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ID Date Authorup Type Category Subject Text Attachments
  2572   Thu May 20 16:57:32 2021 KojiElectronicsGeneralKeithley Source Meter returned to DownsI've returned the Keithley Source Meter
unit
- The unit (Keithley 2450?2460?)
 P_20210520_154439.jpgP_20210520_154505.jpgP_20210520_154523.jpg 
  2589   Wed Jun 16 17:17:12 2021 KojiUpdateGeneralI2 cellI was searching an I2 (Iodine) cells back
to the days of the laser gyro.

I found a likely box at a very
 P_20210616_170104.jpegP_20210616_170038.jpegP_20210616_170021.jpeg 
  2603   Thu Jul 15 23:34:17 2021 KojiSummaryTempCtrlTemprerature Log for cooling down / warming up[Stephen Koji Radhika]

Stephen and Radhika worked on the
cooling down and warming up of the cryostat
 temp_log_cooldown_20210709_1747.pdftemp_log_warmup_20210712_1315.pdf 
  2604   Thu Jul 15 23:37:53 2021 KojiSummaryCryo vacuum chamberBonding work for the prep of the preliminary suspension test[Stephen / Koji]

Bonding work for the prep of the
preliminary suspension test
 P_20210715_170102-1.jpgP_20210715_172218-1.jpgexperiment_plan.pdf 
  2605   Fri Jul 16 23:28:24 2021 KojiSummaryCryo vacuum chamberSus Test Work 07/16/2021[Stephen Koji]

We started cooling down
of the test mass. 
 7x 
  2606   Sat Jul 17 00:55:41 2021 KojiSummaryCryo vacuum chamberTemp Log 210716_2255Temperature log for the first 2 hours (Attachment
1)

I wonder why the temperatures displayed
 temp_log_cool_down_20210716_2255.pdf 
  2609   Mon Jul 19 17:21:19 2021 KojiSummaryCryo vacuum chamberTemp Log 210716_2255Temp Log on Jul 19 2021 17:20

I wonder what is the heat transfer
mode for the test mass right now. Radiative?
 temp_log_cool_down_20210716_2255.pdf 
  2610   Tue Jul 20 11:33:52 2021 KojiSummaryCryo vacuum chamberA cooling model (Temp Log 210716_2255)A naive cooling model was applied
to the cooling curve.
A wild guess:
 cooling_model.pdfIMG_9390.JPGIMG_9391.JPG 
  2611   Tue Jul 20 17:28:30 2021 KojiSummaryCryo vacuum chamberA cooling model (Temp Log 210716_2255)Updated the model the latest log
data with cooling prediction


The radiative cooling is
 cooling_model.pdf 
  2613   Wed Jul 21 14:53:28 2021 KojiSummaryGeneralJul 17, 2021: Canon camera / small silver tripod / macro zoom lens / LED ring light borrowed -> QIL See https://nodus.ligo.caltech.edu:8081/40m/16250   
  2614   Wed Jul 21 21:05:59 2021 KojiSummaryCryo vacuum chamberTest mass cooling (2021/07/16 ~ 2021/07/21)[Stephen and Koji for discussion
/ Koji for the execution]

1. Temperature Trend
 oplev_trend.png20210721201333_IMG_0765.jpeg20210716234113_IMG_0742.jpegScreenshot_from_2021-07-21_20-19-09.png 
  2615   Thu Jul 22 22:03:45 2021 KojiSummaryCryo vacuum chamberTest mass heating in progress (2021/07/21 ~ 2021/07/23)- Temperature Log updated 2021/7/23
12:00 Heating Ended

- Assuming reaching the room temp
 IMG-9395.jpgtemp_log_warmup_20210721_2052.pdf 
  2616   Fri Jul 23 20:53:40 2021 KojiSummaryGeneralJul 17, 2021: Canon camera / small silver tripod / macro zoom lens / LED ring light returned / ELectronics borrowed[Returned] Brought one HAM-A coil driver
(D1100687 / S2100619) and one Satellite Amplifier
(D1002818 / S2100741) from the 40m
 P_20210723_212158.jpg 
  2617   Sun Jul 25 21:45:46 2021 KojiSummaryCryo vacuum chamberAbout the radiation heat transfer modelThe following radiation cooling model well
explained the cooling curve of the test mass
(until ~150K)
  
  2618   Mon Jul 26 01:30:42 2021 KojiSummaryCryo vacuum chamberPrep for the 2nd cooling of the suspensionUpdated Jul 26, 2022 - 22:00

 


Reconstruct the
  
  2619   Mon Jul 26 22:49:00 2021 KojiSummaryCryo vacuum chamberAquadag painting[Stephen Koji]

We decided to paint the
silicon test mass with Aquadag to increase
 10x 
  2620   Wed Jul 28 00:59:47 2021 KojiSummaryCryo vacuum chamberThe test mass successfully suspended[Stephen Koji]

