 Wed Aug 29 11:06:30 2018, Koji, General, General, RF AM RIN and dBc conversion
|
0. If you have an RF signal whose waveform is , the amplitude is constant and 1.
1. If the waveform |
Sun Sep 23 19:42:21 2018, Koji, Optics, General, Montecarlo simulation of the phase difference between P and S pols for a modeled HR mirror 
|
[Koji Gautam]
With Gautam's help, I ran a coating design code for an HR mirror with the standard quarter-wave design. The design used
here has 17 pairs of lambda/4 layers of SiO2 and Ta2O5 (=34 layers) with the fused silica as the substrate to realize |
 Thu Sep 27 20:19:15 2018, Aaron, Optics, General, Montecarlo simulation of the phase difference between P and S pols for a modeled HR mirror
|
I started some analytic calculations of how OMC mirror motion would add to the noise in the BHD. I want to make some prettier plots, and am adding the
interferometer so I can also compute the noise due to backscatter into the IFO. However, since I've pushed the notebook I wanted to post an update.
Here's |
|
Thu Nov 1 19:57:32 2018, Aaron, Optics, General, Montecarlo simulation of the phase difference between P and S pols for a modeled HR mirror
|
I'm still not satisfied/done with the solution to this, but this has gone too long without an update and anyway probably someone else will have a
direction to take it that prevents me spinning my wheels on solved or basic questions.
The story will have to wait to be on the elog, but I've put it in the jupyter notebook. Basically: |
|
Fri Feb 1 12:52:12 2019, Koji, Mechanics, General, PZT deformation simulation
|
A simple COMSOL simulation was run to see how the PZT deforms as the voltage applied.
Use the geometry of the ring PZT which is used in the OMCs - NAC2124 (OD 15mm, ID 9mm, H 2mm)
The material is PZT-5H (https://bostonpiezooptics.com/ceramic-materials-pzt) which |
|
Thu Apr 4 20:07:39 2019, Koji, Supply, General, Purchase
|
== Office Depot ==
Really Useful Box 9L x 6 (delivered)
Really Useful Box 17L x 5 (ordered 4/4) |
|
Fri Apr 5 23:30:20 2019, Koji, General, General, OMC (002) repair completed
|
OMC(002) repair completed
When the cable harness of OMC(004) is going to be assembled, the cable harness of OMC(002) will be replaced with the PEEK one. Otherwise, the
work has been done. |
|
Wed Apr 10 19:22:24 2019, Koji, General, General, OMC(004): preparation for the PZT subassembly bonding
|
Preparation for the PZT subassembly bonding (Section 6.2 and 7.3 of T1500060 (aLIGO OMC optical
testing procedure)
- Gluing fixture (Qty 4) |
|
Thu Apr 11 10:54:38 2019, Stephen, General, General, OMC(004): preparation for the PZT subassembly bonding
|
Quote:
Preparation for the PZT subassembly bonding (Section 6.2 and 7.3 of T1500060
(aLIGO OMC optical testing procedure) |
|
Thu Apr 11 21:22:26 2019, Koji, Mechanics, General, OMC(004): PZT sub-assembly gluing
|
[Koji Stephen]
The four PZT sub-assemblies were glued in the gluing fixtures. There were two original gluing fixtures and two additional modified fixtures for
the in-situ bonding at the repair of OMC(002). |
|
Thu Apr 11 21:22:58 2019, Koji, General, General, OMC(004): PZT sub-assembly air baking
|
[Stephen Koji]
The baking of the PZT subassemblies was more complicated than we initially thought.
The four PZT subassemblies were placed in the air bake oven A. We meant to bake the assemblies with the ramp time of 2.5h, a plateau of 2h at |
|
Sun Apr 14 23:58:49 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection
|
[Koji Stephen]
(Friday afternoon) We retrieved the PZT sub-assemblies to the clean room.
We started removing the ASSYs from the fixtures. We noticed that some part of the glass and PZT are ripped off from the ASSY and stuck with the |
|
Mon Apr 15 00:08:32 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection (Sub-assy #7) 6x
|
Sub-ASSY #7
Probably the best glued unit among the four.
Attachment #1: Mounting Block SN001 |
|
Mon Apr 15 00:39:04 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection (Sub-assy #8) 8x
|
Sub-ASSY #8
Probably the best glued unit among the four.
