 Thu Apr 11 10:54:38 2019, Stephen, General, General, OMC(004): preparation for the PZT subassembly bonding
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Quote:
Preparation for the PZT subassembly bonding (Section 6.2 and 7.3 of T1500060
(aLIGO OMC optical testing procedure) |
 Wed Apr 17 09:08:47 2019, Stephen, General, General, OMC(004): Unwrapping and preparing breadboard 
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[Stephen, Philip, Koji, Joe]
Breadboard D1200105 SN06 was selected as described in eLOG 338. This log describes
unwrapping and preparation of the breadboard. |
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Thu May 9 16:07:18 2019, Stephen, Mechanics, General, Improvements to OMC Bonding Fixture
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[Stephen, Koji]
As mentioned in eLOG 331, either increased thermal cycling or apparent improvements
in cured EP30-2 strength led to fracture of curved mirrors at unintended locations of bonding to the PEEK fixture parts. |
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Tue May 28 12:14:20 2019, Stephen, Optics, General, CM PZT Assembly Debonding of EP30-2 in Acetone 8x
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[LiyuanZ, StephenA]
Downs B119
Summary: Beginning on 20 May 2019, two CM PZT assemblies were soaked in Acetone in an effort to debond the EP30-2 bonds |
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Thu Aug 22 12:35:53 2019, Stephen, Optics, Characterization, Wedging of the debonded PZTs 2019 August
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Wedge and thickness measurements of PZTs 12 and 13 took place after debonding and cleaning - results are shown in the first image (handwritten post-it
format).
These thickness measurements seem to have come back thinner than previous measurements. It is possible that I have removed some PZT material |
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Wed Sep 18 22:30:11 2019, Stephen, Supply, General, EP30-2 Location and Status
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Here is a summary of the events of the last week, as they relate to EP30-2.
1) I lost the EP30-2 syringes that had been ordered for the OMC, along with the rest of the kit.
Corrective action: Found in the 40m Bake Lab garbing area.
Preventative action: log material moves and locations in the OMC |
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Wed Sep 18 23:16:06 2019, Stephen, Supply, General, Items staged at 40m Bake Lab for PZT Subassembly Bonding
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The following items are presently staged at the 40m Bake Lab (see photo indicating current location) (noting items broght by Koji as well):
Bonding fixtures, now modified with larger washers to constrain springs, and with modification from OMC
elog 358.
Curved Mirrors and Tombstones as selected by Shruti in OMC elog 374.
PZTs |
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Wed Sep 18 23:38:52 2019, Stephen, General, General, Dirty ABO ready for PZT Subassembly Bonding
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The 40m Bake Lab's Dirty ABO's OMEGA PID controller was borrowed for another oven in the Bake Lab, so I have had to play
with the tuning and parameters to recover a suitable bake profile. This bake is pictured below (please excuse the default excel formatting).
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Tue Sep 24 12:19:20 2019, Stephen, General, General, Dirty ABO test run prior to PZT Subassembly Bonding
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The 40m Bake Lab's Dirty ABO's OMEGA PID controller was borrowed for another oven in the Bake Lab (sound familiar? OMC
elog 377), so I have had to play with the tuning and parameters to recover. This bake seemed to inadequately match the intended temperature profile
for some reason (intended profile is shown by plotting prior qualifying bake for comparison). |
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Thu Sep 26 17:33:52 2019, Stephen, General, General, Dirty ABO test run prior to PZT Subassembly Bonding - ABO is Ready!
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Follow up on OMC elog 379
I was able to obtain the following (dark blue) bake profile, which I believe is adequate for our needs.
The primary change was a remounting of the thermocouple to sandwich it between two stainless steel masses. The thermocouple bead previously was |
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Tue Oct 22 10:25:01 2019, Stephen, General, General, OMC PZT Assy #9 and #10 Production Cure Bake
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OMC PZT Assy Production Cure Bake (ref. OMC elog 381) for PZT Assy #9 and #10 started 27
September 2019 and completed 28 September 2019. Captured in the below figure (purple trace). Raw data has been posted as an attachment as well.
