 Mon Dec 20 14:10:56 2021, Anchal, Update, BHD, All coil drivers ready to be used, modified and tested
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Koji found some 68nF caps from Downs and I finished modifying the last remaining coil driver box and tested it.
SERIAL #
TEST
result
S2100633
PASS
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Mon Dec 20 17:26:13 2021, Yehonathan, Update, BHD, SOS assembly 7x
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{Yehonathan, Anchal}
I released the AS1 wires from the winches, removed the adapter from the SOS tower, and removed the Lambda optic from the adapter. Attachment
1 shows the pencil markings on the optic before cleaning. I cleaned the pencil marking from the side of the optic with acetone using swabs until there |
 Tue Dec 21 16:35:39 2021, Koji, Update, VAC, ITMX NW feedthru (LO1-1) connector pin bent
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I've received a report that a pin of an ITMX NW feedthru connector was bent. (Attachment 1)
The connector is #1 (upper left) and planned to be used for LO1-1.
This is Pin25 and used for the PD K of OSEM #1. This means that Coil Driver #1 (3 OSEMs) uses this pin, but Coil Driver #2 (2 OSEMs) does not. |
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Tue Dec 21 18:04:46 2021, Yehonathan, Update, BHD, SOS assembly
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| I locked the EQ stops while retaining the XY alignment on the QPD and installed 5 green OSEMs. AS1 is ready for transfer into the vacuum chamber. |
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Wed Dec 22 14:57:05 2021, Koji, Update, General, chiara local backup
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chiara local backup of /cvs/cds has not been running since the move of chiara in Nov 19. The
remote backup has not been taken since 2017.
The lack of the local backup was because of the misconfiguration of /etc/fstab. |
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Wed Dec 22 18:16:23 2021, Koji, Update, SUS, Remaining task for 2021
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The in-vacuum installation team has reported that the side OSEMs of ITMX and LO1 are going to be interfering if place LO1 at the planned location.
I confirmed that ITMX has the side magnet on the other side (Attachment 1 ITMX photo taken on 2016/7/21). So we can do this swap.
The ITMX side OSEM is sticking out most. By doing this operation, we will recover most of the space between the ITMX and LO1. (Attachment 2) |
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Thu Dec 23 16:38:21 2021, Koji, Update, General, Is megatron down? (Re: chiara local backup)
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The local backup seems working fine again. But I found that megatron is down and this is a real issue. This should
be fixed at the earliest chance.
It seems that the local backup has been successfully taken this morning. |
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Fri Dec 24 16:49:41 2021, Koji, Update, General, Is megatron down? (Re: chiara local backup)
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It turned out that the UPS installed on Nov 22 failed (cf https://nodus.ligo.caltech.edu:8081/40m/16479
). As a fact, it was alive just for 2 weeks!
The APC UPS unit indicated F06. According to the manual (https://www.apc.com/shop/us/en/products/APC-Power-Saving-Back-UPS-Pro-1000VA/P-BR1000G), |
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Sun Jan 2 20:46:46 2022, Koji, Update, SUS, End SUS Electronics building
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19:00~ Start working on the electronics bench
The following units were tested and ready to be installed. These are the last SUS electronics units and we are now ready to upgrade the
end SUS electronics too. |
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Mon Jan 3 12:05:08 2022, Paco, Update, BHD, 1Y0 rack work for LO2 AS1 AS4
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[Paco, Anchal]
Continue working on 1Y0. Added coil drivers for LO2, AS1, AS4. Anchal made additional labels for cables and boxes. We lined up all cables, connected
the different units and powered them without major events. |
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Mon Jan 3 16:46:41 2022, Paco, Update, BHD, 1Y1 rack work for SR2, PR2, PR3
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[Paco, Anchal]
Continued working on 1Y1 rack. Populated the 6 coil drivers, made all connections between sat amp, AA chassis, DAC, and ADC adapters for SR2,
PR2, and PR3 suspensions. Powered all boxes and labeled them and cables where needed. Near the end, we had to increase the current limit on the positive |
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Tue Jan 4 18:26:59 2022, Anchal, Update, BHD, Tested 2" PR2 candidates transmission
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I used the rejected light from the PBS after the motorized half-wave plate between PMC and IMC injection path (used for input power control to IMC) to
measure the transmission of PR2 candidates. These candidates were picked from QIL (QIL/2696).
