Weekly Report for Week Ending May 26, 2005

Highlights	LSC	Administration	Hanford Observatory
Livingston Observatory	Detector	40 Meter	Detector
LASTI	Data Analysis	Adv. LIGO Development	Past Weekly Reports

The LIGO Executive Committee meeting for May 30, 2005 is cancelled due to the holiday.

Special Announcements:

Weekly Report Highlights

LSC Issues (Saulson)

No report.

LIGO Laboratory Administration (Lindquist)

STATUS OF LSC MOUs (Petrac)

LSC MOUs and Research Plans and Progress Reports

MOU Attachment updates were signed-off for: Balearic Islands University, Moscow State University, NAOJ-TAMA, Northwestern University, University of Oregon, Southern University, Southeastern Louisiana University, Texas University at Brownsville, Vassar College, and Washington State University. The documents are in DCC awaiting archiving and web posting. [Note, the DCC is jammed up with preparations for the LSC meeting and the activities related to evaluating potential new document management applications. We are discussing with General Computing priorities and ways to break the log jam. –pel]

SITE TELECONFERENCE (Lindquist)

A brief site teleconference was conducted on Thursday, March 26, 2005. The following items were among those discussed:

Action 124: Review Procedure Manual materials and provide comments. The decision tree for paying taxes has been provided.
Livingston SEC Invitation for Bid: It was reported that Ed Jasnow has a lot of actions assigned. We are trying to reconcile Caltech’s General Provisions with those suggested by the Archetect/Engineer. There is more home work to be completed before the bid package is ready. The architect is on schedule. Target is second week in June for sending out request for bids.
TechMart Training: Caltech is exploring the possibility of using Web-X to train staff at the sites. It was noted that if sufficient time is not dedicated ahead of the training session to set up and test, most of the training time will be spent messing with Web-X. A “dress rehearsal” is required. Also Web-X apparently does not work well on Macs.
Operations Adjustments for S5: It was noted that there will be budget needs to cover the costs of travel for Science Monitors during S5. P Lindquist will issue first iterations of the budget models for FY 2006 – FY 2008 so that task managers can begin looking at the areas that will need attention.
The list of assigned actions updated through March 26, 2005 will be found Here.

PROPERTY MANAGEMENT (Chargois)

>From: Ed Chargois <chargois_e@ligo.caltech.edu>

Nothing significant to report.

DOCUMENT CONTROL CENTER (Turner, Mak)

>From: Linda Turner - turner@ligo.caltech.edu>

No report.

>From: Cleveland Mak <mak_c@ligo.caltech.edu>

packages: in - 17, out - 9
faxes: in - 33, out - 13
No special projects to report.

COST SCHEDULE CONTROL SYSTEMS (Cunningham, Brambila, Kaufman, Salone)

>From: Esther Cunningham <esther@ligo.caltech.edu>

For ACCOUNTS PAYABLE HISTORY DATA Press Here.

>From: "Brambila, Ruth" <Ruth.Brambila@caltech.edu>

Followed up on the quotes obtained for Oddvar.
Mailed out the Release of Claims to close out the subcontract with Kratochwill under Change order #3.
Obtained invoices and copies of credit memos for billed pcard transactions. Reconciled the charges billed to date. Followed up on the pending credit for the return of the laser. Followed up on the status of older pcard transactions that are still open.
Requested for an account to be set up for Caltech with LNL Anodizing for new requests that are anticipated by LIGO through Central Engineering Services. The account has been set up.
Completed change order #21 to REO and submitted it to the vendor.
Working on completing the change order to Amerion to change the date of performance.
Completed the purchase order. close out report for May 2005.

>From: Gina Salone <gsalone@ligo.caltech.edu>

Nothing significant to report.

>From: Florence Kaufman <fkaufman>

Nothing significant to report.
Financial reports can be found at: http://docuserv.ligo.caltech.edu/~fireport. (For passwords contact Florence)

SUBCONTRACTS MANAGEMENT (Petrac, Jasnow)

>From: irena@ligo.caltech.edu (Irena Petrac)

No report (see above).

>From: Ed Jasnow <jasnow@ligo.caltech.edu>

No report (vacation).

SUPPORT (Baldon, Hiroto, Lloyd)

>Irene Baldon

Processed the paper work for five (5) new/revised trips. At this time there is (1) new trip that needs to be completed and ticketed before the paper work can be completed. Assisted several LIGO people with their travel arrangements using their P-Cards and made several reservations for outside visitors coming to a LIGO site for meetings and/or workshops. LIGO will be sponsoring thirty-eight (38) SURF Students this summer and all but three (3) have been completed. We have twenty-six (26) coming to LIGO/Caltech, seven (7) to LIGO/Hanford, and five (5) to LIGO/Livingston.
Completed twenty (20) Expense Reports and there are four (4) reports yet to be done. I continue to contact travelers who have outstanding Expense Reports (more than one (1) month old) to ask for their cooperation in sending me their receipts so that these can be closed in a timely manner. Presently there are two (2) reports more than 30 days old. I have no reports awaiting signature at this time. Reconciled forty-four (44) P-Card charges for the week requiring telephoning hotels and car rental agencies to verify which traveler used my card and for what amount.
Coordinated and initiated the opening of thirty-seven (37) new cards with the selected new teleconference company, AccuConference. New card holders have been sent their new information their wallet-size cards. Each card holder has the capability of entering their account in order to observe/manage it. The old RainDance account will be closed as of May 31, 2005 and each holder of a RainDance card has been asked to return their wallet-size card to me and destroy any information containing their account number on the old card that they may have printed out. Continued to track Raindance Teleconference billing and assisted users with any problems that they might have incurred.

>From: Julie Hiroto

Booking travel, updating web pages, processing payments.

>Dorothy Lloyd

Nothing significant to report.
Jim continued with data entry in the LIGO database and helping out in the DCC.

PROPOSALS and REPORTS (Lindquist)

LIGO must submit an Annual Report for Operations by August 1, 2005 and this annual report must be accompanied by a request for a two year extension (FY 2007 and FY 2008) as well as a justification for why Caltech/MIT should be continued in the role of management of LIGO. I have prepared and distributed a general outline and assignments. I have requested contributions by Friday, June 17, 2005. The outline and schedule were presented during the Executive Committee meting on Monday, May 23, 2005.

DCC Steering Committee (Lindquist)

We have conducted teleconferences with references provided by Synergy and AGILE document management systems. We have scheduled an additional reference teleconference tomorrow morning for the SYNERGY system.

We were given a walk through of the Xythos document management system this afternoon via WebX session. We have scheduled a demonstration by Xythos here at Caltech next Wednesday morning. Xythos comes to us a little late in the process but is of interest because their application is tailored for the educational and research environment.

