (each of whom burn hundreds of watts) arrive. He's also getting desks and chairs.
  • Larry has the shop making six picommotor-controlled in-vac shutter flags. Steve is working with Mike Smith on vac-compatible beam dumps.
  • The east end ion pump (EEIP) has been repaired and is working fine.
  • Dennis has completed the vacuum and psl sections of the comprehensive procedures manual, and is moving on to other sections.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob cleaned, baked, and scanned the re-machined OSEM bracket for our PRM and SRM suspensions, and some vented screws and mirror mounts.
  • Bob helped Ken, Mike finish the new LIGO1 errant beam baffles and clean them, they will go too the heat treaters today.
  • Bob is ready to clean and bake the MMT and Faraday isolator, as soon as they're fully checked out.
• Osamu continues to work on development of the dual-recycling summation cavity for E2E, while in Japan for the month.

May 9, 2003

• Suspended optics:
  • Our two ETMs are ready for installation.
  • Steve and Osamu attempted to balance our PRM and SRM, but discovered that the large (2.5degree) wedge on the optic in the SOS suspension causes the magnets to be offset with respect to the OSEMs. After consulting with Janeen and Helena, they decided to remove the OSEM holding brackets, and machine out holes to allow the OSEMS to be shifted a bit, thus centering the magnets in them. The machining is already done, and Bob has cleaned it and it's in the bake oven. Hope to have the PRM and SRM ready for installation by the end of next week. Janeen will submit a DCN with the changes. Conor took some great pictures with his new 4MP digital camera.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor proposes to re-layout the PSL beam, to (1) reduce the number of turns from the MOPA to the periscope by two mirrors; (2) pick off the FSS beam after the PMC, as is done at LLO, to stabilize against PMC displacement noise. Peter and Rich think it's a good idea. We may have to compensate the FSS for the PMC cavity pole, so Conor will attempt to measure it.
• Core digital suspension controllers (DSC), MC WFS, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Ben, with help from Jay and Dennis, have at last completed the troubleshooting and fixing of the newly configured DSC system. All the whitening boards are now fixed. Several software problems were fixed by Alex. Jay and Ben fixed the Anti-Alias chassis that was giving us trouble.
  • Now, all installed optics (MC1, MC2, MC3, BS, ITMX, ITMY) are damping well!
  • Attempts to re-lock the mode cleaner are now in progress. The MCL signal is taking a different path, and problems are being debugged.
  • Alex is continuing work on the IO WFS Linux PC code, in particular getting the GDS test points working.
  • The IO WFS VME code still needs some work; Rolf will need to get the 16K DAQ channels working.
  • Dennis and Conor will see if MC1,MC2,MC3 need re-diagonalizing.
  • Bob continues to wire the auxiliary rack (1X1), which holds the electro-optics shutter signals, video switch, and other misc stuff. Dennis and Bob tested the video switch manually, to be sure it works.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Received parts: Repair of damaged tilt platform S/N 70416 with drive amplifier from Piezo Jena.
  • Orders pending: 1 q-switch E/O shutter from Fast Pulse; 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC;
  • FARADAY ISOLATOR: Parts will be disassembled for cleaning and baking.
  • OPTICAL LEVER ASSY: Assembly on hold.
  • IFO STEERING MIRRORS: Parts are on hand, awaiting assembly for fit checking
  • MODE MATCHING TELESCOPE: MMT was assembled and tested with the COS IR autocollimator. The primary and secondary mirror spacing was varied by means of the attached "Pico motor"; best focus (@infinity) was determined by observing the sharpness of the retro-reflected reticle pattern through the MMT. The best focus could be determined within +/- 0.25 mm of the correct mirror spacing. An approximately Gaussian 1064 laser beam was transmitted through the MMT and the beam profile was scanned before and after the MMT. Within the uncertainty of the slightly non-Gaussian beam profile, the MMT appears to preserve the Gaussian profile of the beam. Further, it focuses the beam well in both x and y, showing no evidence of astigmatism.
  • Alexei got some beam reflected off the newly damped MC1, and thence to the MCR beamline and the newly installed WFS's. There was too much light; the Kepco HV power supply drew too much current. Since there is one supply for 2 WFS's, it affected the other WFS when only one was exposed to the beam. Alexei and Conor are evaluating how much light should be on the WFSs.
  • Meanwhile, however, Alexei sees 29MHz demodulated signals from the WFS.
  • Alexei has ordered 6 kV pulsers for our electro-optic shutters, and has returned our 3 kV ones.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The east end ion pump (EEIP) had a bad fan on the controller; Steve fixed it.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is cleaning and baking the re-machined OSEM bracket for our PRM and SRM suspensions.
  • Bob is ready to clean and bake the MMT and Faraday isolator, as soon as they're fully checked out.
• Osamu has confirmed his understanding of the matrix summation approximation in the dual-recycling summation cavity for E2E, and is beginning to write Matlab code to simulate it. He'll be in Japan for the next month, and will work on this there. He will be working with Japanese students who will come in the summer to work with Seiji and Hiro.

May 2, 2003

• Suspended optics:
  • Steve and Osamu rehung both ETMs after baking. Two more pairs of EQ stop screws are being cleaned and baked, and then these two suspensions will be ready for installation.
  • Steve and Helena have bonded the guide rods and magnet standoffs to our PRM and SRM, and they're ready for balancing.
  • All 4 of these remaining suspended optics should be ready for installation by the end of next week.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor and Dennis re-aligned and mode-matched the PMC; the transmission is around 60%.
  • They have searched for power loss between the laser output (8.9 W) and the PMC input (6.2 W). Most (all?) of the loss is in the HWP and beam cube used to attenuate the power. It can attenuate down to zero, but when opened up, has poor transmission. They will investigate aligning it better.
  • Conor will attempt to measure the FRC pole by dithering the laser current shunt.
  • The mods to the FSS have reportedly caused problems at LLO, so we are putting our plans for implementing those mods at the 40m on hold until the dust settles.
  • Now that Conor has fixed the double-passing of the beam through the AOM, Osamu will re-measure the VCO noise.
  • Ben and Flavio have assembled and functionally tested the new ISS PD. It seems to work fine, and Flavio has brought it to the PSL lab for further testing and incorporation into the ISS there.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott): The Digital Suspension Controllers are in the process of being rebuilt, so there's been no work on the MC.
• Core digital suspension controllers (DSC), MC WFS, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  Ben is now in the midst of troubleshooting and fixing the the DSC rewiring. The AA chassis still has problems, and 3 of 8 blown whitening boards have been fixed. Sander and Todd are on it. Hope to have the system up and working any day now!
  • Once everything is back up, it will be interesting to see whether we need to re-diagonalize all the MC suspension controllers. Dennis will show Conor how to do it.
  • Bob has just about finished wiring the mode cleaner WFS system (1Y2). Some issues were found with the high voltage wiring, but it will be done today.
  • Rolf and company have all the code up and running in 1Y2, for the mode cleaner WFS ASC, analog LSC inputs, and fast PSL and MC signals.
  • Alexei continues preparation for commissioning the MC WFS system. We have reviewed all the new screens that Rolf and company have put together, and are addressing problems and issues.
  • From Rolf: Continued installation of 40m systems. All controls now installed and under test. One problem has been that the suspension VME software would die (or appear to) after anywhere from 5 minutes to 5 days. We installed a bus analyzer and found that the new 2Gbit network card was hanging up, continuously replying on the bus with Target Device Not Ready - Retry. Unfortunately for us, this is not a bus error, therefore the processor PCI interface chip will forever retry and not return to the code. We found this was happening on a read cycle after we did 16 writes to the card, but again, not always as it can run for some time. We contacted the vendor and after sending a few bus analyzer traces to them, they were able to recreate the problem in their lab and are working on it. In the meantime, by changing our code from writing to the network card to instead command the card to become the bus master and read from the CPU memory, we are able to get around the problem.
  • The fast PSL and MC signals have been moved from 1Y7 to 1Y2, but the latter only digitizes at 2kHz. We are considering keeping the MCF signals in 1Y7 to keep the 16kHz sampling. Rolf is checking whether it's possible to read in a few channels at 16kHz.
  • Alexei and Bob have measured the MC WFS RF cables; they are all the same length to 1 cm. They fixed some problems with HV to the WFSs, and can now see signals from the WFSs.
  • Lisa continues to learn how to develop EPICS screens and software, practicing on the 1X1 video switch.
  • Ben will arrange for power to the little racks that hold the EOS electronics.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Orders pending: Repair of damaged tilt platform S/N 70416 with drive amplifier from Piezo Jena expected delivery 5/1; 1 q-switch E/O shutter from Fast Pulse; 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC.
  • FARADAY ISOLATOR: Mike and Alexei aligned the Brewster's angle Faraday isolator and measured >96% transmissivity (dominated by non-AR-coated internal surfaces of the polarizing beam splitter), and (much?) better than 4e-4 extinction ratio. Alexei beam-scanned the input and output alignment beam and found no evidence of beam distortion. It is now being disassembled for cleaning and baking.
  • OPTICAL LEVER ASSY: Assembly on hold.
  • MODE MATCHING TELESCOPE: IR autocollimator alignment equipment is set up and working. SORL Primary mirror was manufactured out of specification, 0.12 too short; however, a standard 0.125 spacer washer has been purchased to adjust for the short length. Mike is now aligning it, and it looks good.
  • PZT VAC STEERING MIRROR Awaiting repair of damaged PZT tilt platform. Mike will get the wiring requirements to Jay.
  • Mike and Steve will look into installing a camera and in-vac mirror to view the beam as it exits the mode cleaner and enters the Faraday Isolator; probably the tightest squeeze in the vacuum chambers.
  • We need new pulsers to operate our electro-optic shutters properly, so we will trade in our 3kV models for 6kV ones (more money, of course).
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Steve began pumping on the main volume with the newly-reinstalled maglev turbopump (TP1), and saw a burst of SO2 on the RGA. It died away, and appears to have been a coincidence. Bursts of SO2 have been seen before, and they die away afer a few hours of pumping. The maglev is working fine.
  • The east end ion pump (EEIP) has a bad fan on the controller, explaining why it was running hot. Steve will fix it.
  • Still waiting for a replacement controller board for cold cathode gauge #3 (CC3).
  • Still waiting for replacement parts for the HEPA filter fan on the PSL enclosure.
  • Steve has developed Carpal Tunnel syndrome. He brought in the "Ergo-lady", who gave him many suggestions. She will bring in the chair-and-desk guy, who will probably tell us that all our chairs need replacing.
  • Speaking of which, Steve will look into getting new desks and chairs for the expected hoardes of summer students and visitors.
• South Annex Bake Ovens (Taylor, Cardenas): Bob is ready to clean and bake the MMT and Faraday isolator, as soon as they're fully checked out.
• Osamu has had a significant breakthrough in understanding the dual-recycling summation cavity for E2E, and thinks that the remainder of the development work will be straightforward. He says that Hiro is happy.

April 25, 2003

• Suspended optics:
  • Steve and Osamu finished balancing both ETMs, and Bob has baked them. They are ready for final suspending.
  • Steve and Helena have bonded the guide rods & standoffs on to the PRM (T = 7.7%), and are gluing the magnet standoffs and magnets. Helena has cleaned the SRM (SRM01) and it's ready for bonding the guide rods & standoffs.
  • All 4 remaining suspended optics should be ready for installation by the end of next week.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor and Dennis have tuned up the FSS optical path over the last couple of weeks, and it looks to be in good shape.
  • Osamu is working on mods to the FSS board that were implemented on the LHO PSLs.
  • Conor is working on the PMC. He has measured the beam size entering the PMC with the BeamScan, and is adjusting the mode-matching accordingly. He will measure and optimize the transmission, visibility,
  • Ben's new stands for the ISS PD are done being fabricated, and fit the head boards well.
  • The ISS PD transimpedance heads seem to work fine, and I hope to attach two of them and test them out with the satellite box by the end of the week.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott): The Digital Suspension Controllers are in the process of being rebuilt, so there's been no work on the MC.
• Core digital suspension controllers (DSC), MC WFS, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  The DSC rewiring is completed, and Ben has tested the AUX crate and the DSC FE Input crate in 1Y4 and 1Y5 after fixing some minor problems with the wiring, they are both functioning fine.
  • Dennis and Ben are now in the midst of troubleshooting and fixing the suspensions racks. The DAQ interface chassis that sends the sensor signals to the ADCs has a variety of problems, including 850 Hz LPF's (inappropriate for 16 kHz readin), and Ben is getting it fixed. It appears that ALL of the whitening boards have failed in some way, and Paul Russell is diagnosing them. ICS110B channel hopping, and VME CPU instability is hampering progress. They are making headway, but it will take some time. We hope to be damping optics sometime next week.
  • Bob will finish wiring the MC WFS system (1Y2) this week, moving the fast PSL and MC signals from 1Y7 to 1Y2.
  • Getting all the code working in this system (including the readout of the MC length signal with a Pentek, and the fast PSL and MC signals with an ISC110B) probably requires Rolf, who is on vacation this week.
  • The MC WFS RF cables need to be measured to make sure they're all the same length.
  • Dennis fixed a problem with the PEM EPICS crate, so we are once again reading out the dust monitor and STACIS.
  • Dennis and Lisa are developing the EPICS screens and software for the 1X1 video switch.
  • Dennis is cleaning up and reorganizing all the EPICS code.
  • Ben will arrange for power to the little racks that hold the EOS electronics.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Received parts: Brewster's angle polarizer mounts for the Faraday isolator were received.
  • Orders pending: Repair of damaged tilt platform S/N 70416 with drive amplifier from Piezo Jena; 1 q-switch E/O shutter from Fast Pulse; 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC.
  • FARADAY ISOLATOR: Polarizer mounts were received and are being checked before preliminary alignment of the Brewster prism Faraday isolator. Brewster mirror parts were received, except for the Brewster calcite prism from KLC. The assembly will be fully checked out by Mike and Alexei, and then passed to Bob for vacuum prep.
  • OPTICAL LEVER ASSY: Assembly on hold.
  • MODE MATCHING TELESCOPE: All parts are in. Mike and Alexei will align with the autocollimator, then pass on to Bob for vacuum prep.
  • PZT VAC STEERING MIRROR: PZT tilt platform collar was received. Awaiting repair of damaged tilt platform. Mike will get the wiring requirements to Jay.
  • Jay is at LLO examining how they wire and control their electro-optic shutters. It is not clear how they can operate these with the pulsers that they have. Alexei is prepared to order higher voltage pulsers to get our EOSs to operate properly, and we are waiting on Jay.
  • Alexei is preparing to commission the MC WFS system. He is calculating the Guoy telescope lens positions and tolerances, and the predicted sensitivity to misalignments.
  • We have a new CrystalLaser IR laser with good beam quality, for aligning the new sensing trains. Hope to get started on this soon.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Steve re-installed the maglev cryopump and RGA scanned it; it looks clean. He's been pumping on the main volume with the cryopump, and will switch to the maglev soon.
• South Annex Bake Ovens (Taylor, Cardenas): Bob is baking the two ETMs in preparation for their final installation. He is ready to clean and bake the MMT and Faraday isolator, as soon as they're fully checked out.
• Osamu and Hiro continue to make progress in the development of a dual-recycling summation cavity for E2E.

April 18, 2003

• Suspended optics:
  • Steve and Osamu (with help from Helena and Jay) suspended one ETM (ETM03), and balanced and damped it.
  • They've glued the magnets and standoffs for the 2nd ETM (ETM02), and are in the process of balancing and damping it as of Thursday afternoon.
  • They will move on to the two recycling mirrors next week, while the ETMs bake. We have three PRMs, with T = 6.5%, 7.0%, 8.0%. We'll start with the 8% mirror (which will give us the lowest gain, most over-coupled PRC), and change if necessary later.
  • Bob is ready to bake both ETMs next week.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor and Dennis have been studying the power fluctuations on the light coming out of the AOM in the FSS path. They see very odd behavior, which depends on the VCO voltage. They will follow up, asking the experts.
  • Last week, Osamu reported increased noise in the FSS loop and strange phase behavior in the open loop tranfer function. He has traced this to saturation due to the large signal he was injecting to do the measurements. He reduced the injected signal size, re-optimized the FSS gains, and now the noise is back to where it was, exept for a large peak at 20 kHz, which is the cross-over frequency for the slow and fast FSS paths. He concludes that the fast (high frequency) path needs higher gain, to increase the UGF and phase margin. So, it's time to implement the mods that Rick and Paul implemented on the FSS card for the LHO PSLs. Osamu will get started on that.
  • Meanwhile, Conor will move on to optimizing the PMC performance.
  • Ben's new stands for the ISS PD are fabricated and are scheduled to be done by the end of this week.
  • The PCBs for the ISS PD transimpedance heads and the satellite electronics have arrived. Ben has stuffed and preliminarily tested three of the head units, and will begin stuffing the satellite electronics PCBs this week.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott): The Digital Suspension Controllers are in the process of being rebuilt, so there's been no work on the MC.
• Core digital suspension controllers (DSC), MC WFS, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Ben and Bob finished all the rewiring (cross-connects, front and back panel) for the DSC system (racks 1Y4 & 1Y5).
  • Ben has modified the DB and made up some new screens for the testing of the AUX crates in these racks, and will begin this testing tomorrow.
  • From Rolf: Began installation of new systems at 40m lab:
    • Suspension and IO WFS VME crates installed and running.
    • Updated auxillary suspension controller EPICS databases and undergoing testing.
    • Epics up and running on a Linux PC. New suspension screens added to epigen and then generated for all suspensions.
    • One suspension controller PC installed and running; Remaining suspension PC and ASC PC are due in today.
    • GDS router installed into the IO WFS VME unit; GDS software for suspension PCs should be complete today or tomorrow.
    • Remaining 2Gbit network cards arrived; still waiting on network hub.
    • Having problems with the AWG CPU; Alex is working on it.
    • DAQ configuration updated to include new systems' DAQ/GDS signals. Main DAQ screen updated to reflect new systems and status. Also added a network layout and status screen.
  • We should be ready for damping optics sometime next week.
  • Bob will finish the last wiring for the mode cleaner WFS system (1Y2) this week. Alexei can begin commissioning that system, starting next week. We need to make sure that the WFS RF cables are all the same length, with a TDR (time delay reflectometer).
  • Bob is wiring the cross-connects on rack 1X1, which controls the electro-optic shutters, mechanical shutters, illuminators, video switch.
  • Lisa is learning how to develop EPICS screens and software, starting with the 1X1 video switch.
  • Bob will maintain documentation for all the rack wiring, and log books for any changes.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Received parts: Received repaired spare tilt platform S/N 70418.
  • Orders pending: Repair of damaged tilt platform S/N 70416 with drive amplifier from Piezo Jena; 1 q-switch E/O shutter from Fast Pulse; 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC; Brewster's angle polarizer mounts for the Faraday isolator are in process; .
  • FARADAY ISOLATOR: Awaiting the polarizer mounts. They should arrive in the next week, after which the assembly will be fully checked out by Mike and Alexei, and then passed to Bob for vacuum prep.
  • OPTICAL LEVER ASSY: Reworked parts were received and are awaiting checking and assembly.
  • IFO STEERING MIRRORS: Awaiting one PZT tilt platform. Mike will get wiring requirements to Jay.
  • MODE MATCHING TELESCOPE: All parts are in. Mike and Alexei will align with the autocollimator next week, then pass on to Bob for vacuum prep.
  • INTEGRATED LAYOUT DRAWING: Updated the IMC_R layout with correctly positioned Guoy phase lens for the WFSs.
  • Alexei will install the MCR WFS Guoy telescopes, verify that they are in the right place with the BeamScan, and proceed to commission the MC ASC system.
  • Alexei confirmed with Mike Zucker that indeed, the electro-optic shutters (EOSs) operate at ~ 3.8 kV, not the ~ 1.8 kV implied by the LaserMetrics spec sheets. The DEI pulsers we purchased cannot operate beyond 3.5 kV, so we will return them for credit towards (more expensive) models that operate up to 6 kV. Jay will figure out what went wrong in ordering these HV pulsers.
  • Alexei has assembled and tested two EOS assemblies, and will begin on the 3rd as soon as the 3rd Q-switch arrives.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The east end ion pump (EEIP) has failed and can't restart. Steve will work on it.
  • One of the two HEPA filter fan motors on the top of the PSL enclosure started to fail, vibrating madly; the PSL FSS and PMC servos stayed in lock! Steve has removed the motor, and it will be repaired and re-installed by Caltech electricians. Meanwhile, we can run with the other HEPA filter.
  • The controller card for the CC3 gauge is busted, and Steve has ordered a replacement.
  • The maglev turbopump came back from the manufacturer, and Steve is trying to find out whether they'll guarantee it's cleanliness, before he re-installs it.
  • The rain revealed a roof leak in the South Annex clean room.
  • The STACIS and dust monitor systems are not being read out; Dennis will investigate, when he returns.
• South Annex Bake Ovens (Taylor, Cardenas): Bob has readied all the ovens for baking the suspended optics, and the MMT and Faraday isolator.
• Osamu is making progress in the development of a dual-recycling summation cavity for E2E.

