Weekly Report for Week Ending August 25, 2005

The LIGO Executive Committee meeting for August 29, 2005 is cancelled due to the scheduled meeting of the LIGO Staffing Committee.

Special Announcements:

Weekly Report Highlights

H1 binary inspiral range, 2dB shy of SRD.  See

LSC Issues (Saulson)

No report.

LIGO Laboratory Administration (Lindquist)

STATUS OF LSC MOUs (Lloyd)

LSC MOUs and Research Plans and Progress Reports

  • Completed posting the following MOUs for panel review and discussion for meeting on August 22-23:

ACIGA, Balearic Islands, Carleton College, Caltech Relativity, Caltech Experimental Gravity Physics, Columbia Univ., Cal State Dominguez Hills, Univ. of Florida, GEO 600, Goddard NASA Flight Center, Hobart & William Smith Colleges, Inst. of Applied Physics, Inter-Univ. Centre for Astronomy and Astrophysics, Louisiana Tech, Loyola Univ., Louisiana State Univ., Univ. of Michigan, Moscow State Univ., National Astronomical Observatory of Japan TAMA, Northwestern Univ., Univ. of Oregon, Pennsylvania State, Univ. of Rochester, Southeastern Louisiana Univ., Southern Univ., Stanford Univ., Syracuse Univ., Univ. of Texas at Brownsville, Trinity Univ., Univ. of Washington, Washington State and Univ of Wisconsin at Milwaukee.

  • Attended the review panel meeting and formatted late and revised reports and attachments as they came in, and posted them on the website for panel review.

Non-LSC MOUs (Lloyd)

  • No report this week.

SITE TELECONFERENCE (Lindquist)

No site teleconference was scheduled for Thursday, August 26, 2005.

  • The list of assigned actions updated through May 26, 2005 (the last time the list was updated) 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

Week Ending

August 25, 2005

In

Out

Packages

14

4

Faxes

29

30
  • Completed processing LSC documents.
  • Update on Scanning Project - 45 boxes of old account files were sent to the shredder yesterday.  There is a small handful of remaining account file boxes needing to be organized, scanned and burned to cd's.

COST SCHEDULE CONTROL SYSTEMS (Cunningham, Brambila, Kaufman)

>From: "Cronin, Holly" <Holly.Cronin@caltech.edu>

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

  • Placed orders on my credit card and on purchase orders for delivery to the campus and to the off-site observatories at Livingston, and Hanford. Followed up with vendors for updated delivery status on several rush orders for the sites. I began receiving requisitions directly from the Hanford site today and have already placed the orders for the data cartridges for LHO. I'm working closely with the vendors to make sure that any issues on our orders are resolved quickly to avoid shipment delays.
  • Coordinating the request for the credit adjustment requested of a vendor that shipped an order to the Livingston site. In addition, we're changing the expenditure type and sales tax code on the order. Coordinating the adjustments with the appropriate parties to effect the changes before payment is remitted.
  • Working on the change orders to the subcontracts with U.S. Civilian R & D and to Hereaus Amersil.
  • The order with Point Source in the UK is on hold as requested by the researcher pending the review of the product specs that have changed since our last order with this vendor.
  • Began reconciliation of the billed pcard charges. All of the older orders that were pending have been resolved and the only orders I have are current orders going back to July 2005.
  • Shopped for several electronic components needed by Riccardo's group and obtained quotes on standard of-the-shelf computer items.

>From: Florence Kaufman <fkaufman>

  • Verified that the expenditure type for stipend payments to students has now been corrected.  The use of an incorrect expenditure type had resulted in the imposition of Indirect Cost; the Indirect Cost has now been reversed.
  • Prepared a summary of all payments for Participant Support Costs thus far for the FY02-FY06 Operations Award.
  • Provided Ken Mason with a detailed listing of all payments to date for the Seismic Isolation effort charged to LIGO.BSCCH/5.18 and LIGO.HAMCH/5.19 from October 1, 2001 to date.
  • Noticed that an incorrect expenditure type had been used for payments of 11 Stipends at Hanford in August.  This resulted in the imposition of Indirect Cost on participant support expenditures which should be exempt from Indirect Cost.  An expenditure type correction will be requested for these expenditures.
  • Responded to a request from Project Accounting to authorize a funding realignment. Such realignments are required whenever the expenditures exceed budget at the project level because this prevents Caltech from invoicing the NSF correctly for reimbursement of expenditures for the Award.
  • Financial reports can be found at: http://docuserv.ligo.caltech.edu/~fireport. (For passwords contact Florence)

SUBCONTRACTS MANAGEMENT (Jasnow, Salone)

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

  • Nothing significant to report.

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

  • The architect for the LLO Science Education Center, Eskew - Dumez - Ripple, has submitted revised drawings to the low bidder, Cangelosi - Ward, for the purpose of reducing the original bid.  These drawings were received by the contractor on Friday, August 19.  On Monday, August 22, the contractor distributed them to his proposed subcontractors in order that they may submit revised quotations.  These quotations are due to the contractor on Tuesday, August 30.  If the revised quotation is acceptable, a request to extend the bid validity date past Friday, September 2, will be issued.
  • A job walk for the relocation of the LDAS equipment at LLO was held on Tuesday, August 24.  All four companies who received copies of the RFQ were in attendance.  The job walk was conducted by Rusyl Wooley and Allen Sibley.  One company, ISC, has submitted a letter stating that they will not bid the job.  Quotations are due on Wednesday, August 31.
  • Training on the TechMart system was give to the staff at LLO on Tuesday, August 24.  The training was conducted over WEB - X by Ms. Monica Marquez of the Caltech Purchasing Services staff.

SUPPORT (Baldon, Hiroto, Lloyd)

>Irene Baldon

Processed the paper work for three (3) new/revised trips.  At this time there are eight (8) trips completed or in the works but are awaiting the necessary paper work to enter the P-Card system.  Assisted several LIGO people with their travel arrangements using their P-Cards and made several reservations for outside visitors coming to LIGO/Caltech or one of the LIGO sites.

Completed eighteen (18) Expense Reports and there are twenty-five (25)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 three (3) reports more than thirty (30) days old.  I have zero (0) reports awaiting signature at this time.  Worked on copying and recording all the expense reports completed last week to be sent to Travel Audit for final auditing and payment.