CHANGE CONTROL/CONTINGENCY MANAGEMENT (Lindquist)

Minutes for the change control meetings held on May 9, 2005 and May 23, 2005 (during the normally scheduled meetings of the Executive Committee) have been prepared and submitted to the document control center (LIGO-M050200-00-P).

CR-050004 Operations 2005 Second Quarter Adjustments: The request reflects adjustments for positions that were budgeted but not filled during the first half of FY 2005 plus corrections, increases to reflect the large number of SURF students accepted this summer, and $100K of budget for a carry-forward commitment to the University of Florida, which will not be used. In addition there were a few planning changes incorporated to reflect reduced NSF funding for FY 2005. On May 9, 2005 the Executive Committee recommended approval of the change request and the change request has been approved. The original signed copy of the change request is in the document control center.
CR-050005 Data Monitor Tool (DMT) Hardware Expansion Hardware Expansion: The request is for funding to cover the cost of expanding the Data Monitor Tool (DMT) hardware infrastructure. The estimated costs after some iteration were estimated to be $70,000--split 60/40 between the Hanford and Livingston Observatories respectively. The expansion provides additional computing nodes for online monitors, an upgrade of the development and testing machines, and an upgrade to the network providing better security. This change request has been approved. The signed original of the change request is filed in the document control center.

HUMAN RESOURCES (Akutagawa)

>From: Cindy Akutagawa <cindy@ligo.caltech.edu>

The minutes and action items from the May SC meeting have been posted. All files are posted and up-to-date on the web page.

Quality/Safety (Tyler)

>From: Bill Tyler tyler@ligo.caltech.edu

Nothing significant to report this week.

LIGO Hanford Observatory (LHO) and Interferometer Operations (Raab)

Summary of Commissioning Activities at LIGO Hanford Observatory (Landry)

Commissioning continued apace at Hanford this week, with many visitors helping out on a variety of tasks. Some are highlighted below.

Coil gains had migrated to weird values with each new hardware installation and modification; gains are now common between H1 and H2 after a re-allocation
H1 TCS temperature spiked, owing to a (site) chiller shut down
Noise budget software has been propagated to LHO. The script runs DTT measurements and a matlab model to produce a calibrated IFO noise, and apply the constituent noise curves to the same plot. A work in progress, currently some curves are suspect, such as the ISS noise.

4K IFO

MMT2 suspensions acted crazy, with sensors indicating large input pointing shifts, both glitches and longer-term drifts. Initial forensics showed no coil voltage problems. Later, the satellite module was swapped out, then the coil driver, and last, the dewhitening and anti-imaging, without effect. Could the mass be hung up somehow?
The AS2 demod phase was found to be way off, and the AS2I spectrum was noisy, so that AS2 electronics were thought to be a problem. Further checkout found AS2 with excess low frequency noise; this went away once cables were jiggled and reconnected
TCS had an 8h lock with continuous 4W TCS operation, with differential annulus TCS control. The TCS team received beautiful new "sunflower" annuli to test out.
Scripts and more scripts: WFS were diagonalized and the bandwidth of the loops increased to 3 and 4Hz
The 4k failed the pinky test, in which an end station pier is nudged to assess backscatter into the IFO by transmission monitor components. The result was new transmission monitor lenses were installed.
Electronic sidebands are seen, much the same as at LLO, on H1 AS PDs. This may arise from interaction with the 61MHz oscillator, demod boards, and pickup by ASI servo boxes.

2K IFO

Coil gains were adjusted to minimized position to pitch and yaw coupling
The NPRO was mode-hopping again. Later, the laser replaced and quickly warmed to an output in excess of 7W. Next, the laser power supply no longer talked to chiller; the power supply was damaged during the restart and thus not responding to chiller via RS232. Some links follow: on the power supply failure, potential communication problems, and the fact that the 2k was still noisy after the laser fix.
POY and Non-resonant sideband REFL diodes were installed
2k ASPD noise had factor of 30 increase; probably something going wrong in the AS whitening

CDS

Linemon, a tool that allows for the demodulating of lines and sending output to Epics channels (handy for trending) was installed on the h0pemms IOC
TDS tools , a series of time-domain tools, are now available under CDS

LIGO Livingston Observatory (LLO) and Interferometer Operations (Zucker)

L1 Interferometer (Frolov)

The upgrade of the end station heater controllers to match the LHO scheme resulted in removal of the 1 Hz sidebands of the 60 Hz power line from the interferometer noise spectrum. Now the 60 Hz power line itself is the largest remaining feature in the spectrum.

Two anti-symmetric port photo-detectors that were in the low noise mode developed large leakage currents between last Thursday and Friday. Upon examination burn marks from the beam were found on the surface of the photo-diodes. The safety shutter operation was verified - no malfunction was found so far. The mechanism of the damage is still under investigation. The interferometer returned into operation after switching to two undamaged photodetectors. The threshold of the safety shutter was reduced by a factor of five.

The low frequency broadband noise below 100 Hz improved after the switch to the new diodes. It isn't understood but backscattering from the damaged spots or spatial beam nonuniformities coupling to motion across the damage sites could be responsible.

The 5 V power distribution to the front end analog electronics was upgraded to include field regulators at each crate. This should improve reliability of the WFS system and reduce interactions between boards.

Reflected beam angular drift has been observed at high input power into the interferometer and is attributed to the Faraday isolator thermal lensing. The beam has to be steered on the WFS photo-detector but stays within the diode size on the LSC detector. A new system to stabilize this drift is being designed.

A temperature scan of the main laser was done to maximize the power output. We now have 6 W available into the Mode Cleaner.

Education and Outreach (Thacker)

Assisted with LIGO Education Program Advisory Committee (LEPAC) meeting, Friday, 5/20 conducted Local Educators Network (LEN) workshop on Saturday, 5/21 met with locat teacher PD provider on Monday, 5/23 assisted in Tour for visitor (astronomer) from Williams College on Tuesday, 5/24

Site Safety and Security (Riesen)

I have found no site nor laser safety concerns this reporting period. Completed a full function checkout of the enhanced laser safety system at both end stations. This concerns the transmission monitors, photon calibrators, and the laser safety signage. Both end stations are fully operational. In-line transmission monitor shutters still need to be installed at both ends.

Mechanical Engineering (Spjeld)

AdL Quad SUS Installation Fixtures

Redesigning vertical drive - lift arm interface
Replacing follower shafts with self-aligning linear bearings
Manufacturing drawings of completed parts in progress
Addressing design issues raised in design review committee report

AdL SEI Engineering

Review of Ad SEI drawings in progress
SEI Critical Review Meeting

LIGO Outreach Building - Pendulum Exhibit

Redesigned support truss for pendulums

General Engineering

HAM door removal tool drawing sent out to quote
Working with John Thacker on poster updates

LLO General Computing and LIGO Computing Security (Roddy)

A drive failed on the Ilog server. Fortunately, it is a mirrored array and no data was lost. I am having some problems with the vendor in getting a replacement drive, but I am expecting it tomorrow. It should have been here on Tuesday. As long as the other half of the mirror holds out, the ilog will stay up. Replaced the CDS NAT router and combined it into the main GC router. Working on the associated firewall rules, etc. that are needed due to this. The new router seems to be working really well now that the syskonnect bugs and the bad MiniGBIC have been taken care of. Working with Dave on some CDS security issues and working on these reconfigurations. Also working on some new configuration with the RGA machines, etc. as discussed in the OCSC meetings. Added scratch space to decatur and touro. There is several hundred gigs of space available now for data. Revisiting snort and IDS installation/configurations. I will have to work with Dave and get this duplicated at Hanford. visibility into the network traffic into CDS is a major concern due to time constraints on other issues.