April 11, 2003

• Conor gave a well-received LIGO seminar on QND and squeezed-light work at Australia National University.
• Suspended optics:
  • Steve helped Helena in preparing an optic for GinGin.
  • Steve and Helena are suspending one ETM this week, and will do the 2nd ETM next week. The two recycling mirrors will follow. All four suspensions are ready to go.
  • Jay got us a new stand-alone SOS controller for this work.
  • Bob is ready to bake the optics after gluing.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • Conor and Dennis made some significant changes to the beam going into the frequency reference cavity (FRC). Conor fixed several problems with the beam through the AOM; he increased the RF drive to the AOM through the VCO, aligned the beam as close as possible to the PZT side of the AOM, and discovered that the beam was not being double passed, so he fixed that. The power going to the FRC was thus increased from 5 to 17 mW. This required the power to the reflected RFPD to be attenuated by a factor 3 to compensate.
  • He and Dennis then re-aligned the beam to the FRC, and fiddled with the mode-matching lenses. The visibility peaked at 50%. This is much lower than before, but before, the reflected beam was not being focused on to the reflected RFPD; it was only sampling the inner TEM00 part of the reflected beam. They will investigate whether the limited visability is due to poor mode matching or due to HOM's coming from the laser (which probably could use a tune-up). This is important, because HOM's from the laser may be the cause of the relatively poor transmission through the PMC.
  • Osamu then played with the FSS gain, and remeasured the in-loop frequency noise. It was 3x worse than before, with a huge peak at 30 kHz (the cross-over frequency for the slow and fast FSS loops) and a pi phase shift at low frequencies. Osamu, Conor and Dennis will go over all the changes that have been made to the FSS, and try to figure out what has gone wrong.
  • Then, they'll move on to the PMC, and, if necessary, tune up the laser.
  • Ben's new stands for the ISS PD are in the machine shop being fabricated. They should be done early next week.
  • Ben has sent in the PCB for the ISS PD transimpedance heads, and the satellite boxes. The heads should be here by Friday, and the boxes' PCB should be back by Tuesday. The whole thing should be ready to go to Livingston for testing, the week of the 21st.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott): The Digital Suspension Controllers are in the process of being rebuilt, so there's been no work on the MC.
• Core digital suspension controllers (DSC), MC WFS, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Ben and Bob should be finished with rewiring the DSC system by the end of this week.
  • New DSC controls, from Rolf:
    • Most of the new VMIC 2Gb/sec reflected memory boards arrived. The PC and VME code was updated to make use of these new cards, which involved writing some new driver code.
    • The suspension control software is complete. We will go with two Pentium 4 PCs (each running 4 optics) and one VME crate, which does the I/O and DAQ for 8 optics in the initial installation.
    • The IO WFS software is complete. Last task was to port the digital signal processing part to a PC, which completed Tuesday.
    • Since we had all the parts in our development lab, we hooked all the systems together and ran timing tests, injecting timing signals at various points and checking them on a scope. All of the timing looks good.
    • We are now in the process of moving the whole system into the 40m lab. With any luck, we should up and running next week.
  • Rolf and Alex Ivanov have installed one of the 2 controls linux PCs for the new DSC system (a third will be needed for the ETMs), and a VME pentium to serve EPICS channels (this will move to a dual-CPU linux PC, once the EPICS port to Linux is complete). They are in process of commissioning the software. The fiber runs are temporary (while we wait for longer ones), and a few 2Gbit reflective memory boards are still on order and expected any day now.
  • Mode cleaner (IO) ASC and LSC: Jay reports that rack wiring and installation is 90% complete. Remaining VME components (3 penteks) will be installed by the end of this week. The controls linux PC should be in, soon. Current holdup is lack of long fibers to connect the reflective memory loops to the DSC, DAQs, and controls PCs.
  • Main IFO ASC and LSC: Jay reports that the rack and wiring diagrams are 90% complete. All that needs to be added are any QPDs used for beam centering.
  • Jay, Ben and Bob have met and agreed to running and labelling cables they way it is done at the sites. A log book will be maintained for any changes to cabling, and any cables that are not plugged in correctly will be summarily removed.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Received parts: Input mode-matching telescope off-axis parabolic mirrors were received from SORL, Guoy phase lenses for IMCR were received from CVI, replacement power connector for the 4 W 940 nm laser was received from Applied Optics.
  • Orders pending: Repair of two damaged tilt platforms expected 4/15 from Piezo Jena; 1 q-switch E/O shutter from Fast Pulse; 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC; Brewster's angle polarizer mounts for the Faraday isolator are in process; alternative spherical mirrors for MMT are expected from CVI in a few weeks.
  • FARADAY ISOLATOR: Awaiting the polarizer mounts. Should get them next week. Then, final checkout of the system, extinction ratio, etc. Then, on to Bob for cleaning and baking, and installation.
  • OPTICAL LEVER ASSY: Reworked parts were received and are awaiting checking and assembly.
  • IFO STEERING MIRRORS: Awaiting one PZT tilt platform. Should arrive next week.
  • MODE MATCHING TELESCOPE Replacement power connector for the missing power cable for the 4 W 940nm alignment autocollimator laser was received, and a power cable was made by Paul R. Received parabolic telescope mirrors, will do alignment week of 4/14. Then, on to Bob for cleaning and baking, and installation.
  • Alexei has made more measurement of the properties of our first electro-optic shutter (EOS), but managed to burn out the HV pulser in the process (at a lower HV than it was supposed to be rated for). We have 2 more, and the broken one will be sent back for repair.
  • The EOS transmitted power follows the predicted cosine curve, but peak transmission occurs at 50% more HV than expected. This may be due to the way Alexei has wired up the q-switch, and he is trying to get the attention of folks at the site who've done this before.
  • Meanwhile, Alexei is preparing a 2nd EOS assembly. A third awaits a back-ordered Q-switch. And, two more EOS controllers are in progress at Wilson House.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Dennis is getting ethernet cables and hubs into the remaining racks that need it, including our auxiliary rack 1X1. He noticed that 1X1 will have to be rebuilt, because the rails are in the wrong place, so that the door won't close.
  • Dennis has set up the screens for the video switch in our auxiliary rack, and is setting up the EPICS cpu in that rack to control it (and the EOSs, mechanical shutters, illuminators, etc).
  • Steve is installing the remaining camera mounts and viewports.
  • The maglev turbopump came back from the manufacturer, who couldn't reproduce its failure. Steve will put it back in when he gets a chance.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob has finished some OSEMs for Hanford, and shipped them out.
  • Bob is doing some airbaking of aluminum pieces for Ken Mailand, to try to darken them for use as baffles.
  • Bob has readied all the ovens for baking the suspended optics, and the MMT and Faraday isolator.

April 4, 2003

• Dennis and Osamu are both on shift at LHO all this week.
• Suspended optics:
  We are preparing to suspend our two ETMs in the next couple of weeks, and shortly thereafter, our two recycling mirrors, completing the suspended optics for the 40m.
  • Helena cleaned the two ETMs. They are ETM02 and 03. Their radius of curvature are very close, 59.92m and 59.75m respectively. The magnet/dumbell standoffs are also assembled. She went over the bonding procedure with Steve.
  • Bob is cleaning and baking the last earthquake stop screws that are needed for the MOS suspensions
  • Bob has fully assembled the two MOS and two SOS suspensions. Janeen reviewed the suspensions and they look ready to go but for these screws.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass, C. Mow-Lowry):
  • The beam on the FSS RFPD is jittering, causing the signal to fluctuate. Conor has been investigating. Conor made several changes to the PSL table around and downstream of the AOM. There were two major concerns: (1) The beam jitter of the double passed AOM beam and (2) Fluctuating power levels. Conor increased the RF drive to the AOM through the VCO from 3.50 Volts to 5.00 V, realigned the AOM, and aligned the beam as close as possible to the PZT side of the AOM crystal. These three actions resulted in an increase in single pass efficiency through the AOM from 40% to 75%. After realignment and iterative adjustment to the retro-reflector angle and the AOM angle, a maximum double pass power of 19.3 mW was obtained, form a 31.5 mW incident beam. This is a double pass efficiency of around 60%. The beam jitter appears to be gone, but this requires further investigation. The single- and double-pass power fluctuations are still present, but appear to be significantly reduced. It may be necessary to translate the AOM along the propagation axis to ensure it is at the beam waist. After all these changes, the FSS will have to be re-optimized.
  • Ben is working on a final design, layout, and packaging for the ISS DC PD. He hopes to have it to the board house by Friday.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott): The Digital Suspension Controllers are being rebuilt this week, and Osamu and Dennis are at LHO, so there's been no work on the MC.
• Core digital suspension controllers (DSC), MC WFS, and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Ben and Bob are rewiring the DSC system. They have finished the crate and module rearrangement, and the cross connect re-wiring, on 1Y4 and 1Y5, and will go on to the back panel and front panel wiring starting today.
  • Jay has modified the system drawings for the IO WFS rack to combine two VME half-crates into one split-backplane crate. This crate collects signals from the IO WFSs through Pentek ADCs and thence to a linux box via RM for ASC filtering, sends signals to the IO PZT steering mirrors through a Pentek DAC, collects fast signals from the PSL through an ISC110B and thence to DAQS via RM, collects the MC length control signal from the MC servo through Pentek ADC and thence to the DSC system via RM. The other half of the crate is an EPICS IOC for signals from the PSL and MC.
  • From Rolf: LSC code updated to include addition photodiode correction filter banks and outputs; undergoing testing with 40m system.
  • From Rolf: New digital suspension software for 40m lab should be ready in the next few days. Still to do:
    - Waiting new high speed reflective memory boards. Call last Thursday said they were shipping, but just received call today that they have not shipped yet. They will ship today.
    - Waiting rack mount 3.0 GHz P4 processor (should arrive today).
    - Finishing cleanup work on timing diagnostics and data acquisition/GDS.
  • From Rolf: Started testing digital IO WFS system. This should be ready to install at 40m lab early next week.
  • Jay reports that the system drawings for our LSC / ASC system are around 90% complete.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Orders pending: Input mode-matching telescope off-axis parabolic mirrors are expected first week in April from SORL; repair of two damaged tilt platforms expected first week in April from Piezo Jena; 1 q-switch E/O shutter from Fast Pulse; 1 Brewster's angle polarizer for SPS anamorphic prism steering mirror from KLC; Brewster's angle polarizer mounts for the Faraday isolator are in process; spherical mirrors for MMT are expected from CVI in a few weeks; Guoy phase lenses for IMCR are expected from CVI in by 4/7; replacement power connector for the 4 W 940n from Applied Optics is expected by 4/7.
  • FARADAY ISOLATOR: Working drawings for the Brewster's angle polarizer mounts for the Faraday isolator were completed, and parts are being manufactured.
  • OPTICAL LEVER ASSY: Reworked parts were received and are awaiting checking and assembly.
  • IFO STEERING MIRRORS: Parts are awaiting checking.
  • MODE MATCHING TELESCOPE: Replacement power connector for the missing power cable for the 4 W 940nm alignment autocollimator laser was ordered. Awaiting telescope mirrors.
  • INTEGRATED LAYOUT DRAWING: The ILD was revised to incorporate the new Brewster's angle Faraday isolator, the SOS anamorphis prism mirror, and the revised SPS beam path.
  • Mike has ordered some replacement Guoy telescope lenses for the IO WFS, that are still missing.
  • Alexei has made one electro-optic shutter (EOS) work. He resolved some questions about how to wire up the Q-switch, and where to ground it. The EPICS controls are not yet ready, so he's patching around that with an old 24-volt power supply and a function generator. He tested the EOS controller box, and works ok for a while; after about 10 minutes, it no longer send the correct gate signal to the pulser. But until then, he can adjust the HV and observes the output power to vary from near-zero to near-max. He is optimizing the HV and alignment. After resolving all the remaining problems, he will install the shutter in the MCR beamline, then turn to the EOS's needed for the SP and AP beamlines. A 2nd Q-switch is in hand, a third on back-order. Two more controllers are in the shop.
  • Ben ordered some SHV connectors to connect the HV to the Q-switches; they should arrive by the end of the week.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The maglev TP1 was at the manufacturer for repairs, but they found no problem. They've shipped it back, we should get it by the end of the week.
  • Steve has set up the camera to view ITMy, in addition to cameras already in place for MC1, MC2, MC3, ITMx, and BS.
  • The CC gauge near TP3 is not working; the controller has a bad board. It's been sent out for repair.
  • Steve completed the laser inventory forms required by the safety officers.
  • Our second new dry scroll pump is making squeeking noises, just as the first one did before it failed.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is baking the remaining EQ stop screws for our suspensions.
  • Bob finished a bake job for Lee.
  • Bob has finished cleaning and baking a new set of cleanroom tools for use in the South Annex.

March 28, 2003

• 40m Laboratory Upgrade Progress Report to the Technical Advisory Committee, March 19, 2003, LIGO-G030033-00-R, O. Miyakawa; and response of the TAC (K. Strain, M. Zucker).
• Also at the LSC meeting, Dennis Ugolini's application for Trinity University to join the LSC we approved.
• Dennis and Osamu are both on shift at LHO all next week.
• Conor Mow-Lowry from ANU is joining the 40m team for a 5-month visit. Make him welcome!
• Suspended optics:
  • Oplev QPDs for the 3 installed core optics (BS, ITMx, ITMy) are in place and see signals, through to the interface boards. Four more Oplev QPDs are ready for installation. The interface boards are part of the DSC system, which is being completely re-wired this week.
  • Steve and Helena have glued magnets onto dumbbells for the two ETMs, in preparation for suspending them in the next week or 2.
  • Bob has completely assembled the two MOS's for the ETMs, and the two SOS's for the PRM and SRM. A few more vented EQ stop screws are still in the shop. Janeen will carefully inspect the suspensions, soon.
  • Mark Barton is testing the silver-tipped EQ stops being developed by Steve.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • Osamu turned up the laser power to maximum, about 7 watts, into the PMC. Only ~ 3 W was transmitted through the PMC. Osamu and Conor will work on improving the transmissivity.
  • Osamu tried tuning the PMC servo notch filter, changing it from 35 kHz to 31.5 kHz, to resuce the frequency noise applied on the beam by the PMC (and measured by the MC). It didn't help. The PMC is being excited by acoustic noise; Osamu suspects the vacuum pumps.
  • The beam on the FSS RFPD is jittering, causing the signal to fluctuate. Osamu, Alexei and Conor will investigate.
  • We are also planning on implementing mods to the FSS that are recommended by Rick Savage, and mods to the MCS recommended by Daniel Sigg.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu measured the cross-over frequency between the MCL and MCF servo paths, with the new (Pentek) path for the MCL signal. It's still at 26 Hz, but the phase margin has increased from 10degrees to 95degrees. The new noise curve no longer has a peak at 26Hz.
  • Osamu installed software compensating filters for the filtering in the Pentek Interface board, and measured the transfer function to verify that they were doing the right thing.
  • Osamu turned up the PSL power to maximum (~ 3 W out of the PMC). After attenuating the sensor beams into the photodiodes and cameras, he re-measured the frequency noise, and found it to be unchanged with respect to low-power (~ 300 mW).
  • Osamu studied the MC2 suspension sensing noise, and the damping Q, for various settings of the position (and P,Y) gain G. He measured Q ~ 4/G. He finds that sensor noise sets in for gain > 0.3, or Q ~ 12. Jay seemed to recall that the sites operate with Q in that range, as well.
  • Osamu then measured the PSL frequency noise for different damping gains, and finds a strong contribution to the overall noise, in the ~100-200 Hz region, for gains > 0.3. He finds G = 0.1 to be optimal. However, the MC won't lock robustly with such low gain. We can imagine acquiring lock with higher gain, then reducing it for low-noise detection operation.
  • Osamu also noticed a dramatic drop in the 60-Hz-harmonics noise when the damping gain was turned down.
  • Osamu turned on the hardware dewhitening, and the sensor noise went down. But, the univ-dewhite board introduces an offset, so lock is not stable. Jay says something is wrong, and he and Ben will look into it (after the DSC re-wire).
  • Alexei made some beautiful measurements of the MC finesse. He actuated on the laser current shunt, and observed the effect on the light intensity before, and after, the MC. Both magnitude and phase of the resulting transfer function are consistent with a finesse between 1400 and 1460 (design is 1550).
  • We have found our missing WFS's, and Alexei installed them in the MCR beamline. A couple of Guoy phase telescope lenses are still missing, Alexei and Mike will hunt. Ben and Bob are almost done with the cabling for the the WFS ASC for the MC.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Ben has finished the wiring diagrams, system drawings, and cross connect list for the DSC re-layout. Ben and Bob are now in the process of ripping apart our DSC system, and rebuilding and re-wiring it.
  • From Rolf: -- VME/PC digital suspensions (DSC): We ran into a problem with the dual Xeon processor PC. Something comes in every 64 seconds and causes a 200usec delay in our code. This is not seen when our code runs on a Pentium 4 unit. After several days of searching for the problem, we opted to finish the software and run on Pentium 4 boxes for now. We'll come back to the Xeon problem as time permits. At some point, we also want to investigate why our code runs slower on the 2.8GHz Xeon than on the 2.6GHz P4.
    Otherwise, on the PC side, the code is complete and undergoing further testing. On the VME side, the DAQ for sensors/coils was added and tested. So, by early next week, we should be ready to move the system into place at the 40m lab.
  • From Rolf: -- Digital IO WFS: The VME side is up and running. In the 40m lab version, this VME unit will also do the DAQ for PSL channels and any other DAQ channel connections in the IO area. Work on that part of the software is in progress.
    The PC side is nearing the point of initial testing. This unit may show up at the 40m lab later than next week, but is not required for initial DSC operations (required MCL signal is already present from IO WFS VME).
  • From Jay: --- 40 Meter ASC/LSC: System drawings have been started and should be complete by 4/4/03.
  • Our SR785, which arrived broken, has been repaired by the manufacturer, and returned.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Received parts: 5 CX-ST50 CCD cameras from Aegis for the ISC tables; insulating bushing from Accurate Screw Machine for the LSC photodiode assy; 1 q-switch E/O shutter from Fast Pulse; 3 Brewster's angle polarizers for input Faraday isolator and SPS anamorphic prism steering mirror; QPD riser mounts and insulator from ASCO.
  • Orders pending: Input mode-matching telescope off-axis parabolic mirrors are expected first week in April from SORL; repair of two damaged tilt platforms expected first week in April from Piezo Jena; 1 q-switch E/O shutter from Fast Pulse.
  • FARADAY ISOLATOR: In process of detailing the redesigned polarizer mounts for the Faraday isolator with Brewster's angle polarizers.
  • OPTICAL LEVER ASSY: Reworked parts were received and are awaiting checking and assembly.
  • IFO STEERING MIRRORS: Parts are awaiting checking.
  • MODE MATCHING TELESCOPE: The wrong curvature spherical mirrors were received for the interim MMT; they were sent back, and replacement mirrors are expected in a few weeks. The COS autocollimator alignment equipment, which will be used for aligning the MMT, was presumed missing in action, but the shipping container from LLO was finally discovered in the 40 m lab masquerading as a scope stand. All the COS alignment equipment is accounted for except for a power cable and a 10V, 2A power supply to run the 4 W 940nm alignment autocollimator laser.
  • Alexei has installed the EOS optics on the MCR and SP beamlines. He also installed CCD cameras on all the beamlines, and Bob is running video cables from them to the video switch in rack 1X1, and from the switch to the control room. Dennis will get the video switch state code and EPICS screens from the sites, and install them.
  • Steve ordered a 100 mw YAG laser from CrystalLaser for optical sensing beam alignment.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The maglev TP1, which failed during last month's pumpdown, refuses to fail at the manufacturer. They are sending it back.
  • Our second new dry scroll pump is making squeeking noises, just as the first one did before it failed.
  • Steve regenerated the cryopump, and calibrated the new RGA filament.
  • Steve and Bob installed several camera mounts and cameras that view the suspended optics, and new viewport covers and illuminators. We now have very nice views of the MC1, MC3, BS, and ITMx optics. The remaining cameras and illuminators will go in soon.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is baking a chamber for Lee.
  • Bob has a new set of clean tools for use in the South Annex cleanroom.

