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ID Date Author Typeup Category Subject Text Attachments
  2558   Tue Apr 20 09:43:49 2021 RadhikaSummary2um PhotodiodesLink to PD testing master docPosting link to PD testing google doc here: 

https://docs.google.com/document/d/1RrtX5nqNeEOazNvT2rPxHnSqumgvYfaBrYTMMGZ-ecc/edit
  
  2563   Mon May 3 17:32:29 2021 RadhikaSummary2um PhotodiodesUpdated PD testing schematic / measurement tableAttached:

- Updated schematic of the current
PD testing setup, including noise levels
 QIL_PD_testing.graffleQIL_PD_testing.pdfScreen_Shot_2021-05-03_at_17.16.20.png 
  2564   Wed May 5 00:34:14 2021 ranaSummary2um PhotodiodesUpdated PD testing schematic / measurement tableLooks very clear, thanks. I guess the next
thing to do is


ask if this will work for
  
  2566   Mon May 10 15:38:36 2021 ranaSummary2um PhotodiodesKeithley connections   Screen_Shot_2021-05-10_at_3.37.29_PM.png 
  2568   Wed May 12 15:43:30 2021 AidanSummary2um PhotodiodesChamber is leakingI tried pumping down the JPL PD chamber
to test the new PD at cryo temperatures.
Unfortunately, the chamber can;t get past
  
  2578   Wed May 26 18:38:25 2021 AidanSummary2um PhotodiodesChamber is leakingI tried Krytox around the O-ring and also
tightening the screws around the valve. The
leaking persists at roughly the same rate.
  
  2586   Fri Jun 11 07:42:54 2021 StephenSummary2um PhotodiodesChamber is leaking[Stephen, Aidan, Wednesday 09 June]

Summary and Plan:


Poor sealing at the output
 IMG_8865.JPGIMG_8881.JPG 
  2588   Fri Jun 11 16:48:31 2021 Aidan, StephenSummary2um PhotodiodesChamber is leakingWe hit another dead-end with leak hunting
the IR labs dewer (we replaced screws and
helicoil on the valve connection but there
 IMG_3002.jpgIMG_3001.jpg 
  2600   Fri Jul 9 10:57:58 2021 RadhikaSummaryCryo vacuum chamberCTC100 temperature extractionI wrote a python script to extract temperature
data from the CTC100 via ethernet, for monitoring
cooldown/warmup of Megastat. This is intended
 terminal1.png 
  2601   Fri Jul 9 13:44:39 2021 RadhikaSummaryCryo vacuum chamber1D cooling model updates*Takeaway*: The current 1D cooling model
is getting closer to matching our observed
cooling trends, mainly in the lower temperature
 model_vs_data_7-1.pdfcoldhead_capacity.pdfmodel_vs_data_7-1.pdf 
  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 
  2608   Mon Jul 19 15:57:17 2021 StephenSummaryCryo vacuum chamberTemp Log 210716_2255Uh oh, review of the
cooldown plot from the previous cooldown
(QIL/2603)
  
  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 
  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 
  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 
  2675   Sun Oct 3 08:22:49 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1
Output going to JPL_PD/data/A1_test2
and DAQ
Test commenced at 8:20AM
and cryo cooler started shortly afterwards
Once
  
  2676   Wed Oct 6 13:50:18 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1
Turned cryocooler off around 1317588441
(about 1:46PM)
Restarted measurement
with output going to JPL_PD/data/A1_test3
Room
  
  2677   Thu Oct 7 08:07:03 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1
We're at 164K as of 8AM this
morning.
  
  2678   Mon Oct 11 08:35:21 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1Terminated the data taking at 8:35Am this
morning. The termperature traces of the cryo
chamber show a couple of discontinuities
 Screenshot_from_2021-10-11_08-36-06.png 
  2679   Mon Oct 18 15:25:14 2021 AidanSummary2micronLasersStarting data taking and second test of JPL PD A1Initial running of analysis code puts the
max QE at ~62 + /- 1% around 130-150K. I
want to explore this temperature regime manually
  
  2691   Wed Oct 27 10:18:33 2021 Aidan, StephenSummaryCryo vacuum chamberInspection of Megastat post 408K event and pumping timeline[Aidan]

I've attached a timeline of
our inspection this afternoon along with
 8x 
  2692   Fri Nov 12 08:21:22 2021 AidanSummary2um PhotodiodesResults from JPL PD: A1-Test3[Aidan]

Here is the analyzed data from
Test 3 of the A1 JPL PD.
 A1_test3_nominal_QE.pdfA1_test3_darkcurrent.pdfA1_test3_noise_spectra_rev.pdf 
  2693   Fri Nov 12 10:54:55 2021 ranaSummary2um PhotodiodesResults from JPL PD: A1-Test3IT would also be good if you could plot
the RMS noise
around 10 Hz and 100 Hz as a function of
  
  2703   Thu Dec 16 17:57:15 2021 Radhika, StephenSummaryCryo vacuum chamberMegastat geometric parametersThis ELOG serves as a compilation of known/measured
geometric parameters of Megastat. This is
informative for thermal modeling of the system,
 D2000310_y-003_20211222.png 
  2714   Fri Jan 28 10:31:15 2022 ranaSummaryTutorial videooh no, stap the units madness, aaaaahhhh!!! noooooo!!!!    
  2772   Wed May 25 14:32:12 2022 RadhikaSummaryEmissivity estimationList of Megastat upgrades for emissivity estimationThis post will serve as a running list
of modifications for Megastat for emissivity
estimation (brain dump). It is divided into
  
  2773   Thu May 26 13:12:25 2022 RadhikaSummaryEmissivity estimationList of Megastat upgrades for emissivity estimationI think this flashlight
would work

  
  2775   Fri May 27 17:33:24 2022 RadhikaSummaryEmissivity estimationList of Megastat upgrades for emissivity estimation[Stephen, Radhika]

Today we further discussed ideas
for the enclosure, suspension/support, and
 IMG_3493.jpegIMG_3494.jpegIMG_3492.jpegIMG_1633.jpeg 
  23   Tue Jan 29 12:50:00 2008 DmassThings to BuyGeneralThings to buy wikiTemporarily located on the 40m wiki until
AdhikariWiki is released.
  
  102   Tue Nov 25 17:12:01 2008 AidanThings to BuyFiberResidual things to buy for FS
A large fraction of the equipment is already
in the lab from Masha's experiment earlier
 adhikari_lab_v1C.jpg 
  105   Wed Jan 14 11:33:58 2009 AidanThings to BuyFiberResidual things to buy for FS - QWPs, HWPs, output coupler[quote]
A large fraction of the equipment is already
in the lab from Masha's experiment earlier
  
  106   Wed Jan 14 18:14:23 2009 AidanThings to BuyFiberResidual things to buy for FS - extra photodiodes[quote][quote]
A large fraction of the equipment is already
in the lab from Masha's experiment earlier
  
  135   Sat May 23 17:19:08 2009 AidanThings to BuyGeneralClamps, pedestals, mirror mounts, photodiodesUnless there is another stash somewhere,
we are now short of clamps (two or three
are now spare), 3" pedestals (four or
  
  249   Tue Aug 11 16:38:25 2009 AidanThings to BuyGeneralOrdered mixers, splitters, LPFs and HPFs 
I've ordered the following:
Mini Circuits
  
ELOG V3.1.3-