>Julie Hiroto

No report.

>Dorothy Lloyd

  • Processed the usual invoices for payment.
  • Jim continued with data entry in the LIGO database and helping out in the DCC.

PROPOSALS and REPORTS (Lindquist)

The Proposal for an Extension to FY 2007 and FY 2008 and Supplemental Funding for LIGO Operations was previously reported as submitted to the NSF.  The NSF has requested additional material.  Contributors to the Annual Report have been contacted to provide additional material.

DCC Steering Committee (Lindquist)

The Executive Committee discussed the change request during the meeting Monday, August 8, 2005.  The committee recommended approval.  Approval is pending additional information in response to questions forwarded through B. Barish by a document management system specialist at SLAC.

CHANGE CONTROL/CONTINGENCY MANAGEMENT (Lindquist)

  • I have scheduled a meeting of the LIGO Change Control Board Wednesday, August 31, 2005 at 10am PDT in the Engineering Conference Room to discuss Change Request CR-050009.  The Seismic Isolation Critical Review Committee issued a report (LIGO-M050035-01-M) recommending that we proceed with the fabrication and testing of the ASI version of the BSC seismic isolation prototype at LASTI. Approval of this change request will release the remaining funds allocated to begin fabrication.

HUMAN RESOURCES (Akutagawa)

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

  • The next Staffing Committee meeting is scheduled for August 29.  All files for the Staffing Committee are up-to-date and posted on the SC web page.
  • Prepared a number of appointment memos for various Visitors.

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)

The LSC and sundry F2F meetings wrapped successfully on the 18th at Hanford.  Many thanks to those who helped organize, including (but not limited to) Terry Gunter, Linda Turner, Mike Pedraza, Christine Barker, Richard McCarthy, Larry Wallace and Terry Santini.

Modifications to the PRC loop recently put the H1 binary inspiral range 2dB shy of SRD, or, at 11Mpc.  Once the PRC correction had cavity pole compensation removed, and the (measured, flat) transfer function instead employed (if not understood), PRC and DARM were better decoupled by a factor of ten.  The noise in the bucket at 150Hz is shown here, grazing the SRD curve.  The full H1 noise budget is available in the previous link.

Some highlights from the last two weeks of elogs are linked below:

  • both the 2k and the 4k have photodiodes sporting burn spots and thus need replacement prior to S5
  • acoustic enclosures for 2k and 4k REFL ports arrived by truck on Thursday Aug 25

4K IFO

  • Before getting to 11Mpc, QPD and beam centering (BC) servos were jointly optimized.  Several steps were involved, with a key one being the minimization of AS_I DC via QPD pitch settings.
  • the modulation depth of the resonant sideband was modified by 3dB, increasing SNR and cementing noise improvements that had previously yielded 10Mpc.
  • [this bullet entry by Bill Kells, regarding testing of the ITMX that was removed from H1 several weeks ago - ML] People are back from vacation, we are starting up the next round of OTF absorption measurements (back to the HR surface now). We eagerly await analysis of cleaning swipes.  In particular the ones Doug [Cook] has from ITMy cleaning. They no doubt hold a valuable clue. However how they are handled/analyzed will be crucial: was all the contaminant removed in the ~first swipe (needle in the haystack scenerio)? Or: was it absorbing dust which was removed, in which case an analysis based on dissolving material caught in the swipe will not work! -BK
  • a laundry list of tasks on the 4k was compiled

2K IFO

  • The 2k 7 kHz peak is actually at 9.25 kHz and has been observed simply because of aliasing.  The new NPRO laser appears to be responsible for this recent addition to the spectrum.
  • ISCT10 was docked after floating.  Table velocities were down by nearly an order of magnitude, broadband.  Air compressor cycling briefly showed floating could sometimes be problematic.  Ranges while floating have been as high as 4.5 Mpc

DAQ

  • a comparator for the MX new timing system and the atomic clock was installed
  • we continue to chase the source of .25, and 1Hz lines in H1:DARM_CTRL, without a clear understanding just yet

Outreach (Dale Ingram)

A Web note summarizes the WSU Tri-Cities course for teachers mentioned previously.  The dust storm on 8/12 cleared in time for our visitors to see a nice meteor shower.  Thanks to Nergis Mavalvala for a fine Public Lecture on 8/14.

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

CDS Data systems

(Lisa Bogue)

  • Order Status for the CDS equipment:  raid enclosures expected on 8/26, disks and scsi cards 9/1, LTO3 tape drive & tapes 8/29, Sun 1500 workstations for the LVEA 9/6.
  • Began installing a jumpstart server (sol9).  CDS has been seeing a lot of equipment failures and every machine has a different configuration and patch level.  Jumpstart will make it easier and faster to roll out new machines and update existing ones.
  • Control4 died.  Moved the mode cleaner autolocking script and the disk array for the burt snapshots to control3.  I still need to pull the disk and see if I can get a backup of it.
  • Discovered a problem with one of the disk arrays on FB0.  This array is currently at 100% but with data that is mostly from 2004.  I will be dumping the data to tape and seeing if I can fix the problems with the array.
  • Began looking at ways to automate the login of control7 (which launches many displays on different workspaces that get fed out to a web page.)  The simple idea of starting them up in .dtprofile isn't going to work.  I'm looking at writing a dtksh script to do it.
  • Made changes to the wiki configuration so I could put it into prime time.  London isn't currently at a software revision that can host the software, so for now I'm going to keep it on wikidev and put a link from London.  There will still be restrictions on how it gets accessed, but the time has come to get the redbook documentation into it.  The last thing that needs to be resolved is an automated script to dump the database someplace where it will get backed up on a regular basis.
  • Worked with Peter Shawhan on resolving a problem with the conlogger.  Because conlogger was down for a week, we had a problem getting the astrowatch segments archived.  Thanks to Ben Johnson for writing a script to do this.

(Ash Kahn)

  • Identifying epics channels that need to be added or removed from the trend list of the framebuilders.
  • Updating the tools on cdscomp1 computer to reflect changes made to the CDS network.
  • Helped troubleshooting the CDS team from the fallout of the power outage.

Administration (Bonnie Wooley):

Tech Mart training was conducted this week for those at LLO who will/need to make purchases.