HPLF, Optics Modeling, Data Analysis and L1 Commissioning (Franzen)

1) HPLF news: The 100 W IPG laser has been repaired and returned to LLO. An engineer is now visiting us in order to advice us on the operation and to install some diagnostics software for us.

2) Designing a REFL port beam stabilization system.

CDS software (Khan)

Worked with Rolf and alex on the code and Frame builder upgrade. This new upgrade involves changing the floating point point variable from single precision to double precision format and also the size of the daq channel name length is increased from 40 to 255 characters.

Developed a new stat screen for the TCS servo.

LDAS/Condor Sysadmin and Burst Analysis (Yakushin)

Data archival/Condor/LDAS:

Generated new set of possible layouts for the LDAS room to consider.

1) The minimal upgrade that would only be good for S5:

http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/v1/ LDAS_210_layout.1.pdf

2) Slightly better version. Communication and LDAS rooms are joined, AC is rotated 90 degrees:

http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/v2/ LDAS_500_layout.2.pdf

3) The ideal solution that also involves rearranging the racks 90 degrees:

http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/v3/ LDAS_500_layout.3.pdf

4) The modification of the ideal solution (it is probably cheaper but at the expense of wasted space) that would allow to reuse 30 tons AC needed for 210 nodes later after S5 when we upgrade to 500 nodes:

http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/v4/ LDAS_500_layout.4.pdf

Sent final numbers for power and AC requirements to Mike, Rusyl and Allen.

Data analysis:

1) Comparing waveburst S4 triggers (version 1) on DARM_ERR, AS_Q and h(t) to decide which ones to use in the final analysis.

2) Participating in the waveburst code review. We had a f2f meeting at LLO last week, one telecon this week and another one coming today.

3) Processed SG15 burst MDC frames and discovered a problem: signal injections in SG15 were often done too close to each other. Keith Thorne has regenerated the frames and I am about to launch waveburst jobs on them.

4) Regenerating S4 triggers using V2 calibration and some minor fix to the waveburst code (during the waveburst f2f code review meeting we discovered some unexpected feature that is corrected now) that could affect reconstruction of low frequency long duration bursts, for example SG100Q100.

5) Preparing my Amaldi talk for LSC review.

Initial LIGO Detector Science & Engineering (Coyne)

from Dennis Coyne

CDS

see also the CDS weekly meeting minutes in the commissioning archives

CDS Software

Rolf Bork

There was a bug noted by Peter and Daniel that the "bumpless" filter coeff reload feature was not working properly. Alex and I did some off-line testing and found a bug which would allow the feature to work some, but not all, of the time. This has been fixed and will be loaded at LHO today for on site testing. If the fix works, then the remaining front end code will need to be recompiled and installed.
Alex recently ported the fast ADCU software to our faster Linux VME processor. However, this CPU is still not fast enough to do all of the data calculations for the number of channels required by Daniel. One option we are going to try is to run the fast ADCU calculations on a faster Linux processor (non-VME). If this works, we could look at moving the ADC data to this processor via the Front Panel Data Port (FPDP) on the ADC module to a FPDP-PCI card in the PC (160MByte/sec link). We could also look at running a fiber optic serial FPFP link, such that the PC could reside in the MSR instead of near the ADCU VME crate.
We are currently testing a Sun V40Z computer for possible use as a Framebuilder. LDAS has suggested it would be good if the Framebuilders could write compressed data into frames to allow greater data storage and that this machine may have the computational power to do it. So, we have a loaner unit from LDAS and are trying to port the Framebuilder code, along with the drivers for the various reflected memory network drivers. This is not a straight port, as this is a multiple AMD64 bit processor unit running some version of Solaris X86 instead of the usual Sun CPU Solaris.

CDS Hardware

Rich Abbott (at LLO)

Replaced ASPD 1, 2, and 3 due to damage

Replaced ASPD 4 demodulator board due to line spikes

Repaired ASPD 2 diode by replacing the diode element and re-testing

Ben Abbott

I got a call that Livingston had failures of photodiodes on Monday, and they needed three replacements. I had a group of PDs here that were assembled, but needed updating to the latest rev D. Todd and I updated three of the PDs to the newest rev, and then I ran them through their test procedures. Once the PDs were all tested and final assembly of the enclosures had occurred, I shipped them off yesterday with their associated paperwork. They should be arriving this morning.

DMT

no report

PSL

PeterKing

The high power photodetector testing continues. No problems so far. Another higher power (greater than 500 mW) NPRO laser was fired up to test another photodetector since the 10-W laser was no longer available. The output beam of the NPRO was characterized and circularized.

Vacuum Bake

Bob Taylor

Completed a vacuum bake Job for Betsy Bland ( LHO) for the ITMy possible replacement:
25 Quartz Wire Standoffs. Shipped the Items Back to LHO.

4ITM05 Absorption Measurement

Liyuan Zhang, Lee Cardenas

(report edited & augmented by D. Coyne)

A bulk absoprtion measurement was performed on the 4ITM05 optic (the optic which may be used to replace ITMx on the LHO 4km interferometer). The scan was made at at the middle layer (Z=-2" from AR) and is quite uniform at ~3ppm/cm: see scan. After the measurement, we found two small laser burns on the AR coating most likely due to dust on the mirror surface. Therefore, we have decided to make coating absorption measurements on some 1.0" diameter small mirrors first, as a test before we proceed with the HR coating on the 4ITM05 mirror.

We have tested two 1.0" dia. mirrors, intentionally made "dirty" to see if it will cause laser burns. One mirror was left exposed for about 1 day in the lab and accumulated "natural dust". The second mirror was 'littered' with particles from clean room cloth (tissue?) and optics cleaning tissues. The mirror with "natural dust" showed no sign of damage after the scan. The mirror with optics tissue particles showed damage. Under the microscope we can clearly see the pit left by the laser burn on the surface. Attempts to clean off the burn mark were not successful.

We next plan to scan the 4ITM05 HR coating for absorption but only on the perimeter outside of the 1/e radius of the beam and perhaps at lower power(?). We will make scans over ~1 sq. in at several locations along the outer perimeter, but still within the region where the coating should be uniform and similar to the central region.

