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ID Date Author Type Category Subjectup Text Attachments
  728   Wed Jul 23 22:34:07 2008 YoichiUpdateLSCArm cavity g-factor measurementI tried the same thing as the X-arm to the
Y-arm.
I'm puzzled. I found exactly the same behavior
  
  730   Thu Jul 24 01:27:00 2008 KojiUpdateLSCArm cavity g-factor measurement[quote]I locked the Y-arm and mis-aligned
the end mirror in Yaw until the transmission
power gets half.
  
  731   Thu Jul 24 02:57:26 2008 robUpdateLSCArm cavity g-factor measurement[quote]
So, now I feel that the method for the TEM01
quest should be reconsidered.
  
  733   Thu Jul 24 08:09:26 2008 YoichiUpdateLSCArm cavity g-factor measurement[quote]
A-ha! Do you always expect the 30Hz signal,
don't you?
  
  2996   Wed May 26 22:22:03 2010 AlbertoConfiguration40m UpgradingArm cavity lengthThe second sideband is resonant in the
arms for a cavity length of 37.9299m.
The nearest antiresonant arm lengths
 reflRFpowerVsArmLength_3658m.pngreflRFpowerVsArmLength_3750m.png 
  2070   Thu Oct 8 20:18:56 2009 KojiSummaryGeneralArm cavity lossLast night (Oct 07), I ran armLoss script
in order to obtain the latest numbers for
the arm cavity loss.
  
  2416   Mon Dec 14 22:32:56 2009 KojiUpdateGeneralArm cavity loss ~ resultI like to ask someone to review the calculation
on the wiki.
  
  8844   Sun Jul 14 18:19:00 2013 AnnalisaUpdateGreen LockingArm cavity scanYesterday evening Nic and me were in the
lab. The Mode Cleaner was unlocked, but after
many attempt we could fix it and we did many
  
  15860   Wed Mar 3 23:23:58 2021 gautamUpdateALSArm cavity scanI see no evidence of anything radically
different from my PSL table optical
characterization in the IMC transmitted
 armScan.pdf 
  14944   Sun Oct 6 15:23:27 2019 gautamUpdateALSArm control using error signals achievedSummary:

I
 ALSY_20191006.pdftransitionIRALS.pngarms_ALS.pdf 
  5079   Mon Aug 1 04:08:24 2011 kiwamuUpdateABSLArm length measurement : cavity kick techniqueI made some
attempts to measure the current length of
 ETMY_kick.png 
  5095   Tue Aug 2 16:55:21 2011 ranaUpdateABSLArm length measurement : cavity kick technique

    

       
            
 L.png 
  11098   Wed Mar 4 19:03:19 2015 ericqUpdateLSCArm length remeasurementAs discussed at today's meeting, we
would like to (re)measure the Arm cavity
lengths to ~mm precision, and their g-factors.
 Xscan.pngYscan.png 
  11107   Fri Mar 6 02:10:35 2015 ranaUpdateLSCArm length remeasurementThis has been done before:

http://nodus.ligo.caltech.edu:8080/40m/6938

Arm length measurements and g-factor
  
  3001   Thu May 27 12:52:02 2010 AlbertoUpdate40m UpgradingArm lengths
For both sidebands to be antiresonant
in the arms, the first modulation frequency
  
  11524   Sat Aug 22 15:48:32 2015 KojiSummaryLSCArm locking recoveryAs per Ignacio's request, I restored
the arm locking.

- MC WFS relief
  
  1576   Tue May 12 01:22:51 2009 YoichiUpdateLSCArm lossUsing the armLoss script (/cvs/cds/caltech/scripts/LSC/armLoss),
I measured the round trip loss (RTL) of the
arms.
  
  12533   Wed Oct 5 19:10:04 2016 gautamUpdateGeneralArm loss measurement review[ericq,gautam]

There are multiple methods by which
the arm loss can be measured, including,
  
  10248   Mon Jul 21 17:32:43 2014 ericqSummaryLSCArm losses

    

       
            
  
  15264   Tue Mar 10 19:59:09 2020 YehonathanUpdateLoss MeasurementArm transfer function measurementI want to measure the transfer function
of the arm cavities to extract the pole frequencies
and get more insight into what is going
 YArmFrequencyResponse.pdf 
  15269   Thu Mar 12 10:43:50 2020 ranaUpdateLoss MeasurementArm transfer function measurement 
           
  
  15277   Mon Mar 16 15:23:03 2020 YehonathanUpdateLoss MeasurementArm transfer function measurementI measured the cross-calibration of the
two PDs on the PSL table.

I used the existing flip mounted
 Cross_calibration_setup.jpgPDA520overPDA255_Response.pdfYArmFrequencyResponse.pdf 
  15307   Sat Apr 18 14:57:44 2020 YehonathanUpdateLoss MeasurementArm transfer function measurementOk, now I understand my foolishness. It
should definitely be 1/sqrt(f^2+fp^2)
.
  