Data archiving/Condor/LDAS admin (Igor Yakushin):

  • 4 T3 drives failed after last week power outage. They have been replaced by drives from the spare T3s by Tom. The replacement drives are ordered from SUN. T3s did not go down during the outage but continued running on UPS. Some servers were rebooted and some continued running on UPS.
  • Old dataserver was repaired yesterday: one of memory dimms was replaced. The tests done at the OK prompt did not show any problem with the 2Gb fiber channel card which we had trouble using in dataserver.  More tests can be done after we get an extra blade in the fiber channel switch to connect it to.
  • Failing primary drives were replaced in cluster nodes 3,6,10,12,16,32. There are at least 12 more drives that have bad blocks and need to be replaced but at the moment I am out of available spare drives. 30 more 200Gb drives were ordered from CDW and should arrive within couple days.
  • I scheduled firmware upgrade of tape robot drives from 1.34.408 to 1.35.402 on Monday.
  • All user home directories but one were moved from /data2 to /archive/home. One account could not be moved so far because the user is running Condor jobs.
  • LDAS room upgrade status: so far we are on schedule for the move to the temporary location

a) we had bidding contractors on site yesterday; Rusyl showed them what needs to be done;

b) 140 nodes are shipped today from CIT and should arrive no later than Sep 7 according to Ed Chargois;

c) I asked StorageTek for a written quote to move the tape robot, I should get it on Monday during Roger Helms' visit to upgrade tape drives firmware;

d) The current suggested layout of the equipment in the high bay area is available here: http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/TEMP1

Data analysis:

1) LIGO-GEO simulations on SG21 are done and the results after waveburst are published here:

http://www.ligo-la.caltech.edu/~igor/S4/TRIGGERS/18/index.html

2) LIGO-GEO production triggers (using latest GEO calibration and DQ flags) and the corresponding figures of merit are published here:

http://www.ligo-la.caltech.edu/~igor/S4/TRIGGERS/17/index.html

3) Made a presentation at the data analysis plenary session during the LSC meeting "Status of S4 untriggered burst search":

http://www.ligo.caltech.edu/docs/ScienceDocs/G/G050375-00/

4) Made a presentation at the DetChar session during the LSC meeting: "Comparison of h(t) and AS_Q on WaveBurst and CorrPower triggers":

http://www.ligo.caltech.edu/docs/G/G050407-00/

5) More LIGO simulation waveburst triggers were published:

http://www.ligo-la.caltech.edu/~igor/S4/TRIGGERS/16/index.html

http://www.ligo-la.caltech.edu/~igor/S4/TRIGGERS/15/index.html

Networking, security and general computing (Shannon Roddy):

As a result of the power outage last week, Touro lost its hard drive.  This is one of few GC servers that was not on a UPS.  It started acting up after the outage.  On Sunday I attempted to reboot it remotely after Natalia complained about some weird behavior on the machine.  However, it would not reboot, nor would it run any command.  Monday I rebooted the machine via stop-A, etc. and it would not boot at all from the system disk.  probe-scsi-all did not show the disk as present, so I assumed that the disk failed.  I have taken a disk out of another machine that is not presently in use and I am in the process of rebuilding Touro with Solaris 10.  This will be the first general purpose GC machine on Solaris 10.  This is also a well used machine and as such should help us weed out any bugs with our software and Solaris 10.  After a testing period with Touro on Solaris 10, I will likely start migrating the rest of the GC machines to Solaris 10 in order to take advantage of some of the new features.

Someone showed up with a copy of the latest windows virus on Monday.  They were not on the network long enough for me to track them down, so I am unsure of who it was at this point.  It does not look like they successfully infected any other machines since I have not seen any other port scanning on port 445 which is a sign of the virus on the network.

Using the upgrade/repair on Touro to develop a generic Solaris 10 security document.

Usual round of parts orders, etc.

High Power Laser Facility (Ken Franzen):

We received the repaired the 100 W laser. After installation and safety inspection I have started to test its performance.

LLO Education & Outreach (John Thacker):

Completed detailed preps for upcoming partnership meeting, Oct 4th.

Visited Paul LeMahieu, The National Writing Project, Berkeley, to discuss LIGO Local Educators Network ideas.

Detector Commissioning (Valera Frolov):

The laser power supply and the laser chiller controller were damaged during the last weekend lightening storm.  The laser was not damaged and the power into the mode cleaner is still above 7 W.  Both damaged units were replaced and interferometer operation was restored. Two multi hour locks were achieved last night with the best inspiral range of 7.8 Mpc. The corner weather station was also damaged during the storm.  Other commissioning activities during last week included the test implementation of the HEPI tilt correction, work on the epics mapping of the LCS photo-detector interface, and commissioning of the reflected port fast shutter for the non-resonant photo-detector.

(Franzen) We have received most of the REFL port beam stabilization hardware except the PZT systems which are estimated to be shipped overnight September 6.

Initial LIGO Detector Science & Engineering (Coyne)

CDS

see also the CDS weekly meeting minutes in the commissioning archives

CDS Software

no report

CDS Hardware

Ben Abbott

LSC RFPD

  • The mostly-stuffed boards have returned from Screaming Circuits, and the remaining parts will be stuffed shortly.
  • I am discussing with Rich the changes to the test procedure that will include the tank transimpedance measurements, high-power testing, and others.

Fast Shutter

I am experimenting with a fast shutter that is based on a design Rich found where the shutter is made from a hard disk drive armature.  Initial tests are promising.  I am in the process of refining the design to maximize shutter speed.

DMT

John Zweizig

This week I have been preparing a new release of the DMT software. Changes include implementation of a new DMT trend channel naming scheme, upgrading of the segment class and trigger client to interface with the online segment database and reading calibration frames from the LscCalib (reference calibration management) class. Once the new revision is tagged and compiled it will be installed at the observatories for testing during the Astrowatch running.

PSL

PeterKing

The chiller control module from the PSL Lab chiller was shipped down to LLO.  In the meanwhile I made some enquiries with ThermoElectron about getting the failed units repaired.  [Note from D Coyne: The RS232 chip on the chiller failed in a recent lightning storm, as did its companion in the laser power supply. It seems that the original chiller units are no longer available; for spares, we need to develop a replacement or acquire a number of reconditioned chillers.]

