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ID Date Authorup Type Category Subject Text Attachments
  230   Wed Jan 9 20:36:42 2008 GoUpdateTreasureMoney in labGo's Desk.  DSC_0370.JPG 
  3103   Wed Jun 23 12:31:36 2010 GopalUpdateGeneral6.16.10-6.23.10 Weekly UpdateSummary of This Week's Activities:
6/16: LIGO Orientation; First Weekly
Meeting; 40m tour with Jenne; Removed WFS
  
  3166   Wed Jul 7 11:35:59 2010 GopalUpdateWIKI-40M Update6.30.10 - 7.7.10 Weekly Update Summary of this Week's Activities:
6/30: 2nd and 3rd drafts of Progress
Report
  
  3180   Thu Jul 8 16:24:30 2010 GopalUpdateOptic StacksCompletion of single stack layerSingle layer of stack successfully modeled
in COMSOL. I'm working on trying to add Viton
springs now and extend it to a full stack.
  
  3186   Fri Jul 9 11:41:58 2010 GopalSummaryOptic StacksTop Optic Layer Complete; Mechanical Tests Giving Problems



 7x 
  3199   Mon Jul 12 18:37:10 2010 GopalUpdateOptic StacksEigenfrequency Analysis of Simple ObjectsEigenfrequency analysis has been successfully
completed in COMSOL on both a tutorial camshaft,
as well as a homemade metal bar.
  
  3206   Tue Jul 13 13:56:29 2010 GopalConfigurationOptic StacksVitol Material PropertiesViton flouroelastomers have somewhat variable
material properties. The following parameters
are being used for eigenfrequency analysis.
  
  3207   Tue Jul 13 14:59:04 2010 GopalUpdateOptic StacksEigenfrequency Analysis of Single Stack CompleteVia reconfiguration of Viton parameters
(previously posted), I managed to debug the
COMSOL run time errors and null pointer exceptions.
 Eigenmode_Stack_4.pngEigenmode_Stack_4_xdisp.pngEigenmode_Stack_4_ydisp.pngEigenmode_Stack_4_zdisp.png 
  3222   Wed Jul 14 19:00:56 2010 GopalConfigurationOptic StacksVitol Material Properties, REVISED

    
        
  
  3223   Wed Jul 14 19:15:26 2010 GopalSummaryOptic StacksREVISION: Eigenfrequency Analysis of Single Stack CompleteMy previous eigenfrequency analysis
was incorrect by two orders of magnitude
due to the misuse of Young's Modulus information
 Eigenfrequency_1_Stack4.pngEigenfrequency_2_Stack4.pngEigenfrequency_2_Stack4.pngEigenfrequency_3_Stack4.pngEigenfrequency_4_Stack4.png 
  3224   Wed Jul 14 19:36:17 2010 GopalUpdateOptic StacksExperimental Confirmation of COMSOL AnalysisI experimentally determined the spring
constant of a single Vitol spring in
order to obtain a rough estimate for the
 Untitled.png 
  3246   Mon Jul 19 16:11:17 2010 GopalUpdateOptic StacksEigenfrequency Analysis of Full StackExpanding on the single-layer model, I
added the second, third, and fourth layers
to the stack in COMSOL. Eigenfrequency
 Eigenfrequency_1_4Stacks.pngEigenfrequency_2_4Stacks.pngEigenfrequency_3_4Stacks.pngEigenfrequency_6_4Stacks.png 
  3252   Tue Jul 20 17:38:16 2010 GopalConfigurationOptic StacksStack Type ClarificationsSome clarification is warranted regarding
the different shapes of stacks. Corrections
  
  3255   Wed Jul 21 11:57:59 2010 GopalUpdateWIKI-40M Update7.14.10-7.21.10 Weekly UpdateSummary of this week's activities:
7/14: Analytical calculation of Viton
spring constant; updated Viton values in
  
  3261   Wed Jul 21 17:41:17 2010 GopalConfigurationOptic StacksPictures of StacksNow that venting is complete, this is a
request for anyone who opens any chamber:
1) Please notify me immediately
  
  3276   Fri Jul 23 14:26:01 2010 GopalUpdateOptic StacksSimple Frequency Response Measurements in COMSOLOver the past couple days, I discovered
a simple, direct method for calculating
frequency responses with a combination
  