40 Meter Interferometer (Weinstein)

IFO commissioning:

Osamu re-installed the MC length monitor (Freq_Diff); (the IQdemod board that was being used was fried a few weeks ago; Ben fixed it, and Osamu just now re-installed it). He calibrated the signal: 0.76 count/ 100 Hz @ 33.2 MHz (ie, if the monitor reads 0.76 counts, the 33 MHz RF sidebands are 100 Hz away from being fully resonant in the MC). The reading varies from day to night. When it's significantly off, we need to re-tune all the demod phases; so it's important to monitor (and eventually, feed back on) this signal.
Osamu and Rob have been working nights, on lock acquisition. Typically, they spend an hour or 2 to tune up the mirror alignment and the demod phases. The change of the demod phases over a day is 5-10deg for AP 133 MHz and 199 MHz; 10-20deg for SP 133 MHz and 199 MHz. This is too much! It requires daily retuning of demod phases. It may or may not be entirely due to the drifting of the mode cleaner resonant sideband frequency.
After tuning up, the dual-recycled Michelson (DRMI, arms blocked) typically locks in ~ 10 seconds. They then unblock one arm, and offset-lock it via DC transmission. They unblock the other and lock it the same way. It takes a few minutes to get both arms offset-locked; often they have to nudge ITMY to get it to cross a fringe. They can then switch to CARM and DARM control using combinations of the DC transmitted light (TRX and TRY). They then reduce the DARM offset to zero (no carrier at the AS port). In this way, they can lock all 5 degrees of freedom 20-30 times per night.
However, when they try to reduce the CARM offset to bring both arms into full resonance, they find that the CARM servo starts to oscillate and lock is lost. Rob did some modelling with FINESSE, and has an explanation: When CARM is offset-locked, it is detuned for the carrier. The coupled-cavity (PRM-CARM) pole, normally ~ 100 Hz, is much higher (~1.6 kHz). As they reduce the offset, the coupled-cavity pole lowers, until it passes through the CARM servo UGF of ~ 300 Hz. The ensuing phase delay at the UGF causes CARM to oscillate and lock to be lost. This scenario would not happen in AdLIGO (where the detuned coupled-cavity pole is still below the CARM UGF). It's a real impediment to smoothly transitioning from offset-locked arms to the final configuration. We need to think hard for a solution. One possibility being pursued by Rob is to compensate for the instability by changing the loop shape.
Monica is writing up the results of her measurements for calibrating the ITM and ETM response.
Monica and Virginio have a model for the decay time of the light through the mode cleaner and arm cavity. They are plugging in the numbers to get a measure of the arm finesse (the mode cleaner finesse is known) and writing up the measurement.

IFO modeling and DC detection development:

Monica continues to study error signal sweeps in her e2e simulation of the 40m optical plant. She is now working on the control plant for her e2e simulation of the 40m. Ideally, the lock acquisition and control code developed by Rolf and Rob for the front end controls can be "plugged in" to the e2e simulation directly. She will work with Rob to see if this can be made to work.
A draft version of a document, Proposal for a Homodyne (DC) Detection Experiment at the LIGO Caltech 40-Meter Laboratory is available for comment. We hope to have a design review for this experiment when Mike Smith returns from vacation in mid-June.

Electronics, controls:

DC signals from our RFPDs currently get into our front end electronics via separate cables from the DC-test-out port of the RFPD head. They should, instead, come from the LSC RFPD interface board. Ben got some PD interface Data Acq Boards (D010005-00) from Rich Abbott which tap the signals out from the LSC RFPD interface board P2 connector, and is wiring them into our LSC whitening boards to get them into the front end. DC signals will be available from ONE each of SP, AP, PO, POX, POY. In progress.
Rob tried to establish a good CARM signal using the new 166 MHz RFPD at the SP. He found large electronic cross-couplings from other PDs in the rack. We've seen this before, they all talk to each other via unregulated power lines on the IQ demod boards. The fix is to power the demod circuit with regulated power. This ha been done for several of the existing demod boards. Ben will fix this new one.
Rob rebalanced the coil gains on the 3 new RevB coil drivers (for SRM, PRM, BS).
Steve noticed that the OSEM coil voltages for the BS are drifting steadily over many days. Under investigation.
Osamu noticed that the SRM seems poorly damped when the oplev servo is switched off. There is evidence that the SRM, BS, and ITMX all damp poorly for one reason or another. We need to diagonalize the suspension controllers, systematically and correctly!
Dan is at LHO, diagonalizing all the digital suspension controllers. Now that he knows how, we will ask him to do the same for our 10 DSCs, when he gets back. (Hopefully, including coil balancing, input matrix, output matrix.)

Lab Infrastructure:

The air conditioning thermostat setting in the IFO hall was mistakenly changed on Thursday, causing a several-degree change in the temperature. This wreaked havoc on the PSL and mode cleaner. Steve re-set all the thermostats in the hall to 70 C. The temperature was set back up on Friday, and by Monday, Osamu was able to re-align and recover everything.
Steve finished grounding the ISC tables to the vacuum envelope via 1.2 MOhm resistors.
Steve has placed delrin electrical isolation between the optical table and various components (thorlabs 520 PDs, ccd cameras, optical spectrum analyzers, mechanical shutters).
Steve has labelled all the AC power sockets, indicating whether it is conditioned rack power or unconditioned wall plug power.
We plan to un-ground all the rack kill switches in the next week.
Ben continues to develop a document of the grounding and shielding for the 40m electronics, racks, tables, chambers.
Bob finished checking and correcting the grounding problems in the cross connects in the LSC & ASC racks 1Y2 & 1Y3 on Friday of last week.

Thermal Noise Interferometer (Black)

This week, Akira pumped out the bond-noise chamber, locked the shadow sensor, and took noise data. While the system is substantially quieter than it had been in air, our first in-vacuo noise spectrum does not appear to be thermal noise limited. The vacuum, however, holds nicely even with the pump off, and there appear to be neither leaks nor substantial outgassing.

Helena checked with Jean-Marie on our optics with advanced coatings, and he is on track for a mid-June delivery.

LASTI (Ottaway)

No report.

Data Analysis and Computing (Lazzarini)

Simulation and Modeling (Bhawal)

E2E Weekly Physics Meeting

Sany Yoshida presented results of e2e simulation for a locally damped suspended Mirror that is experiencing violin modes. Violin modes were recently implemented in e2e models by Sany using Virginio's mechanical model.

WaveFront Sensor (WFS) signals for H2

(Biplab) After LLO, now we want to check if WFSs are well optimized for thermal states in Hanford 2 Km interferometer too. Joe and Rana gave all parameters (elog 24th Tue) for the optical paths of WFSs. With calculations done so far, not much of qualitative differences from 4km interferometers have been observed. Most of the quantitative differences come from recycling factors etc.