Optical Metrology

Lee Cardenas, Liyuan Zhang

The previous bulk absorption test for the 4ITM07 has been completed.  New test is underway for the same mirror with higher spatial resolution.

Helena

FTIR and preliminary XPS/ESCA analysis results on the elliptical baffle glass removed from the 4K ITMX can be found at the DCC OUT under document numbers: T050143 and T050144.  Another XPS/ESCA analysis point has been ordered on the control side 1 (surface that faced the MC) to corroborate the initial finding.

40 Meter Interferometer (Weinstein)

IFO commissioning

  • Ryan Kinney's SURF talk, 8/18/05, "Noise Budget Development for the LIGO 40 Meter Prototype", in pdf or ppt. Final paper in progress.
  • Marcus Ng's SURF talk, 8/18/05, "Design of an Output Mode Cleaner to Enable DC Readout in the LIGO 40- Meter Interferometer", in pdf or ppt. Final paper in progress.
  • After Osamu diagnosed the poor damping and strong inter-OSEM coupling in ETMX (UL and LR OSEMs are particularly bad), we agreed that a short vent to adjust ETMX was justified. This should hopefully greatly reduce the noise in the x arm, making lock acquisition easier. We agreed that this vent should be limited to adjusting ETMX only.
  • Osamu measured the ETMX OSEM couplings in vacuum. Steve and Bob vented the 40m on Tuesday morning. By 2pm, the ETMX chamber was opened. Steve, Osamu, Rob, Dan and Monica did the following: transfered the stack load from STACIS to the offloading jack screws, leveled the optical table, adjusted the OSEMS to minimize cross-couplings (rotated the side OSEM by 80 degrees) and sensitivity to bounce and roll modes, took in-air measurements, took many pictures. They sealed up by 5:30. Pumpdown began Wednesday morning at 7:30, and was complete by 2pm, with no significant problems. All optics came back to the same oplev readings, and the beam came back to the same QPD readings. All cavities were locked, everything checks out ok.
  • David Blair re-measured the coherence between the ITMX and ETMX OSEMs. Before the vent, there was little coherence between ITMX and ETMX, in contrast to the Y arm, which has near 100% coherence from 0.15 Hz to more than 3 Hz. After the vent, the X arm looks very similar to the Y arm. Success!
  • Osamu measured the ETMX OSEM. He sees -28db suppression of POS on the side OSEM, uniform response on all the face OSEMs, significantly reduced bounce & roll mode motion, and improved noise spectrum of PIT and YAW. ETMX has gone from being the worst suspension (in terms of couplings) to the 5th best, and completely acceptable.
  • Dan and Osamu are now working to re-balance the ETMX coils, re-diagonalize the POS2ANG matrix, and re-diagonalize the input matrix. We expect significantly reduced noise spectra.
  • Dan is writing up the suspension coil balancing and diagonalization procedure as implemented at the 40m.
  • Osamu and Monica measured the arm reflectivity and the PRC losses a couple of weeks ago. These numbers imply a maximum achievable PRC gain of 5, undercoupled. Rob will check affect on length signals at SP.
  • Ryan has made a great start on the noise budget for the 40m, with lots of help from Rana and Rob. Dan and Monica will take on the calibration and noise budget task and bring it to completion.
  • David Blair and Ryan have completed a draft of a technical report on seismic noise at the 40m, concluding that there is a ~20% difference in seismic velocity between the x and y arms. They also developed the arm OSEM coherence diagnostic, which was very useful in diagnosing the problems with ETMX and the effectiveness of the solution.
  • Rob has been working with Seiji on understanding the length control signals as the CARM offset is reduced. They lock the full IFO with a CARM DC offset (all other degrees of freedom are controlled by RF signals with zero offset). They then HOLD the CARM servo and let the mirrors swing towards resonance; or, they give the mirrors a CARM kick in the right direction. They have the CARM RF signal (SP 166I) switched on, in the hopes that it will catch lock with zero offset, but so far, no success. They are studying the signals (clear Doppler ringing as nicely described in Malik's Applied Optics paper. Monica is working on fitting the signals.

IFO modeling and DC detection development

  • Monica has merged her optical plant with Matt's control plant and LA procedure, and is testing the resulting system.

Electronics, controls

  • Ben has completed the controls for the common mode servo fast analog path to the laser frequency. All of the wiring, databases, screens, module procurement modification and addressing, and functional testing is complete. Osamu & Rob will commission the system. (The slow path digital to MCL has been in place for some weeks).
  • Ben has been developing a fast shutter that is based on a design Rich found, where the shutter is made from a hard disk drive armature. Initial tests are promising. He is in the process of refining the design to maximize shutter speed. We will want these to protect our MCR, SP, and AP beamline photodiodes.
  • One of the Epics computers (c1losepics) died last week. Rolf replaced it with his development computer until we can get a replacement. It was running a DHCP server, which was preventing the reboot of other embedded computers; took a while to figure this out. Currently, an elaborate procedure must be followed to reboot any embedded computer. Hope to get this fixed soon!

Lab Infrastructure

No report

Thermal Noise Interferometer (Black)

Nothing to report this week.

LASTI (Ottaway)

No report.

Data Analysis and Computing (Lazzarini)

Simulation and Modeling (Bhawal)

E2E Weekly Physics Meeting

Sany Yoshida discussed about a Simulink model developed by Brian Lantz and others at Stanford U for the seismic isolation system and the possiblity of incorporating the same in e2e model for Advanced LIGO.

Diffraction losses of Hermite-Gauss Modes in Adv. LIGO arm cavity

(Biplab) In the meeting on 'Parametric Instability in Advanced LIGO' organised by David Blair on Tuesday I presented FFT  model results on diffraction loss vs radius of curvature for high order modes. Results show losses are generally 3-5 times higher than the simple clipping approximation and the ratio FFTloss/clipping loss has  varying dependence on  mirror radius.Clipping approximation always underestimated the losses.

Viewgraphs at:  http://www.ligo.caltech.edu/~bbhawal/Blair/Biplab_G050460.pdf

mirror curvature tolerance of adv.LIGO optics

(Hiro) The requirement of the mirror curvature tolerance is being studied for finite aperture mirrors. Numerical evaluation will be done using melody, if necessary, because FFT version is not ready.