March 14, 2003

• The 40 Meter Technical Advisory Committee will meet at 3:15 CST, Wednesday 3/19/03, at the LSC meeting at LLO. Osamu will present our status report.
• Also at the LSC meeting, Dennis will present his application for Trinity University to join the LSC.
• Suspended optics:
  • Ben has designed a rigid and insulated table mount for the oplev QPDs; 7 of them are being manufactured now, and will be done by nend of this week.
  • Bob is completing the MOS suspensions, including the newest rev mods. EQ stop screws are still in the shop. Should be ready next week. We plan to suspending ETMx and ETMy in the near future.
  • Steve continues to pursue EQ stop tip R&D, in coordination with Janeen and Mark Barton. He has switched from indium wire (too soft) to silver.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • Dennis and Osamu measured the phase noise of our VCO, in situ. They had to rig up a simple servo to stabilize the Marconi oscillator to the VCO at low frequencies, so that they could measure the VCO phase noise at high frequencies. Thanks to Rich Abbott for the servo design! The noise, expressed as frequency noise, is roughly flat at 5e-3 Hz/rtHz from 100 Hz to 10kHz, above which, the Marconi is insufficiently stable. This noise is roughly a factor 2 better than what is reported at the sites (~ 1e-2 Hz/rtHz), and is completely consistent with the mode cleaner noise curve in that frequency range. Dennis and Osamu will now calibrate the VCO response in Hz/volt.
  • Osamu plans to reduce the low-f gain of the VCO, thus increasing the dynamic range and eliminating saturation, to compensate for the increased seismic noise at the 40m relative to the sites.
  • Osamu and Alexei improved the FRC alignment, and found and fixed a place where the reflected beam was clipping a mirror mount. Now, the excess noise noticed in the MC error signal last week is gone.
  • Osamu retuned the beam alignment on the PSL table, so the initial pointing into the MC has changed.
  • We are also planning on implementing mods to the FSS that are recommended by Rick Savage, and mods to the MCS recommended by Daniel Sigg.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  After the work described above, Osamu and Alexei recovered robust locking of trhe MC, and re-measured the frequency noise. It is now the same as it was before last week's pump-down.
  • There's still excess noise from 100-300 Hz at the new cross-over frequency between MCL and MCF. This should go away when additional filtering is added to MCL. Osamu is working on that, now.
  • Osamu and Alexei set up the OSA at MC transmitted and observed the transmitted 33 MHz sidebands (and no reflected 29 MHz sidebands). They optimized the tranmission by tuning the Marconi frequency; maximum was at 33.194709 MHz, corresponding to a MC half-length of 13.547 m. Just right. They are trying to understand, and increase, the sideband modulation depth. They will work on quantifying the sideband transmission, but it looks consistent with the total transmission (~ 95%).
  • They measure a MC visibility of 1 - 0.052 (ie, a trasnmission of ~ 95%), which is as good as we've seen before, and close to specs.
  • Ben and Bob continue working on the cabling for the the WFS ASC for the MC. They're almost done, but are awaiting more RG405 cable.
  • Our MC WFS's are missing...! We're looking for them.
  • Lori is still working on the MC WFS ASC software (at Wilson House).
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Ben is ~25% through the drawings for the re-wiring of the DSC system (newly designed by Rolf to be PC-based, with significantly less VME-based processing). He hopes to be finished by next week, and then he and Bob can start the re-wiring.
  • Jay continues to work on the drawings for a LIGO-I-like LSC system for the 40m dual-recycled IFO, including 8 I/Q demod boards from LSC PD's.
  • Ben has made arrangements for Bob to return the SR785 analyzer that isn't working. Bob shipped it out yesterday.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • OPTICS PARTS LIST, Received parts: drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror were received; re-worked IFO MMT parts and light-weight PZT steering mirror holder received.
  • Orders pending: Order was placed with KLC for Brewster's angle polarizers for input Faraday isolator. Input mode-matching telescope off-axis parabolic mirrors are expected first week in April from SORL; repair of two damaged tilt platforms expected first week in April from Piezo Jena; 5 CX-ST50 CCD cameras from Aegis for the ISC tables; 3, 33% 45S polarization beam splitters from CVI for the ISC tables; insulating bushing from Accurate Screw Machine for the LSC photodiode assy; 2 q-switch E/O shutters from Fast Pulse for the ISC tables; QPD riser mounts and insulator from ASCO.
  • FARADAY ISOLATOR: In process of detailing the redesigned polarizer mounts for the Faraday isolator with Brewster's angle polarizers.
  • OPTICAL LEVER ASSY: Reworked parts were received and are awaiting checking and assembly.
  • IFO STEERING MIRRORS: All the parts were received and will be checked before cleaning, baking and assembly. Lee will assemble the DLC mounts.
  • MODE MATCHING TELESCOPE: All the parts are in hand for the interim, spherical mirror version of the MMT. The telescope will be assembled and aligned for testing next week, before being taken apart again for cleaning, baking, and final assembly. The silvered parabolic mirrors should be available by early April.
  • ERRANT BEAM BAFFLES: Mike is working on a new baffle design using coated aluminum, which will be used for the 40m.
  • Steve will order some 100 mw YAG lasers for optical sensing beam alignment.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The maglev TP1 failed during last week's pumpdown. Steve was able to reset it, but it failed again a short while later. He has removed it and is crating it up to be sent back to the manufacturer for repair.
  • We are now running with all 4 ion pumps.
  • Steve is preparing to install all the camera mounts and cameras that view the suspended optics, as well as the new viewport covers and illuminators.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob ordered cleanroom supplies and tools for the south annex lab.
  • Bob continues to work on OSEMs for GinGin.
  • Bob is ready to bake out a chamber for Lee, as soon as it arrives.

March 7, 2003

• Overall status and near-term plans:
  • We pumped back down last Friday. There were a variety of problems (see below), but none too serious.
  • All 6 suspended optics (MC1, MC2, MC3, BS, ITMx, ITMy) are installed in their chambers, and are being damped by the DSC system.
  • The PSL and mode cleaner are performing reasonably well; details below.
  • We are preparing to completely rebuild our DSC system as discussed below. Hope to complete this within one month.
  • We are preparing to suspend our remaining optics: ETMx, ETMy, PRM, SRM. Hope to complete this within one month.
  • IFO sensing optical trains are all installed; details below.
• Suspended optics:
  • Dennis, Bob, and Ben are setting up oplev QPDs and cables to readout the optical levers on all the core optics.
  • Ben has designed a rigid and insulated table mount for the oplev QPDs; 7 of them are being manufactured now, and will be done by next week.
  • Bob is acquiring, and cleaning and baking, the remaining missing parts to complete the remaining suspensions (for ETMx and ETMy, and PRM and SRM) and two MOS's (for ETMx and ETMy).
  • OSEMs for these suspensions have long been ready, but Bob discovered that the screw holes in the back were 180degrees away from their correct positions. This is not a problem; the OSEMs themselves can be rotated to compensate.
  • Steve has acquired some indium wire, and will investigate its use to replace the viton and springs in the suspension earthquake stops.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • After pumpdown, Osamu and Dennis re-established MC lock. The MC2 length control (MCL) is going through a Pentek now, instead of an ISC110B. There was a sign flip due to this change, which was compensated for with a jumper on the MCS board.
  • The Pentek Interface Board introduced some new filtering, which reduces the phase difference between the MCL and MCF loops. Osamu measured the new OLTF and time delay, and is modeling and understanding the differences. The phase improvement helps lock acquisition and the stability of lock.
  • However, the changes necessitate the addition of (software) filtering in the MCL loop to keep its high gain at low frequencies, while giving more authority to MCF (and thus the frequency stabilization) at higher frequencies. Osamu will attempt to implement the same filtering that is now done at the sites.
  • Osamu sees a different noise spectrum with these changes: (a) above 400 Hz, the noise spectrum is the same as before; (b) the peak due to the 180degree phase difference between MCL and MCF at the cross-over frequency of 30 Hz is gone; (c) instead, there is a new large peak at the new cross-over frequency of 100 Hz. This should go away when additional filtering is added to MCL; (d) Line harmonics at 120 and 180 Hz are now much larger; not understood why.
  • However, we will soon be completely rebuilding the DSC system, which should improve the 60-Hz-harmonics pickup greatly.
  • Ben and Jay fixed problems with the switching of the universal dewhitening boards, and they now no longer introduce excess noise in the 40-60 Hz region.
  • Ben and Bob are working on the cabling for the the WFS ASC for the MC. They're almost done. Some needed connectors were ordered and should be in sometime soon.
  • Lori is still working on the MC WFS ASC software (at Wilson House). The sites want this system as well (right after S2). Jay and Rolf await specifications for this system for the sites, which will require a review.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • From Rolf: Continued work on using a PC in conjunction with a VME crate to run the suspensions on the 40m. We pretty much have a full system running now and have done some initial testing. It looks like on the VME side, we can do all the I/O plus data acquisition for 8 optics with one VME crate. There is no longer a distinction on the VME side of large or small optics, so we can run all 40m lab vertex optics with this one crate. The fact that the VME crate also does handles all the DAQ channels (sensor/coil readouts) eliminates the need for a separate DAQ VME crate.
  • On the PC side, it look like one 2.5GHz P4 box can run all the control algorithms for 5 optics and still get its output to the VME unit in time. We ran it is high as 6 optics, but I/O timing with the VME unit became border line. Ben has ordered a dual 2.8GHz Xeon processor unit, which should be in late next week. We hope to be able to run all the 40m lab optics (10) with this one box.
  • In the course of the next week or two, we need to do some finishing and clean up work on the software. This includes getting all the white/dewhite and run/acquire switching in. We also want to use this system to test if we can trap ICS110B ADC channel hopping (by forcing it to jump). If we can trap it in some fashion, then this trap code would be also applied to DAQ and watchdog timer software.
  • Jay and Ben are working on drawing up all the rewiring necessary to implement this new DSC design. No new hardware is required; in fact, the new design makes efficient use of the existing hardware, freeing up quite a few modules... which we need for the LSC system!
  • Jay is drawing up a LIGO-I-like LSC system for the 40m dual-recycled IFO, including 8 I/Q demod boards from LSC PD's.
  • Rolf is developing a number of ways to improve I/O in the LSC system, offloading the work to the VME IO bridge chip, freeing up the CPU for LSC filtering alone. He will test this scheme at the 40m in a couple of weeks.
  • Jay and Rolf borrowed a Pentek from our DSC system to run some tests; as a result, we had to move the BS to the SRM DSC, temporarily.
  • Ben sent back the blown RAID array disk to IBM.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • Dennis and Osamu are attempting to measure the phase noise of our VCO, in situ. They are struggling with some apparent instability...
  • Osamu is developing plans to modify the gain and dynamic range of our VCO, to compensate for the increased seismic noise at the 40m relative to the sites.
  • Osamu and Alexei are improving the FRC alignment.
  • Rich moved the ISS hardware from the 40 to Peter King's lab for further development. Our PSL table was shaking too much!
  • We are also planning on implementing mods to the FSS that are recommended by Rick Savage, and mods to the MCS recommended by Daniel Sigg.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • Alexei and Lisa completed the installation of the optics for the POB, POX, TRX, and TRY sensing beamlines. Now, all sensing beamlines needed for the first phase of the 40m experiment are in place. A long list of missing parts (LSC PDs, WFSs, monitoring QPDs, EOSs, MM lenses, OSAs, cameras) has been compiled and will be chased down by Mike Smith and Ben Abbott.
  • Alexei will soon begin the assembly and commissioning of electro-optic shutters (EOSs) for the MCR, AP and SP beams.
  • OPTICS PARTS LIST, Orders pending: Input mode-matching telescope off-axis parabolic mirrors are expected 3/10/03 from SORL; drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror are expected 3/3/03 from Piezo-Jena; repair of two damaged tilt platforms expected week of 4/7. Re-worked IFO MMT parts and light-weight PZT steering mirror holder are pending.
  • FARADAY ISOLATOR: A discussion with Karl Lambrecht revealed that glan laser polarizing prisms have uncoated air-gap surfaces not at Brewster's angle, and therefore a reflection loss of a few percent for each of the four air gap surfaces is to be expected, which will result in a transmissivity of around 90-94 %. In addition, since the polarizing prisms are designed for broadband usage, in order to meet the total internal reflection angles at near IR wavelengths the prism entrance angle must be tilted in the horizontal plane. These facts explain the behavior of our tested Faraday isolator, which required that we tilt the polarizer horizontally in order to achieve a decent extinction ratio. Osamu also pointed out that the beam from the NPRO laser that we used to measure the extinction ratio was fairly divergent, and seemed to have a halo of scattered light around the main beam, which would degrade the measured extinction ratio.
    I have redesigned the Faraday isolator to incorporate Brewster's angle polarizers, which we know from the measured LIGO COS output Faraday isolator performance, that will have a much higher throughput and extinction ratio than the normal glan laser polarizer. The astigmatism of the reflected output beam from the Brewster's angle polarizer will be compensated by using a Brewster's angle prism steering mirror, which exactly undoes the horizontal magnification of the output beam profile caused by the Brewster's angle polarizer. Hope to complete the redesign in a week, and have the device rebuilt and ready for installation in a month.
  • OPTICAL LEVER ASSY: Reworked parts were received and are awaiting checking and assembly.
  • IFO STEERING MIRRORS: The IFO beam displacement PZT steering mirror was moved from the MMT2 mirror to a separate mirror holder placed on the table next to the mode-matching telescope (MMT). This required two additional folding mirrors to jog the output beam from the MMT to the re-located PZT steering mirror and back to the original beam path, adding an additional optical path length from the MMT to the IFO beam waist. Greater than 99.9% mode-matching of the MMT output beam into the IFO beam waist can still be obtained with the increased path length by a slight change in the defocus of the MMT. This was checked, independently, by Alexei.
  • Mike is working on a new design for baffles, using AR-coated aluminum rather than black glass.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The 40m was pumped back down on Friday.
  • The maglev TP1 failed, and appears to be dead. It is 10 years old; one of the very few devices remaining from the old vacuum system. Steve is talking with the manufacturer to see if a quick fix is available. Else, a repair, if possible, will be at least $4K. A new replacement is $16K.
  • Without TP1, Dennis and Steve pumped from 500 to 25 mtorr using TP2 and TP3 (through TP1). That took a couple of days!
  • Then, the cryopump CP1 took over and has brought us down to 1.8e-6 torr and falling.
  • In the process of doing this unusual procedure, a software interlock was tripped off an an unanticipated way, shutting VC1 (the valve in front of CP1). It didn't cause any problems. Nonetheless, Dennis has rewritten the software interlock code to make it much simpler and better behaved, and will install it at the next convenient opportunity.
  • CC1 has been observed to fluctuate a lot. Steve had installed a new CC1, and switch to using it; it fluctuates much less.
  • Steve switched on the ion pumps, but the SE IP belched nastily. This had been observed before. Steve is arranging to run 3 of the 4 ion pumps, leaving out the SE.
  • Steve replaced the filament on the RGA and on CC4; both are behaving reasonably now.
  • Our new in-vacuum cables, which have a non-insulated copper braiding, are lying on the optical tables and the floor of the chamber. They exit through pin 25 of the feedthrough. That will be left dangling (not grounded), so as to avoid ground loops.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob sent baked HAM spacers to Ken at MIT.
  • Bob continues to work on OSEMs for GinGin.
  • Bob has placed the new RGA in service, and compared it with the old RGA. All looks good, and this will eliminate the major source of downtime in the lab.
  • Bob is baking out a chamber for Lee.

February 28, 2003

• Suspended optics:
  • The 40m has been vented since Thursday to install suspended optics.
  • The BS, ITMx, and ITMy were installed in their respective chambers by Steve, Dennis, and Osamu.
  • They were all hooked up to their digital suspension controllers, and they all are damping fine.
  • Steve, Dennis, Osamu, and Alexei installed optical levers on all 3 optics, using small red lasers and in-vacuum mirrors. Getting 5-7% of the light back; not bad. Detectors not yet installed.
  • Bob has assembled two SOS's (for PRM and SRM) and two MOS's (for ETMx and ETMy), in preparation for suspending the optics. A few missing parts (screws, top assembly) are missing, and have been ordered. The OSEMs are ready. Janeen will do some mechanical tests on the MOS.
  • Steve is investigating the use of indium, to replace the viton and springs in the suspension earthquake stops. He's been discussing this with Mark Barton.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu measured the seismic noise on top of the MC2 stack (up to 100 Hz, but with little coherence with the floor above 50 Hz; from 50-100 Hz, it's probably dominated by acoustic noise). Including the pendulum TF, the curve explains the MC noise spectrum well, below 50 Hz, except for: (a) f < 1 Hz, which is very time-variable; (b) bounce mode peak at 16 Hz; (c) peak at 30 Hz, right near the cross-over frequency between the MCL and MCF servo paths; the servos are 180degrees out of phase there, and that needs to be fixed.
  • After all the installation, Dennis and Osamu re-established alignment of the MC optics, and observed fringes while in air. The light power was very low, so the MC servo signal was very small; too small to lock robustly.
  • Still, it looks like the modified MCL path (through a Pentek ADC instead of an ICS110B) works.
  • Ben's re-wiring for the universal dewhitening board was completed and checked out. Many problems with the board were discovered and fixed. However, the software is not controlling the hardware universal dewhitening properly; Ben and Alex Ivanov are working together to fix it.
  • All the electronics required to complete the WFS ASC for the MC have been passed on to Lori, to complete the ASC software.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Heefner, Bork, Taylor):
  • Rolf and Jay are developing a complete re-layout of our DSC system, using a commodity PC rather than a VME Pentium to do the filtering, leaving the VME Pentium to do IO only. Instead of 4 VME crates to run 8 DSC's, (limited by the filtering in the VME Pentium), only ONE would be needed (freeing up modules for completion of our endstation DSCs and LSC system). Tests at Wilson House are ongoing; should know whether the new scheme will work in the next week. Jay and Ben will rework the rack wiring (1Y4 and 1Y5). We hope to meke the mods by the end of March.
  • Ben and Jay will review the necessary mods to get gps timing signals to the end racks.
  • Jay is drawing up a LIGO-I-like LSC system for the 40m dual-recycled IFO, including 8 I/Q demod boards from LSC PD's.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • We are planning on making phase noise measurements to our VCO, and potentially also increasing its dynamic range (to compensate for the higher seismic noise at the 40m lab).
  • We are also reviewing the mods to the FSS that are recommended by Rick Savage.
  • Work on ISS has been slow this week; Flavio is sick and Rich is on vacation.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • Alex and Lisa completed the installation of the optics for the SP beamline. Alexei gave a list of missing parts to Mike, who is updating the parts list.
  • Alex has completed his code and a nice GUI for calculating the beam size and Guoy phase for all beamlines in the main IFO. As a first exercise, he'll study the effect of moving the PZT steering mirror from the MMT to the next table (which Mike found was necessary for mechanical reasons).
  • Alex will soon begin the assembly and commissioning of an electro-optic shutter for the MCR, AP and SP beams.
  • OPTICS PARTS LIST, Orders pending: Input mode-matching telescope off-axis parabolic mirrors are expected 3/10/03 from SORL; drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror are expected 3/3/03 from Piezo-Jena; repair of two damaged tilt platforms expected week of 4/7. Re-worked IFO MMT parts and light-weight PZT steering mirror holder are pending. 1.5 in mirrors for the light-weight PZT steering mirrors are pending from CVI.
  • FARADAY ISOLATOR: The Faraday isolator was assembled and aligned by Mike and Alex. The transmissivity was 0.97 and the extinction ratio was an appalling 0.11. Subsequently, the horizontal input and output polarizers were rotated by approximately 3 deg in the horizontal plane and the extinction ratio improved to 2.5E-3, with the transmissivity dropping to 0.91. Coincidentally, the 3 deg rotation brought the front face of each polarizer normal to the beam; however, the polarizers were designed with a 3 deg wedge on the entrance face, so that the beam would not enter normal to the face to avoid glint reflections. Clearly something is wrong, and further testing and discussions with Karl Lambrecht and EOT will be necessary before we can resolve the problem.
  • OPTICAL LEVER ASSY: Reworked parts were received and are awaiting checking and assembly.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The 40m has been vented since Thursday, for optics installation. We'll pump back down on Friday.
  • Steve noted that our new in-vacuum cables, which have a non-insulated copper braiding, are lying on the optical tables and the floor of the chamber, and Jay said that this was not good. Steve and Osamu will look for evidence of ground loops with this situation.
  • Steve replaced the failed TP3 dry scroll forepump with a spare. He's not sure why the pump failed.
  • Steve and Bob are adding a new large dry scroll forepump behind TP2.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob completed bake jobs for Janeen, Mike Smith, Ken Mason, and Larry Jones.
  • Bob is assembling the in-vacuum camera mirror parts for the 40m. A missing screw has been ordered.
  • Bob is making 5 more OSEMs for Janeen / Glasgow.

