 Sat Nov 21 13:58:30 2020, Koji, Electronics, Characterization, Dark Current Measurement for InGaAs QPDs 
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Dark current measurement for InGaAs QPDs (OSI FCI-InGaAs-Q3000) has been done using Keithley 2450 and Frank's diode test kit. Frank's setup uses
various custom instruments which are no longer exist, therefore the kit was used only for switching between the segments.
The diodes were serialized as 81, 82, 83, 84, continuing the numbering for the OMC QPDs. The numbers are engraved at the side and the back of |
 Sun Nov 22 13:49:12 2020, Koji, Electronics, Characterization, Impedance Measurement for InGaAs QPDs
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To know any anomaly to the junction capacitance of the QPD segments, the RF impedances were tested with a hand-made impedance measurement.
All segments look almost identical in terms of capacitance.
Measurement setup: |
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Mon Nov 23 23:17:19 2020, Koji, Electronics, Characterization, The dark noise of the Q3000 QPDs
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The dark noise levels of the four Q3000 QPDs were measured with FEMTO DLPCA200 low noise transimpedance amp.
The measurement has been done in the audio frequency band. The amp gain was 10^7 V/A. The reverse bias was set to be 5V and the DC output of
the amplifier was ~40mV which corresponds to the dark current of 4nA. It is consistent with the dark current measurement. |
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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 Nov 24 12:27:18 2020, Koji, Electronics, Characterization, The dark noise of the Q3000 QPDs
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The amplifier BW was 400kHz at the gain of 1e7 V/A. And the max BW is 500kHz even at a lower gain. I have to setup something special to see the RF band
dark noise.
With this situation, I stated "the RF dark noise should be characterized by the actual WFS head circuit." in the 40m ELOG. |
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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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Thu Jun 23 21:03:33 2022, Koji, Facility, General, Moving the small optical table to CAML (TCS Lab)
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I've cleared the small optical table and wondered how to move it out of the room. Fortunately, the north side of the big table had wide enough clearance
and let the 36" wide table go through. This was easy without moving other heavy stuff.
From here to the door, a bit of work is required. A possibility is to roll the laser blocking wall to the south side of the big table. This will |
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Tue Jun 28 16:13:34 2022, Koji, General, General, The small optical table not small enough to get out
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The table width was an inch too large compared to the door width. We need to tilt the table and it seemed too much for us. Let's ask the transportation
for handling.
Photo courtesy by Juan |
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Thu May 20 17:03:50 2021, Koji, General, General, SRS LCR meter SRS720 borrowed from Downs
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Item loan: SRS LCR meter SRS720 borrowed from Downs. The unit is at the 40m right now for testing with an excelitas PD. Once it is done, the setup will
be moved to the OMC lab for testing the high QE PDs |
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Sun May 30 15:17:16 2021, Koji, General, General, DCPD AF capacitance measirement
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Attachment 1: System diagram. The reverse bias voltage is controlled by DS335. This can produce a voltage offset up to 10V. A G=+2 opamp
circuit was inserted so that a bias of up to +15V can be produced. The capacitances of the photodiodes were measured with SR720 LCR meter with a probe.
DS335 and SR720 were controlled from PC/Mac via serial connections. |
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Sun May 30 15:32:56 2021, Koji, General, General, DCPD AF capacitance measirement
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Measurement result:
The capacitance at no bias was 460~500pF. This goes down to below 300pF at 1.0~1.5V reverse bias. At maximum +15V, the capacitance goes down
to 200~220pF. |
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Fri Jul 22 17:41:01 2022, Koji, General, General, SRS LCR meter SRS720 returned to Downs
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SRS LCR meter SRS720 was returned to Downs as before.