Mechanics Modeling

(Sany Yoshida) Continued working on the local damping control of the LOS box with suspension wire violin mode dynamics. Found an error in the expression of the transformation from the coordinate system of the space state representation for the violin mode dynamics to the e2e coordinate system (i.e., the coordinate that the damping force is based on). After fixing the problem, the position motion damps much better.

(Sany & Hiro) The simulation of the mechanics part for Advanced LIGO is being coordinated with Sany Yoshida with the help of the Seismic Isolation (SEI) group. Sany started to collect models of the seismic isolation for AdvLIGO. Received a seismic isolation model from Brian L (Stanford).  This model for AdvLIGO BSCs is in the state space representation. It will be incorporated into an e2e file to simulate the table motion.

Simulation of 40m Advanced Interferometer

(Monica) Adding 40m-like suspensions to the e2e optics package for the 40m.  Currently trying to acquire lock correcting the error signal for the mirror motion; Next step is to try lock acquisition when suspensions are used in the optics package.

modeler

(Hiro) Still working on the development of the fast dual recycling cavity module. Improvements of the formulation were done to cover wider parameter space. This could possible remedy a discrepancy between the matlab code based on this approximation and the one based on e2e primitives.

Alfi

(Melody) Continuing with fixing Problem reports (PR).  Currently fixing PRs 496 and 498.

Data Analysis Activities (Lazzarini)

Chatterji:

  • Continued development of QSCAN, a post-processing tool to search for statistically significant excess signal energy in auxiliary and environmental channels around a time of interest.  As a test, the tool was applied to the 10 most significant events identified in the S4 triple coincident burst search.  The tool appears to perform well for all channels in the level reduced data set, with the exception of deterministic signal channels such as the excitation channels containing the calibration lines.
  • Continued work on implementing an improved H1-H2 consistency test for the Q Pipeline based on investigations by Sahand Hormoz.
  • Investigating discrepancies in measurements of 1/4 Hz and 1 Hz line features that are observed in S4 gravitational-wave channels by some methods, but not by other methods.

Creighton:

This week I continued working on the Einstein@home validator, eliminating constraints on file format, improving efficiency, and increasing verbosity.

Shawhan:

  • Worked with SURF student Sebastian Cassel on his project.
  • Modified conlog code to use new method of determining what site it is running at, and got it running again at LLO after changes on 'llo1'.
  • Currently working on a program to veto triggers in the inspiral analysis pipeline, given a set of time intervals derived from data quality flags and/or auxiliary channel glitches.

Yakushin:

1)      LIGO-GEO simulations on SG21 are done and the results after waveburst are published here: http://www.ligo-la.caltech.edu/~igor/S4/TRIGGERS/18/index.html

2)      LIGO-GEO production triggers (using latest GEO calibration and DQ flags) and the corresponding figures of merit are published here: http://www.ligo-la.caltech.edu/~igor/S4/TRIGGERS/17/index.html

3)      Made a presentation at the data analysis plenary session during the LSC meeting "Status of S4 untriggered burst search": http://www.ligo.caltech.edu/docs/ScienceDocs/G/G050375-00/

4)      Made a presentation at the DetChar session during the LSC meeting, "Comparison of h(t) and AS_Q on WaveBurst and CorrPower triggers": http://www.ligo.caltech.edu/docs/G/G050407-00/

5)      More LIGO simulation waveburst triggers were published: http://www.ligo-la.caltech.edu/~igor/S4/TRIGGERS/16/index.html, http://www.ligo-la.caltech.edu/~igor/S4/TRIGGERS/15/index.html

LIGO Data Analysis System

Software Systems (Blackburn)

LDAS:

Upgraded the IBM Database server on the LDAS-DEV system to version 8.2.2.  This included adding the new header files and libraries to the LDAS-DEV LDCG tools directory.  LDAS was recompiled with these new libraries and the new server is running as expected.  Have begun the process of upgrading the Tandem system to use the new DB2 server and header/libraries.  Have now upgraded suntest1 and Tandem-II.  Testing: ran system test for ldas 1.7.1 and 1.7.3, and weekend testing. Adjusted loop delay time for added /archive S1 S2 and S3 mount points to dev for weekend test.  Began integration of TclGlobus package into the controlMonitorAPI's components:

  • cmonClient - Complied globus 4.0.1 on quark. Applied for a DOE certificated. Compiled tclglobus package on quark. Put in a new cmonGlobus package to contain verify proxy, load tclglobus libraries and open connection to server.
  • cntlmonAPI(server) - Put in a new cntlmonGlobus package to contain load tclglobus libraries and accept connections as a server with a new port. Testing on tandem-iii.

TCLGLOBUS:

Completed porting TclGlobus into Solaris 9 using GT4.0.1 and Tcl version 8.3.5 (the version used by LDAS) on ldas-sundev1.  All test cases are passing now.

Fixed UDP port problem while porting TclGlobus into Solaris.  In Solaris, if we do not specify not to use IPv6, globus_xio_register_open creates IPv6 socket by default.  Therefore, Tcl programmer has to set the attribute of the UDP socket in the following way to disallow IPv6 sockets from being used:

globus_xio_attr_cntl $udpattr $udpdriver \

GLOBUS_XIO_UDP_SET_NO_IPV6 $GLOBUS_TRUE

GriPhyN/iVDGL/OSG:

  • OSG ITB test bed has successfully executed over 11,000 OSG grid jobs since the July 20 OSG roll out according to the OSG ITB GridCat.
  • Obtained LIGO VOMS GroupMapping information from PSU. Requested VOMS client configuration documentation from PSU.
  • Determined that a component on the GUMS server - Tomcat can not be started/stopped from its batch scripts - will re-install.
  • Published the new test bed cluster Site Policy web page to the ITB GridCat.
  • Fixed the CPU count(16)in the ITB GridCat for the test bed cluster.
  • With consultation from the GriPhyN team at ISI, determined the order of tests to verify (and debug) the VDS packaged in the OSG 2.1 release:
    1. determine that a condor DAG can be submitted on an OSG  ITB resource.
    2. determine that VDS can transform  a DAX to a DAG and successfully submit the DAG to an OSG ITB resource.  Diamond DAG will be used as the test case.
    3. determine that VDS can transform the inspiral DAX to a DG and successfully submit the DAG to an OSG ITB resource.
  • Item  1 above was completed this week.
  • Performed a yum update of the OSG ITB test bed and rebooted.