SimLIGO studies for mirror shifts

(Biplab) Studied what happens if one of the end mirrors suddenly changes its transversal position by about a micron. In case of such a vertical shift, the DARM (Differential Arm) signals record clearly-visible signature and the subsequent ringing down but such a clear signature is not present in case of a horizontal shift. Studying what could make effects for 2 sides so different. Also, studying how noise curves might change due to (constant) transversal shifts of optics and/or beam.

Simulation of 40m interferometer

(Monica) The error signal sweeps for the degrees of freedom have been simulated. A bad implementation in the E2e code for the 40m of the pick off port has been pointed out: the anti-reflectivity coating was missing and it will soon put into the simulation.

The control plant for the simulated 40m is under construction.

Code development

(Hiro) Development of modeler codes to support the simulation for adv.LIGO. Designing the code structure of the new C++ version of FFT.

Alfi

(Bruce) Bundle content caching is being implemented in order to speed up the writing process for boxes with a heavy use of bundled connections.

(Melody) Continuing on fixing existing Problem Reports. Currently working on the user interface for allowing the user to choose the display for nodes: graphic, node name, or a multiline description. Worked on allowing primitive nodes to be able to display an icon from a jpg or gif file. Currently working on saving the information into the box files and modifying the parser.

Data Analysis Activities (Lazzarini)

Charlton:

Continued working on my matlab code for comparing stochastic pipeline strain with calibrated strain. I reported last week that the RMS found by the stochastic pipeline was consistently a little larger than that of the calibrated strain, and that there were a few larger deviations at individual frequencies. Albert pointed out that the calibration lines will be present in AS_Q but not in the calibrated strain, which may account for some of the differences. I've added code to mask out the offending frequencies. Some other minor bug fixes/changes were made.
Started work on some scripts to display the results of the above comparison more easily. Albert suggested using a 2-dimensional histogram (horizontal axis being GPS time) so we can get a clear idea of the RMS differences over the science run.
Worked with Keith Thorne on some issues with the Matlab code used in my strain-checking code, stochastic.m etc.

Mandic:

I calculated the Bayesian 90% UL on Omega_GW(100 HZ) as a function of the spectral slope alpha for S3 H1L1. I also estimated such upper limits for S4, S5, and AdvLIGO.

I continued studying the accessibility of the pre-Big-Bang models to LIGO.

Peter Shawhan and I formulated a proposal for the S5 harware injections. The proposal includes a predetermined schedule of injections, and a continuously running injection code, which performs the injections according to the schedule and automatically switches between science and injection modes (it also allows the operator to override the injection).

Mendell:

I have checked into lscsoft/lalapps CVS, under the /src/pulsar/StackSlide directory, updated code and scripts for generating condor DAGs. Previous DAGs results in estimated upper limits. New options in the code allow iteration of the Monte Carlo Simulations until these converge on a desired confidence level, and and the DAG producing scripts allow the pipeline to start jobs with these options set. The DAGs can now produce a converged upper limit, though testing and further adjustments will be need to produce final results.

Example results for the June LSC meeting are being generated.

Shawhan:

Attended Statistics for Gravitational Wave Data Analysis (GravStat) workshop at Penn State.
With Vuk Mandic, planned improvements in hardware injection software and scheduling.
Reviewed pulsar analyses / paper drafts.
Planned presentations for LSC Meeting and Burst Group face-to-face.

Sutton:

Last week I attended the 11th Canadian Conference on General Relativity and Relativistic Astrophysics in Vancouver, and gave a talk on LIGO and the search for GWs. I'm now working on the "LIGO cheese" problem, mainly studying chirplets as max-entropy waveforms. I've also revised and circulated a draft of the LIGO-TAMA bursts paper that addresses all of the new comments since the last review telecon. Hopefully this draft will be approved by the executive committee.

Weinstein:

lots of Inspiral analysis review work.
Working with Lisa and Duncan on the ringdown search.

LIGO Data Analysis System

Software Systems (Blackburn)

LDAS:

Spent the bulk of this week preparing for and release LDAS 1.6.0. As of today, the release is in place at CIT, MIT, LLO, LHO. LDAS-TEST will be updated today. MIT, LLO, and LHO have all passed the post-release system testing. CIT has been taken down for hardware upgraded which prevented completion of a few createRDS systems tests on that system, but other than that, CIT is ready to go when the hardware upgrades are completed at the end of this week. At LHO, Greg Mendell is currently conducting extensive createRDS testing to further challenge the new release in a real-world (astrowatch) fashion. Greg has seen no issues at this time and expects to complete his challenge by Friday.

This release primarily address enhancement requests to the createRDS command to allow better integration of frames from different interferometers and to more cleanly handle data drop out issues associated with input frames.

Other minor changes included an upgrade of the IBM Database to version 8.2.1, fixes to several GUI elements in the controlMonitorAPI and a new option for the diskCacheAPI while scanning duplicate datasets. Also, several packages in LDCG were cleaned up to be removed if obsolete or upgraded to new versions.

Three new problem reports were filed in conjuntion with the release of LDAS. Two of these were in the controlMonitorAPI and associated with a confusion of the difference between system site name and gateway hostname. These two abstraction are degenerate on the LDAS development system causing the bugs to not be discovered until after the release. Only new enhancements were effected by these. The other bug is in the diskCacheAPI and has possibly been around but undetected for some time. It is associated with the API incorrectly identifying a subdirectory as changed under raw circumstances which we only learned how to reproduce effectively this week. It is likely that this bug will not impact normal operations of LDAS.

At the request of the burst group, the versions of LDAS and LAL/LALwrapper used for the LIGO-TAMA data analysis last summer were tracked down for inclusion in an upcoming paper.

TCLGLOBUS:

Completed the revision of the Globus XIO test cases to now user the new debugging mechanism which has been useful for tracking down memory leaks.

Fixed the memory leaks related to asyncronous calls using the client/server test cases and now have a new issue with memory corruption. This is currently under investigation.

Continue to work on the problem with credential object not being properly passed into the actual Globus function call in the GSI client/server test case. This is also currently being investigated.

Made changes to the callback model to support threaded Globus builds. This may be related to the problems discussed above.

GRID COMPUTING:

Updated the Linux kernel on our OSG gatekeeper. Restarting the computer after the upgrade did not automatically restart the condor daemon and it had to be manually started up. Unclear at this time why this happened, but plan to investigate next week.

Hardware Systems (Anderson)

Caltech

(Dan Kozak)

Retrieved/rearchived all files from bad tapes HL0164 & LL0184 at LHO.
Continuing to fill in "missing" (at CIT) postS3 data from LHO using tar/globus-url-copy.
Relabeled some trend and dmt tapes at LHO to free up tape space.
Test new firmware on test 3510 (/samtest) at CIT.
Did prep work for making CIT /archive use md devices (plus upgrades of 3510 firmware, SAM, SAN).