We have monitored the temperature in two ways: |
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Tue Oct 22 11:52:53 2019, Stephen, General, General, Epoxy Curing Timeline of OMC PZT Assy #9 and #10
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This post captures the curing timeline followed by OMC PZT Assys #9 and #10.
Source file posted in case any updates or edits need to be made. |
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Tue Oct 22 11:56:09 2019, Stephen, Supply, General, Epoxy Status update as of 22 October 2019
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The following is the current status of the epoxies used in assembly of the OMC (excerpt from C1900052)
Re-purchasing efforts are underway and/or complete
DONE
Masterbond EP30-2 currently located in Downs 303, Modal Lab (see image)
( WILL EXPIRE JANUARY 2020 |
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Fri Dec 13 14:59:18 2019, Stephen, General, General, OMC Beam Dump Production Cure Bake
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[Koji, Jordan, Stephen]
The beam dumps, bonded on Fri 06 Dec 2019, were placed in the newly tuned and configured small dirty ABO at the Bake Lab on Fri 13 Dec 2019.
Images are shared and references are linked below |
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Fri Feb 5 07:40:37 2021, Stephen, Supply, General, OMC Unit 4 Build Machined Parts
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OMC Unit 4 Build Machined Parts are currently located in Stephen's office. See image of large blue box from office, below.
Loaned item D1100855-V1-00-OMC08Q004
to Don Griffith for work in semi-clean HDS assy. |
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Wed Jul 7 14:21:50 2021, Stephen, Supply, General, OMC Unit 4 Build Machined Parts
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More explicit insights into the inventory for the Unit 4 build. Image of inventory included below.
Machined Parts:
New fabrication = Contents of Storage-11112 are consistent with |
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Wed Jun 20 20:37:45 2012, Zach, Optics, Configuration, Topology / parameter selection 8x
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EDIT (ZK): All the plots here were generated using my MATLAB
cavity modeling tool, ArbCav |
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Thu Jun 21 03:07:27 2012, Zach, Optics, Configuration, Parameter selection / mode definition
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EDIT 2 (ZK): As with the previous post, all plots and calculations
here are done with my MATLAB cavity modeling utility, |
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Fri Jun 29 11:26:04 2012, Zach, Optics, Characterization, RoC measurement setup
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Here is the proposed RoC measurement setup. Koji tells me that this is referred to as "Anderson's method".
We would like to use a linear cavity to measure the RoC of the curved mirrors independently (before forming the ring cavity), since the degeneracy
of HOMs will make the fitting easier. |
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Sun Jul 22 15:56:53 2012, Zach, Optics, Characterization, RoC measurement setup
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Here is a more detailed version of the setup, so that we can gather the parts we will need.
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Tue Mar 5 19:37:00 2013, Zach, Optics, Characterization, eLIGO OMC visibility vs. power measurement details
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EDIT (ZK): Koji points out that (1 - Ti) should really be the non-resonant reflectivity of the aligned cavity, which is much closer to 1. However,
it should *actually* be the non-resonant reflectivity of the entire OMC assembly, including the steering mirror (see bottom of post). The steering mirror
has T ~ 0.3%, so the true results are somewhere between my numbers and those with (1 - Ti) -> 1. In practice, though, these effects are swamped by the |
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Wed Mar 6 23:24:58 2013, Zach, Optics, Characterization, eLIGO OMC visibility vs. power measurement details
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I found that, in fact, I had lowered the modulation depth since when I measured it to be 0.45 rads --> Psb = 0.1.
Here is the sweep measurement:
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Wed Mar 20 09:38:02 2013, Zach, Optics, Characterization, [LLO] OMC test bench modified
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For various reasons, I had to switch NPROs (from the LightWave 126 to the Innolight Prometheus).