While Stephen worked on the RTD
reattachment, I worked on the suspension
 P_20210727_154143.jpegP_20210727_190356.jpegP_20210727_190426.jpegP_20210727_190543.jpeg 
  2621   Thu Jul 29 00:42:38 2021 KojiSummaryCryo vacuum chamberThe test mass successfully suspended[Stephen Koji]

Road to cooling down


The suspension with the
  
  2622   Thu Jul 29 13:11:17 2021 KojiSummaryCryo vacuum chamberCooling progress: UpdateThe current cooling curve suggests that
the radiative cooling factor Fe (black body
=1) increased from 0.15 to 0.5.
 temp_log_cool_down_20210728_1830.pdfcooling_model1.pdfcooling_model2.pdfOSEM_cooling.pdf 
  2625   Fri Jul 30 12:22:56 2021 KojiSummaryCryo vacuum chamberCooling curve comparisonsIn all aspects, the latest cooling shows
the best performance thanks to better thermal
connection, thermal isolation, and the black
 comparison_cold_head.pdfcomparison_inner_shield.pdfcomparison_test_mass.pdf 
  2628   Fri Jul 30 18:18:21 2021 KojiDailyProgressCDSConnecting CTC100 to EPICS/rtcds system[Radhika, Koji]

During the process, we corrected
the channel labeling for RTD #3/#4. So 
  
  2629   Sun Aug 1 22:22:00 2021 KojiSummaryCryo vacuum chamberCooling updateThe test mass temperature indicates 121K@100hr
but there seemed a few sensor glitches for
the test mass (𝛥=-4.2K) and the inner
 temp_log_cool_down_20210728_1830.pdfcooling_meas.pdfOSEM_cooling.pdfcooldown_210728.zip 
  2632   Mon Aug 2 21:51:37 2021 KojiDailyProgressCDSConnecting CTC100 to EPICS/rtcds systemThe legit
way to restart st.cmd is

  
  2633   Tue Aug 3 23:56:00 2021 KojiDailyProgressCryo vacuum chamberWarmup started 02 August- Confirmed the heating stopped in the
evening -> The heater was deactivated
@~23:00
 P_20210804_000247.jpgP_20210803_235421.jpg 
  2642   Wed Aug 11 18:00:19 2021 KojiDailyProgressCryo vacuum chamberCooldown model fitting for MSHow about incorporating radiative and conductive
terms from the object at 300K?

 
  
  2645   Sun Aug 15 00:33:15 2021 KojiSummaryCryo vacuum chamberAquadag painting on the inner shield[Stephen Koji]

We applied Aquadag painting on
the inner side of the inner shield.
 IMG_9636.JPGIMG_9632.JPGIMG_9646.JPG 
  2740   Mon Mar 28 18:00:43 2022 KojiSafetyCleanlinessLab floodingFlood photo album: https://photos.app.goo.gl/BZAG8DyQzFVTfMNz6
(This link is read-only who has no access
to the account)
  
  2743   Wed Mar 30 16:25:06 2022 KojiSafetyCleanlinessLab floodingMuddy Waters is not new, but if the facility
can fix it we'd take it.

 
  
  178   Thu Jul 16 15:01:48 2009 Koji & Connor LaserPSLRazor Blades!


   
        
            
  
  2029   Sun Feb 21 22:02:01 2016 Koji Antonio,MiscPD QEPD window removal few notesRich removed the window from PD on Friday.
The basics steps for the removal are the
following:
 Screen_Shot_2016-02-21_at_8.34.59_PM.pngScreen_Shot_2016-02-21_at_8.34.43_PM.pngScreen_Shot_2016-02-21_at_8.34.43_PM.png 
  2012   Thu Feb 4 21:23:31 2016 KojiNMiscPD QEPreparation of some componentsI prepared some basic optics for a PD QE
enhancement experiment.

Specifically, two half wave plates,
 2016-02-04_21.12.47.jpg 
  2013   Fri Feb 5 21:06:14 2016 KojiNMiscPD QEInitial alignment of opticsTo pick off adequate laser power for
our PD QE enhancement experiment, the first
HWP in front of the laser was rotated.
 2016_02_05_setup.png 
  2014   Tue Feb 9 00:00:11 2016 KojiNMiscPD QEMeasurement of a beam profileFor measuring  a current beam profile,
the setup as shown in Fig. 1 was prepared.

At first, laser powers at Point
 setup.pngBeamProfile.jpgBeamAfterPBS.pdf 
  2015   Wed Feb 10 00:17:31 2016 KojiNMiscPD QEAlignment of the single mode fiber and re-measurement of the beam profileThe beam measued yesterday was very elliptic.

Thus, for obtaining a round beam, we
decided to use a single mode fiber.
 2016_02_09_setup.pngRoundBeam.jpgBeamAfterFiber.png 
  2016   Thu Feb 11 00:03:24 2016 KojiNMiscPD QEBeam AdjustmentFor adjusting the beam, the setup was prepared
as shown in Fig. 1.