(Stuart Anderson)

Worked with several Cluster Condor users to improve the efficiency of their analysis code.
Upgraded, but not yet tested, Condor from version 6.7.3 to 6.7.7.
Helped with the SAM-QFS upgrade/reconfiguration at Caltech to support small files.

MIT

(Keith Bayer)

pcraid3 raid failed with multiple drive errors - lost raid on 3ware 7500 card. Will rebuild with FC3.
Added several accounts.
Got quote for T3's added to Sun support contract.
Got quote for new 5U RM dual opteron pcraid unit.

Livingston

(Igor Yakushin)

Generated new set of possible layouts for the LDAS room to consider.

The minimal upgrade that would only be good for S5:

http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/v1/ LDAS_210_layout.1.pdf

Slightly better version. Communication and LDAS rooms are joined, AC is rotated 90 degrees:

http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/v2/ LDAS_500_layout.2.pdf

The ideal solution that also involves rearranging the racks 90 degrees:

http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/v3/ LDAS_500_layout.3.pdf

The modification of the ideal solution (it is probably cheaper but at the expense of wasted space) that would allow to reuse 30 tons AC needed for 210 nodes later after S5 when we upgrade to 500 nodes:

http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/v4/ LDAS_500_layout.4.pdf

Sent final numbers for power and AC requirements to Mike, Rusyl and Allen.

Hanford

(Greg Mendell)

I am testing the RDS generation process, and new options available for createRDS jobs, using the newly released version of LDAS, 1.6.0, and updated versions of the driver scripts.

General Computing (Wallace)

MIT:

(Keith)

LDAP work:

Automounting on linux seems to cause kernel panics (perhaps it's time to pass the automount map by hand..) crypt-md5 passwords work from both FC3 and Solaris 9 passwd command works from both FC3 and Solaris 9 NIS+ password load into LDAP works as well

Added new grad-student to gc (Jared Markowitz)
Investigated a little bit with Mac OSX
Installed and configured new SB1500 workstation (for use as new webserver / print server): troubleshooting SCSI bus errors on it installed latest patch set from LSI - that might solve it

Livingston:

(Shannon)

A drive failed on the Ilog server. Fortunately, it is a mirrored array and no data was lost. I am having some problems with the vendor in getting a replacement drive, but I am expecting it tomorrow. It should have been here on Tuesday. As long as the other half of the mirror holds out, the ilog will stay up.
Replaced the CDS NAT router and combined it into the main GC router. Working on the associated firewall rules, etc. that are needed due to this. The new router seems to be working really well now that the syskonnect bugs and the bad MiniGBIC have been taken care of.
Working with Dave on some CDS security issues and working on these reconfigurations. Also working on some new configuration with the RGA machines, etc. as discussed in the OCSC meetings.
Added scratch space to decatur and touro. There is several hundred gigs of space available now for data.
Revisiting snort and IDS installation/configurations. I will have to work with Dave and get this duplicated at Hanford. Visibility into the network traffic into CDS is a major concern due to time constraints on other issues.

Hanford:

(Christine)

Network usage can be seen at http://www.ligo-wa.caltech.edu/~christin/mrtg/ 198.129.208.1_198.129.78.122.html
The previous years' SURF student home directories and files are now in an area where they can be accessed from a web page. Created one generic user account which the former students and mentors can use to login and modify any of the files.
Moved some user home directories and files to new disks because some of the old disks were getting full again. I have one more empty disk available. This gives me some time to research and purchase a larger disk system.
Created user accounts for this years SURF students.
Rebuilding two PCs by formatting the disk, installing Windows XP and all the standard GC software.
Purchased and setup a new monitor for a user whose old monitor died.
Working with technical support at Wolfram to fix our mathematica install. The latest version will not recognize the license file.
More talks with Amerion and PNNL to finalize the paper work for the Amerion contract extension and work out details for the new network connection.

CIT:

(Mike)

Cleaned some network cables in Lisa Bogue's old office. This allowed a network connection from the 125 subnet into my office, for testing purposes.
Installed 2U rack mount server with Larry, in one of the computer racks located in our server room.
Loaner Pool: Loaded a laptop with OS and GC software. I also updated another loaner laptop with software updates, and added security.
Dennis Coyne: Loaded an engineering workstation for him. This includes OS and many engineering packages.
Work on updating General Computing's IP database. This week I was able to do an inventory on Millikan's PC/Sun workstation's. Now I need to record nodename, mac-address, computer type/model, and location into our database. I still need to attend to 40 meter, Wilson House, Sychrotron and all labs.
Continued work on Spam Filters.
Onsite/phone support, which includes printer, software, and some networking issues.

(Veronica)

LIGO: Website updates. Security patches on Windows servers. Working on the makeover of the Advanced LIGO Schedule Progress webpages. PAC meeting website updates. User support with Photoshop. Roster database update. Editing a video for Riccardo. Prepared a high-resolution image for a publisher.
LSC: Updates to the reviewed papers webpages. Updates of the June meeting website.
CaJAGWR: Website updates / support.
Project Science: Issues related to the website transfer to ITS and its continued support.

(Larry)

Worked a number of purchase issues. Equipment purchased a few weeks ago has started to arrive. Installation of s/w and distribution to end users should start next week. Working on a couple of misc. orders for different people.
Spending a lot of time getting ready for the SURF students. Still have a number of items to clean up and accounts to setup.
Attended a number of meetings concerning the DCC upgrade. So far things are looking pretty positive.
Modified a number of user accounts.
Rebuilt a couple of disk systems. Working on getting the old disks replaced.
Working the heat issues with Bridge and Bridge Annex. Just a few more weeks to go and the new air-conditioning system should be working. I've been informed that they will wrap things up by the end of June. The computer room is not going to get as much air as originally promised. It should be enough to get the existing equipment powered up and going. I am already working with PMA in getting more cool air for the room.
Assisted the TMT group with a couple of minor issues.
Resolved a couple of minor network and printer issues. The Campus phone technician was in one of the network closets again and that caused a minor disruption for a few people.
Worked the mail filters, and working on the logistics for changing out the mail services in the not too far future.

Mail Statistics for May 19-25, 05

Accepted Messages 17,474

False Positives 212

Virus Messages 1,268

Rejected Messages 16,047

Total Messages 33,521

Advanced LIGO and Supporting R&D (Shoemaker)

Systems and Management

From: Carol Wilkinson <wilkinson@ligo-wa.caltech.edu>

Advanced LIGO Project Management

Development Progress Updates

The next update exercise will be at the end of June for progress through June 30, 2005. A teleconference for subsystem leaders on tracking budget using Florence Kaufman's allocation and accounting worksheets will be held in early June. Sub-system leaders will be contacted with details. Progress updates through April 30, 2005 on development of advanced LIGO subsystems are available at the usual web site:

See http://www.ligo.caltech.edu/~tfrey/index.html for a complete listing of all project related cost and schedule data.