Attachment #1: Mounting Block SN007 |
|
Mon Apr 15 01:07:30 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection (Sub-assy #9) 7x
|
Sub-ASSY #9
The most fractured unit among four.
Attachment #1: Mounting Block SN017 |
|
Mon Apr 15 01:23:45 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection (Sub-assy #10)
|
Sub-ASSY #10
Attachment #1: Mounting Block SN021
Attachment #2: PZT-Mounting Block bonding looks just excellent. |
|
Tue Apr 16 23:11:43 2019, Koji, General, General, Borrowed items from the other labs
|
Apr 16, 2019
Borrowed two laser goggles from the 40m. (Returned Apr 29, 2019)
Borrowed small isopropanol glass bottole from CTN. |
|
Wed Apr 17 09:08:47 2019, Stephen, General, General, OMC(004): Unwrapping and preparing breadboard
|
[Stephen, Philip, Koji, Joe]
Breadboard D1200105 SN06 was selected as described in eLOG 338. This log describes
unwrapping and preparation of the breadboard. |
|
Wed Apr 17 10:30:37 2019, Philip, Optics, General, OMC optical set-up day 1
|
[Joe, Koji, Liyuan, Philip, Stephen]
Work done on 16.04.2019
|
|
Thu May 9 16:07:18 2019, Stephen, Mechanics, General, Improvements to OMC Bonding Fixture
|
[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. |
|
Thu May 9 17:35:07 2019, Koji, Optics, General, Alignment strategy
|
Notes on the OMC cavity alignment strategy
- x3=1.17 γ + 1.40 δ, x4=1.40 γ + 1.17 δ
- This means that the effect of the two curved mirrors (i.e. gouy phases) are very similar. To move x3 and x4 in common is easy, but to do differentially |
|
Wed May 15 19:07:53 2019, Koji, Clean, General, What is this???
|
Suddenly something dirty emerged in the lab. What is this? It looks like an insulation foam or similar, but is quite degraded and emits a lot of particulates.
This does not belong to the lab. I don't see piping above this area which shows broken insulation or anything. All the pipes in the room
are painted white. |
|
Thu May 16 12:41:28 2019, Chub, General, General, fire pillow found on optics table
|
That is an expanding fire pillow, also known as firebrick. It is used to create a fire block where holes in fire-rated walls are made and prevents
lab fires from spreading rapidly to adjacent labs. I had to pull cable from B254 to our labs on either side during a rather narrow window of time.
Some of the cable holes are partially blocked, making it difficult to reach the cable to them. The cable is then just guided to the hole from a distance. |
|
Tue May 28 12:14:20 2019, Stephen, Optics, General, CM PZT Assembly Debonding of EP30-2 in Acetone 8x
|
[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 |
|
Mon Jun 24 12:54:58 2019, Koji, Clean, General, HEPA BOOTH
|
| https://www.airscience.com/purair-flow-laminar-flow-cabinets |
|
Wed Sep 18 22:30:11 2019, Stephen, Supply, General, EP30-2 Location and Status
|
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 |
|
Wed Sep 18 23:16:06 2019, Stephen, Supply, General, Items staged at 40m Bake Lab for PZT Subassembly Bonding
|
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 |
|
Wed Sep 18 23:38:52 2019, Stephen, General, General, Dirty ABO ready for PZT Subassembly Bonding
|
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).
|
|
Mon Sep 23 21:29:51 2019, Koji, Optics, General, OMC(004): PZT sub-assembly gluing (#9/#10)
|
[Stephen, Shruti, Koji]
We worked on the gluing of the PZT sub-assy (#9 and #10) along with the designed arrangement by Shruti (OMC
ELOG 374). |
|
Tue Sep 24 12:19:20 2019, Stephen, General, General, Dirty ABO test run prior to PZT Subassembly Bonding
|
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). |
|
Thu Sep 26 17:33:52 2019, Stephen, General, General, Dirty ABO test run prior to PZT Subassembly Bonding - ABO is Ready!
|
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 |
|
Mon Sep 30 23:16:53 2019, Koji, Optics, General, OMC(004): PZT sub-assembly gluing (#9/#10)
|
Friday: [Stephen, Koji]
As the oven setting has qualified, we brought the PZT assys in the air bake oven.