Our taget is 80 um beam waist in
 2016_02_10_setup.pngTargetBeam.pngBeamAfterLenses.pngBeamProfileScreen.jpg 
  2017   Thu Feb 11 23:54:48 2016 KojiNMiscPD QEPolarization measurementFor measuring the polarization, the setup
as shown in Fig. 1 was prepared.

The angle of the HWP #2 was 30
 2016_02_11_setup.pngpol.png 
  2018   Sun Feb 14 01:04:07 2016 KojiNMiscPD QEMeasurement of PD reflectivities and PD efficiencies for P-pol. and S-pol.According to the polariztion measurement,
we found that the laser is not linear
polarization.
 2016_02_12_setup.pngReflctivity2.pngQE2.png 
  2019   Tue Feb 16 23:51:31 2016 KojiNMiscPD QERe-measurement of the PD efficiencies for P-pol. and S-pol.We aligned the single mode fiber again
and We obtained the linear polarization
without QWP as shown in Fig. 1.
 2016_02_16_setup.pngQE.pngD980454-00(QE).pdfD980454-00(QE)_2.pdfD980454-00(QE).pdf 
  2020   Thu Feb 18 08:12:53 2016 KojiNMiscPD QERe-measurement of the reflectivities and the EQEs of the PD for S-pol and P-polThe reflecrivities and the EQEs of
the PD (C30665GH, with the glass window) for
S-pol and P-pol were measured at every 10
 QE3.pdfQE_ll.pdf 
  2022   Fri Feb 19 00:01:36 2016 KojiNMiscPD QERe-measurement of the reflectivities and the EQEs of the PD for S-pol and P-polI calculated IQEs using the measured
EQEs and reflectivities and the following
formula:
 6x 
  2023   Fri Feb 19 00:39:24 2016 KojiNMiscPD QEFirst QE measurement with the reflectorQEs (with the glass window) with the reflector
were measured as shown in Fig. 1.

The radius of curvature of the
 QE_enh.txtQE_enh.pdf 
  2024   Fri Feb 19 20:15:03 2016 KojiNMiscPD QEMeasurement of the reflectivity, EQE, and IQE of the PD without glass window The glass window of the PD was removed
and is placed in our shelf.

The reflectivity, EQE, and
 Ref.pdfQE.pdfQE2.pdfRef_QE_wow.txtQE_cal3_NK.m 
  2025   Fri Feb 19 20:25:14 2016 KojiNMiscPD QEMeasurement of the enhanced QE of the PD without glass window The enhanced QE of the PD without the glass
window was measured in the same setup
as elog2023.
 QE_enh.pdfQE_enh2.pdfQE_enh.txtQE_enh_ref.txtQE_enh_cal_NK.m 
  2027   Sun Feb 21 21:16:10 2016 KojiNMiscPD QEMeasurement of the enhanced QE of the PD without glass window > My interpretation of this is that
we get ~2% increase in the peak EQE for p-pol
by doing the extra bounce. Is that correct?
 2016_02_19_setup.pdf 
  2028   Sun Feb 21 21:53:04 2016 KojiNMiscPD QEMeasurement of the enhanced QE of the PD without glass window If we want to check soon the EQE with a
different beam size, we may want just to
add (for a kind of quick check) an additional
  
  2030   Mon Feb 22 23:51:18 2016 KojiNMiscPD QEBeam shape reflected by the PDThe beam shape reflected by the PD was
measured.

The measurement was done 5 cm and
 BeamAt15deg15cm.pdfBeamAt45deg15cm.pdf 
  2031   Tue Feb 23 00:22:01 2016 KojiNMiscPD QERe-measurement of the QE of the PD without window glassThe QEs were measured again at every 10
deg incident angle.

The power meter to measure the
 6x 
  2033   Wed Feb 24 08:18:06 2016 KojiNMiscPD QESystematic error of the power meter (RM9, Ophir)In the spec sheet, the systematic error
of RM9 (power meter, Ophir) is 5%.

This is not very good.
 RM9_RM9-PD_0.pdf 
  2034   Wed Feb 24 23:51:07 2016 KojiNMiscPD QETest of the BRDF measurementFor confirming if the BRDF of the PD (C30665GH)
can be measured, the setup as shown in Fig.
1 is established.
 BRDF_mes.pdfBRDFat0deg.pdfBRDFat0deg2.pdfBRDFat0deg.txtBRDF.m 
  2035   Fri Feb 26 10:00:18 2016 KojiNMiscPD QEBEDF measurement for wide angleThe BRDFs at 0 deg and 15 deg in incident
angle were measured for the wide angle with
the same way as elog2034 and
 BRDF_setup.pdfBRDFat0deg_log.pdfBRDFat30deg_log.pdfBRDF_log_P.pdf 
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