February 21, 2003

• Suspended optics:
  • The 40m has been vented since Thursday to install suspended optics.
  • Steve, Dennis, and Osamu installed ITMx in its chamber on Friday, and cabled up the the DSC. Several problems with the DSC cables were discovered (flipping of connectors), which blew out the whitening board. The cables and board were promptly fixed, with help from Rich and Ben, and DSC damping was established. The table was levelled and all OSEMs read in the middle of their range.
  • BS was installed, DSC damping established, and table levelled for OSEM centering, on Tuesday.
  • ITMy was installed, DSC damping established, and table levelled for OSEM centering, on Thursday.
  • Dennis used DI N2 to blow dust off of the mirrors before installation.
  • Steve checked that the suspension wire was in the correct place, after installation.
  • Steve will try to set up in-vac mirrors for oplevs on these 3 newly installed optics, before pump-down.
  • Steve will also see if he can install in-vac mirrors for camera views of the optics, before pump-down.
  • Bob has assembling one of 2 SOS's (for PRM and SRM) and one of 2 MOS's (for ETMx and ETMy), in preparation for suspending the optics. The OSEMs are ready. Janeen will do some mechanical tests on the MOS.
  • The old (green light) BS, in its SOS suspension, was removed from the chamber. It is available to whoever might need it.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu measured the MC noise one last time before venting. It was ~ 5-10 dB worse than usual, above 1kHz. Not sure why.
  • Osamu, Dennis, and Ben are reviewing the modifications that Daniel Sigg suggested to our MC servo board, to increase our UGF from 67 kHz to ~ 100 kHz, and are preparing to implement them.
  • Ben has moved the MC length control to MC2 from an ICS110B to a Pentek ADC. He and Bob are now working on rewiring to use a universal dewhitener instead of the current SOS dewhitener for the MC2 output to the coil driver.
  • Ben has obtained all the electronics required to complete the WFS ASC for the MC. He will work with Bob on all the cabling. Jay says that Lori is almost ready with the ASC software.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • We are planning on making the mods to our FSS that are recommended by Rick Savage, to our FSS board and RF summing box, to increase our UGF from 300 kHz to 600 kHz.
  • The ISS PD is now downstream of the PMC. It continues to work well, but an out-of-loop PD reads more noise, and extreme sensitivity to acoustic and mechanical vibrations on the PSL table.
  • Using a QPD, Rich has established that the apparent intensity noise is strongly correlated with beam jitter on the sensing PD.
  • Rich continues the struggle to obtain -160 dB, with help from Dennis and Ben (Flavio is on vacation).
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Heefner, Taylor):
  • Rolf proposes a complete re-layout of our DSC system, using a commodity PC rather than a VME Pentium to do the filtering, leaving the VME Pentium to do IO only. A fiber link shuffles data between the 2 computers. Instead of 4 VME crates to run 8 DSC's, (limited by the filtering in the VME Pentium), only 2 would be needed. And, there'd be cpu cycles to spare (unlike the present situation). This has already been tested at Wilson House. This will require significant re-wiring. Jay will take the opportunity to split analog and digital between the two racks (1Y4 and 1Y5).
  • Ben and Jay will review the necessary mods to get gps timing signals to the MC ASC system, the end racks, and the future LSC system.
  • Jay is drawing up a LIGO-I-like LSC system for the 40m dual-recycled IFO, including 8 I/Q demod boards from LSC PD's. He is considering incorporating a redesign of the LSC whitening filter boards. He's also thinking about a redesign of the IQ demod boards, to fix known problems and to easily incorporate double demodulation.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • Alex and Lisa completed the installation of the optics for the AP1 beamline, and are nearing completion for the SP beamline. Alexei gave a list of missing parts to Mike, who is updating the parts list.
  • Alex is nearing completion of his code and a nice GUI for calculating the beam size and Guoy phase for all beamlines in the main IFO.
  • Alex will soon begin the assembly and commissioning of an electro-optic shutter for the MCR beam (they are also needed for the AP and SP beams).
  • OPTICS PARTS LIST, Orders pending: Input mode-matching telescope off-axis parabolic mirrors are expected 3/10/03 from SORL; drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror are expected 3/3/03 from Piezo-Jena; repair of two damaged tilt platforms expected week of 4/7.
  • IFO MODE-MATCHING TELESCOPE: All the telescope parts were assembled okay. However, the PZT tilt platform was damaged during assembly into the MMT. I have decided to remove the tilt mirror from the MMT assembly, because the assembly is risky and the parabolic mirror presents too large a cantilevered load on the PZT mechanism. An adapter that attaches the mirror holder directly to the secondary mirror mount was designed. The PZT tilt mirror will be mounted separately.
  • FARADAY ISOLATOR: The reworked Faraday isolator is awaiting assembly and alignment. An alignment procedure is being written.
  • OPTICAL LEVER ASSY: Reworked parts were received and are awaiting checking and assembly.
  • VAC STEERING MIRROR: A light-weight mirror holder for a 1.5 in dia x 0.25 in thick steering mirror, instead of the original 2 in mirror, was designed to be used for the IFO steering mirrors that are mounted on the PZT tilt platforms in separate DLC mirror mounts. The first steering mirror, SM1, will be located next to the MMT and an additional turning mirror willbe used to return the output beam from the MMT back to SM1. The second steering mirror, SM2 will be located near the PRM as before, but will utilize a smaller 1.5 in light-weight mirror holder on the PZT tilt platform.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The 40m has been vented since Thursday, for optics installation. We'll pump back down sometime in the next week.
  • The TP3 dry scroll forepump failed on Sunday night, causing the pressure to rise in the RGA and annulus regions. CC4 did not switch off, as it should. Steve is investigating the cause for both these failures.
  • Steve realized that the counterweights used to balance the optical tables in the chambers are not vented; so they trap air in the table holes. He is now placing the counterweights on washers to prevent this.
  • Osamu plans to measure the horizontal transfer function of the small MC2 stack, before we pump down.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob completed bake jobs on Janeen's OSEMs for GINGIN and Ken's HAM spacers.
  • Bob baked in-vacuum camera mirror parts for the 40m.

February 14, 2003

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu estimated the contribution of the measured frequency noise to the main IFO GW sensitivity (assuming a CMRR of 1/100), and compared it with our design sensitivity. It barely meets the specs, whereas a factor 10 safety margin is desired. Improvements to the servos (described below) will help a lot, and a common mode servo will help a lot. So we should be in good shape with frequency noise when we commission the main IFO.
  • Osamu presented his studies of PSL / MC frequency noise (transparencies) at last Monday's commissioning telecon. There were lots of good ideas and suggestions.
  • In particular, Rick Savage suggested that we modify our FSS board and RF summing box, to increase our UGF from 300 kHz to 600 kHz. Osamu, Dennis, and Ben are reviewing the modifications and preparing to implement them.
  • Daniel Sigg suggested modifications to our MC servo board to increase our UGF from 67 kHz to ~ 100 kHz. Osamu, Dennis, and Ben are reviewing the modifications and preparing to implement them.
  • Ben is working on the mods to the MC length control to MC2: using a Pentek ADC instead of the ICS110B, and using a universal dewhitener instead of the current SOS dewhitener. Ben developed a test procedure for the Pentek Generic Interface Board Driver, and tested and installed it at the 40m. He has altered the MC2 Universal Dewhite boards to fit the component values given to him by Rana, and brought them to the 40m Lab. All the boards are in place, but the changes require some rewiring, and Ben is modifying the protel drawing before the wiring mods are made.
  • Ben has obtained all the electronics required to complete the WFS ASC for the MC. He will work with Bob on all the cabling. Jay says that Lori is almost ready with the ASC software.
  • We vented today (Thursday) to install suspended optics. Plan is to pump back down on Wednesday morning, re-establish the MC noise behavior, and begin to implement the mods to the FSS and MC servos, one step at a time.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Heefner, Taylor):
  • Ben and Jay will begin purchasing the additional electronics needed to complete the end racks (Pentiums, Penteks, ISC110B's, and custom modules; for ETMx and ETMy DSC, and transmitted port sensing).
  • Ben and Jay will review the necessary mods to get gps timing signals to the MC ASC system, the end racks, and the future LSC system.
  • Jay is drawing up a LIGO-I-like LSC system for the 40m dual-recycled IFO, including 8 I/Q demod boards from LSC PD's. Mike Smith estimates ~ 20 mW of laser power on the asymmetric port LSCPD's, so it should not be necessary to have more than one LSCPD for each degree of freedom to be sensed. (Of course, this means that our shot noise limit will be larger than we thought, but for the 40m, this may be a good thing!).
  • Jay and Ben will start thinking about the design of a "double-demod" board for sensing signals at (33 x 166) MHz.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • Ben has made a new mount for the ISS DC photodiode. It is a very sturdy monolithic aluminum block the holds only the photodiode. From there, it is connected to the PD circuitry by a short shielded cable. This was done in an attempt to minimize acoustic sensitivity of the PD enclosure. The ISS is no longer sensitive to vibrations of this component, but the bottom line noise in the ISS is unchanged.
  • Next step is to move the ISS PD from its current position upstream of the PMC to downstream, to take advantage of the increased stability of the PMC-filtered beam. An additional ISS PD would look at the MC-transmitted light, and the servo would blend these two signals together.
  • Rich Abbott improved the current shunt actuator, replacing several components, including an amplifier that was limiting the slew rate. Results of the test with the new shunt are not yet in.
  • Meanwhile, Steve took the opportunity to clean and vacuum out the Lightwave laser box, while it was open to replace the current shunt. It still had some detritus from a small water leak many months ago.
  • Dennis has completed the PSL part of the "Comprehensive 40m Procedures Manual", and posted it near the PSL.
• Optical sensing (Smith, Ourjoumtsev, Goggin, Miyakawa):
  • Alex is completing the installation of the optics for the AP1 beamline, including some lenses that just arrived yesterday. He and Lisa Goggin will proceed with the SP optical sensing train, then on to POB, POY, TRx, and TRy beams.
  • Alex is continuing to develop his code and a nice GUI for calculating the beam size and Guoy phase for all beamlines in the main IFO.
  • Steve ordered four 1mW 670nm Coherent diodes with power supplies and mounts, for oplevs. He measured the reflectivity of the BS and ITM at an incident angle ~35 degrees. From front surface, reflected ~5% and the back surface ~15%.
  • IFO MODE-MATCHING TELESCOPE: All the MMT parts for the alternate (spherical mirrors) telescope are in house and are in process of being checked and assembled before cleaning and baking (next week). Input mode-matching telescope off-axis parabolic mirrors are expected 3/10/03 from SORL. Drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror (mounted on the MMT) are expected 3/3/03 from Piezo-Jena. The MMT also contains a pico-motor for focusing; in-vacuum cables for this device need to be designed and made with proper shielding.
  • FARADAY ISOLATOR: The reworked Faraday isolator assembly has been cleaned and baked and is awaiting assembly and alignment.
  • OPTICAL LEVER ASSY: Several parts of the optical lever focus lens assembly are being reworked to enable electrical isolation of the QPD from the table mounting base. The lenses were assembled into the lens tube.
  • OPTICAL SENSING: The beam size matching lenses for the AP1 optical train were designed, were ordered, and were received. The layout drawing of the AP1 optical table was updated with the revised component locations. An assembly drawing for the IMCR, SPS, and AP1 sensing beam's E-O shutters was made for clarification of assembly, because each beam uses different size polarizing beam splitters that require different spacer mounts. A new spacer was designed for the IMCR E-O assy. The parts list is being updated.
• Optics (Billingsley, Armandula), suspensions (Romie), OSEMs (Bob):
  • Dennis and Steve vented the 40m today (Thursday) to install the 3 suspended optics (BS, ITMx, ITMy) on Friday and Monday, cable them up, coarse align and damp with the DSC system.
  • Janeen originally ordered 7 SOS suspensions for the 40m, with the assumptions that one was a spare. That spare is the one Mark is using for his earthquake stop testing. Bob and Janeen have verified that the "6th" SOS suspension is indeed in the 40m lab, and is in fact already cleaned and baked and ready for assembly. Today, Janeen ordered mechanical parts for a new spare for the 40m, as Mark assumes testing will be ongoing for a while.
  • Bob is assembling the 2 SOS's (for PRM and SRM) and 2 MOS's (for ETMx and ETMy), in preparation for suspending the optics.
  • Bob has finished baking, cleaning, and scanning the 24 OSEMs needed to complete the 40m suspended optics, and they are ready for installation.
  • Bob and Steve checked the DI water in the 40m South Annex; it is 2 MOhm. Helena says that we need 18 MOhm DI water for cleaning the remaining optcs before suspending them. Helena will thus prepare the PRM, SRM, ETMx and ETMy optics in the Bridge optics lab before bringing them over to the 40m, as she did with the already-suspended MC1, MC2, MC3, BS, ITMx, ITMy.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Alex Ourjoumtsev is now fully trained in laser safety.
  • We vented today (Thursday). Plan is to pump back down on Wednesday morning.
  • Dennis continues to work on a procedures manual for all 40m systems and components.
  • Two large storage containers (one for the 40m and one for CDS) were installed in the storage area south of the South Annex on Monday, with help from Bob. They're already filling up!
  • A UPS was installed in the vacuum controls rack, and Steve is running all the pumps to test its ability to hold the power.
  • The CC1 gauge controller has been reporting fluctuating pressure readings, and Steve reports that this is as expected, in our current pressure range.
  • Steve and Larry Jones made a filter for the N2 jet, to provide the cleanest jet for blast-cleaning the optics surfaces.
  • Camera mounts and illuminators for viewports, designed by Larry and fabricated at CES, are now in hand. An in-vacuum mirror for viewing the optics with the cameras is being cleaned by Helena.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob cleaned and has started the bake job on Janeen and Ken's HAM spacers. They will be ready on Wed. of next week.
  • Bob cleaned and assembled four Hybrid OSEMs for Janeen.
  • Bob cleaned and baked the Faraday Isolator parts for Mike. They are ready.
  • Bob cleaned and baked the camera mirror parts for Larry & Steve.
  • Bob has received the new RGA and will test it next week.

February 7, 2003

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu has prepared a set of transparencies summarizing his studies of PSL / MC frequency noise, which he will present at next Monday's commissioning telecon.
  • Osamu has compared his OLTF measurment of the MCL and MCF loops with the detailed model by Rana. He finds beautiful agreement iff an additional 4.5 msec phase delay is present in the MCL path. This is presumably due to the ADC (currently an ISC110B) and SOS dewhitener; at the sites, they use a Pentek and universal dewhitener.
  • Ben is arranging to replace the ISC110B and SOS dewhitener with a Pentek and universal dewhitener. Ben is testing a required Pentek Generic Input Module. This will go into the DSC rack to make use of the unused Pentek ADC channels there. When we have a MC ASC crate (with penteks, Pentium, and reflective memory), we'll move the MCL Generic Input Module to the MC rack.
  • Ben has calculated the required filtering on the MC2 universal dewhite boards, but will instead wait for Jay to hear from Russ or Rana to tell us the exact component values that they used instead of just the transfer function, so that the 40m boards are site compatible. (We will use rev B5 for the core optics, but Jay thinks there's a "rev B3+" for MC2).
  • Osamu measured the contribution to the frequency noise due to the coil drivers. This is negligible compared to frequency noise, but will become important for the main IFO asymmetric port noise (assuming frequency noise is rejected to 1% at the asymmetric port).
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Taylor):
  • All of the DSC's for the BS, PRM, SRM, ITMx and ITMy are complete and fully tested.
  • Ben has identified some ~ $90K in additional electronics purchases need to complete the end racks (Pentiums, Penteks, ISC110B's, and custom modules; for ETMx and ETMy DSC, and transmitted port sensing). He and Jay will begin purchasing this equipment.
  • Jay is drawing up a LIGO-I-like LSC system for the 40m dual-recycled IFO, and estimates that it will require ~ $100K in additional electronics.
  • We will hold off on the design of the WFS-based ASC system, for two reasons: it will be expensive and not essential at the beginning (we can use the oplevs, as at the sites), and new techniques for WFS at 200 MHz must be developed. However, Jay will leave room in the racks for an ASC system!
  • Ben has acquired a PZT driver and ordered a Kepco 100v PS to complete the MC alignment control system sensing and actuation system. Ben wrote a test procedure for the PZT driver, and has tested and installed it at the 40m. We also need the VME system and software, and Jay reports that Lori is nearly ready with it.
  • Our new and much-needed SR785 signal analyzer is not working correctly, and we are communicating with the manufacturer on how to fix it.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • Flavio has demonstrated better than -140 dB relative intensity noise between 80-2000 Hz (see plot) but there clearly are large contributions from acoustic noise on the PSL table, especially the HEPA filters. (Osamu sees the same thing). The target is -160 dB.
  • Ben is working on a repackaging of the ISS PD to mount it on a rigid block, making it less sensitive to acoustic noise.
  • After discussions with Stan, Rich believes that the excess noise is due to slew-rate limitation at high frequency (a time delay) causing a saturation at low frequency. One remedy being explored is to replace the amplifier in the laser current shunt (the actuator) with a faster one.
  • We have observed poor transmission through the PSL PMC, but Dennis suspects its due to mode-hopping of the laser. He observes large changes in laser power when the PSL FSS lock is re-acquired without first zeroing the slow loop slider. If lock is lost and re-acquired with a large slow loop slider value, the NPRO mode-hops. Everyone promised to follow the standard procedure of zeroing the slow loop slider before beginning to re-acquire lock. Meanwhile, Osamu and Alex Ourjoumtsev will re-measure the PMC transmission.
  • Alex Ourjoumtsev re-aligned the FSS reference cavity (FRC), and also the cameras and photodiodes looking at both the reflected and transmitted beams. He found that the FRC transmitted beam was almost completely off the monitoring PD, and fixed it.
• Optical sensing (Smith):
  • Osamu and Alex Ourjoumtsev have begun to assemble the main IFO sensing optics. They laid down most of the optics for the AP1 beamline, and made a list of missing parts. They will continue, with help from Lisa Goggin, with the SP, POB, POY, TRx, and TRy beams.
  • Alex is writing code and a nice GUI for calculating the beam size and Guoy phase for all beamlines in the main IFO.
  • OPTICS PARTS LIST, Orders pending: Input mode-matching telescope off-axis parabolic mirrors are expected end of Feb. from SORL; drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror are pending from Piezo-Jena.
  • IFO MODE-MATCHING TELESCOPE: All the MMT parts for the alternate (spherical mirrors) telescope are in house and are in process of being checked and assembled before cleaning and baking.
  • FARADAY ISOLATOR: The reworked Faraday isolator parts are being cleaned and baked.
  • OPTICAL LEVER ASSY Several parts of the optical lever focus lens assembly are being reworked to enable electrical isolation of the QPD from the table mounting base. The lenses were assembled into the lens tube.
• Optics (Billingsley, Armandula), suspensions (Romie), OSEMs (Bob):
  • Our BS, ITMx, and ITMy, are suspended and sitting on the South Annex clean room flow bench. They have clean OSEMs, are balanced and have been damped successfully, and are ready for installation as soon as we are.
  • Bob has the ETM suspension parts (MOS), and one of the two RM suspension parts (SOS), cleaned and baked. The other is still being used by Janeen. Bob is meeting with Janeen to go over all the parts, and begin assembly in preparation for suspending the remaining core optics.
  • Bob has 24 OSEMs for the remaining core optics suspensions assembled, tested, cleaned and baking; they get RGA scanned on Monday.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Dennis continues to work on a procedures manual for all 40m systems and components.
  • The fence enclosing the storage area south of the South Annex has been torn down to allow for the installation of two large storage containers on Monday (one for the 40m and one for CDS).
  • Dennis noticed an anomalous loss of N2 (used for vacuum valve pneumatics) during a switchover from one bottle to another, for unknown reasons. He has searched for, but found, no leak. He's seen no further evidence of anomalous loss.
  • A UPS was installed in the vacuum controls rack. Ever since then, the CC1 gauge controller has been acting funny, showing a much larger, and fluctuating, total pressure. Steve is back from vacation next week and will investigate.
  • Camera mounts and illuminators for viewports are still being worked at CES; expect them in 1-2 weeks.
• South Annex Bake Ovens (Taylor, Cardenas): Bob is cleaning and baking in-vacuum mirrors for camera views.