  3291   Mon Jul 26 11:15:23 2010 GopalHowToCOMSOL TipsPictures from Transfer Function Tutorial on the WikiThe attached pictures give a brief overview
of my transfer function measurement procedure
in COMSOL. For more details, please see the
 7x 
  3298   Tue Jul 27 12:02:31 2010 GopalUpdateOptic StacksPreliminary Transfer Function Measurements on MC1/MC3I have successfully
completed a preliminary transfer function
 MC1_MC3_FDA_1.pngMC1_MC3_FDA_2.pngMC1_MC3_FDA_3.pngMC1_MC3_FDA_4.pngMC1_MC3_FDA_5.png 
  3301   Tue Jul 27 18:42:57 2010 GopalUpdateOptic StacksBode Magnitude Plot and ConcernsI  completed
the frequency domain analysis mentioned previously
 Bode_Mag_MC1_MC3.png 
  3306   Wed Jul 28 12:16:03 2010 GopalUpdateSEIBode Magnitude Plot and Concerns

    
        
 Bode_Disp_MC1_MC3_y.png 
  3307   Wed Jul 28 12:31:00 2010 GopalUpdateWIKI-40M Update7.21.10-7.28.10 Weekly UpdateSummary of this week's activities:
7/21: Frequency Domain Analysis of
rectangular bar; discussed with Koji how
  
  3322   Thu Jul 29 17:11:16 2010 GopalUpdateCOMSOL TipsIncluding Gravity in COMSOL[Gopal, Jan]
  
  3324   Thu Jul 29 20:43:32 2010 GopalSummaryOptic StacksModeling Tips and TiltsI have discovered a method of completely  XTrans_XDisp.pngXTrans_XDisp.pngYTrans_XDisp.pngZTrans_XDisp.png 
  3339   Sat Jul 31 04:03:11 2010 GopalSummaryOptic StacksComplete Displacement Translational Transfer Function MatrixOver the past 36 hours, I've run full-fledged
FDAs on KALLO.
 Progress_Report_2.png 
  3363   Wed Aug 4 20:58:22 2010 GopalUpdateWIKI-40M Update7.28.10 - 8.4.10 Weekly UpdateSummary
of this week's activities:
  
  3376   Fri Aug 6 15:50:29 2010 GopalUpdateOptic Stacks(Much Better Looking) Displacement-Displacment Transfer FunctionsI reran
the FDA in COMSOL on the MC1/MC3 Stack and
produced the following Displacement-Displacement
 MC1_MC3_XTrans.pngMC1_MC3_YTrans.pngMC1_MC3_ZTrans.png 
  3380   Fri Aug 6 19:46:59 2010 GopalUpdateOptic Stacks(Much Better Looking) Displacement-Displacment Transfer Functions


   
        
            
  
  3418   Fri Aug 13 01:53:12 2010 GopalUpdateOptic StacksGravity Implementation ConfirmedTime Domain
Analysis on a Driven, Damped Simple Pendulum
 Pendulum_Length.pngPendulum_Length.pngPendulum_Length.png 
  3142   Wed Jun 30 11:35:06 2010 Gopal UpdateGeneral6.23.10 - 6.30.10 Weekly UpdateSummary of this Week's Activities:
6/23: LIGO Safety Tour; Simulink
Controls Tutorial
  
  3193   Mon Jul 12 11:20:56 2010 Gopal HowToCOMSOL TipsIntrusions (Negative Extrusions)For the sake of future users, I have decided
to periodically add tips and tricks in using
COMSOL that I have figured out, most probably
 6x 
  3219   Wed Jul 14 13:03:04 2010 Gopal UpdateWIKI-40M Update7.8.10 - 7.14.10 Weekly UpdateSummary of this Week's Activities:
Wed. 7/7: COMSOL Busbar tutorials;
began stack design; began base; Viton rubber
  
  3397   Wed Aug 11 11:51:45 2010 Gopal UpdateWIKI-40M Update8.5.10 - 8.11.10 Weekly UpdateSummary of
this Week's Activities:
  
  2193   Fri Nov 6 12:56:30 2009 HaixingUpdateSUSMagnet has been levitated  

 DSC_0964.JPGblock_diagram.PNG 
  2202   Fri Nov 6 23:02:44 2009 HaixingUpdateGeneralSR785 Spectrum AnalyzerI am using SR785 Spectrum Analyzer now
and also tomorrow.  
I will put it back on Sunday. If anyone
  