Hardware Systems (Anderson)

Caltech

(Dan Kozak) (Phil Ehrens) (Stuart Anderson)

  • Split the LDAS-CIT cluster apart and shipped 140 nodes to LLO.
  • Upgraded QFS patch on all SAM-QFS servers at Caltech to 4.3.15.
  • Further refined the Synchrotron computer upgrade plan with the Caltech Engineers and Contractors. The cooling and power distribution units have been ordered.
  • Rebuilt the 9 IDE-RAID servers at Caltech with FC4 and a single 2.2 TB filesystem per unit (stripped across HW RAID devices) holding the S3/S4 L1/L3 RDS frames for cluster users.
  • Upgraded Condor to version 6.7.10.

MIT

(Keith Bayer)

  • Investigating 5 Ton Liebert a/c unit at LHO for use at MIT.
  • Installing o/s on new 24 slot 5URM pcraid box moved syskonnect fiber card from another machine over to it.
  • Troubleshooting/rebuilding degraded raid on pcraid4.

Livingston

(Igor Yakushin)

  • 4 T3 drives failed after last week power outage. They have been replaced by drives from the spare T3s by Tom. The replacement drives are ordered from SUN. T3s did not go down during the outage but continued running on UPS. Some servers were rebooted and some continued running on UPS.
  • Old dataserver was repaired yesterday: one of memory dimms was replaced. The tests done at the OK prompt did not show any problem with the 2Gb fiber channel card which we had trouble using in dataserver.  More tests can be done after we get an extra blade in the fiber channel switch to connect it to.
  • Failing primary drives were replaced in cluster nodes 3,6,10,12,16,32. There are at least 12 more drives that have bad blocks and need to be replaced but at the moment I am out of available spare drives. 30 more 200 GB drives were ordered from CDW and should arrive within couple days.
  • I scheduled firmware upgrade of tape robot drives from 1.34.408 to 1.35.402 on Monday.
  • All user home directories but one were moved from /data2 to /archive/home. One account could not be moved so far because the user is running Condor jobs.
  • LDAS room upgrade status: so far we are on schedule for the move to the temporary location
    1. we had bidding contractors on site yesterday; Rusyl showed them what needs to be done;
    2. 140 nodes are shipped today from CIT and should arrive no later than Sep 7 according to Ed Chargois;
    3. I asked StorageTek for a written quote to move the tape robot, I should get it on Monday during Roger Helms' visit to upgrade tape drives firmware;
    4. The current suggested layout of the equipment in the high bay area is available here: http://www.ligo-la.caltech.edu/~igor/POWER_HVAC_LAYOUT/TEMP1

Hanford

(Ben Johnson)

  • Upgraded Condor to 6.7.10. Also symbolicly linked the new memory limiting /etc/init.d/condor script.
  • SAMFS at LHO (gateway and dataserver only) is now at version 4.3.15.  The import/export fix has yet to be tested.
  • Helped get the post-filtered LDRdataFindServer up and running.
  • Transferring GEO v2 S4 frames to Hanford.
  • Moved last user from the /dso-tes IDE-RAID. All users are now have /archive/home as their true $HOME directory.

General Computing (Wallace)

MIT:

(Keith)

  • Helped out with MOU meetings at MIT.
  • Ran FEA benchmarks on dual-core cad machine to see if disk i/o is causing bottlenecks - it is.
  • Testing out spam filter with SMTP-AUTH mechanism.
  • Working on LSI22320 raid card in SunBlade1500 with LSI.

Livingston:

(Shannon)

  • As a result of the power outage last week, Touro lost it's hard drive.  This is one of few GC servers that was not on a UPS.  It started acting up after the outage.  On Sunday I attempted to reboot it remotely after Natalia complained about some weird behavior on the machine.  However, it would not reboot, nor would it run any command.  Monday I rebooted the machine via stop-A, etc. and it would not boot at all from the system disk.  probe-scsi-all did not show the disk as present, so I assumed that the disk failed.  I have taken a disk out of another machine that is not presently in use and I am in the process of rebuilding Touro with Solaris 10.  This will be the first general purpose GC machine on Solaris 10.  This is also a well used machine and as such should help us weed out any bugs with our software and Solaris 10.  After a testing period with Touro on Solaris 10, I will likely start migrating the rest of the GC machines to Solaris 10 in order to take advantage of some of the new features.
  • Someone showed up with a copy of the latest windows virus on Monday.  They were not on the network long enough for me to track them down, so I am unsure of who it was at this point.  It does not look like they successfully infected any other machines since I have not seen any other port scanning on port 445 which is a sign of the virus on the network.
  • Using the upgrade/repair on Touro to develop a generic Solaris 10 security document.
  • Usual round of parts orders, etc.

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
  • Packed up and shipped back the projectors and laptops that were borrowed for LSC.  Discovered another Ligo, CIT loaner laptop that someone had left in one of the conference rooms.  Removed the NAT router from the Auditorium.  Reset the Auditorium wireless access point.  Collected and put away all the power strips, ethernet cables, hubs, mice, and wireless cards that had been loaned out or used in the conference rooms.
  • Packed up a laptop left by Andri Gretarsson and shipped it to Mike Zucker at LLO.
  • Re-built a loaner laptop to be used as a presentation laptop.
  • Re-initiated contact with all parties involved in the network upgrade.  The new LHO WAN will consist of a GigE circuit provided by PNNL from Richland to Seattle, a GigE circuit over ESnet 10 GigE network from Seattle to the Internet.  We will also have a backup 10 mb circuit provided by Amerion/NoaNet from Richland to Seattle and connecting to a 100 mb circuit on the ESnet router in Seattle.  LHO will continue to use our existing IP addresses provided by ESnet.  The schedule for testing and cut over to the new circuits are as follows:

Monday, 8/29 - Routing established on PNNL GE. This circuit operates as a secondary to the existing ATM circuit. Circuit will be tested by temporarily shutting down the ATM circuit (or other means?) as schedule permits.