January 31, 2003

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu discovered a misalignment (of unknown but recent origin) in the input beam to the MC. He has re-aligned, and measured a MC visibility of 95% (was 96.5%). The frequency noise is back to where it was.
  • Osamu continues to investigate the origin of various noise sources in the PSL frequency noise as measured by the MC. He's developing methods to measure the contribution of various electronics noise (especially the VCO) to the frequency noise.
  • The large 7 Hz oscillation is associated with actuating with MC1 or MC3, and goes away when actuating with MC2. This has been traced to a phase delay in the SOS dewhiteners. MC2 also has an SOS dewhitener, but it was turned off. We will replace the MC2 SOS dewhitener with a universal dewhitener and AI board. Ben reports that these are now in fabrication.
  • The MC length control OLG shows a large delay, amounting to a loss of 50degrees of phase margin at 30 Hz. This has been traced to the fact that the length control signal is being digitized by an ISC 110B. At the sites, a Pentek ADC is being used. We will switch to a Pentek. For this we need a Pentek interface board and cable. Ben reports that the interface board is now being fabricated.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Taylor):
  • Ben and Dennis have finished testing all of the hardware and software for all 6 DSC's in rack 1Y4 (ETMx/ETMy, PRM/BS, and SRM/MC2), including all the satellite amplifiers, and they are now all working well.
  • Alex Ivanov fixed some remaining problems with the SRM DSC software.
  • Ben has inventoried all the electronics we need to complete the end racks (with DSC's for the ETMs) and the mode cleaner WFS system. He continues to work with the CDS group to obtain all the hardware.
  • To complete the MC alignment control system, We need a PZT driver and 100 V power supply; Ben will acquire these. We also need software, and Jay reports that Lori is nearly ready with it.
  • Jay is starting to look at the design of the main interferometer length control electronics, which will look like the Initial LIGO design. An Advanced-LIGO-like design is in the future.
  • Ben ordered and received a much-needed SR785 signal analyzer.
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • Ben continues to work with Fred Mann on a better design for the DC PD box, to allow for changes in height while staying as rigid as possible.
  • Osamu, Steve, and Alex Ourjoumtsev are preparing to work on the mode matching into the PMC to increase the transmitted power.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Received parts: Re-worked half-wave plates were received from KLC, for the Faraday isolator.
  • Orders pending: Input mode-matching telescope off-axis parabolic mirrors are expected end of Feb. from SORL; drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror are pending from Piezo-Jena. MMT telescope parts are being reworked. Alternative mirror holders for holding spherical mirrors are being fabricated.
  • IFO MODE-MATCHING TELESCOPE: A correct drawing was received from Piezp-Jena for the hole pattern in the PZT mirror. Modifications to the MMT drawings were made and parts were sent out for rework.
  • FARADAY ISOLATOR: The Faraday rotator was received from EOT, and the actual part dimensions are different than the data sheet dimensions. Therefore, several fabricated parts of the Faraday isolator assembly will have to be reworked to accomodate the actual dimensions of the Faraday rotator. Hopefully done in 1-2 weeks.
  • OPTICAL LEVER: Some of the mechanical parts for magnified focus lens are still in process of being fabricated.
  • Alex Ourjoumtsev is beginning to inventory all the components of the sensing beamlines.
  • Alex is also calculating the beam size and Guoy phase at all points in the sensing beamlines.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Dennis continues to work on a procedures manual for all 40m systems and components.
  • Steve did a vacuum test of an optical viewport that was accidentally chipped at CES, and it looked fine to him.
  • Rather than mount an in-vac mirror for camera viewing directly onto one of our viewports, Steve will have CES mount it onto a zero-length reducer flange, so that accidents like this won't happen again.
  • Camera mounts and illuminators for viewports are still being worked at CES; expect them in 2-3 weeks.
  • Steve ordered two large storage containers, one for the 40m and one for CDS. They'll sit outside in the cage to the south of the 40m.
• South Annex Bake Ovens (Taylor, Cardenas):
  • All bake ovens are in good repair and available.
  • Bob is on vacation.

January 24, 2003

• Plans for 40m: In the next few months, we expect to install most/all of the remaining instrumentation (suspended optics, DSCs, optical sensing trains, etc) to begin our interferometer experiment, *except* for the length and alignment control systems (LSC and ASC). These are complex and expensive systems. Without them, we can only control one or 2 degrees of freedom at a time. However, Jay points out that it is clearly too early to design a real Advanced LIGO control scheme, and thoughts on how to "do it right" are only beginning to take shape. One doesn't want to start too early, because computers and ADC/DAC modules keep getting better. Also, the 40m doesn't have multiple suspensions, and this will be a central issue in the design of the Advanced LIGO LSC and ASC systems. So, we should not rush into our "Advanced LIGO controls" experiment. However, we are eager to proceed with our "Advanced LIGO interferometry experiment". It should be possible to do so, with an Initial LIGO controls architecture, which might then have to be replaced with a better-thought-out Advanced LIGO controls architecture later on. We have to decide how to proceed in the near term!
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu continues to investigate the origin of various noise sources in the PSL frequency noise as measured by the MC.
  • He has traced the 60 Hz harmonics peaks to the MC2 DSC. If he length actuates instead with MC1 or MC3, the 60 Hz harmonics peaks go away. Under investigation.
  • The large 7 Hz oscillation, by contrast, is associated with actuating with MC1 or MC3, and goes away when actuating with MC2! Recall that MC1 and MC3 DSC's are in rack 1Y5, and operate at 2048 Hz; MC2's DSC is in rack 1Y4 and operates at 16384 Hz.
  • A big peak at ~16.5 Hz is believed to be the suspension bounce mode. Dennis has tried several notch filters designed with PHOTON, but they don't have much effect. Under investigation.
  • Loose screws in the PSL and AP1 tables were tied down by Steve and Larry.It made a small (~ 3 dB) improvement in the broad-band frequency noise.
  • The cluster of peaks from 500-700 Hz are likely due to vibrating mirror mounts on the PSL table. Osamu moved one mount from the periscope to the table and eliminated one peak at ~ 600 Hz. Osamu is pretty sure it's due to beam jitter (due to vibrating mounts) downstream of the PMC. We are considering stiffening the periscope.
  • Broadband frequency noise above 2 kHz is due to PMC and FSS noise. The frequency stability servo (FSS) has not been tuned up since we started actuating on the VCO with the MC error signal. The UGF is worse than before (it's ~ 250 kHz, should be > 1 MHz!). Osamu will continue to look at this.
  • Still, the frequency noise is now bettere than spec over most of the spectrum!
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Taylor):
  • Dennis and Ben found numerous problems with the DSC software, and then Alex Ivanov came in and fixed almost all of them! Now the DSC software loads correctly for all 6 DSC's in rack 1Y4 (ETMx/ETMy, PRM/BS, and SRM/MC2). There were lots of problems with the databases, and Dennis has fixed most or all of them. The rack power supplies were current limiting, so the current limits were set higher, but still safe. Numerous cabling problems were found and fixed.
  • Dennis and Ben have now checked out all of the new 6 DSC's, and they all damp MC2 well. All 8 satellite amplifiers (including ones for the ETMs) have been checked out. They have some problems (wrong gain resistors) which will be fixed, next.
  • Alex fixed it so that if the frame builder is rebooted, or if for any reason the DAQS crashes, it will automatically restart.
  • Still some problems: most but not all excitation test points work. Alex is still looking at it.
  • Also, the new Pentiums forget where they are supposed to go to find their startup.cmd; we don't know why. So, if/when they get rebooted, a laborious procedure must be followed to get the DSC code running again.
  • We still need to implement appropriate filtering for our 5" ("MOS") test mass suspensions; Jay says that, to lowest order, only the gain needs to be adjusted.
  • Ben has inventoried all the electronics we need to complete the end racks (with DSC's for the ETMs) and the mode cleaner WFS system. He's working with the CDS group to obtain all the hardware, and he just ordered 2 new VME crates that are required. Alex says that he will be ready to install the ETMx/y DSC software as soon as the hardware is in place.
  • We will push for completion of the MC alignment control. We need a PZT driver from CDS. Ben reports that Laurie will be available to implement the digital control software for the system during the "E9 lull in CDS workload" ;)
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini, S. Vass):
  • The laser power fluctuations observed by Osamu and Steve appear to be correlated with chiller temperature variations, and we suspect that the latter variations may be due to the ISS system; this is under investigation.
  • Flavio continues to make good progress on the ISS at the 40m PSL.
  • Ben is working with Fred Mann on a better design for the DC PD box, to allow for changes in height while staying as rigid as possible.
  • Osamu and Steve plan on improving the mode matching into the PMC to increase the transmitted power.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Received parts: Most of the mechanical parts for the mode matching telescope were received. Mounting collar for mounting the PZT tilt platform onto the DLC vacuum mirror mount and the mirror holder were received from CA Machine; but because of wrong hole pattern information, the mounting holes of the secondary mirror holder don't match with the PZT tilt platform and the mirror holder will have to be reworked..
  • Orders pending: Input mode-matching telescope off-axis parabolic mirrors are expected end of Feb. from SORL; re-worked half-wave plates are expected this week from KLC, for the Faraday isolator; drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror are pending from Piezo-Jena.
  • IFO MODE-MATCHING TELESCOPE: Because of wrong hole pattern information, the mounting holes of the secondary mirror holder don't match with the PZT tilt platform and the mirror holder will have to be reworked. Alternative mirror holders for holding spherical mirrors were designed and are being fabricated; spherical mirrors will be used in the interim until the parabolic mirrors are received. Hope to assemble system in next few weeks.
  • OPTICAL LEVER: Some of the mechanical parts for magnified focus lens are still in process of being fabricated.
  • FARADAY ISOLATOR: The HWP assembly from KLC is in shipment. All of the other parts have been cleaned and baked. Hope to assemble system in next week.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Loose screws in the PSL and AP1 tables have been fastened down.
  • Steve is working with Larry on a particle filter for the N2 purge line.
  • Steve is working with Larry on aluminum racks to hold chamber doors, to replace the wood ones.
  • CES mounted an in-vac mirror for camera viewing onto one of our viewports, but they chipped the glass on the viewport. Steve will do a vacuum test to see whether it presents a risk for installation.
• South Annex Bake Ovens (Taylor, Cardenas):
  • In-vacuum mirrors are being prepared for installation by Steve and Bob. They have been marking the mirrors with an etching pen, on the sides. They learned that mirrors from CVI need special low-temp baking or the coatings will peel off!
  • Bob is cleaning, baking, and testing the OSEMs that he built to complete all the 40m optics. He notes that we can expect a ~ 25% failure rate, but he can catch the failures early and reliably.
  • All bake ovens are in good repair and available.

January 17, 2003

• Student Alexei Ourjoumtsev, from Ecole Normale Superieure in Paris, is visiting us for 6 months. He will be focusing on the implementation, optimization, and characterization of the alignment sensing and control for our suspended-mass mode cleaner. He will also contribute to the commissioning of the our new faraday isolator and MMT systems (with Mike Smith), and our new optical sensing trains. Please make him welcome!
• A Safety audit team, headed by Bill Tyler, visited the 40 Meter lab on Thursday morning. A variety of safety and ergonomic issues were discussed with the 40m lab team, and action items identified.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • There was a lull in ISS commissioning and other activity, so that the MC was allowed to maintain lock continuously for 39 hours over the last weekend; it may be a record.
  • Osamu continues to measure and analyze the frequency noise of the PSL, using the mode cleaner error signal.
  • The 7 Hz oscillation that prevented the MC servo gain from being turned up, disappeared when MC2's suspension controls moved from the 1Y5 rack (running at 2048 Hz) to the 1Y4 rack (running at 16 kHz). It re-appears when length control is applied to Mc1 or MC3 (still in the 2048 Hz rack). This could have something to do with digital filtering on the ISC110B which digitizes the OSEM sensor signals. Investigation continues.
  • Now, a peak ~ 18 Hz dominates the MC frequency noise spectrum. It is likely that this is the suspension bounce mode, and Dennis will implement a digital notch filter for all 3 suspended optics.
  • There is a family of noise peaks at 500-700 Hz in the frequency noise spectrum. Osamu believes that he has traced it to mirror mounts on the periscope at the end of the PSL table. He will try different mirror mounting schemes.
  • Osamu traced broad-band noise to loose scres on the PSL and other optical tables. Larry Jones implementing some hardware to prevent these screws from vibrating.
  • Osamu continues to investigate the excess noise in the 40-200 Hz region, which he suspects is alignment noise in the MC suspensions. He is trying to excite the pitch and yaw of the mirrors, but the digital excitation points don't appear to be working.
  • Osamu is working with Alexei and Ben to implement alignment control of the MC launch beam.
  • Osamu found that the spectrum analyzer itself was contributing noise to the noise measurements, and is now filtering the signal being sent to the analyzer.
  • The line harmonic noise (60 Hz multiples) remains large, despite grounding of the DSC cables. We continue to investigate.
  • Ben remade the LO cable for the mode cleaner servo. The phase delay is now optimized.
  • Dennis and Ben altered the generic DAQ interface board to allow 16kHz MC signals (MC Trans and MC Refl DC light) to be brought into DAQ. Now, these signals are available in frames, dataviewer, and DTT.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Taylor):
  • Dennis and Ben insulated the backs of seven Satellite Amplifier Termination boards, and put them into the remaining 7 Sat Amps that we have for the 40m.
  • Dennis and Ben are now attempting to test the new suspension controllers with the 3 suspended optics that are still sitting on a bench in the South Annex: BS, ITMx, ITMy. They have assembled all the electronics and cabling. They are encountering a variety of problems with the DSC software for which they need the help of Alex Ivanov.
  • We still need to implement appropriate filtering for our 5" ("MOS") test mass suspensions. Ben will talk to Jay about this.
  • Bob has wired up as much as he can on the 1X4 end station rack, until Ben gives him more to do.
  • We will push for completion of the MC alignment control. We need a PZT driver from CDS. Ben reports that Laurie will be available to implement the digital control software for the system during the "E9 lull in CDS workload" ;)
• PSL and ISS (O. Miyakawa, B. Abbott, R. Abbott, F. Nocera, D. Ugolini):
  • Flavio, Rich, and Ben continue to work on ISS at the 40m PSL. Flavio is cleaning up all the cables and pickoffs, and will re-test with the PD downstream of the PMC (but still before the MC).
  • Osamu and Steve completed their measurements of the beam power everywhere on the PSL table, showing no anomalies in the power budget.
  • However, they observed noticable intensity variations, and they continue to investigate.
  • They plan on improving the mode matching into the PMC to increase the transmitted power.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Received parts: Some of the mechanical parts for the mode matching telescope were received.
  • Orders pending: Input mode-matching telescope off-axis parabolic mirrors are pending from SORL; re-worked half-wave plates from KLC, for the Faraday isolator; drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror, from Piezo-Jena. Mounting collar for mounting the PZT tilt platform onto the DLC vacuum mirror mount and the mirror holder, from CA Machine.
  • IFO MODE-MATCHING TELESCOPE: Some of the telescope mechanical parts are still in process of being fabricated. Hope to have the parabolic mirrors, and begin to assemble the telescope, within the month.
  • OPTICAL LEVER: Mechanical parts for magnified focus lens are in process of being fabricated by two outside machine shops. Hope to assemble prototype in next couple of weeks.
  • FARADAY ISOLATOR: The HWP assembly from KLC is in shipment. All of the other parts have been cleaned and baked. Hope to assemble system in next couple of weeks.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Dennis discovered that the autoburt system failed to create a "2003" directory, and thus did not store autoburt files for the 1st week of 2003. He has fixed it.
  • Housings for illuminators and cameras for the chamber viewports are still in fabrication at CES. Expect them in the next 2 weeks.
  • Beam tubes from ports to optical tables, specially designed by Larry, are still in fabrication at CES. Expect them in the next month.
  • The crane repairman repaired the vertex crane, and Steve reports that all 3 cranes are working properly.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob completed a bake job on the Faraday Isolator TGG rods and magnet.
  • Bob has prepared 12 long and 12 short OSEM coil bodies for the 40m and they are now in the oven for the hot bake @ 200C. He also has built enough boards to complete all the 40m OSEMs.
  • Steve and Bob have been marking the small in-vacuum optics with an etching tool, prior to clean / bake.
  • Bob continues to assemble an inventory of the clean room, and do maintenance on the bake ovens.

January 10, 2003

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu has been measuring and analyzing the frequency noise of the PSL, using the mode cleaner error signal. After much work, the noise is 10x lower than it was last month (between 40-400 Hz). Except for narrow-band peaks (60 Hz harmonics and an excess from 500-750 Hz which may be due to the periscope), the noise spectrum meets the spec from 50 - 10,000 Hz. see plot in 40m ilog.
  • The improvement was mainly due to the ability to turn up the MC length servo gain. The gain was limited because of the presence of a 7 Hz oscillation, which is believed to originate on the PSL table; Flavio saw it while working on the ISS. It might even be due to the ISS; this is under investigation. It's gone now, due either to changes in the ISS, OR due to the movement of the MC2 digital suspension controls from rack 1Y5 to 1Y4. Not sure, but we'll figure it out.
  • Anyway, with the 7 Hz gone, Osamu turned up the MC length control gain. He believes that this reduced the coupling of alignment noise in the MC suspensions to the MC error signal between 40-400 Hz, leading to the observed in total MC error signal in that band.
  • However, the line harmonic noise (60 Hz multiples) is now larger. This is likely due to the movement of the MC2 digital suspension controls from rack 1Y5 to 1Y4. Ben says that new cables definitely need better grounding, and he'll do that.
  • With the higher MC length control gain, the x-over frequency from length to frequency control has gone up from 6.7 Hz to 26.6 Hz. That has improved the noise and also the lock stability (no VCO saturation); however, the net effect is that the MC contributes less to the laser frequency stabilization.
  • To assess this, Osamu has compared the frequency noise to the required stability for the main interferometer (assuming CM rejection to 1%). He finds that we barely meet specs (a terrific achievement!), except in the region where GW sensing is optimized with RSE detuning (4000 Hz for the 40 m). A common mode servo will improve this.
  • We will measure the frequency noise (and CM rejection) with a short-arm Michelson core interferometer as soon as we have assembled one.
  • Osamu has assembled a frequency noise budget from many sources: seismic, PSL/FSS frequency noise, intensity noise, shot noise, mode cleaner sensing noise, PMC length noise. It almost saturates the total observed noise, but not completely. see plot in 40m ilog.
  • These results are very impressive, and Osamu will present them in a commissioning meeting very soon.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Taylor):
  • Our new DSC rack (1Y4) is almost fully instrumented. Four of 6 controllers (for MC2, BS, ITMx, ITMy) are fully working, but only the MC2 controller has yet been fully tested. Ben ran timing cables to all the front end controllers in the rack. The controllers for the two recycling mirrors require only a pentium and 2 penteks.
  • Dennis et al will test the new controllers with the 3 suspended optics that are still sitting on a bench in the South Annex: BS, ITMx, ITMy.
  • Dennis is looking into what filters need modification for our test masses, which are more massive than our SOS optics and with different pendulum, pitch, yaw frequencies.
  • Dennis and Ben are chasing down the source of the 60 Hz noise which appears to be associated with the MC DSC electronics.
  • Ben has assembled an inventory of electronics modules that will be needed to complete the End Racks. He talked to Todd, and they have worked out an agreement to fill the list.
  • Bob continues to work on the wiring of the south end (1Y9) rack, the east end (1X4) rack, and the auxiliary controls rack (1X1).
  • Ben installed a permanent (3m long) MC servo LO cable.
  • Still need to arrange for the MC Trans and MC Refl DC light to get to the DAQ for 16K logging.
  • We will push for completion of the WFS alignment control. We need a PZT driver from CDS, and the completion of digital ASC control software and hardware (at the sites, ASC for the MC is done with analog electronics).
  • Dennis and AJW are reviewing all the info that gets logged to frames from fast and slow channels, to make sure it is all correct and as desired.
• PSL (O. Miyakawa, M. Smith):
  • Osamu and Steve measured beam power everywhere on the PSL table. None of the PDs we have can take the full power; they are attenuating the power in various ways.
  • The power survey shows no anomalies, except for a large loss of power in the PMC transmitted beam (T < 50%; used to be ~ 80%, and should be ~ 87%). Presumably, the mode matching and/or alignment has been screwed up, and Osamu will re-optimize.
• Intensity stabilization (B. Abbott, R. Abbott, F. Nocera, D. Ugolini):
  • Flavio, Rich, and Ben continue to work on ISS at the 40m PSL, with their improved servo with two actuators: a DC-coupled path with LF actuation on the current adjust on the laser power supply, and an AC-coupled path with HF actuation on the current shunt on the laser package.
  • As of Wednesday, they've gotten it all to work, achieving intensity noise suppression of ~ 140 dB above a few hundred Hz, with large bandwidth. The remaining required 20 dB may be harder to get, for optical reasons (polarization-dependent effects, etc).
  • They did this with the ISS PD upstream of the PMC. Now, they're cleaning up all the cables and pickoffs, and will re-test with the PD downstream of the PMC (but still before the MC).
  • Ben sent packaged ISS PD's to all the sites: two to Hanford, and one to Livingston. These were followed by their tester boards, travellers, and test procedures. He is interfacing with Flavio regarding his use of the DC PD in his Intensity Servo.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Received parts: Faraday rotator from EOT was received and is being baked. All lenses for the optical lever prototype were received.
  • Orders pending: Input mode-matching telescope off-axis parabolic mirrors are pending from SORL; re-worked half-wave plates from KLC, for the Faraday isolator; drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror, from Piezo-Jena.
  • IFO MODE-MATCHING TELESCOPE: Telescope mechanical parts are in process of being fabricated. Hope to have the parabolic mirrors, and begin to assemble the telescope, within the month.
  • OPTICAL LEVER: Mechanical parts for magnified focus lens are being fabricated by two outside machine shops. Hope to assemble prototype in next couple of weeks.
  • IFO STEERING MIRROR: A purchase requisition for the mounting collar for mounting the PZT tilt platform onto the DLC vacuum mirror mount and the mirror holder was issued.
  • FARADAY ISOLATOR: Waiting on the HWP assembly from KLC. Hope to assemble system in next couple of weeks.
• Modeling of Advanced LIGO in E2E (Miyakawa): Osamu continues to work on the design of a dual-recycled summation cavity module.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Dennis has changed the passwords on all 40m lab accounts on all platforms.
  • Housings for illuminators and cameras for the chamber viewports are in fabrication at CES.
  • Dennis is working with TMC on our STACIS seismic isolation problems (which are multiplying). This will require some effort, but it not a high priority at the moment.
  • Per request from Bill Tyler, Steve assembled an inventory of all lab lasers, summarized all the things we did in response to last year's safety audit, and is assembling a folder full of safety information, minutes, etc.
  • The end cranes are now fully repaired and working, but the repairman broke the vertex crane in the process. Hope to have it fixed by the end of the week.
  • We will have a safety audit of the lab next week.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob did 6 bake jobs over the holidays, from Mike Smith and Janeen.
  • Bob cleaned, and is baking, the faraday isolator parts.
  • Bob repaired some problems with one bke oven, and is planning routine maintenance tasks.
  • Bob and Janeen have agreed on QC procedures for the OSEMs he's been building.
  • Bob gave a bunch of OSEMS that were for the 40m to Janeen, so he will be making new ones over the next month.
  • In response to a safety inspection of the South Annex, Bob has moved all the flammable cleaning chemicals to a locked cabinet in the gated area outside the lab. He has also arranged for carpenters to stiffen his equipment racks.