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Mon Jul 25 18:25:04 2022, Koji, General, General, A/C Filter was replaced
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New filter PN
Grainger
TK70457312T Mini-Pleat Air Filter, Style - Air Filters Box, Performance Rating MERV 14, Nominal Filter Size 12x24x2
Previous |
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Fri Jul 15 22:14:14 2022, Koji, General, General, OMC Lab recovery for the OMC #002 test
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- The lab is chilly (18degC)
- Cleaned the lab and the optical table a bit so that the delicate work can be done. The diode test rig (borrowed from Downs - see OMC
ELOG 408 and OMC ELOG 409) was removed from the table and brought to the office (to return |
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Tue Jul 26 00:01:59 2022, Koji, General, General, OMC #002 delamination check 2
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More epoxy delamination check:
DCPD R (Attachment 1): Found half delaminated
DCPD T (Attachment 2): Found half delaminated |
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Mon Jul 18 14:20:09 2022, Koji, General, General, OMC #002 Plan Portal
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== Initial Preparation ==
[Done] OMC #002 placement
[Done] OMC #002 locking
Details OMC
ELOG 414
== Measurements == |
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Tue Jul 19 03:17:56 2022, Koji, General, General, OMC #002 Power Budget before mirror cleaning
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o Power Budget (2022/07/18)
NPRO ADJ -50 (min)
Fiber incident 62.8mW |
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Thu Jul 21 02:55:06 2022, Koji, General, General, OMC #002 Power Budget after mirror cleaning
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o Power Budget after FirstContact cleaning (2022/07/20)
NPRO ADJ -50 (min)
Fiber incident --.-mW |
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Thu Jul 21 14:35:35 2022, Koji, General, General, Bond reinforcement blocks for the invar brackets
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Bond reinforcement blocks for the invar brackets:
Attachment 1: CLASS A glass prisms (the surplus of the 2016 repair)
Attachment 2: Dirty
reiforcement bars made of Aluminum
There are also many dirty prisms in the kit obtained from Stephen
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Thu Jul 21 14:55:48 2022, Koji, General, General, Optics bonding for the backscatter measurement
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The backscatter beam is supposed to appear in the backpropagation path. The transmission of the OMC has a couple of optics, it's not easy to access
that beam.
To try to deflect the beam either horizontally or vertically, small optical pieces were made. (Attachment) |
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Thu Jul 21 17:47:00 2022, Koji, General, General, The profile of the beam incident on the fiber input coupler
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The profile of the beam incident on the fiber input
The fiber input was deflected by a 45deg mirror. The beam profile was measured with WincamD. The beam was too strong (~60mW) even at the smallest
pump power (ADJ -50) of the NPRO. So the two ND20 filters were added to the lens right before the 45 deg mirror and the camera. |
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Fri Jul 22 00:31:17 2022, Koji, General, General, OMC #002 backscatter measurement
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Measure the power ratio between the forward-propagating and reverse-propagating beams.
Place a small deflecting mirror at the transmission.
Place a flat mirror at the deflected transmission. When the alignment
of this mirror is adjusted to retroreflect this beam, the DC of the cavity reflection PD increases, and also the CCD shows spurious fringes.
This |
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Fri Jul 22 17:47:38 2022, Koji, General, General, C&B request for the reinforcement blocks
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OMC Reinforcement blocks
1. P/N D1600316; Version v4; Type 01; Qty 30; Source Chemistry Machine Shop
2. P/N D1600316; Version v4; Type 02; Qty 15; Source Chemistry Machine Shop |
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Tue Jul 26 00:12:58 2022, Koji, General, General, High QE PD: QE measurements
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- Installed the High QE PDs to OMC #002
B1-22@Cage B1 was installed to the transmission DCPD
B1-23@Cage B1 was installed to the reflection
DCPD
Upon the installation, the legs of the PDs were cut by 3mm. Also, the tab of the PD could not be embedded in the DCPD housing. |
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Wed Jul 27 10:34:09 2022, Koji, General, General, High QE PD: QE measurements 2
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- DLPCA-200 trans-impedance amplifier was calibrated.
Keithley source meter 2450 was connected to the amp. Provide current and read the output voltage with the precision digital voltage meter
(Agilent/Keysight). |
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Wed Jul 27 10:09:51 2022, Koji, General, General, 4+4 wire clamp in hand
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Regarding: D1200971
- 4 CLASS A wire clamp obtained from the OMC spare
- 4 more DIRTY wire clamp obtained from WB experiments (they no longer use these) |
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Wed Jul 27 10:34:30 2022, Koji, General, General, OMC #002 Protective FirstContact Paint
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The optical surfaces were coated with FirstContact to keep them clean / somewhat protected during the transportation.
The PD aperture was sealed with FirstContact "caps" (made by Kate in 2016?). |
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Wed Jul 27 23:52:18 2022, Koji, General, General, OMC #002 Cable bracket replacement (1)
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Parts check
- D1300052-V3 SN001 is going to be used (Attachment 1)
- This is the PEEK version of the cable bracket (Attachment 2). The side thread holes have no Helicoils inserted. This |
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Thu Jul 28 00:28:15 2022, Koji, General, General, OMC #002 Cable bracket replacement (2)
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Connector unmounting
- (Attachment 1) The connector nut rings were removed using an angled needle nose plier. The connector shell has a tight dimension
relative to the hole on the bracket. But of course, they could be extracted. |
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Thu Jul 28 00:46:47 2022, Koji, General, General, Subject: OMC #002 Cable bracket replacement (3)
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Checking the spare parts
- Conclusion for OMC#2: need PEEK cable ties
- for more OMCs: need more BHCS / PEEK cable ties / Helicoils |
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Wed Aug 10 18:42:27 2022, Koji, General, General, OMC #002 Cable bracket replacement (4)
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[Stephen Koji]
Now we got the C&Bed parts to continue to work on the cable bracket replacement.