Advanced LIGO Planning:

Work is progressing on recalculating bottoms-up estimates for the costs and shedule for the Advanced LIGO construction project. Recent re-estimates of SEI equipment costs and labor that have resulted in increases in the overall project budget forecast have been partially offset by significant reductions in projected SUS and COC fabrication costs. Fabrication and installation costs and schedules for the remaining Advanced LIGO subsystems will be scrubbed in the next month. Subsystem leaders should be prepared for a planning session in that time window. The goal is to have the new overall project costs and schedule by the end of June.

Advanced LIGO Reviews:

A Critical Review of the SEI BSC preliminary design was held on May 25. The review committee report is expected in early June. Recent progress for the ETF tech demo and results of modeling can be found at the review documents site: http://ligo.phys.lsu.edu/SEI/May05Review

Systems and Management

from Dennis Coyne

Systems

See also:

AL Systems web page

AL Systems email archives

Planning

A development schedule for SEI was shown at the SEI Critical Design Review in the context of the fabrication timeframes and start of installation at the observatories.
Efforts to refine the project costs & schedule continue.
Supported the ACIGA proposal for advanced LIGO support with scope, costing and schedule information.

Records Of Decision or Agreement (RODA)

Requirements

A small group has been looking into setting the Beamsplitter (BS) size (GariLynn Billingsley, Peter Fritschel, Phil Willems, Bill Kells, Mike Smith, Dennis Coyne). Assuming no surprising results comes from the FFT model confirmation of Mike Smith's Zemax analysis, the BS will be recommended to be 370mm diameter, 60mm thick with 95mm long flats for attaching the 'ears'. A RODA to follow soon, which will point to the various supporting documents, generated during this investigation.

Interface Issues

See the "Interfaces" section of the AL Systems web page

Justin Greenhalgh, Janeen Romie and Dennis Coyne met to discuss collecting all SUS interface information into a set of documents with bilateral agreements (i.e. SUS to each other interfacing subsystem) in accordance with the SYS Interface Control Document (ICD) outline. Much work is required to flesh out undefined interfaces; A list of action items and assignments has been made. The plan (hope?) is that the more important items will be addressed in advanced of the SUS Preliminary Design Update Review

Vacuum Compatibility

Residual Gas Assay (RGA)

High-Irradiance, Contamination-Exposure Cavities

Lee Cardenas, Liyuan Zhang

Cavity (Location)	Material/Item	Start	End	Comments
Cavity #1 (OTF Lab, Bridge)	new set of 70ppm REO mirrors	NA	NA	174 mW laser power, compares well with 180mW with previous ATF mirrors. Cavity is ready for samples
Cavity #2 (OTF Lab, Lauritsen)	NA	NA	NA	cavity is close to being ready for samples; completion on hold for other priority work
Cavity #3 (OTF Lab, Lauritsen)	Glenair Micro-D connectors (qty=20)	3/2	~6/3	Cavity is locked and we are taking measurements for absorption and ring down every day. test will be completed next week
Queue	OSEM emitter & photodiode	~6/6	~9/6	In vacuum testing currently
Queue	Stepper Motor	TBD	TBD	RGA outgassing vs temperature taken, ready for cavity

Large Item Cleaning Plan/Facility

Ken Mailand Working on the 40m Lab Air Bake Qualification, and met with Bob Taylor today to discuss details.

Mike Gerfen (Caltech machine shop) is adding some hole and tap features to the two test plates to make them identical as possible for the FTIR test to qualify the new air bake oven.

Meetings & Reviews

Held the 2nd Critical Design Review of the SEI Subsystem Wed, 5/25
A report from the review committee is pending.
Synopsis (D. Coyne): Based upon tests of the technology demonstrator at the Engineering Test Facility (ETF) at Stanford, the SEI subsystem is shown to just meet requirements at 1 Hz, but fails to meet requirements below 1 Hz and at 10 Hz. The SEI team offered explanations and potential remedies for the performance shortfall. Costs are considerably higher than planned. A schedule for the balance of development was presented.
Future near term planned meetings & reviews:

Date	Subsystem	Review or Meeting Title
6/?	SUS	Requirements & Interface Update (enable SUS/UK final design efforts in parallel with SUS/US completion of the quad controls prototype and preliminary design)
7/11	SYS	Systems Issues Summit Meeting PASTE PF's agenda here
?	AOS	AOS: Scattered Light Control Design Requirements Review (DRR)
?	COC	?

Control & Data Systems (CDS)

Data Acquisition (DAQ)

from Rolf Bork

I have been looking into some possible networking schemes for AdvLigo. In the future, we do not want VME crates or processing in the VE areas or near the ADC/DAC modules. The ADC/DAC modules instead would have some sort of data uplink on board (FPDP, gigE, fiber channel, etc) which must move data to/from processors located elsewhere. In order to still make the 16 KHz loop times, this data net must have minimal latency as well as speed. A couple of us are going over to a local company today that makes 2Gbit full duplex networks with advertised few usec latencies. It may have advantages over our present RFM networks, including can be configured as star network w/crossbar switching instead of ring and price is about ¼ to 1/3 that of RFM networks.
With several systems due to go into LASTI over the next year, Jay and I are starting to look at an integrated layout to fit these into a LIGO-like system. Doing VME is out, just by cost, and new ADC/DAC modules will not be ready in time. So, I think we need to develop something that proceeds toward an AdvLigo layout for testing w/capability of retrofit of new ADC/DAC and their data links.

from Ben Abbott

I am waiting for the arrival of a new VCO for the PLL for Jay's Daq-in-the-box. Once it arrives, testing will resume.

Seismic Isolation

From: "Joseph A. Giaime" <jgiaime@ligo.phys.lsu.edu>

Advanced LIGO:

Electronics: (Jay). looking for source of 24 Hz peak. Plots sent to Matt at ADE, got some feedback with suggestions of things to check. 25 kHz modulation signal may be the source.

Work at LASTI:

HEPI control on the BSC (see LASTI ilog for week ending 5/20/2005. Where are the noise plots?)
BSC HEPI controllers designed and tested, but not sensor correction. Rich reports that the design was the same or easier than it was with the stack in place. No need to make the sensor correction design. Still some crosstalk that need to be ironed out in Y and Z loops.
Mass driver measurements: 10 kg actuator mounted on vacuum flange, radially out. swept sine measurements to ground and tank sensors. Assumption is that the force - displacement TF from flange to ground (e.g.) is the same as the f - d TF in the reverse direction.
Ken is still working on model; Nastran requires manually constraining the connecting meshes. FEMAP?
1st priority is to measure the first dozen modes w/o BSC chamber.