  2203   Sat Nov 7 23:50:45 2009 HaixingUpdateGeneralOpen-loop transfer function of the magnetic levitation systemI measured the open-loop transfer function
of the magnetic levitation system.
The schematic block diagram for this
 Transfer_function_meas.jpgmagnetic_levitation.jpgtransfer_function_meas_bd.PNG 
  2245   Wed Nov 11 21:30:20 2009 HaixingUpdateGeneralmagnetic levitation modelling files uploaded to svnI have created a directory under the svn.
The link is https://nodus.ligo.caltech.edu:30889/svn/trunk/docs/haixing
  
  2307   Fri Nov 20 11:32:48 2009 HaixingUpdateSUSMagnetic levitationI added an integrator to increase
the gain at low frequencies (below 5 Hz).
In addition, I increased
 IntDiff.PNGS8007340.jpgS8007333.jpg 
  2494   Sun Jan 10 13:32:09 2010 HaixingUpdateSUStransfer function measurement of the quadrant maglev circuit I have assembled the circuit and the
control box for the quadrant magnetic
levitation yesterday. The final setup
 6x 
  2497   Sun Jan 10 16:50:34 2010 HaixingUpdateSUStransfer function measurement of the quadrant maglev circuit

    
        
  
  2510   Tue Jan 12 13:24:50 2010 HaixingUpdateSUSQuadrant Magnetic LevitationI have tried to make the quadrant magnetic
levitation work but unfortunately I did
not succeed. During the experiment, I
 schmematic.png 
  15224   Tue Feb 25 19:58:06 2020 HangUpdateIOOMC2 coil balancing[Yehonathan, Hang]

We did some quick DC balancing
of the MC2 coil drivers to reduce the l2a
  
  15265   Wed Mar 11 16:46:25 2020 HangUpdateIOOMC2 coil balancingMy old scheme was flawed as I used pitch
as the readback. The pitch signal could not
distinguish the cross-coupling due to coil
  
  15322   Fri May 8 14:27:25 2020 HangUpdateBHDNew SRC gouy phase[Jon, Hang]

After updating the 40 m finesse
file to incorporate the new SRC length (and
 mode_spec_finesse.pdfmode_spec_ideal.pdf 
  15336   Mon May 18 18:00:16 2020 HangUpdateBHDBHD mode-matching study[Jon, Tega, Hang]

We proposed a few BHD mode-matching telescope
designs and then preformed a few monte-carlo
 MM.pdf 
  15339   Wed May 20 18:45:22 2020 HangUpdateBHDBHD mode-matching study--corner plot & adjustment requirementAs Rana suggested, we present the
scattering plot of the AS path
mode matching for various variables.
 AS_MM_scat2.pdfAS_MM_adj2.pdf 
  15357   Tue May 26 19:19:30 2020 HangUpdateBHDBHD MM-- effects of astigmatismPlease see the attached doc. 

I think the conclusion is that
if the AS1 RoC error is not significantly
 MM.pdf 
  15363   Tue Jun 2 14:05:24 2020 HangUpdateBHDMM telescope actuation range requirmentsWe computed the required actuation range
for the telescope design in elog:15357. The result
 TM_OL_spec_1274418500_512.pdfCORNER_OL_spec_1274418500_512.pdf 
  15380   Mon Jun 8 11:50:02 2020 HangUpdateBHDAstigmatism and scattering plotsWe consider the astigmatism effects of
the stock options. The conclusions are:

1. For the AS path, the stock should work
 6x 
  15503   Tue Jul 28 13:55:11 2020 HangUpdateBHDExploring bilinear SRCL->DARM couplingWe explore bilinear SRCL to DARM noise
coupling mechanisms, and show two cases that
by doing BHD readout the noise performance
 SRCL_bilin_DHARD.pdfARM_RIN.pdfSRCL_bilin_SRCL.pdf 
  16373   Mon Oct 4 15:50:31 2021 HangUpdateCalibrationFisher matrix estimation on XARM parameters[Anchal, Hang]

What: Anchal and I measured the
XARM OLTF last Thursday.
 tf_meas.pdffisher_est_vs_data.pdfPxx_evol.pdffisher_evol.pdf 
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