1) Helicoil insertion |
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Thu Aug 11 15:24:57 2022, Koji, General, General, OMC #002 Cable bracket replacement (5)
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- The hole size extension is going forwared now.
- Madeline and Chub are cleaning (sonicating) a drill (29/64=0.4531") |
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Mon Aug 15 21:31:56 2022, Koji, General, General, OMC #002 Cable bracket replacement (6)
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The cable bracket was successfully replaced.
Looking from the QPD side (North side in Attachment 1), the connectors for the DCPDs and PZT are sticking out, and the
ones for QPDs are sticking to the other side. So only two rectangular holes (for QPDs) are facing north.
Top left is DCPDT
Top |
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Mon Aug 15 22:06:18 2022, Koji, General, General, OMC #002 new cable tie installed
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[Stephen Koji]
New cable ties were installed on the cable pegs attached to the long sides of the cable bracket.
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Mon Aug 15 22:43:35 2022, Koji, General, General, OMC #002 Delamination repair Part1 (1)
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[Stephen Koji]
Checked the delamination status:
The Invar bar on the cable bracket (DCPD side): Almost all delaminated (Attachment 1 left)
The invar bar on the cable bracket |
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Mon Aug 15 22:49:03 2022, Koji, General, General, OMC #002 Delamination repair Part1 (2) 7x
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EP30-2 preparation
Two Al foil cups + A sheet of Al foil (for test cure)
Set a tube on the glue gun
Attach an applicator tube
Push
a couple of times, and dispense the glue for a single stroke on a waste Al cup
Pour the 6g of glue to the other cup.
Add 0.3g of |
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Wed Aug 24 02:51:23 2022, Koji, General, General, OMC #002 Delamination repair Part1 (3) 8x
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| Inspection of the bonding on the suspension interface side. All look good. |
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Wed Aug 24 02:53:46 2022, Koji, General, General, OMC #002 Delamination repair Part2 (1)
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| Inspection of the delaminations in the optics side |
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Wed Aug 24 03:20:59 2022, Koji, General, General, OMC #002 Delamination repair Part2 (2) 11x
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| Bonding |
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Wed Aug 24 03:26:43 2022, Koji, General, General, OMC #002 Delamination repair Part2 (3) 8x
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Inspection
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Wed Aug 24 02:57:43 2022, Koji, General, General, EP30-2 bonding setup
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| EP30-2 bonding setup |
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Wed Aug 24 11:29:47 2022, Koji, General, General, OMC #002 ready for shipment
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[Stephen Koji]
The OMC #002 is ready for shipment.
Attachment 1: Work done on Sept 19, 2022 |
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Thu Aug 25 14:22:08 2022, Koji, General, General, LLO OMC #001 Ballast Mass investigation
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Inspected the past LLO add-on mass configuration.
There are unknown masses at the DCPD side. It looks like a small SS mass with an estimated mass of 5g. But the DCC number is unknown.
We are going to add 10g on each corner as well as the damping aterial. We should be able to figure out the fastener / mass configuration. |
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Thu Aug 25 20:05:00 2022, Koji, General, General, LLO OMC #001 Ballast Mass investigation
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Here is the balance mass info for the LLO OMC#001 analyzed from the photographs
Added masses are: 50+10g, 50+20, 10+20+5, and 20+20+10 for the mass right above FM1/CM1/FM2 and CM2, respectively.