  15355   Tue May 26 14:32:44 2020 gautamUpdateLSCArm transmission RINSummary:

The measured RIN of the arm cavity
transmission when the PRFPMI is locked is
 armRIN.pdf 
  15359   Wed May 27 19:36:33 2020 KojiUpdateLSCArm transmission RINMy speculation for the worse RIN is:

- Unoptimized alignment -> Larger
linear coupling of the RIN with the misalignment
  
  15361   Thu May 28 18:36:45 2020 gautamUpdateLSCArm transmission RINI agree, I think the PRC excess angular
motion, PIT
in particular, is a dominant
 PRFPMIcorner_ASC_PIT_1274419354_1274419654.pdfPRFPMIcorner_ASC_YAW_1274419354_1274419654.pdfPRFPMIcorner_ASC_coherence_1274419354_1274419654.pdf 
  15362   Fri May 29 00:34:57 2020 ranaUpdateLSCArm transmission RINhow bout corner plot with power signals
and oplevs? I think that would show not just
linear couplings (like your coherence), but
  
  2611   Wed Feb 17 19:36:05 2010 KojiUpdateCOCArm visibilityI
have measured the arm visibilities.
I did not see any change since the
  
  15225   Wed Feb 26 17:17:17 2020 YehonathanUpdate Arms DC loss measurements{Yehonathan, Gautam}

In order to measure the loss in
the arm cavities in reflection, we use the
 6x 
  10558   Wed Oct 1 19:40:46 2014 ericqUpdateLSCArms IR alignedSummary:

    Beamsplitter
was put into MC refl path.
    HWP
was rotated to maximize power into PMC. 
  
  2605   Tue Feb 16 10:01:16 2010 AlbertoConfigurationLSCArms and PRC not lockingSince last Friday either the arms or the
PRC can't lock.
The montors show the beam flashing
  
  2607   Tue Feb 16 14:10:06 2010 josephb, rob, kojiConfigurationLSCArms and PRC not locking

    
        
  
  2608   Tue Feb 16 15:25:00 2010 AlbertoConfigurationLSCArms and PRC not locking 
 
 shock.jpg 
  9213   Mon Oct 7 13:55:26 2013 JenneUpdateLSCArms locked in IR for many hoursSomeone left the arms aligned, and the
LSC engaged, so the arms have been locked
almost continuously for several days
 BothArmsLocked3Days_7Oct2013.png 
  8974   Tue Aug 6 19:53:15 2013 JenneUpdateLSCArms locked in IR, aligned. IFO at nominal power[Koji, Manasa, Jenne]
The Y arm was locked in IR, and we
saw flashing in the Xarm (Gautam had the
  
  8975   Wed Aug 7 10:09:30 2013 KojiUpdateLSCArms locked in IR, aligned. IFO at nominal powerI have a concern about the SRM suspension.
The yaw alignment bias produces huge pitch
coupling.
  
  9008   Tue Aug 13 21:09:03 2013 manasaUpdateGreen LockingArms ready for ALSI aligned
both the X and Y end green to the arms.
The transmitted green were aligned
  
  1233   Fri Jan 16 18:25:32 2009 Yoichi, Kakeru, RanaUpdateLSCArms were unstableThe single arm lock had been unstable for
both arms in the past few days.
 TRXY.pdfErrorSignals.pdfcoherenceBetweenArms.pdfArmPowersAfterPDwasCentered.pdf 
  3582   Fri Sep 17 03:32:11 2010 KojiUpdateSUSArrangement of the SUS towersThe day before yesterday, I was cleaning
a flow bench in the clean room.
I found that one SOS was standing
  
  3761   Fri Oct 22 15:06:43 2010 JenneUpdateSUSArts and Crafts!This afternoon I epoxied the guiderod and
wire standoff to the new PRM.  I also
epoxied the magnets that Suresh picked out
 StatusTable.png 
  16725   Tue Mar 15 10:45:31 2022 PacoUpdateGeneralAssembled small in-vac optics[Paco]

This morning I assembled LO3,
LO4 and AS3 (all
  
  3936   Tue Nov 16 23:36:29 2010 Suresh, JenneUpdateSUSAssembly of ETMs[Jenne,
Suresh]
 
 StatusTable.png 
  15111   Mon Jan 6 15:36:55 2020 JonUpdatePSLAssembly underway for c1psl upgrade[Jon, Yehonathan]

We've begun assembling the
new c1psl Acromag chassis based on Yehonathan's
  
  15112   Mon Jan 6 16:07:12 2020 gautamUpdatePSLAssembly underway for c1psl upgradeRTFE.
Where did the spares go?

  
  15113   Mon Jan 6 19:05:09 2020 not gautamUpdatePSLAssembly underway for c1psl upgradeI found them, thanks. After c1psl, there
are 4 2GB DIMM cards and 1 SSD left. I moved
them into the storage bins with all the other
  
  15116   Fri Jan 10 19:48:46 2020 yehonathanUpdatePSLAssembly underway for c1psl upgrade{Yehonathan, Jon}

I finished pre-wiring the PSL chassis.
I mounted the Acromags on the DIN rails and
 20200110_194429.jpg20200110_194516_HDR.jpg 
  15118   Mon Jan 13 16:05:18 2020 yehonathanUpdatePSLAssembly underway for c1psl upgrade{Yehonathan, Jon}

I configured the Acromag channels
according to the Slow
  
  15120   Tue Jan 14 17:16:43 2020 yehonathanUpdatePSLAssembly underway for c1psl upgrade{Yehonathan, Jon}

I isolated a BIO Acromag completely
from the chassis and powered it up. The inverted
  
  15124   Wed Jan 15 10:12:46 2020 gautamUpdatePSLAssembly underway for c1psl upgradeI don't think this is an accurate statement.
XT1111 modules have sinking digital
outputs, while XT1121 modules have sourcing digital
  
  15127   Wed Jan 15 16:08:40 2020 not gautamUpdatePSLAssembly underway for c1psl upgradeYou're right. We had the right
idea before but we got confused about this
issue. I changed all the XT1121s to XT1111
  
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