I installed the laser, realigned the polarization and modulation
optics, and then began launching the beam into the fiber, though I have not coupled any light yet. |
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Thu Mar 28 03:37:07 2013, Zach, Optics, Configuration, Test setup input optics progress
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[Lisa, Zach]
Last night (Tuesday), I finished setting up and aligning most of the input optics for the OMC characterization setup. See the diagram below, but
the setup consists of: |
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Fri Mar 29 08:55:00 2013, Zach, Optics, Configuration, Beam launched into fiber
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Quote:
Lisa and I concurred that it felt like we had converged to the optimum alignment and polarization, which would mean that the lack of |
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Thu Apr 4 00:35:42 2013, Zach, Optics, Configuration, MMT installed on breadboard, periscope built
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[Koji, Zach]
We installed the MMT that matches the fiber output to the
OMC on a 6"x12" breadboard. We did this so that we can switch from the "fauxMC" (OMC mirrors arranged with standard |
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Fri Apr 5 18:18:36 2013, Zach, Optics, Configuration, AOM probably broken
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Quote:
Then, I started to check the AOM path. I noticed that the 1st (or -1st) order beam is very weak. |
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Wed Apr 10 00:40:30 2013, Zach, Optics, Configuration, fauxMC locked
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[Koji, Zach]
Tonight, we locked the "fauxMC". We obtained
a visibility of >99%. |
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Wed Jun 5 01:06:35 2013, Zach, General, Characterization, L1 OMC as-built diagram
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D1300507
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Thu Jun 13 12:12:20 2013, Zach, General, General, [LLO] OMC and OMCS in LVEA
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https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=7395
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Thu May 3 21:45:58 2018, awade, General, Loan / Lending, Borrowed toaster oven
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| I’ve borrowed the black and decker toaster oven to dry some sonicated parts. It is temporarly located in the QIL lab. |
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Tue Nov 24 10:45:07 2020, gautam, Electronics, Characterization, The dark noise of the Q3000 QPDs
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I see that these measurements are done out to 100 kHz - I guess there is no reason to suspect anything at 55 MHz which is where this QPD will be reading
out photocurrent given the low frequency behavior looks fine? The broad feature at ~80 kHz is the usual SR785 feature I guess, IIRC it's got to do
with the display scanning rate. |
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Tue Oct 16 14:50:54 2012, jamie, jeff, General, General, OMC breadboard/plate measurement dimensions
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We have measured the dimensions and mass of the OMC glass plates/breadboards:
S/N
Mass (g)
Length
(mm)
Width (mm)
Height (mm)
Notes
01
6146
449.66
149.85
41.42, |
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Sat Jul 29 18:44:38 2017, rana, Electronics, Characterization, PDH amp
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| attachment 6: DCPD preamp looks like the opamp is wired for positive feedback? |
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Mon Sep 28 16:03:13 2020, rana, General, General, OMC Beam Dump Production Cure Bake
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are there any measurements of the BRDF of these things? I'm curious how much light is backscattered into the incoming beam and how much goes
out into the world.
Maybe we can take some camera images of the cleaned ones or send 1-2 samples to Josh. No urgency, just curiosity. |
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Fri Aug 23 11:11:44 2019, shruti, Optics, Characterization, Finding the curvature bottom
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I attempted to fit the data taken by Koji of the beam spot precession at the CCD in order to find the location of the curvature bottom in terms
of its distance (d) and angle () from the centre of the mirror. This was done using
the method described in a previous similar measurement and Section 2.1.3 of |
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Thu Aug 29 11:51:49 2019, shruti, Optics, Characterization, Wedging of the debonded PZTs - Calculation
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Using the measurements of PZTs 12,13 taken by Stephen, I estimated the wedging angle and orientation following Section 2.3.1 of T1500060. The results
can be found in Attachment1 and is summarised as follows.
For PZT 12, PZT 13 respectively: |
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Thu Sep 5 15:40:42 2019, shruti, Optics, Configuration, PZT Sub-Assembly
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Aim: To find the combinations of mounting prism+PZT+curved mirror to build two PZT sub-assemblies that best minimises the total vertical beam
deviation.
(In short, attachment 1 shows the two chosen sets of components and the configuration according which they must be bonded
to minimize the total vertical angular deviation.) |