December 20, 2002

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • All 3 MC suspended optics are again damped. The MC length control is being applied to MC2. The MC now acquires and maintains lock reliably.
  • A lens on the PSL table was accidentally bumped, so Osamu realigned the beam all the way through to the MC. He then measured the visibility of the MC to be 95%, the best we've achieved so far.
  • Osamu had changed a filter on the PMC servo board and then turned up the gain on the PMC length control servo; UGF is now 7.6 kHz. As a result, frequency noise out of the PMC, as measured by the MC, has gone down significantly in the 100-500 Hz region.
  • Frequency noise as measured by the MC is now within specs above 200 Hz. From 50-200 Hz, we suspect that alignment noise dominates. We will check this by playing with the gain of the pitch and yaw damping servos for the MC suspensions.
  • We will push for completion of the WFS alignment control. We need a PZT driver from CDS, and the completion of digital ASC control software (at the sites, ASC for the MC is done with analog electronics).
  • At lower frequencies, there's lots of noise when the PSL enclosure HEPA filter is turned on. We're not sure if the noise is transmitted mechanically or acoustically; but we will try various acoustic and mechanical shielding.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Taylor):
  • Alex Ivanov is completing the remaining work on new software for the DSC system.
  • After chasing down some birthing problems with our newly-modified digital suspension controllers, all 3 MC suspended optics are nicely damped; many thanks to Alex Ivanov!
  • Dennis re-diagonalized MC2 after its controls moved to a different crate, and saw little change.
  • Dennis is looking into what filters need modification for our test masses, which are more massive than our SOS optics and with different pendulum, pitch, yaw frequencies.
  • Dennis and Ben are chasing down the source of the 60 Hz noise which appears to be associated with the de-whitening filter for MC2. We've been running with hardware dewhitening turned off for MC2. We suspect an ungrounded cable to the dewhitening board, and Ben will investigate.
  • Ben and Bob are running a few more cables: timing cables from the GPS fanout to the DSC front end crates; permanent (3m long) MC servo LO cable; cable for 16K readout of MCR and MCT power signals.
  • Bob continues to work on the wiring of the south end (1Y9) rack, the east end (1X4) rack, and the auxiliary controls rack (1X1).
  • Ben has placed an order with Todd for all our remaining needed electrooptics: LSCPDs, WFSs, QPDs, oplev QPDs, electrooptic shutter controllers.
  • We will need another GPS receiver and timing fanout module to service the front end crates for the end suspensions and for the LSC and ASC systems.
  • Dennis and AJW are reviewing all the info that gets logged to frames from fast and slow channels, to make sure it is all correct and as desired.
• PSL (O. Miyakawa, M. Smith):
  • Osamu and Steve are measuring the beam power everywhere on the PSL table.
  • After that, they will set the beam attentuators to provide maximum beam to the PMC, and appropriate levels of beam into the PMC reflected RFPD, the ISS PD, and then into the mode cleaner.
• Intensity stabilization (B. Abbott, R. Abbott, F. Nocera, D. Ugolini):
  • Flavio, Rich, and Ben continue to work on ISS at the 40m PSL.
  • They are hampered by intermittant very large intensity fluctuations which saturate their PD and servo. Osamu does not believe it's on the beam; we suspect the ISS PD itself. They will investigate.
  • They are developing a servo with two actuators: a DC-coupled path with LF actuation on the current adjust on the laser power supply, and an AC-coupled path with HF actuation on the current shunt on the laser package.
  • Ben is making several ISS PD's for the sites.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 3 each, 1in mirror mounts are pending from Newport; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; Faraday rotator from EOT; . The half-wave plates from KLC, for the Faraday isolator, are being re-worked to vacuum-compatibility standards. An additional set of servo controlled drive electronics to drive the x and y axes of the 2nd PZT vacuum IFO steering mirror was ordered. Lenses for the optical lever prototype were ordered.
  • IFO MODE-MATCHING TELESCOPE: Telescope mechanical parts are in process of being fabricated.
  • OPTICAL LEVER: Working drawings for magnified focus lens are complete and were released to DCC. RFQ's were sent out to two machine shops. Mike will design the required power supplies and controls for the lasers and the zoom lenses.
  • IFO STEERING MIRROR: The mounting collar for mounting the PZT tilt platform onto the DLC vacuum mirror mount and the mirror holder are in the process of being designed.
• Modeling of Advanced LIGO in E2E (Miyakawa): Osamu is studying the design of the power-recycled summation cavity in E2E, and how to generalize it for a dual-recycled summation cavity.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Larry Jones has designed housings for illuminators for the chamber viewports, and they have been sent to CES for fabrication.
  • Dennis is working with TMC on our STACIS seismic isolation pedestal problem (we have one, but they did not see it when we sent it back to them for repair).
  • Per suggestion from Helena, Steve is looking into replacing the HEPA filters, and installing a de-ionization bar, on our south annex flow benches.
  • Per request from Bill Tyler, Steve will assemble an inventory of all lab lasers, and will summarize all the things we did in response to last year's safety audit.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is working through a long list of bake jobs from Mike Smith and Janeen.
  • Bob is working with Janeen and the advanced suspensions crew to resolve problems with the OSEMs that he made for them.
  • We are looking into the purchase of a new RGA system (Dycor LC 200M) to replace one that is not repairable.

December 13, 2002

• Core IFO: We continue to work towards constructing a short-arm Michelson with our three newly suspended optics (BS, ITMx, ITMy). The digital suspension controllers are nearly ready and we hope to have 3 suspended optics (BS, ITMx, ITMy) damped in the next week or 2. (Exactly what I said last week!).
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Alex has completed most of the work on the digital suspension controllers (DSC), and all three suspended MC mirrors are now being damped with the new system. Osamu is working on re-aqcuiring MC lock as I write.
  • Osamu quantitatively compared the laser frequency noise as measured in the PSL PMC and in the suspended mass mode cleaner. He finds excellent agreement (ie, the MC frequency noise is saturated by the frequency noise transmitted by the PMC) in the ~300 - 20K Hz region, except for a broad peak around 500 Hz and a narrow one around 12 kHz. The origins of these excess noise peaks are unknown and will be hunted down.
  • Above 20kHz, shot noise in the PMC measurement dominates, and we will address this by increasing the laser power in the PMC. We had been attenuating the beam upstream of the PMC, and we will stop doing that, but not before Osamu completes new measurements with the MC.
  • Still on the to-do list: permanent (3m long) MC servo LO cable; cable for 16K readout of MCR and MCT power signals.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Taylor):
  • Alex Ivanov has nearly completed work on new software for the DSC system: upgrading the SOS controller software, new code for core optics controller hardware, DAQS and EPICS links, new EPICS screens, etc.
  • Ben and Bob have finished all mods to the 40m vertex suspensions wiring: moving MC2 controls from 1Y5-7 to 1Y4-33 and SRM controls from 1Y4-8 to 1Y4-33, including all the associated EPICS controls wiring and database changes.
  • Ben and Dennis have finished testing all the epics controls and readbacks for the 40m vertex suspensions controls.
  • All hardware for the 40m vertex suspensions controls are in place except for one Pentium and 2 timing modules, which are under test at Wilson House.
  • We now have all three suspended MC optics damped by the new system, and are close to being able to damp three more suspended optics (BS, ITMx, ITMy).
  • Bob continues to work on the wiring of the south end (1Y9) rack, the east end (1X4) rack, and the auxiliary controls rack (1X1).
  • Dennis put all of the STACIS readback info into master.config for logging to frames.
• PSL (O. Miyakawa, M. Smith):
  • Osamu continues to study PSL PMC noise, as discussed above.
  • A lens near the PMC was bumped yesterday, and Osamu is working on re-establishing good alignment of the beam downstream.
  • Osamu finds that the PSL PMC frequency noise requirement (T990025-00-D, p28, fig18) is inconsistent with the overall PSL frequency noise requirement (T990025-00-D, p19, fig9, or T970080-09-D, pg 10, table 1). Fortunately, the PMC performs at least a factor 10 better than the design requirement (even on our noisy PSL table), allowing us to (just barely) meet the overall PSL spec.
  • Steve purchased a compact laser power PD to make it easier to study the laser power everywhere on the crowded PSL table.
  • Ben worked with Flavio on the ISS actuation at the 40m.
  • Ben continues to test the DC PD for ISS to prepare it for delivery to the sites in time for S2.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Received parts: 3 PZT tilt platforms and 1 servo control drive electronics and strain gauge read-out electronics from Piezosystems Jena.
  • OPTICS PARTS LIST, Orders pending: 3 each, 1in mirror mounts are pending from Newport; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; Faraday rotator from EOT; . The half-wave plates from KLC, for the Faraday isolator, are being re-worked to vacuum-compatibility standards. Only one set of servo controlled drive electronics to drive the x and y axes of the two PZT vacuum IFO steering mirrors was inadvertently ordered. A second set will be ordered.
  • Part numbers were scribed and the in-vacuum mirrors and beam splitters are being cleaned and baked.
  • FARADAY ISOLATOR: Faraday Isolator mechanical parts and polarizing prisms for Faraday isolator have been cleaned and baked, and are awaiting assembly. Hope to have it ready for installation by next month.
  • IFO MODE-MATCHING TELESCOPE: Telescope mechanical parts are in process of being fabricated. Hope to have it ready for installation by next month.
  • OPTICAL LEVER: Working drawings for magnified focus lens are almost complete. Hope to have an assembled prototype by next month.
  • Mike assembled a list of electro-optical parts (LSCPD's, WFS's, QPD's, oplev QPD's, EOS's) needed to complete the core IFO sensing, and Mike and AJW have "placed the order" with the Wilson House, through Ben.
• Modeling of Advanced LIGO in E2E (Miyakawa): Osamu continues to come up to speed with E2E / Han2K / SimLIGO in his spare time, and is making progress.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Steve fitted a video camera with a telecope and can now easily see the wire, standoff, and magnet assemblises on the optics, *through* the OSEM hole. This will be very helpful during installation, debugging, and repairs of our suspended optics in the vacuum chambers.
  • A STACIS seismic isolation pedestal was oscillating, so we sent it back to TMC for repair. They found nothing wrong with it, and returned it to us. Steve and Dennis have re-installed it, and it is still misbehaving. Sigh.
  • Steve purchased some needed video monitors.
• South Annex Bake Ovens (Taylor, Cardenas):
  • A load of mechanical parts for the 40m Faraday Isolator has been cleaned, baked, scanned, and packaged with traveller, ready for assembly.
  • Bob has bake loads in 3 ovens: some 40m OSEM parts; stainless steel for Janeen, and a big Al load for Janeen.
  • Several more bake loads are in the queue.
  • Bob wants to purchase a new RGA system (Dycor LC 200M) to replace one that is not repairable.

December 6, 2002

• Core IFO: We continue to work towards constructing a short-arm Michelson with our three newly suspended optics (BS, ITMx, ITMy). The digital suspension controllers are nearly ready and we hope to have 3 suspended optics (BS, ITMx, ITMy) damped in the next week or 2.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Currently, work on the digital suspension controllers (DSC) means that the MC cannot acquire lock. We hope to get back to MC lack in the next few days.
  • Osamu measured the intensity noise after the PSL PMC, and estimated its contribution to the frequency noise in the PSL as monitored by the MC. It is ~ 50db below the observed frequency noise (ie, negligible). It contributes due to a non-zero offset of the MC servo from exact resonance; Osamu estimates this to be around 6e-12 m. It's different from lock to lock; Osamu will study the variations. It is possible to better zero this offset, but Osamu does not think that it will be necessary, since the contribution to frequency noise is so small. However, this intensity noise will contribute to noise in the main IFO GW channel due to the imperfect contrast defect; so it definitely should be reduced (by the ISS servo, being commissioned now).
  • Steve and Osamu have searched for couplings of mechanical and/or acoustic noise onto the beam in the PMC and MC. They find no evidence for noise from the air conditioning, vacuum pumps, room lights, etc.
  • On the other hand, they have determined that the PMC, mounted firmly on the PSL table, is very sensitive to mechanical and/or acoustic noise at the PSL table. A small tap on the table or table legs is easily seen in the PMC servo error signal. This introduces intensity and frequency noise onto the beam. (No such coupling was observed for the frequency stability servo). This noise is clearly seen in the MC frequency noise spectrum.
  • Osamu and Steve are investigating two fixes: the first is to better isolate the PMC from noise. Steve is trying out different acoustic shields, and is thinking about placing the PMC on a sheet of rubber. He will check out the effect of the laser cooling water.
  • Another fix is to increase the PMC servo gain to tie it better to the quiet (FSS-stabilized) input beam. Osamu noted that the PMC servo gain was limited by a 66 kHz (mechanical) resonance; the notch filter in the servo card was not well tuned to that resonance, even with the trim pot turned all the way. Osamu changed a capacitor on the board, and successfully notched out the resonance. He was able to turn up the PMC gain slider from 15 dB to 30 dB, increasing the UGF from 1.5 kHz to 5.8 kHz (spec is 3.0 kHz). He will check the effect of these changes on the beam (as monitored by the MC error signal) as soon as th upgrade of the DSC system is complete (so that we can re-aquire MC lock).
  • Still on the to-do list: permanent (3m long) MC servo LO cable; cable for 16K readout of MCR and MCT power signals.
• Core digital suspension controllers (DSC), and other Electronics (B. Abbott, Taylor):
  • Alex Ivanov has been working hard on software for the DSC system: upgrading the SOS controller software, new code for core optics controller hardware, DAQS and EPICS links, new EPICS screens, etc.
  • Ben has finished re-drawing the wiring diagrams for the 40m vertex suspensions. These changes include moving MC2 controls from 1Y5-7 to 1Y4-33 and SRM controls from 1Y4-8 to 1Y4-33. It also included all of the associated epics control and other changes that was dictated by these other changes.
  • Ben has most or all of the modules in place, and he and Bob are making the wiring changes. Hope to be complete by the end of the week!
  • Dennis is helping with the CPU boards, boot software, EPICS data bases, etc, in the DSC electronics rack (1Y4).
  • Bob continues to work on the wiring of the south end (1Y9) rack, the east end (1X4) rack, and the auxiliary controls rack (1X1).
  • The stand-along SOS analog suspension controller that we borrowed from Betsy will be used by Paul Russell for Janeen's earthquake stop rework prototyping (which ises an SOS borrowed from us).
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Received parts: 1.5 in and 2.0 in fixed vacuum mirror mounts.
  • Orders pending: 3 each, 1in mirror mounts are pending from Newport; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; Faraday rotator from EOT; 3 PZT tilt platforms and 2 servo control drive electronics and strain gauge read-out electronics from Piezosystems Jena.
  • In-vacuum mirrors and beam splitters are being cleaned and baked.
  • FARADAY ISOLATOR: Faraday Isolator mechanical parts are being cleaned and baked. Polarizing prisms for Faraday isolator have been cleaned by Helena and are ready for baking. The half-wave plates from KLC, for the Faraday isolator, are being re-worked to vacuum-compatibility standards. Expect the Faraday Rotator in a couple of weeks. Hope to have a complete system within a month.
  • IFO MODE-MATCHING TELESCOPE: Telescope mechanical parts are in process of being fabricated. Expect off-axis parabolic mirrors in a month, Hope to have a complete system shortly thereafter.
  • OPTICAL LAYOUT: An ASAP ray model of the 40m IFO optical beams is complete. An evaluation copy of Hijaak, file conversion software, was used to convert the ASAP graphic files to DWG drawing files, which were then x-refed onto the integrated layout drawing. Ghost beams were generated; beam dumps, baffles, and pick-off mirrors were placed and oriented in the integrated layout drawing to agree with the ASAP model.
  • OPTICAL LEVER: IR laser and projection telescope for optical lever prototype were received. Working drawings for magnified focus lens are in process. A cheaper and more local source for a suitable 830-nm laser has been found. The laser power / controls must be designed.
  • INITIAL POINTING BEAM A pick-off beam to monitor the position of the initial pointing beam on the power recycling mirror was added to the integrated layout drawing.
• Optics (Billingsley, Armandula), suspensions (Romie), OSEMs (Bob):
  • Our BS, ITMx, and ITMy, are suspended and sitting on the South Annex clean room flow bench. They have clean OSEMs, are balanced and have been damped successfully, and are ready for installation as soon as our DSC system is ready for them.
  • Mods to the ETM suspension parts (MOS) are complete. Bob Taylor has the traveler and reworked parts for cleaning and baking.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Steve replaced the backup batteries on the maglev turbopump (TP2) power supply.
  • Larry Wallace ordered a UPS system for our vacuum rack, to replace the one that tripped off 2 weeks ago, bringing the vacuum controls down.
  • The misbehaving STACIS seismic isolator (SENW-x) was repaired by TMC and is enroute back to us.
  • CES is working on the anodized custom beam tubes (between chamber viewports and sensing tables) that were designed by Larry Jones; should be ready by January.
  • CES is working on the camera viewport mounts and in-vacuum mirror mounts for the cameras that view the core optics beam spots, that were designed by Larry Jones; should be ready by January.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is working through many bake jobs for the coming months, including parts for the Faraday Isolator and MMT, in-vacuum mirrors, OSEMs, and 6 loads for Janeen.
  • Bob has received a re-worked RGA head for oven C. A second re-worked RGA head (a spare) was sent back due to many problems.