Unfortunately, I don't think either of these mirrors can be used for PR2. |
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Tue Jan 4 18:27:23 2022, Paco, Update, BHD, SOS assembly -- PR3
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[yehonathan, paco, anchal]
We continue suspending PR3 today. Yehonathan and Paco suspended the thick optic in its adapter. After fixing some nominal height and undoing
any residual roll angle (see Attachments 1,2 for pictures), we noticed a problem with the pitch angle, so we insert the counterweights all the way in. |
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Wed Jan 5 17:46:04 2022, Anchal, Update, BHD, Tested 2" PR2 candidates transmission
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I tested 2 more optics today, the old PR2 that we took out and another optic I found in QIL. Both these optics are also not good for our purpose.
Polarization
Incident Power [mW]
Transmitted Power [mW]
Transmission [ppm]
Existing |
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Wed Jan 5 19:18:06 2022, Yehonathan, Update, BHD, SOS assembly -- AS4
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{Paco, Yehonathan, Anchal}
Today we suspended AS4 (E2000226-B). Anchal mounted Lambda Optic mirror with an RoC closest to AS4 in a thin optic mount. He noted that this |
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Thu Jan 6 12:52:49 2022, Anchal, Update, CDS, Yearly DAQD fix 2022!
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Just as predicted, all realtime models reported "0x4000" error. Read the parent post for more details. I fixed this by following the instructions.
I add folowing lines to the file /opt/rtcds/rtscore/release/src/include/drv/spectracomGPS.c
in fb1: |
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Thu Jan 6 13:54:28 2022, Koji, Update, CDS, Yearly DAQD fix 2022!
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Just restarting all the c1sus2 models fixed the issue. (Attachment 1)
SUS2 ADC1 CH21 is saturated. I'm not yet sure if this is the electronics issue or the ADC issue.
SUS2 ADC1 CH10 also has large offset. This should also be investiagted. |
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Thu Jan 6 14:08:14 2022, Koji, Update, CDS, More BHD SUS screens added to sitemap
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| More BHD SUS screens added to sitemap (Attachment 1) |
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Thu Jan 6 15:10:38 2022, Koji, Update, SUS, ITMX Chamber work
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[Anchal, Koji]
=== Summary ===
- ITMX SD OSEM migration done |
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Thu Jan 6 17:00:20 2022, Yehonathan, Update, BHD, SOS assembly -- LO2
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{Paco, Yehonathan}
Today we suspended LO2 (E1800089) which Anchal has loaded into the thick optic
adapter. Attachments 1,2 show the height and roll balance adjustments. |
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Thu Jan 6 17:16:51 2022, Yehonathan, Update, BHD, Using Peek screws/nuts
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There were several cases where the long EQ stops didn't perform as expected.
In one type of case, we used a counterweight at the front of the adapter but not in the back leaving a recess where the lower back EQ stop should
touch. |
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Thu Jan 6 22:18:47 2022, Koji, Update, CDS, SUS screen debugging
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Indicated by the red arrow:
Even when the side damping servo is off, the number appears at the input of the output matrix
Indicated by the green arrows: |
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Fri Jan 7 17:54:13 2022, Anchal, Update, BHD, PR2 Sat Amp has a bad channel
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[Anchal, Paco]
Yesterday we noticed that one of the ADC channels was overflowing. I checked the signal chain and found that CH3 on PR2
Sat Amp was railing. After a lot of debugging, our conclusion is that possible the PD current input trace is shorted to the positive supply through |
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Fri Jan 7 17:59:45 2022, Yehonathan, Update, BHD, SOS assembly -- SR2
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{Yehonathan, Paco}
{Paco, Yehonathan}
Today we suspended SR2 (E1800089) which Anchal has loaded into the thick optic |
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Fri Jan 7 18:24:25 2022, Koji, Update, BHD, SOS assembly -- SR2
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Vacseal in the freezer. It could have been expired sooooo many years ago, We need some cure testing.
Can you release the part numbers of the ordered components (and how/where to use them), so that we can incorporate them into the CAD model?
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Fri Jan 7 18:28:13 2022, Koji, Update, BHD, PR2 Sat Amp has a bad channel
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Leave the unit to me. I can look it at on Mon. For a while, you can take a replacement unit from the electronics stack.