Thursday, 9/1 - Routing established on LIGO GE. This circuit operates as a secondary to the existing ATM circuit. Circuit will be tested by temporarily shutting down the ATM circuit (or other means?) as schedule permits.

Tuesday, 9/6 - PNNL GE and LIGO GE operate as the primary. PNNL ATM circuit in hot standby. LIGO ATM circuit decommissioned to reclaim fiber for LIGO FE.

Tuesday, 9/13 - Routing established on LIGO FE. This circuit operates as backup to LIGO GE.

After 9/13 - PNNL ATM circuit decommissioned.

CIT:

(Christian)

  • 2nd Floor W/B: Replaced old 8550 network printer with new HP Color LaserJet 5550.
  • Downs: Phil Willems needed an additional workstation to be loaded with the standard Ligo image.
  • Janeen Romie: Janeen is moving to Livingston and needed everything copied from her workstation to laptop.
  • 40 Meter: exchanged 3 old CRT monitor with 3 new LCD Flat Screens.
  • Other misc.: continued onsite software/phone support.

(Mike)

  • Worked up at Hanford part of the week helping Christine with the LSC conference.
  • Spam Filters: Continued work on spam filters, with Larry.
  • Configuring PRIMAVERA server. I have been working on this most of the week, going over documentation, and running some trial and error tests to come up with a secure scheme to push this server out.
  • Server room B/A: Re-routed network cables to connect additional rack mount servers.
  • Additional user support that included trouble shooting pc, network connection issues, plus adding additional mac addresses to the wireless access points for visitors/new laptops to connect to AIRLIGO.

(Veronica)

  • LIGO:  Finished reloading my new machine and worked on rebuilding the old one.  Troubleshot the SCR VRVS box, as in order to block the WMPlayer popups, it got pulled off the network.  Helped the speakers with the setup of their presentations.  Loaded PhotoShop7.0 to Julie's machine.  Updates of the MIT mirror website.  Updates of the roster database.  Working on code changes to implement changes in webpage output.  Updates to the Advanced LIGO Project Management webpages.  Working on the website for the NSF Review.  Prepared high-resolution images for a publisher.  Installed a webpage with a writeup by Dave Beckett on the LIGO PhD Award, photo editing on the image provided.
  • LSC:  Updates to the Papers Under Review database and some code tweaking.  Updates to the LSC webpages.  Posted remaining presentations from the August meeting.
  • Project Science:  Member database updates.

(Larry)

On vacation.

Advanced LIGO and Supporting R&D (Shoemaker)

Systems and Management

No report

Seismic Isolation

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

Agenda for the weekly SEI phonecall

Friday, Aug 19, 2pm Eastern, 1pm Central, 11am Pacific time

Announcements

We are working on a procedure to describe how to facilitate useful tests of the SAS technology at LASTI and to present the question for review.  We are also working to augment the staffing at LASTI during the upcoming crunch period.

ASI contract news (Dennis)

Analysis complete, design geometry will begin in a week.  Sept 23rd delivery is expected.

Electronics (Jay, Brian)

Jay is preparing the modified boards.  ETA next week.  AC-coupled pre-amp for displacement sensor characterization are also done.

BSC amplification (Ken)

Ken posted early output from his BSC model.  Springs are 2-D elements.  The second mode is largely tank motion reacting against the floor.  The chamber sits on concrete, which in turn is clamped to infinite stiffness.  The next iteration is to simulate the soil with softer connections below the slab, and the inclusion of bellows to couple the BSC vacuum tank modes with the SEI system.  Some of the modes now seen would also change when the tank doors are included.

Rich has the optical levers running, and is working out the connections, gains, etc.

HAM modeling (Laurent)

Measured motion of the second crossbeam, posted on LASTI log.  Also, coordinate system mixup has been corrected.  The measured system has a support table, spacers, optics table, pendulums, geophones.  Total mass 800  kg.  Mode shapes similar to the FE model, but the frequencies are not.  The actuators are 10 x stiffer than the springs reflected in the FE model, so once these are included (which is now the plan), better frequency agreement may result.  The horizontal modes look almost like rigid body motion of the payload with the springs distorting.  The lowest vertical mode looks more like gull-wing flex.

Control Tools (William)

William is working on a GUI that loads a system TF, identifies resonances, and designs notch filters. He will post it soon.

Suspension

From: Janeen Romie romie_j@ligo.caltech.edu

Advanced LIGO Suspensions

Waiting for new clamps from the Physics machine shop to replace the drum ended wires. Helena & I talked to Ian this morning and got the wire fixture set up to make the clamp-wire-clamp assemblies. We also worked with Calum and Mark to get the reaction chain ready. The new tablecloth covers are installed. Ian worked with us on Monday, via phone and video, instructing us how to replace a blade in the top stage. The cartridge has been re-installed in the upper structure.

Rich and Laurent are planning to come here in September to assemble the 2nd MC in the So. Annex. Then they'll ship it to MIT.

Mike Gerfen has only a couple of more assemblies to do before he is finished with the quote for the transport and lift tables for the installation fixtures.

From: Ken mailand kmailand@ligo.caltech.edu

I have contacted Gordon Yano at Lawerence Livermore r re. their large part cleaning vendors, he will contact me tomorrow with any information available.

Making simplified S/W drawings of the Adv. LIGO optical component assemblies for import to Zmax, for Mike Smith, and converting Mechanical Desktop LHO full site layout to S/W

Core Optics

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

Still forging ahead on the PI issues. The Russians are here now, also ! We have had a couple (LSC follow thru) of meetings to discuss the overall issue. I must say that the whole picture has (to me) gotten more complicated: cant cleanly be dismissed nor solidly pegged as serious. Everyone is leaving with much on going study to be done.

Pre-Stabilized Laser

From: Peter King pking@ligo.caltech.edu

AdvLIGO PSL

Unfortunately there was no sign of the 300 mW Innolight NPRO as of yet.  As part of preparing to do a round of measurements on it, I was thinking of a new quadrant photodetector design.