Work at the ETF:

Brian has been working on the model. He currently models the undamped dynamics, and has shown agreement with resonance frequencies.
The two main goals for next Wednesday are:
noise model compared with ETF results, extrapolated to LIGO.
expectation of performance with softer vertical spring between stages 0-1
Since it is not easy to include the multi-rate FIR filters in the matlab model, Brian is using a set of IIR filters that look the same high frequencies (i.e., 1 Hz and above.)
Brian O'Reilly will put together a set of calibrated spectra in 6 DOFs of one of the LLO BSCs, with HEPI.
Brian and Corwin are thinking about strategies for shielding stage the stage 0-1 actuator fields from stage 2. Vertical stage 1 drive results in stage 2 horizontal motion.
Received control desk 4.2, and they are trying to install it on their other dSpace system.
William East working on notch-ology, and is working on a tool kit to make matlab notch design easier in large quantities.

From: Ken Mason kmason@ligo.mit.edu

SEI Structure:

The final phase of the SEI Critical Review was held on Wednesday.
Some highlights are:
Brian Lantz has shown he can get good isolation at 1hz and a design change to the stage 1 springs is required to improve performance at 10 hz.
Measurements and modeling continues on the BSC structure to determine if modifications are needed to the existing structure.
Dennis Coyne and Carol Wilkinson presented an updated schedule which would have the prototype seismic isolation installed and tested in time for the UK quad suspension testing.
The final report from the review committee is expected in two weeks.

Suspension

From: Janeen Romie romie_j@ligo.caltech.edu

Advanced LIGO Suspensions

Checking drawings for Calum. Statusing machine shop work. About to issue more POs for more parts. Reviewing documents for the DRR Update. Working on redlines to the Universal SUS DRD. Met with Mike Gerfen on a number of machining and welding issues. E-mailed David McClelland some background information for the mode cleaner costs.

Attended the SEI Critical Review

From: ctorrie <ctorrie@ligo.caltech.edu>

From: Ken mailand kmailand@ligo.caltech.edu

Working on the 40m Lab Air Bake Qualification, and met with Bob Taylor today to discuss details. Mike Gerfen is adding some hole and tap features to the two test plates to make them identical as possible for the FTIR test

From: Jay Heefner <jay@ligo.caltech.edu>

AdL Controls

Began testing of the FPDP interface to the AD7679 ADC. Preliminary indications are that the interface is working and we can read 18- bit data at the full 580Ksps. As soon as the interface is completely verified we will begin noise tests on the ADC.
Kicking around various ideas for the slow and fast controls for AdL.

AdL SUS

Conducting transmission line effects experiment on GEO electro-static driver.

From: "Mark Barton" <mbarton@ligo.caltech.edu>

This week I worked with Mohana and Paul to connect up and debug the electronics for the dual quad prototype at Caltech. We have all the bits and pieces for the OSEMs on the top three levels of the two chains except for two adapter cards that interface between the DB37 connectors on the dSpace and the IDC40 connectors on the anti-imaging boards. Mohana is having these fabricated. With sufficient swapping of cables everything else seems to work except for three drive channels, apparently due to a faulty LIGO-I satellite amp.

Core Optics

From: Helena Armandula <ahelena@ligo.caltech.edu>
Report from CSIRO - The report came from Mark Gross

In an effort to produce low stress coatings, the films were exposed to subsequent annealing that seems to have damaged the coatings. The original plan was to try and get the net film stress of a standard 30 layer mirror down to zero by step-by-step annealing. Previous experiments done by CSIRO suggested that the net stress in a silica/tantala multilayer could go from compressive to tensile after annealing at temperatures up to 550C and hence at some point must have gone through zero net stress. They now realize that this is true only under certain circumstances.

CSIRO believes that during the annealing process, the silica material changes far less than the tantala material. They found that tantala films deposited in a standard IBS process have compressive stress which is readily annealed out and can then easily become tensile with further annealing. Silica films, however, are far more resistant to annealing and basically they now see that even temperatures up to 600C will not anneal out the compressive stress completely and at these sorts of temperatures re-crystallization of the film, and certainly of other materials, may occur.

So, for the net stress to be annealable to zero, they believe the film must contain a sufficient total thickness of tantala so that its net tensile stress (after sufficient annealing) can balance the net compressive stress in the silica component of the film. In the case of earlier experiments they were dealing with multilayers with about 40% total silica and 60% tantala. The standard 30 layer quarter-wave mirrors, however, have the reverse of this. In other words, there is too little tantala in the film to balance the large compressive component in the silica.

All this also suggests that if the same annealing conditions are applied to multilayer films with differing thicknesses of each layer type, then the net stresses obtained will be rather variable.

They have taken the coated samples to over 600 C (after 10 annealing stages) and the net stress is still not zero. However, the films are now showing signs of possible re-crystallization, and they will verify this by XRD.

For the purposes of testing a zero stress sample, the only way they can see to achieve this is to use a silica/tantala design that has more tantala in it (eg 1/8 lambda, 3/8 lambda) or to use something other than silica which also has the ability to anneal to a tensile film (eg alumina).

From: Bill Kells <kells@ligo.caltech.edu>

After hearing the concept, at least , a couple of weeks back for optimizing the various layer thicknesses in HR stack reflectors for the purpose of minimizing thermoelastic noise, I have been doing some studies of what this is likely to buy. So far I am working independently of whatever Riccardo is up to (havent officially come to understand that direction). The concept seems sound, so it’s interesting to look at, and we have a nifty code for studying film stacks here (written years ago by Hiro). I've got some interesting results, which do indicate possible improvement (reduction of net Tantala thickness), but the best I've seen quantitatively is only about ~15%.

Pre-Stabilized Laser

From: Peter King pking@ligo.caltech.edu

The pricing and availability of an OEM-version of the Innolight NPRO laser was made. Enquiries were also made about the model number and manufacturer of the laser pump diodes used in the 200-W laser. Maik Frede will get back to me after returning from CLEO.

Auxiliary Optics

From: Michael Smith <smith@ligo.caltech.edu>

No report this week.

Other Laboratory R&D

From: Riccardo DeSalvo desalvo@ligo.caltech.edu

Marco (25May)

Cavity successfully locked with the implemented dithering servo loop scheme. Several transverse mode shapes were collected and analyzed. I also performed the PZT calibration.

I’m studying different collected data (profiles and spectra) in order to verify our capability to understand the cavity behavior, before to switch to the MH mirrors. In order to understand the profiles power density residuals I’m re-calibrating the profiling camera with different test beams: a possible gain slope in the ccd array can affect our evaluations. The last results indicate a slope < 5% intensity but with an evident direction, the same showed by TEM10 profile.

Juri

Completed the theoretical model for the coating thermoelastic noise for finite size mirrors starting from the model found in literature for the semi-infinite mirrors. Now writing a Mathematica notebook in order to make calculations with Gaussian and Flat Top beams.

Chiara

Going through the experimental set-up for measurements of transfer functions of the horizontal attenuation system prototype for the 40m interferometer.

For additional information about this report, contact S. Whitcomb or P. Lindquist