Monday: [Stephen, Shruti, Koji] |
|
Tue Oct 22 10:25:01 2019, Stephen, General, General, OMC PZT Assy #9 and #10 Production Cure Bake
|
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: |
|
Tue Oct 22 11:52:53 2019, Stephen, General, General, Epoxy Curing Timeline of OMC PZT Assy #9 and #10
|
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. |
|
Tue Oct 22 11:56:09 2019, Stephen, Supply, General, Epoxy Status update as of 22 October 2019
|
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 |
|
Fri Dec 6 00:55:25 2019, Koji, Optics, General, Beamdump gluing 6x
|
[Stephen, Koji]
20 glass beamdumps were bonded at the 40m cleanroom.
Attachment 1: We had 20 fused silica disks with a V-groove and 40 black glass pieces |
|
Fri Dec 13 14:59:18 2019, Stephen, General, General, OMC Beam Dump Production Cure Bake
|
[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 |
|
Wed Dec 18 21:54:53 2019, Koji, General, General, OMC Beam Dump Production Cure Bake
|
The beamdumps were taken out from the oven and packed in bags.
The bottom of the V are completely "wet" for 17 BDs among 20 (Attachment 1/2).
3 BDs showed insufficient glue or delamination although there is no sign of lack of rigidity. They were separated from the others in the pack. |
|
Thu Feb 27 14:31:13 2020, Koji, General, General, Item lending
|
Item lending as per Ian's request: Particle Counter from OMC Lab to QIL
|
|
Mon Aug 10 15:29:54 2020, Koji, General, General, Item lending
|
The particle counter came back to the OMC lab on Aug 10, 2020
|
|
Mon Aug 10 15:53:46 2020, Koji, General, General, Lab status check
|
Check-in to the OMC lab to see the status. Nothing seemed changed. No bug. The HEPA is running normal. The particle level was 0.
Went into the HEPA enclosure and put a cover on the OMC. Because of the gluing template, the lid could not be close completely (that's expected
and fine). |
|
Mon Sep 28 16:03:13 2020, rana, General, General, OMC Beam Dump Production Cure Bake
|
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. |
|
Mon Sep 28 16:13:08 2020, Koji, General, General, OMC Beam Dump Production Cure Bake
|
According to the past backscatter test of the OMC (and the black glass beamdump: not V type but triangular type on a hexagonal-mount), the upper limit
of the back reflection was 0.13ppm. https://nodus.ligo.caltech.edu:8081/OMC_Lab/209
I don't have a BRDF measurement. We can send a few black glass pieces to Josh. |
|
Fri Oct 9 01:01:01 2020, Koji, General, General, TFT Monitor mounting
|
To spare some room on the optical table, I wanted to mount the two TFT monitor units on the HEPA enclosure frame.
I found some Bosch Rexroth parts (# 3842539840) in the lab, so the bracket was taken for the mount. This swivel head works very well. It's rigid
and still the angle is adjustable. |
|
Fri Oct 16 00:53:29 2020, Koji, General, General, TFT Monitor mounting
|
The image flipping of the display unit was fixed. The vendor told me how to fix it.
- Open the chassis by the four screws at the side.
- Look at the pass-through PCB board between the mother and display boards. |
|
Fri Oct 23 19:09:54 2020, Koji, General, General, Particle counter transfered to Radhika
|
| See this entry: https://nodus.ligo.caltech.edu:8081/40m/15642 |
|
Fri Nov 6 18:38:00 2020, Koji, General, General, Powermeter lent from OMC Lab to 2um ECDL
|
Thorlabs' powermeter controler + S401C head was lent from OMC Lab.
https://nodus.ligo.caltech.edu:8081/SUS_Lab/1856 |
|
Mon Nov 9 22:06:18 2020, Koji, Mechanics, General, 5th OMC Transport Fixture
|
I helped to complete the 5th OMC Transport Fixture. It was built at the 40m clean room and brought to the OMC lab. The fixture hardware (~screws) were
also brought there. |
|
Fri Nov 20 18:51:23 2020, Koji, General, General, Instrument loan
|
FEMTO DLPCA200 low noise preamp (brand new)
Keithley Source Meter 2450 (brand new) => Returned 11/23/2020
were brought to the OMC lab for temporary use. |
|
Fri Feb 5 07:40:37 2021, Stephen, Supply, General, OMC Unit 4 Build Machined Parts
|
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. |