November 22, 2002

• Core IFO: We continue to work towards constructing a short-arm Michelson with our three newly suspended optics (BS, ITMx, ITMy). The suspended optics are ready to go. Currently, there's much effort towards getting the digital suspension controllers for those optics going. Mike Smith is assembling a faraday isolator and crude mode matching telescope.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • After re-aligning our two IOO pockels cells, Osamu got the MC visibility up to 91.7%.
  • Osamu is reviewing all the RF signals in the MC controls rack, and determined the optimal signal strength for the local oscillator into the MC servo to get the strongest and cleanest error signal.
  • Osamu optimized the gain on the PSL frequency stability servo (FSS). He turned the gain up a bit from where it was before. This allowed him to turn up the MC servo gain in both paths. As a result, the mode cleaner servo UGF could be pushed up from ~ 50 kHz to 67 kHz, with a phase margin of 28degrees. The resultant frequency noise is now a few dB lower.
  • The PSL frequency noise as measured by the MC (in loop) is now close to specs, but there remains excess noise: seismic, from 10-30 Hz; acoustic, from 30-300 Hz; (believed to be) acoustic, from 300-3000 Hz; and electronic, above 4 kHz. Osamu will continue to investigate.
  • Dennis and Ben made another phase shifting cable for the MC servo This one is longer, as we were 180 deg. off for the last one. We can now lock using this cable; but it's a temporary BNC-to-SMA; a proper permanent (3m long) cable will be made soon.
  • Ben has made a path for the mode cleaner fast signals into DAQ. Filters on the AA DAQ interface board have been switched to 16 kHz. Some of the gains need to be adjusted to deal with the signals at hand. And, one more 4-pin-lemo cable needs to be run. One channel, at least, is being correctly read out, and a DTT spectrum looked right. However, it looks like one half of an ISC110b ADC (16 of 32 channels) is dead.
• Core digital suspension controllers, and other Electronics (B. Abbott, Taylor):
  • Rolf says that Alex will work towards getting digital suspension controller software up and running for our vertex core suspensions. He's already putting 2 VME pentiums through their paces. The DAQS system will have to be upgraded (in particular, the test point manager in DAQSCTRL0, so that we can excite pitch and yaw degrees of freedom with GDS). The SOS control software will also be upgraded. And, he will arrange to have EPICS screens automatically generated for the 40m, as well as for the sites.
  • Rolf tells us that we can't control 5 vertex core optics (BS, PRM, SRM, ITMx, ITMy) with only 2 front-end output crates, as we originally thought. Ben is rearranging some of the crates in the 1Y4 and 1Y5 racks to allow another output crate.
  • Rolf tells us that we can extract data from the DSC reflective memory into EPICS, using a Sun EPICS server (this is a new and welcome development). We will get a new Blade 100, and are scrambling to find 2 reflective memory PCI cards (VMIPCI-5579) for the DAQS and DSC reflective memory networks. An alternative is to use our under-utilized br40m, which already has a DAQS reflective memory PCI card.
  • Rolf tells us that we will want to upgrade to 2 Giga Baud Reflective Memory with Fiber Optic connections (Our current RM network is 250 MB). We'll need on the order of 10 cards, at ~ $2K/card.
  • Ben has finished testing the epics control of the core optics DSC rack, after fixing some problems.
  • Bob has moved crates from the south end (1Y9) rack to the east end (1X4) rack, which has been wired and powered. Now he's working on the south end rack.
  • Dennis has almost completed and checked out the EPICS database for the EPICS control (C1MOSAUX) in the core optics DSC rack (1Y4). It successfully exhanges information with the watchdog code in 1Y5.
  • All of the Pentiums for 1Y4 are now in hand, and the Penteks should be by the end of next week. All cables, satellite amplifier boxes, etc, are ready.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 3 each, 1in mirror mounts are pending from Newport; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; IFLEX1000 IR laser for optical lever is pending from Point Source Ltd; ; polarizers for Faraday isolator from KLC; Faraday rotator from EOT; 3 PZT tilt platforms and 2 servo control drive electronics and strain gauge read-out electronics from Piezosystems Jena; 1.5 in and 2in fixed vacuum mirror mounts from ASCO are expected by 11/16/02.
  • FARADAY ISOLATOR: Faraday Isolator mechanical parts were check-assembled and are ready for cleaning and baking. The half-wave plates were received from KLC, but they will be sent back for re-work since they were not manufactured to vacuum-compatibility standards.
  • IFO MODE-MATCHING TELESCOPE: Working drawings for the telescope mechanical parts are complete and were released to the DCC. An RFQ package was sent to two machine shops for bid.
  • OPTICAL LAYOUT: An ASAP ray model of the 40m IFO optical beams is complete except for the two end chambers. Ghost beams were generated and beam dumps, baffles, and pick-off mirrors were placed and oriented in the ASAP model. An evaluation copy of Hijaak, file conversion software, was obtained in order to convert the ASAP graphic files to a DWG drawing file that can be imported into the ACAD 40m optical layout.
  • Alignment: Mike has all the equipment for initial alignment of the 40m core IFO and sensing beams, including an 850-nm laser with a reticule pattern.
• Optics (Billingsley, Armandula), suspensions (Romie), OSEMs (Bob):
  • Our BS, ITMx, and ITMy, are suspended and sitting on the South Annex clean room flow bench. They have clean OSEMs, are balanced and have been damped successfully, and are ready for installation as soon as our DSC system is ready for them.
  • Janeen made small changes to the 40m test mass suspension top assembly drawing.
  • Bob continues to assemble and test OSEMs for the remaining 40m suspensions, and for other projects. Janeen is using one of the 40m SOS's for earthquake stop testing.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Our PEM EPICS server cpu (particle counter, STACIS, weather station) was crashing daily. Dennis commented-out the reading of the weather station, which is half broken and useless anyway, and the crshes have disappeared.
  • Steve reports that the vacuum system has been running in "vibration-free" mode (ion pumps only) for 22 days, with no problems, and AMU 41 peak has been low (previously, the IP's were belching on occasion; this has stopped happening).
  • The vacuum controls crate lost power shortly after midnight on November 20. This appears to have been caused by the UPS system tripping off. Steve notes that the battery was due to be replaced 2 months ago. The hardware interlocks all worked correctly, and the vacuum system experienced no problems. Steve has taken the UPS out of the system. He'll replace the battery, but it is not clear whether we want this thing back in! We will investigate UPS systems for other places around the lab.
• South Annex Bake Ovens (Taylor, Cardenas): Bob is scheduling many bake jobs for the coming months, including parts for the Faraday Isolator and MMT, in-vacuum mirrors, OSEMs, and 6 loads for Janeen.

November 15, 2002

• Core IFO: We continue to work towards constructing a short-arm Michelson with our three newly suspended optics (BS, ITMx, ITMy). We need to complete, and commission, the digital suspension controllers for those optics; assemble and install a faraday isolator, mode matching telescope, optical levers, and cameras. And, we won't have length or aligment control systems. We will rig something up with SR560's to control the Michelson.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Dennis and Ben made the phase shifting cable for the MC servo local oscillator (we had been using a Marconi for the task!). The LO signal is now 20 times bigger than before, increasing the gain by that amount. We will need to turn the gain back down in order to get the MC to lock. Work in progress.
  • Osamu has measured the intensity noise at the MOPA, the PMC, and the output of the MC. The MC intensity noise has a big broad peak at the pendulum (1 Hz) and pitch and yaw resonances. Osamu measured these spectra with the PSL enclosure HEPA filter on and off, and he sees a huge difference, a clear factor 10 above 200 Hz.
  • The intensity noise out of the PMC is a bit higher than out of the MOPA; Osamu suspects acoustic noise introducing intensity noise in the PMC, and will continue to investigate.
  • Osamu measured the PSL frequency noise using the MC as an out-of-loop reference. With the HEPA filter turned off, the frequency noise is almost within spec above 300 Hz. Osamu will optimize this by adjusting the gain in the PSL frequency servo.
  • In both the intensity noise and frequency noise spectra, acoustic noise appears to dominate below 300 Hz. Osamu will investigate and try to track down the source.
  • Steve and Larry Jones are investigating ways of making the MC2 suspension chamber less sensitive to people walking by.
  • Ben and Dennis continue to work on getting the mode cleaner fast signals into the DAQ at 16384.
• Electronics (B. Abbott, Taylor):
  • Bob has completed the cross-connect wiring for 1X4, the east end rack, and powered it up. He will move to 1Y9 (the south end rack) next. Power for 1Y4 (the DSC for the vertex core suspensions) is in.
  • Dennis booted up the EPICS control cpu (C1MOSAUX) in 1Y4, the DSC for the vertex core suspensions. Dennis has put together the EPICS database for it, and Ben has put together the EPICS screens. Ben and Lisa Goggin have begun checking out the EPICS controls They're having some trouble with the switch control through the XYCOM 220. Work in progress.
  • Ben has delivered the remaining 7 suspension satellite amplifier boxes required for the core optics.
  • Ben is acquiring hardware for the end racks (DSC, oplev, etc). He is also acquiring optical levers and other components necessary for suspensions completion.
  • We await installation of the code for the core optics suspension controller rack (1Y4) by Rolf and/or Alex. Their availability is in question...
  • All of the Pentiums for 1Y4 are now in hand, and the Penteks should be by the end of next week.
  • Ben continues to work on the interface between the Glasgow suspension electronics and CIT electronics. He has begun testing the Dspace whitening interface board, and it seems to be functional, and working as expected so far.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 3 each, 1in mirror mounts are pending from Newport; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; IFLEX1000 IR laser for optical lever is pending from Point Source Ltd; ; polarizers and half-wave plates for Faraday isolator from KLC; Faraday rotator from EOT; 3 PZT tilt platforms and 2 servo control drive electronics and strain gauge read-out electronics from Piezosystems Jena; 1.5 in and 2in fixed vacuum mirror mounts and an adapter spacer from ASCO are expected by 11/16/02.
  • FARADAY ISOLATOR: Faraday Isolator mechanical parts were received from CA Machine Co. Mike will begin to assemble it, soon.
  • IFO MODE-MATCHING TELESCOPE: Working drawings for the telescope mechanical parts are expected to be completed by 11/15, and will be sent out for quotes shortly thereafter.
  • OPTICAL LAYOUT: An optical layout of the 40m IFO using ASAP has verified the ACAD layout that was based on hand calculations of the beam trajectories. Ghost beams will be generated with ASAP to determine the detailed placement of pick-off mirrors and beam dumps, etc.
  • Mike will try to add a QPD just before the beam enters the main IFO, to monitor drifts in the beam position there. The beam angle will be monitored by a QPD ("initial pointing") at the east end.
• Optics (Billingsley, Armandula), suspensions (Romie), OSEMs (Bob):
  • Our BS, ITMx, and ITMy, are suspended and sitting on the South Annex clean room flow bench.
  • Last week, Steve and Osamu swapped out dirty OSEMs for clean ones in our ITMx, ITMy, and BS, in the South Annex test bench. Although the ITMs (on bigger suspension towers) damped just fine, the BS did not damp properly (with our test-bench stand-alone analog suspension controller). The wire was found to be touching the side magnet stand-off. On advice from Janeen, Helena, and Betsy, Steve replaced the wire according to procedures. But, the new wire is also touching the side magnet stand-off. And, it still did not damp properly. Bob made a 40m long suspension controller cable and ran it from our digital suspension controller system to the test bench where the BS is sitting. It damped well, with no problem. We conclude that the stand-alone analog suspension controller has developed a problem which shows up only for SOS's. Anyway, we now have a working suspended BS and a nice long cable for running the DSC to the South Annex test bench.
  • Janeen wrote up the DCN for the the remaining two 40m TM suspension changes. Dennis signed the DCN and the test mass supsension parts are at CES for rework. Mike expects to complete the work by Thanksgiving. Bob Taylor is expecting them on Dec 2nd for cleaning and baking. They will be assembled soon after that.
  • Janeen borrowed one of our unassembled SOS suspensions for prototyping some earthquake stop re-designs.
  • Bob continues to build and clean OSEMs. He has enough long and short OSEM bodies to build all the remaining ones needed for the 40m core optics.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Dennis is arranging the shipment of one of our STACIS seismic isolators (SENW-x) to TMC for repair.
  • Larry Jones will work on camera mounts for viewing the suspended core optics.
  • Larry Jones is designing beam tubes from the IFO exit ports to the optical sensing tables.
  • Steve is arranging for crane power disconnects / protection to be installed on all of our cranes.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob reports that two RGA heads sent to Dycor for repair will cost $4660.

November 8, 2002

• Core IFO:
  • We are working towards constructing a short-arm Michelson with our three newly suspended optics (BS, ITMx, ITMy).
  • We should have complete suspension controllers for those optics in the next couple of weeks, and aim to have them installed into the vacuum chambers, and damped, by the end of this month.
  • We won't have final versions of three key elements of the input optics (from the suspended mass mode cleaner into the core IFO) for another couple of months: Faraday isolator, MMT, and steering mirrors. Without a finished Faraday isolator, we are investigating various ways to bring out the bright port signal for locking the Michelson.
  • We also won't have final versions of the optical lever telescopes, so we will assemble temporary versions. We are working towards having cameras looking at all the suspended optics.
  • And, we won't have length or aligment control systems. We will rig something up with SR560's to control the Michelson.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • ISS work at the PSL has meant that the MC has not been maintained in lock for most of this week.
  • Osamu and Steve continue to study effect of seismic and acoustic noise (at MC2) on the MC lock stability.
  • Steve discovered that there is a channel in the concrete floor cutting east-west right underneath the MC end chamber; this is likely contributing to the sensitivity of our MC lock to motion near that chamber. Steve proposes supporting the MC end chamber table on some steel beams to "bridge" the channel.
  • Osamu measured the mode-cleaner frequency noise while *clapping*, and found a significant increase in the noise between 200 Hz and 1 kHz, suggesting that acoustic noise dominates here. It may be coming in through the PSL enclosure, and we are considering acoustic shields such as are employed at the sites.
  • Osamu found that an increase in the MCA gain causes an exponentially- growing 7 Hz oscillation that quickly saturates the VCO path and breaks lock. He thinks it is a result of a 7 Hz resonance in the end chamber stack, and will continue to investigate.
  • Osamu found that if you increase the normal daily seismic noise by about a factor of 4, the MC will not be able to hold lock. So nobody should be kicking the end chamber.
  • Ben made a generic DAQ interface card to get the mode cleaner fast signals into the DAQ at 16384, and has made and run the cables to the DAQ rack. He's swapping the filter chips in the anti-alias chassis.
  • Dennis and Ben will get the fast channels into master.config.
• Intensity stabilization (B. Abbott, R. Abbott, F. Nocera, D. Ugolini):
  • Ben and Flavio continue to work on the PSL ISS, which is working, but an order of magnitude short of spec.
  • Seven ISS DC photodiode PCB boards are stuffed, and await testing.
• Electronics (B. Abbott, Taylor):
  • Bob assembled the cross-connects for the two end racks (for the ETM suspension controllers, and transmitted beam sensing). He is already beginning the wiring on the east end. Ben is populating the racks with crates and modules.
  • Dennis and Ben are getting ethernet into our core optics suspension controller rack (1Y4).
  • Rolf says that the code for the core optics suspension controller rack (1Y4) is very similar to the sites and should take only 2 days to install.
  • Jay plans to think about the mode cleaner digital WFS code with Laurie.
  • All of the Pentiums for 1Y4 are now in hand, and the Penteks should be by the end of next week.
  • Ben continues to design the interface between the Glasgow suspension electronics and CIT electronics. The Dspace whitening interface boards are being stuffed.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 3 each, 1in mirror mounts are pending from Newport; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; IFLEX1000 IR laser for optical lever is pending from Point Source Ltd; ; polarizers and half-wave plates for Faraday isolator from KLC; Faraday rotator from EOT; 3 PZT tilt platforms and 2 servo control drive electronics and strain gauge read-out electronics from Piezosystems Jena; 1.5 in and 2in fixed vacuum mirror mounts and an adapter spacer from ASCO are expected by 11/16/02; Faraday Isolator mechanical parts from CA Machine Co are expected by 11/9/02.
  • FARADAY ISOLATOR: Awaiting parts.
  • IFO MODE-MATCHING TELESCOPE: Redesign of the remote focus mechanism for telescope housing are almost complete; a vertical degree of freedom adjustment was added to the secondary mirror mount, similar to the LIGO design.
• Optics (Billingsley, Armandula), suspensions (Romie), OSEMs (Bob):
  • Our BS, ITMx, and ITMy, are suspended and sitting on the South Annex clean room flow bench.
  • Steve, Dennis, and Osamu have swapped the dirty OSEMs on our suspended ITMs with clean ones, and rebalanced them. They're having a lot of trouble with the BS, which isn't damping properly. The wire appears to be touching the side magnet. Investigation continues.
  • Janeen is writing up the DCN for the the remaining two 40m TM suspension changes. She expects that the re-machining should take a week, and then another week for cleaning and baking.
  • Janeen will borrow one of our unassembled SOS suspensions for prototyping some earthquake stop re-designs.
  • Bob continues to build and clean OSEMs.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • Dennis is working on getting RGA information into the DAQ system.
  • Dennis is pusuing repair of one of our STACIS seismic isolators (SENW-x).
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is baking more OSEM parts. He's preparing for a big (600+ pieces) bake job for Janeen.

November 1, 2002

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu is studying the effect of seismic and acoustic noise (at MC2) on the MC lock stability. He estimated the contribution of seismic and acoustic noise to the MC frequency noise, and it quantitively explains the noise spectrum below 30 Hz (but he's still working on refining this). Seismic noise at the 40m is 10 times noisier than typical seismic motin of 10^(-7)/f^(-2).
  • Osamu finds that lock is lost after an impulsive event (deep-knee bends near MC2, shouting, etc) with low frequencies, below a few Hz. Lock is lost when the MC frequency loop error signal runs out of dynamic range. The MC length loop does have enough dynamic range, but not enough gain. The proposed cure is to increase the length path gain at low frequencies, which is difficult because of a 7 Hz oscillation in that path at high gain, which Osamu does not yet understand. He will continue to investigate the MCL path.
  • The MC beamtube appears to act like a microphone, amplifying acoustic noise at the MC2 table. The MC2 table itself may also be behaving this way, with a resonance at ~ 50 Hz.
  • Steve put a box of sand around the MC beamtube to damp acoustic noise from propagating into MC2; Osamu finds that it does indeed reduce vibrations at the MC2 table by 5-20 dB between 10-500 Hz.
  • Two notable acoustic noise sources are the dry scroll pumps and the HEPA filter on the PSL enclosure. These generate +20 dB noise peaks at the MC2 table, at 830 and 500 Hz, respectively. These don't seem to affect the lock, and Osamu does not think these are a problem.
  • Dennis is working on implementing a resonant gain stage in the MC length path, at the bounce frequency of 16.3 Hz. So far, it just causes the MC to lose lock; Dennis continues to tune the parameters. (The work is hampered by the fact that we still don't have fast MC signals in DTT/DAQ; but we will, soon).
  • An earthquake (4.8M) a couple of days ago knocked all the suspensions out of whack, and the watchdogs that limit the actuation appear to have worked correctly.
• Intensity stabilization (B. Abbott, R. Abbott, F. Nocera, D. Ugolini):
  • Ben continues to work with Flavio and Rich on the testing of the Intensity Stabilization Servo (ISS) at the 40m.
  • Ben continues to stuff the ISS DC photodiode PCB board.
• Electronics (B. Abbott, Taylor):
  • Ben has consulted with Richard M about how to get fast signals from ISS and MC into DAQ. He has a second DAQ interface board, and there should be sufficient empty channels in our DAQ Lemo Intfc Board to accomodate them.
  • Ben has begun stuffing the end racks (mostly DSC stuff for the ETMs) in order to get an idea of what we have, and what we need. Bob will start working on the cross-connects for these racks.
  • Steve and Bob have made implemented protective trays and cable strain relief for the 3 installed satellite amplifiers.
  • Ben is testing 7 more satellite amplifiers for the core optics DSCs.
  • Completion of the vertex core optics DSC system (rack 1Y4) awaits Penteks, Pentiums, and software. We aim to have a working system in 2 weeks.
  • Ben continues to design the interface between the Glasgow suspension electronics and CIT electronics. The Dspace whitening interface and interface boards were finished and were sent to PCB Express last week.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 29 each, 1in mirror mounts are pending from Newport; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; IFLEX1000 IR laser for optical lever is pending from Point Source Ltd; ; polarizers and half-wave plates for Faraday isolator from KLC; Faraday rotator from EOT; 3 PZT tilt platforms and 2 servo control drive electronics and strain gauge read-out electronics from Piezosystems Jena; 1.5 in and 2in fixed vacuum mirror mounts and an adapter spacer from ASCO; Faraday Isolator mechanical parts from CA Machine Co.
  • FARADAY ISOLATOR: Awaiting parts.
  • IFO MODE-MATCHING TELESCOPE: Detail working drawings for telescope housing are complete; however, the remote focus mechanism will be re-designed for a more cost-effective approach. Aiming for a complete system in 1 month.
  • LIGO: Working with Dennis Rose to analyze all potential stray laser beams in the 2K and 4K IFOs that might damage the COC suspension wires and/or electronic cables.
• Optics (Billingsley, Armandula), suspensions (Romie), OSEMs (Bob):
  • Our BS, ITMx, and ITMy, are suspended and sitting on the South Annex clean room flow bench.
  • Steve, Dennis and Osamu will swap out dirty OSEMs for new clean ones in these 3 suspended optics, next week.
  • Janeen is making drawing changes for 40m TM suspension optimizations. Will continue and then gets the parts reworked.
  • Bob continues to build and clean OSEMs.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • The ion pumps continue to belch out on occasion; CC1 pressure is observed to jump up for a few minutes every once in a while. It's not a serious problem.
  • Dennis will try to get RGA information into the DAQ system.
  • Dennis has fixed the hair-trigger software interlocks on the vacuum system, eliminating spurious trips.
  • Dennis installed a long ethernet cable to read out the STACIS SV controller; now all controllers are being read out and logged.
  • One STACIS seismic isolator (SENW-x) is failing; this is the third such failure since the system was installed. Also, one of the controllers (now at the east end) is reading faults from all three feet, even though the isolators are fine and the EPICS readings are normal. Dennis will pursue this.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is putting his new oven F through its paces.
  • Bob is repairing temperature controllers to ensure a full complement for all 5 bake ovens.