Also: Was this unit tested before? If so, what was the testing result at the time? |
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Mon Jan 10 13:35:52 2022, Anchal, Update, BHD, PR2 Sat Amp has a bad channel
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The unit was tested before by Tege. The test included testing the testpoint voltages only. He summarized his work in
this doc. The board number is S2100737. Here are the two comments about it:
"This unit presented with an issue on the PD1 circuit of channel 1-4 PCB where the voltage reading on TP6, TP7 and TP8 are -15.1V, -14.2V, |
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Mon Jan 10 14:00:44 2022, not Koji, Update, BHD, SOS assembly -- SR2
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Yes,
For the thin optics adapter design, we want Peek 1/4-20 screw (part # 98885A131) to replace the lower back long EQ stop. On it, we will have
a Peek washer (part # 93785A600) fastened between two Peek nuts (part #98886A813). |
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Mon Jan 10 15:45:55 2022, Paco, Update, Electronics, ITMY feedthroughs and in-vac cables installed - part I
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The ITMY 10" flange with 10 DSUB-25 feedthroughs has been installed with the cables connected at the in-vac side. This is the first of two
flanges, and includes 5 cables ordered vertically in stacks of 3 & 2 for [[OMC-DCPDs, OMC-QPDs, OMC-PZTs/Pico]] and [[SRM1, SRM2]] respectively from
right to left. During installation, two 12-point silver plated bolts were stripped, so Chub had to replace them. |
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Mon Jan 10 15:59:46 2022, Koji, Update, BHD, PR2 Sat Amp has a bad channel 6x
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The issue was present in the cable between the small adapter board and the rear panel. The cable and the Dsub 25 connectors were replaced. The removed
parts were resoldered. Did the basic test of the channel.
Attachment 1: I cleaned up the area of the PD3 circuit of S2100556 and checked the voltage when the circuit was energized. |
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Mon Jan 10 17:04:47 2022, Anchal, Update, BHD, AS1 Sat Amp CH2 had offset
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We found that there was a small offset (~300 mV) at TP6 and TP8, in PD2 circuit (CH2 of the board). I replaced U3 AD822ARZ but did not see any affect.
I disconnected the adaptor board in the back and saw that the offset went away. This might mean that the cable had some flaky short to a power supply pin.
However, when I just reinserted the adaptor board back again, there was no offset. We could not find any issue with the board after that to fix, so we |
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Mon Jan 10 18:20:45 2022, Anchal, Update, BHD, Tested 2" PR2 candidates transmission
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I tested 2 more optics found by Paco and Yehonathan in QIL.
Polarization
Incident Power [mW]
Transmitted Power [mW]
Transmission [ppm]
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Tue Jan 11 09:53:14 2022, not Koji, Update, BHD, SOS assembly -- Peek screws and nuts
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| I handed the Peek parts we got from McMaster to Jordan for C&B. |
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Tue Jan 11 10:23:18 2022, Paco, Update, Electronics, ITMY feedthroughs and in-vac cables installed - part II
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[Paco, Chub]
The ITMY 10" flange with 4 DSUB-25 feedthroughs has been installed with the cables connected at the in-vac side. This is the second of two
flanges, and includes 4 cables ordered vertically in stacks of 2 & 2 for [[AS1-1, AS1-2, AS4-1, AS4-2]] respectively. No major incidents during this |
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Tue Jan 11 10:46:07 2022, Tega, Update, CDS, SUS screen debugging
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Seen. Thanks.
Red Arrow: The channel was labeled incorrectly as INMON instead of OUTPUT
Green Arrow: OK, I will create a custom medm screen for this. |
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Tue Jan 11 10:58:58 2022, Tega, Update, SUS, Temporary watchdog
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Started working on this. First created a git repo for tracking https://git.ligo.org/40m/susaux.git
I have looked through the folder to see what needs doing and I think I know what needs to be done for the final case by just following the same
pattern for the other optics, which I am listing below |
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Tue Jan 11 13:43:14 2022, Koji, Update, SUS, Temporary watchdog
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I don't remember the syntax of the db file, but here this calc channel computes A&B. And A&B corresponds to INPA and INPB.