The length
of the 1/4-20 screws seem L=3/4"~1"
If we attach the additional mass, longer 1/4-20 screws (1", 1" 1/8, 1" 1/4) |
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Fri Aug 26 22:29:02 2022, Koji, General, General, Tool Shipping Prep
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Shipping preparation for the LLO trip
Started July 15, 2022 and finished Aug 30. So it took ~1.5 months (with a
couple weeks of break)
Class B special tools |
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Tue Sep 20 08:54:33 2022, Koji, General, General, PD cage arrangement
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Upon the LLO work, the current PD arrangement in the cages are:
CAGE B
B1 OMC1 PDT (A1-23) |
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Mon Sep 26 14:27:49 2022, Koji, General, General, LLO OMC ICS work
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OMC #001
ICS Link: https://ics.ligo-la.caltech.edu/JIRA/browse/ASSY-D1201439-1
Already
marked as disassembled
Removed two PDs
https://ics.ligo-la.caltech.edu/JIRA/browse/IHGQEX3000-0-00-A1-25
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Mon Nov 7 21:16:16 2022, Camille, Optics, Configuration, Setting up the fiber couplers
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[Camille, Koji]
Began setting up fiber assembly for OMC testing:
-Aligned fiber mount to maximize transmission through fiber |
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Mon Nov 7 22:00:33 2022, Koji, Optics, Configuration, Setting up the fiber couplers
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Fiber matching: 43.2/56.7 = 76%
S/P-pol ratio 0.7/43.2 = 1.6%
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Fri Nov 11 19:07:48 2022, Koji, Supply, General, Supply Order
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Clean Supply Ordered
TexWipe TX8410 AlphaSat Vectra Alpha 10 50 sheets x 12 pk (VWR TWTX8410)
Mask KIMTECH PURE®
M3 Pleat-Style Face Masks 50 masks x 10 pk (VWR 15628-213)
Stainless Pan x3 (VWR 10193-562)
Ansell Accutech Latex Gloves 6.5 |
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Mon Nov 14 08:34:45 2022, Camille, Optics, Characterization, transmission measurements through OMC #1 (before cleaning)
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[Camille, Koji]
Friday, Nov 11th, 2022
Setting up OMC #1 for transmission measurements: |
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Mon Nov 14 09:27:13 2022, Koji, Optics, Characterization, transmission measurements through OMC #1 (before cleaning)
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The measured total optical loss of the OMC was
1st: 0.015 +/- 0.003
2nd: 0.085 +/- 0.005 |
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Thu Nov 17 18:56:22 2022, Koji, Optics, General, Transmission measurements of OMC #1 after deep cleaning
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[Camille, Koji]
- Removed the first contact we left on Monday.
- Measured transmission (Set1) Very high loss! Total optical loss of 18.5%! Observation |
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Thu Nov 17 19:50:00 2022, Koji, Optics, Characterization, Conclusion on the cleaning of OMC #001
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Conclusion on the cleaning of OMC #001
- After a couple of first contact cleaning trials and deep cleaning, the total loss was measured to be 0.045+/-0.004.
This indicated a slight improvement from the loss measured at LLO before any cleaning (0.064+/-0.004). |
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Fri Nov 18 18:41:05 2022, Camille Makarem, General, General, 2nd deep cleaning of OMC #1
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The four cavity mirrors in OMC #1 were each scrubbed using acetone and a cotton swab.
Then, the four mirrors were painted with First Contact (picture attached). The First Contact was allowed to dry for 20 minutes, then removed while
using the top gun. |
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Mon Nov 21 19:13:35 2022, Koji, General, General, Transmission measurement (2nd deep cleaning of OMC #1)
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OMC Transmission measurement after the 2nd deep cleaning
The 2nd deep cleaning didn't improve the transmission. (See Attachment 2)
The measured loss was 0.044+/-0.002 |
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Thu Jul 21 13:21:27 2022, Koji, General, Configuration, Windows laptop for WincamD Beam'R2 recovery
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The Windows laptop for WincamD/Beam'R2 (DELL Vostro3300) was not functional.
- Windows 7 got stuck in the starting up process (Google "startup repair loop")
- The battery can't charge and the adapter connection is flaky |
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Tue Nov 29 15:54:47 2022, Koji, General, Configuration, Windows laptop for WincamD Beam'R2 recovery
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Aaron took the set to Cryo lab
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Fri Dec 2 11:42:03 2022, Koji, Optics, Characterization, OMC #1 cleaning for water soluble contaminants
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[Camille, Koji] Log of the work on Nov 30, 2022
The following is the notes from GariLynn
Cleaning for water-soluble contaminants:
It uses deionized water instead of acetone.
Cleaning is based on this: LIGO-E1200326-v2
Your |
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Fri Dec 2 12:38:15 2022, Koji, Optics, Characterization, OMC #1 cleaning for water soluble contaminants
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Another set of FC cleaning was applied to FM1/FM2/CM1/CM2 and SM2. Some FC strings are visible on SM2. So I decided to clean SM2 as well as the cavity
mirrors close to SM2 (i.e. FM2 and CM2)
As a result, the bright scattering spot on CM1 is now very dim. And the loss was reduced to 4.0%. This is 0.4% better than the value before the |
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Fri Dec 2 23:58:33 2022, Koji, Optics, Characterization, OMC #1 cleaning for water soluble contaminants
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The second trial of the water scrub
A bright scatter is visible on FM1, so I tried water scrub on FM1. This time, both surfaces of FM1 and both surfaces of BS1 were cleaned.