October 25, 2002

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu put together a very detailed status report on the performance of the 40m mode cleaner, with comparisons to models and to the sites, and a preliminary noise budget.
  • We worked through this document in a telecon with Peter Fritschel, Rana, and others. This was very helpful, cleared up many sources of confusion, and put us on a good track.
  • Bottom line: the PSL/IOO/MC works pretty well, not too different from the sites, and we know what to work on (the usual suspects):
    • To further suppress frequency noise, we must turn up the gain of the MC servo (increase the UGF beyond 30 kHz); but this will not work stably until we first turn up the gain in the PSL frequency stability servo (increase its UGF beyond 300 kHz). There's precious little phase margin to do this, so we will look for contributors to this phase.
    • Reduction of excess electronics noise.
    • Reduction of excess seismic noise, with suspicion centering on the table that supports the MC2 chamber.
  • Osamu continues to make ever more careful measurements of frequency noise and its contributors.
  • Osamu found that the large, time-dependent 60 Hz harmonics peaks in the MC intensity noise spectrum were an artifact of his measurement method, and he fixed it.
  • Osamu, Steve and Dennis are studying the ambient and impulsive seismic and acoustic noise on MC2, and searching for ways to suppress it. Steve built a "sandbox" to damp acoustic excitation of the beam tube. He's exploring ways to damp or eliminate acoustic noise from the table on which the MC2 chamber rests. But, everything rests on a 4" concrete slab, which bends whenever anyone walks by.
• Digital Suspension Controllers (B. Abbott, Heefner, Taylor, Ugolini, Miyakawa):
  • Dennis has been trying to reduce the 16 Hz bounce mode with the suspension controller damping. We are learning that this isn't possible... instead, we should remove sources of excitation, by adding resonant gain at 16 Hz to the signal from the MC servo to MC2. Dennis will try to implement this.
  • The DSC crashed yesterday, and Dennis traced it to some connectors that had come loose, pulling the power supply down. He pushed them back in, and everything came back up fine.
• Intensity stabilization (B. Abbott, R. Abbott, F. Nocera, D. Ugolini):
  • Ben continues to work with Flavio and Rich on the testing of the Intensity Stabilization Servo (ISS) at the 40m. The inner loop is working.
  • Ben continues to stuff the ISS DC photodiode PCB board.
  • Dennis has set up ISS EPICS screens, databases, control channels, autoburt files, etc.
• Electronics (B. Abbott, Taylor):
  • The Satellite amplifier boxes for the remaining 7 core optics suspensions are being stuffed, and they should be ready for installation shortly. Steve and Bob are working on protective boxes and cable strain relief for these.
  • Completion of the vertex core optics DSC system (rack 1Y4) awaits Penteks, Pentiums, and software.
  • Ben continues to design the interface between the Glasgow suspension electronics and CIT electronics. The PCB for the Dspace whitening interface is finished. Ben should send it to PCB Express tomorrow. There is one more simple interface board to be layed out.
• DAQ (Ugolini, Ivanov):
  • Ever since the dataviewer upgrade last month by Alex, some channels (deviating from the C1:XXX-YYY_ZZZ syntax) cannot be displayed in dataviewer. Dennis is modifying their names in master.config to fix this.
  • Need to get fast signals from ISS and MC into DAQ. Ben will find out how it's done at the sites. There are sufficient empty channels in our DAQ Lemo Intfc Board to accomodate them.
  • Our AWG crashed yesterday, for unknown reasons. Alex rebooted it, and it came up fine.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 67 each, 1in mirror mounts are pending from Newport; miscellaneous optical posts and mounts are pending from ASCO; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; IFLEX1000 IR laser for optical lever is pending from Point Source Ltd; ; polarizers and half-wave plates for Faraday isolator from KLC; Faraday rotator from EOT; 3 PZT tilt platforms and 2 servo control drive electronics and strain gauge read-out electronics from Piezosystems Jena; 1.5 in and 2in fixed vacuum mirror mounts and an adapter spacer from ASCO; Faraday Isolator mechanical parts from CA Machine Co.
  • FARADAY ISOLATOR: Awaiting parts.
  • IFO MODE-MATCHING TELESCOPE: Corrected a small error in the specification of the primary mirror; alerted SORL about the change, which won't impact their production schedule. Detail working drawings for telescope housing are in process.
• Facilities and vacuum envelope (Ugolini, Vass, Jones):
  • All 4 ion pumps up and going. After a few days of outgassing, AMU 41 is falling again.
  • Varian has agreed to send us a higher capacity dry scroll pump to back up TP3, to replace the under-spec pump they sold us.
  • The ion pumps software interlock tripped off a couple of times due to pressure glitches. Dennis has put a 5-second timer on the SW interlock. He also fixed software problems associated with turbopump readout and VC1 control.
  • Dennis added ion pump readout to frames.
  • Dennis is stringing long ethernet cables to read out the STACIS SV controller and MCCM pressure gauge.
  • One STACIS seismic isolator is failing, and its controller is also behaving funny. Dennis will pursue this.
  • Steve and Larry have completed the construction and installation of table covers for all optical sensing tables. Now Larry can custom-fit beam tubes.
  • The south end crane was repaired. The repairman recommends installation of relay switches to protect the crane power supplies, which have been failing at an alarming rate.
• South Annex Bake Ovens (Taylor, Cardenas):
  • Bob is testing the effect of 114degree water bake on fully assembled OSEMs. Two of 18 new OSEMs were baked this way, and 2 failed electronics tests afterwards. Bob identified the problems. It's a good "stress test"!
  • 16 Fully assembled and clean OSEMs are ready to be installed in our 3 suspended optics, replacing the dirty OSEMs that were used to hang them. Bob thinks he knows how to get these clean.
  • Bob is building end-assemblies for more OSEMs.
  • Bob is putting his new oven F temperature controller (and the new oven F) through its paces.

October 18, 2002

• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • Osamu measured the intensity noise of the MC transmitted light with a thorlabs PD and spectrum analyzer. It wasn't clear how to interpret it. He will repeat the measurement with the new ISS servo on and off, and will also measure and compare with the PSL intensity noise.
  • Osamu remeasured the MC length, by placing a small 3kHz signal on MC2, and checking for a dip in its presence in Q-demodulated MC reflected light, as he stepped through the resonant RF frequency. He obtained L = 13.5469328(2) m, where the 0.2 um error is due to the resonant RF frequency readback. Of course, other errors dominate; but this measurement is likely good to a fraction of a mm. The design is 13.542 m, so we are < 5 mm off. We'll adjust the PRC length accordingly (when we install it!), but the PRC is low finesse so it shouldn't matter much.
  • Osamu has been investigating the MC transmitted frequency noise (by measuring the MC error signal). It is orders of magnitude larger than spec at high frequencies, and Osamu has demonstrated that both PSL frequency noise and MC length noise contribute. Since we believe that our PSL and MC perform about as well as the ones at the sites do, we wonder if the sites measure similar MC transmitted frequency noise. We will try to compare notes with site experts.
  • Large 60 Hz and harmonics lines are present in the MC transmitted frequency noise spectrum, and they are strongly time-dependent (they're now 40 dB lower than they were last week). We are searching for culprits.
  • Although we can aquire and maintain lock reliably, during the day, in "aqcuire" mode, maintaining lock in detection mode is fragile. Suspicion rests on excess seismic noise in the MC2 suspension. This suspension sits in a small chamber, with a small seigmic stack, with resonant frequencies between 12 and 55 Hz. This chamber sits on a metal table, which can be shaky; and that, in turn, sits on our 4" concrete slab lab floor. It's easy to imagine how human activity can transmit seismic motion into MC2. We will look into ways of reducing the coupling.
  • We still need to get the automatic switching from acquisition to detection mode.
  • Dennis continues to work on the MC commissioning document.
• Suspension Controllers (B. Abbott, Heefner, Taylor, Ugolini, Miyakawa):
  • Ever since the MC suspensions were adjusted during our last vent, there has been no evidence of anomalous excitation of the roll mode at 23 Hz. Dennis has removed the notch filters that we put in last month, and we've had no problems with it.
  • Dennis has been testing bounce mode (16 Hz) filters and has had no effect on the suspension. He'll look more at how it's done at the sites.
  • Jay suggests we look into getting the new "FOTON" filter design tool.
• Electronics (B. Abbott, Taylor):
  • Ben continues to work with Flavio and Rich on the testing of the Intensity Stabilization Servo (ISS) at the 40m. The ISS DC photodiode PCB board is arriving tomorrow. Stuffing will begin late this week.
  • The Satellite amplifier boxes for the remaining 7 core optics suspensions are finished being fabricated, they are being filled with boards in the back shop, and they should be ready shortly.
  • Completion of the vertex core optics DSC system (rack 1Y4) awaits Penteks, Pentiums, and software. All the wiring is done.
  • Mike will compile a list of all electrooptics required from Wilson House: oplev QPDs, IR QPDs, WFS PDs, LSC PDs, etc.
  • Ben is assembling all 40m electronics schematics in a White Book.
  • Ben continues to design the interface between the Glasgow suspension electronics and CIT electronics.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 67 each, 1in mirror mounts are pending from Newport; miscellaneous optical posts and mounts are pending from ASCO; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; IFLEX1000 IR laser for optical lever is pending from Point Source Ltd; ; polarizers and half-wave plates for Faraday isolator from KLC; Faraday rotator from EOT; 3 PZT tilt platforms and 2 servo control drive electronics and strain gauge read-out electronics from Piezosystems Jena; 1.5 in and 2in fixed vacuum mirror mounts and an adapter spacer from ASCO; Faraday Isolator mechanical parts from CA Machine Co.
  • New orders received: Tilted spherical mirrors for a temporary IFO MM telescope and 2 deg wedged beam-splitter for sampling the initial pointing beam were received from CVI.
  • OPTICAL LEVER FOCUS LENS: Detail working drawings are on hold.
  • FARADAY ISOLATOR: Awaiting parts.
  • IFO MODE-MATCHING TELESCOPE Detail working drawings are in process .
  • IO POSITION AND ANGLE SENSOR Pending a new alignment procedure.
• Optics (Billingsley, Armandula) and suspensions (Romie):
  • Our BS, ITMx, and ITMy, are suspended and sitting on the South Annex clean room flow bench.
  • Janeen has started making drawing changes for 40m TM suspension optimizations.
• Computing: Steve's and Bob's PCs were upgraded from W98 to W2K, and now there is no PC in our lab which can read the floppies from the HP spectrum analyzers, which require the DOS "lif" command, unavailable on W2K. We will try to obtain a W98 box to serve this purpose.
• Facilities and vacuum envelope (Vass, Jones):
  • Steve and Dennis got all 4 ion pumps up and going.
  • Dennis has installed a second MVME162 cpu (scipe4/c1vac2) in the vacuum epics crate to read out the ion pump and turbopump controllers. After some effort, it works fine.
  • Dennis is working on a short list of additional readout tasks: readout of pressure gauge near the MCCM chamber; readout of new SV ion pump controller, which is newer and different than the other 3; new turbopump controller spits out gibberish when in transition from standby to full speed, and the state code must ignore it; obtain long ethernet cables to read out the STACIS SV controller and MCCM pressure gauge.
• South Annex Bake Ovens (Taylor, Cardenas):
  • RGA scans of OSEMs newly built by Bob have come back dirty. Bob and Steve established that the problem is with the RGA. Bob moved the OSEMs to another vacuum oven with a cleaner RGA head, and the scans came back clean and within specs. Bob is sending the dirty RGA head back for re-conditioning.
  • Bob baked one fully assembled OSEM at 120degC (a "water bake"), despite fears that it would damage the LED/PD assembly. It did not; the baked OSEM performed electronically as well as it did before bake. Thus, it appears that Bob can recover the 15 dirty, un-baked but fully assembled OSEMs that were used to suspend our BS, ITMx, ITMy optics, without dis-assembling them.
  • Bob has built a neat oven temperature controller for oven F. After discovering that one of the 5 temp controllers was uncalibrated, it works fine.

October 11, 2002

• AJW presented the 40m program, G020429-00.pdf at the AdvLIGO R&D review on October 8. Mike Smith presented a proposal for a feasibility test of a photon actuator for AdvLIGO at the 40m.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • We pumped down last week.
  • Ben switched the resistor values in the satellite amplifiers for all 3 MC suspension controllers, and revved the drawing in the DCC (D961289-C).
  • Dennis re-diagonalized the input and output matrices of the MC1, MC2, MC3 suspension controllers.
  • After re-establishing alignment of the MC, attempts to lock were unsuccessful until Osamu turned the gain on the MC path down by a factor 10 (using the suspension controller output matrix, since it was already at the minimum in the MC servo screen). Shortly thereafter, Dennis noticed that the pole-zero filters were not turned back on. After turning them back on with EPICS, lock was easily acquired and maintained with the nominal gain settings.
  • Dennis has added autoburt to IOO so that the pole-zero filters are automatically turned back on after rebooting the DSC; in addition, lights were added to the suspension controller screen to indicate whether the PZ filters are on or not.
  • Osamu remeasured the visibility of the MC to be 88.7%.
  • Osamu measured the power fluctuation in the reflected light to be 0.4% of off-resonant reflected power. It had been 4%. Improvement is attributed to repair of MC1 OSEMs last week, yielding better damping.
  • Osamu measured the frequency noise of the MC from the MC servo error signal, and found it to be much higher than spec, above 100 Hz. This does not seem to be due to oscillation of the PSL FSS. He will investigate, and compare with the sites.
  • Osamu plans to optimize the gain of the MC servo, and the gains of the suspension damping. He'll also measure the MC transmitted light intensity fluctuations, transverse profile, angle jitter, and RFAM. And he'll re-measure the MC length.
  • Since Ben worked on the MC servo board to eliminate a small DC offset which interrupts lock when switching from acquisition to detection mode, there hasn't been strong evidence of this problem; but we'll look closer tomorrow.
  • We still need to get the automatic switching from acquisition to detection mode.
  • Ben will work with Rich Abbott and Flavio to install and test the inner and outer ISS loops (before and after the MC) in the next few weeks. Ben sent out the gerber files for the ISS DC photodiode PCB. It should return sometime next week ready for stuffing.
  • Dennis continues to work on the MC commissioning document.
• Suspension Controllers (B. Abbott, Heefner, Taylor, Ugolini, Miyakawa):
  • Ben has changed the resistors (and thus the readout gain) on the satellite amplifiers for all 3 suspensions, from 40 kohm to 29.4 kohm (to get the OSEM sensor full scale match the ADC full scale). He revved the satellite amplifier schematics in the DCC to show the changes that have been done to those in the 40m (D961289-C).
  • Ben is having the the Satellite amplifier boxes for all the core optics suspension controllers fabricated, and they should be ready by the end of next week.
  • We still have to notch out the 16 Hz bounce mode, and understand the origin of the 23.7 Hz roll mode excitation.
  • We hope to get the latest greatest DSC software from Rolf, including software for the vertex core optics DSC.
  • Richard McCarthy will allow us to keep the stand-alone suspension controller that we borrowed to suspend optics in the South Annex. Ben will fix it up, so that we can adjust the gains, etc.
• PSL (O. Miyakawa, M. Smith):
  • Osamu re-measured the frequency noise of the frequency stability servo (FSS), which is still within spec (and thus not explaining the apperent excess frequency noise in the MC).
  • Osamu continues to write the PSL re-commissioning document.
  • Osamu and Mike Smith continue to work on the calibration of the input optics beam position and angle sensors (QPDs and associated optics, looking at the beam picked off just before it leaves the PSL table).
• Electronics (B. Abbott, Taylor):
  • Bob and Ben are continuing work on the wiring for the core optics DSC rack (1Y4); they are close to completion. From there, they go on to the ends (1Y10 and 1X4).
  • Bob also continues to work on wiring and cabling of the auxiliary rack (1X1: video switch, camera power, illuminator controls, mechanical and EO shutter controls).
  • Electronics in process at Wilson House: 6 satellite amplifiers, universal dewhitening boards, parts for the DSC for the ends.
  • Reports that Penteks have arrived for the vertex DSCs were premature. We await them.
  • Ben continues to design the interface between the Glasgow suspension electronics and CIT electronics.
• Optical sensing (Smith):
  • OPTICS PARTS LIST, Orders pending: 67 each, 1in mirror mounts are pending from Newport; miscellaneous optical posts and mounts are pending from ASCO; input mode-matching telescope off-axis parabolic mirrors are pending from SORL; IFLEX1000 IR laser for optical lever is pending from Point Source Ltd; ; polarizers and half-wave plates for Faraday isolator from KLC; Faraday rotator from EOT; 3 PZT tilt platforms and 2 servo control drive electronics and strain gauge read-out electronics were ordered from Piezosystems Jena; 1.5 in and 2in fixed vacuum mirror mounts and an adapter spacer were ordered from ASCO; 2 deg wedged beam-splitter for sampling the initial pointing beam was ordered.
  • New orders received: Mirror clips for vac mirror mounts were received from CA Machine Co.
  • OPTICAL LEVER FOCUS LENS: Detail working drawings are on hold.
  • FARADAY ISOLATOR: Detail working drawings are complete and were issued as Rev A drawings with the DCC. Faraday Isolator mechanical parts were ordered from CA Machine Co.
  • IFO MODE-MATCHING TELESCOPE: Detail working drawings are in process. Tilted spherical mirrors of approximately the correct focal lengths for a temporary IFO MM telescope were ordered from CVI.
  • IO POSITION AND ANGLE SENSOR: A translation stage with a fine adjustment screw was installed in the angle sensor. Osamu and I were not able to properly align the angle sensor because there are too many degrees of freedom requiring the correct placement of 4 lenses in the optical train. A new alignment procedure will be developed to overcome this problem.
• Optics (Billingsley, Armandula) and suspensions (Romie):
  • Our BS, ITMx, and ITMy, are suspended and sitting on the South Annex clean room flow bench.
  • Bob is finished baking 7 short and 14 long OSEMs to replace the dirty ones in the above suspensions. Dennis and Steve will replace the dirty with the clean OSEMs in the next 2 weeks, and Bob will try to salvage the dirty ones. He continues to prepare the remaining OSEMs needed for our core optics.
• Facilities and vacuum envelope (Vass, Jones):
  • We pumped down without much problem at the end of last week.
  • The V1 valve tripped shut due to a software interlock, which checks for a problem with our new turbopumps. In fact, this happened 3 times, and we suspect that it is due to one-shot brief glitches in communication with the turbopump controller. Dennis has put in a counter, so that communication with the controller must fail 5 times in a row (over ~ 7 seconds) before V1 trips shut. No trips have been observed since this change.
  • Dennis has installed a second MVME162 cpu (scipe4/c1vac2) in the vacuum epics crate to read out the ion pump and turbopump controllers. (The readout by the first cpu would hang after some days, and we suspect that it was too much of a burden for one cpu). We will be watching it closely!
• South Annex Bake Ovens (Taylor, Cardenas): Bob is suspicious that one of our Dycor RGA 200 systems is beyond repair and is requesting $7K for a new Dycor LC RGA.

October 4, 2002

• Final papers from all 5 SURF students have been completed and submitted to the SURF office and to LIGO DCC. Check them out at the 40m web page.
• Mike Smith is proposing to use the 40m for a feasibility test of a photon actuator for AdvLIGO, which he will describe at the AdvLIGO R&D review on October 8.
• Suspension Controllers (B. Abbott, Heefner, Taylor, Ugolini, Miyakawa):
  • Dennis and Steve have properly shimmed the MC1 suspension (with a 0.28 mm thick piece of metal) so that all OSEMs read back near the middle of their range. They have rebalanced the OSEMs on MC1 and MC3, and checked for sensible readback from OSEMs on all 3 suspensions.
  • Ben has changed the resistors (and thus the readout gain) on the satellite amplifiers for all 3 suspensions, from 40 kohm to 29.4 kohm (to get the OSEM sensor full scale match the ADC full scale). Full scale is 2 V, and all OSEMs are near 1 V. All yaw offsets are < 0.2 V.
  • We are now pumping down, and Dennis will re-diagonalize all 3 suspensions shortly thereafter.
  • We still have to notch out the 16 Hz bounce mode, and understand the origin of the 23.7 Hz roll mode excitation.
  • We hope to get the latest greatest DSC software from Rolf, including software for the vertex core optics DSC.
• Suspended mass mode cleaner (Ugolini, Miyakawa, Vass, Abbott):
  • As mentioned above, OSEMs on all 3 suspensions have been checkout out, and they're all near to the middle of their range.
  • Dennis, Osamu and Steve have re-established alignment of the suspensions, with the PSL beam, prior to pumpdown. Clean TEM00 fringes were observed.
  • Ben swapped out an 1125 on our Mode Cleaner Servo board in hopes that the boost gain induced offset will be minimized. We will test the change tomorrow.
  • Dennis continues to work on the M