Auxiliary Optics

From: Phil Willems <willems@ligo.caltech.edu>

Mesa Beams

We are now resonating what appear to be flat-topped, circularly symmetric modes in the mesa beam cavity- mesa beams.  The last steps that contributed to this achievement appear to have been redesigning the flat mirror mounts so as not to deform the flat mirrors so much (previously they were more saddle-shaped), wrapping the cavity with shields to cut down air currents which would otherwise reorient the cavity, and persistent, loving alignment of the input beam into the cavity.  All credit to Marco Tarallo and John Miller. (Marco Tarallo, John Miller, Riccardo DeSalvo, Phil Willems).

Advanced LIGO TCS

While we have found that operationally the digital micro-mirror array was operationally capable of operating in air with its shield removed and with 35W of incident CO2 laser radiation, optically its mirrors are just too small and close together to act as anything more than a blazed diffraction grating for 10.6 micron radiation.  Thus, the array cannot work as a reflective mask in a CO2 laser projector.  However, it could potentially work at 2.7 microns, where fused silica has an absorption peak.  We are theoretically analyzing this possibility (lacking a 2.7 micron laser).  (Alex Smith, Phil Willems)

Based upon advice from Efim Khazanov at the Institute for Applied Physics and Guido Mueller, we have begun analyzing thermal depolarization as a potentially harmful thermal effect in Advanced LIGO.  (Thermal gradients cause anisotropic stresses in the substrate and thereby a spatially dependent birefringence).  Early analysis indicates this effect is insignificant in Advanced LIGO fused silica test masses but we are double-checking the formulae.  Analysis of the beamsplitter is probably prudent.  (Phil Willems)

Other Laboratory R&D

From: Riccardo DeSalvo desalvo@ligo.caltech.edu

Ilaria

I finished to design, in every detail, the leg of the IP, the flex joint connector (at the base of the IP), the small flex joint (on the top of the IP), the base and the disk where the flex joint lays.

Valerio Boschi

I began to work a simple SimMechanics model of the HAM seismic attenuation. The goal is to determine the controllability of the system and to estimate the rms closed-loop motion of the IP. This will enable us to compare the performances obtainable using a position control system with that of a combined position-acceleration control (inertial damping). At the present stage we can simulate the open-loop motion of the suspension, given the initial conditions of the optical table. The next step is to excite the bases of the IP flex joints with seismic noise, design a simple position control loop and evaluate the IP closed-loop rms motion.

Maddalena.

Paper “One Hertz Seismic Attenuation for Low Frequency Gravitational Waves Interferometers” accepted for Publication in Nuclear Instruments and Methods

David

We are down to two sets of blades. The CuBe blades went plastic and became bent, and one of the Glassy metals (LM002) broke quite spectacularly (fortunately no one was hurt). We plan to continue to experiment and compare the properties of the two remaining materials (LM001 and Maraging Steel), obviously proceeding with more care. We also scrapped the electromagnet excitation system for the experiment and are switching to a mechanical excitation method involving rolling steel balls through tubes. Yes, it is as fun as it sounds. Anamaria She is enjoying her time in the Romanian sun.

Linden and Glenn.;

Our new DAQBoard hardware arrived yesterday, and it WORKS! - kind of.

We can't get it to work with labview, but it works with Daqview (from IOtech) the little program that came with it. We may be able to use that program; we're not sure yet. We are able to send an output and recieve and input which is some great progress.

Juri

I’m doing some calculations and analysis on the non-standard coating optimized with a Genetic Algorithm. I’m writing a technical note (and a paper for publication) on the work I have done on the thermal noises calculations considering Gaussian and Mesa beams.

Chiara

I made the support for the electro magnetic piston, that will shake the system, and for the two accelerometers. I gave some help to Alberto to start taking measurements of the transfer function of his mechanical system. I’m studying the drawings of the HAM-SAS system.

Alberto

Finally the experiment is ready to start. Now two new acceleremoetrs are mounted on the prototype. I spent the last two days calibrating the instruments and balancing the system in order to set the best working point for each LVDT. I'm trying to get more confidence with the Spectrum Analyzer wich provides for the transfer function measurement. I used it to get some first rough data, just to make tests, looking for resonances and fix a schedule for the frequencies scan. I've found some and not all were they are expected to be. Watching and listening to the system response at different frequencies we noticed a malfunction of the Spectrum Analyzer output signal as an anomalous sound from the voice-coil and a spike in the first accelerometer. However it should not be a source of noise for the low frequencies I'm going to use. We noticed also that we could have an attenuation in the imput signal at high frequencies due to the suspension system, basically a stainless steel cross wich vibrate at about 60 Hz. So we decided to move the accelerometer to the plate for the range of frequencies above 10 Hz. Next work will be trying to improve the transfer functions studying the effect of counterweight added in the rods.

Francesca:

I'm working with Alberto.

John

This week was mostly spent working in the lab. The alignment of the cavity and input optics were continually refined. Various high order modes were observed.  The ends of the cavity were covered to reduce atmospheric disturbances, better in lock stability was found to result.  On Monday the best fundamental to date was recorded. The improved alignment was achieved by ‘walking’ the input beam whilst observing the spectrum.  The laying of new flooring in the sub-basement has hampered further data taking. Once this is complete we shall endeavour to make quantitative measurements of alignment tolerances.  Remaining problems include a slight astigmatism and a lack of power symmetry in higher order modes.

Sean

Justin has left for Europe. I have spent most of this week working with ANSYS. I have found that the program is having issues getting the correct vibrational mode and the correct frequency together. I will have either the correct mode at 1.4 Hz, or the correct frequency (~164 Hz) with a completely different mode. I have tried scaling up the acceleration due to gravity from 0 to 9800 mm/s. However, this does not give me comprehensible results. I will continue toying with the simulation and exploring the possiblity of a transfer function in ANSYS.

Maria Paola

I have been looking for the optimal load of the circuit, using a potentiometer and analyzing the changes in shape and amplitude of the waveform on the oscilloscope. The best one seems to be around 1,8 KOhm, since the amplitude of the waveform reaches a maximum, although the square wave is a little bit distorted. The transformer I have built last week has an input resistance which seems to be too low (about 1 Ohm), probably because the number of the coils on the primary winding is not big enough: what I have to do now is to build another one, using a bigger bobin and a thinner and more sophisticated wire, to achieve a better result. Moreover, I have to start thinking about how to control the stepping motor: passband filters can be used to do it, but a f-V converter could also be a good solution to control the switches that feed the four coils of the motor.

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