Smaller Vectra swabs were used for the scrub. Then the water was purged by IPA splashed from a syringe. Right after that FC was applied. |
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Mon Dec 5 20:09:39 2022, Koji, Optics, General, (re)starting the OMC #4 build
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[Camille Koji]
We started buikding the OMC #4.
Removed OMC #1 from the optical setup and placed it at a safe side on the optical table/
Fixed OMC #4 in the optical setup
Cleaned |
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Fri Dec 9 13:13:13 2022, Koji, Optics, Characterization, FSR/TMS/Spot Positions/Transmission
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[Camille Koji]
We quickly measured the basic parameters of the OMC as is.
=== FSR === |
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Mon Dec 12 19:04:40 2022, Koji, Optics, Characterization, FSR/TMS/Spot Positions/Transmission 2nd trial
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[Camille Koji]
We replaced CM2 with a PZT mirror subassembly serialized by PZT "13" (Attachment 1).
This made the transmission increase to 96.x%. Therefore the quick measurement of FSR and TSM were done. Also more careful measurement of |
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Mon Dec 19 18:51:50 2022, Koji, Optics, Characterization, TMS measurement with the PZT voltages altered
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[Camille, Koji] Log of the work on Dec 15, 2023
The vertical and horizontal TMSs for OMC #4 were measured with the PZT voltages scanned from 0V to 200V.
We concluded that this alignment nicely avoids the higher-order mode structure up to ~19th order. We |
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Wed Jan 25 23:51:04 2023, Koji, General, General, The items packed for Downs
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Qty1 1/2 mounts
Qty2 prism mounts
Qty6 gluing fixures |
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Thu Jan 19 23:45:44 2023, Koji, Optics, General, OMC #4: cavity mirror bonding
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[Koji, Camille]
We worked on the bonding of the flat mirrors for the OMC cavity with UV epoxy.
- Prepared the UV illumination setup. Cleaned up the table a bit to spare some space for the illuminator. |
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Mon Jan 23 19:51:20 2023, Koji, Optics, General, OMC #4: cavity mirror bonding
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[Camille, Koji]
We continued to bond two CM mirrors and the other two steering mirrors for QPD2.
Before the bonding work, the FSR and TMSs were checked again. |
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Thu Jan 26 22:57:19 2023, Koji, Optics, General, OMC #4: One Invar block bonded with tilt
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[Camille, Koji]
The bottom side template was separated into two pieces and successfully removed from the breadboard. The template was assembled together again
and bagged to store it in a cabinet. |
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Thu Jan 26 23:07:14 2023, Koji, Optics, General, OMC #4: Input beam dump bonding
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[Camille, Koji]
During the second UV epoxy session, we did not bond the input beam dump. This is because this beam dump was not the one planned from the beginning
and if it was bonded in place, it would have created difficulties when removing the template. |
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Thu Jan 26 23:16:35 2023, Koji, Optics, Configuration, OMC #4: Top side bonding.
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[Camille, Koji]
1. Flipping the OMC |
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Tue Nov 15 07:46:58 2022, Camille Makarem, Optics, General, cleaning OMC #1
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Monday, November 14, 2022
Camille and Koji did a "deep cleaning" of OMC#1:
1) Applied First Contact to the mirror surfaces. Removed first contact after ~10 minutes. |
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Tue Nov 15 10:58:53 2022, Koji, Optics, General, OMC #1 damaged black glass removal
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[Camille, Koji]
The damaged black glass was removed from the OMC breadboard leaving the glass base.
The black glass pieces were bonded very tightly on the FS base with EP30-2. The apparent amount of the bond was not so much but it was such hard |
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Tue Nov 15 11:12:24 2022, Koji, Optics, General, OMC #1 fogging on the AR side of BS1 cleaned
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[Camille, Koji]
Photo of the BS1 AR cleaning process
Attachment 1: Before cleaning. Foggy surface is visible. |
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Thu Jan 26 23:46:13 2023, Koji, Optics, General, OMC #1 input beam dump bonding
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A beam dump was stacked on the base of the previous beam dump. The angle was determined so that the main transmission goes through while the stray OMC
reflection is blocked without clipping at the edge.
The resulting alignment of the beam dump is shown in Attachment 1. |