field(CALC,"A&B")
field(INPA,"C1:SUS-LO1_UL_COMM PP NMS") |
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Tue Jan 11 14:21:53 2022, Paco, Update, Electronics, BS feedthroughs and in-vac cables installed
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[Paco, Yehonathan, Chub]
The BS chamber 10" flange with 4 DSUB-25 feedthroughs has been installed with the cables connected at the in-vac side. This is the second
of two flanges, and includes 4 cables ordered vertically in stacks of 2 & 2 for [[LO2-1, LO2-2, PR3-1, PR3-2]] respectively. |
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Tue Jan 11 15:21:16 2022, Anchal, Update, BHD, PR2 transmission calculation
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I did this simple calculation where I assumed 1W power from laser and 10% transmission past IMC. We would go ahead with V6-704/V6-705 ATFilms 3/8"
optic. It would bring down the PRC gain to ~30 but will provide plenty of light for LO beam and alignment. |
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Thu Jan 13 16:08:00 2022, Yehonathan, Update, BHD, gluing magnets after AS1/4 misfortune
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{Yehonathan, Anchal, Paco}
In the cleanroom, we removed AS1 and AS4 from their SOS towers. We removed the mirrors from the adapters and put them in their boxes. The broken
magnets were collected from the towers and their surfaces were cleaned as well as the magnet sockets on the two adapters and on the side block from where |
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Thu Jan 13 17:10:55 2022, Anchal, Update, BHD, PR2 transmission calculation
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I corrected the calculation by adding losses by the arm cavity ends times the arm cavity finesse and also taking into account the folding of the cavity
mirror. I used exact formula for finesse calculation and divided it by pi to get the PRC gain from there. Attachment 3 is the notebook for referring to
the calculations I made. |
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Fri Jan 14 03:07:04 2022, Koji, Update, BHD, PR2 transmission calculation
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I opened the notebook but I was not sure where you have the loss per bounce for the arm cavity.
PRC_RT_Loss = 2 * PR3_T + 2 * PR2_T + 2 * Arm_Cavity_Finesse * ETM_T + PRM_T
Do you count the arm reflection loss to be only 2 * 13ppm * 450 = 1.17%? |
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Fri Jan 14 11:00:29 2022, Anchal, Update, BHD, PR2 transmission calculation
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Yeah, I counted the loss from arm cavities as the transmission from ETMs on each bounce. I assumed Michelson to be perfectly aligned to get no light
at the dark port. Should I use some other number for the round-trip loss in the arm cavity? |
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Fri Jan 14 12:01:21 2022, Anchal, Update, Electronics, BS & ITMY feedthroughs labeled and connected to Sat Amps
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I labeled all the newly installed flanges and connected the in-air cables (40m/16530) to
appropriate ports. These cables are connected to the CDS system on 1Y1/1Y0 racks through the satellite amplifiers. So all new optics now can be damped
as soon as they are placed. We need to make more DB9 plugs for setting "Acquire" mode on the HAM-A coil drivers since our Binary input system |
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Fri Jan 14 13:46:25 2022, Anchal, Update, BHD, PR2 transmission calculation updated
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I updated the arm cavity roundtrip losses due to scattering. Yehonathan told me that arm cavity looses 50ppm every roundtrip other than the transmission
losses. With the updated arm cavity loss:
PRFPMI |
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Fri Jan 14 14:04:51 2022, Paco, Update, Electronics, RFSoC 2x2 board arrived
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The Xilinx RFSoC 2x2 board arrived right before the winter break, so this is kind of an overdue elog. I unboxed it, it came with two ~15 cm SMA M-M cables,
an SD card preloaded with the ARM processor and a few overlay jupyter notebooks, a two-piece AC/DC adapter (kind of like a laptop charger), and a USB 3.0
cable. I got a 1U box, lid, and assembled a prototype box to hold this board, but this need not be a permanent solution (see Attachment #1). I drilled |
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Fri Jan 14 17:33:10 2022, Yehonathan, Update, BHD, AS4 resurrection
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{Yehonathan, Anchal}
Came this morning, the gluing of the magnets was 100% successful. Side blocks, counterweights were assembled. We suspend AS4 and adjust the roll
balance and the magnet height (attachments 1,2). OpLev was slightly realigned. |
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Wed Jan 19 14:41:23 2022, Koji, Update, BHD, Suspension Status
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Is this the correct status? Please directly update this entry.
LO1 [Glued] [Suspended] [Balanced] [Placed In Vacuum] [OSEM
Tuned] [Damped] |
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Wed Jan 19 16:22:48 2022, Anchal, Update, BHD, PR2 transmission calculation updated
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I have further updated my calculation. Please find the results in the attached pdf.
Following is the description of calculations done:
Arm cavity reflection:
Reflection fro arm cavity is calculated as simple FP cavity reflection formula while |
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Wed Jan 19 18:15:34 2022, Yehonathan, Update, BHD, AS1 resurrection
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Today I suspended AS1. Anchal helped me with the initial hanging of the optics. Attachments 1,2 show the roll balance and side magnet height. Attachment
3 shows the motion spectra.
The major peaks are at 668mHz, 821mHz, 985mHz. |