 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. |
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Wed Jan 19 21:39:22 2022, Tega, Update, SUS, Temporary watchdog
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After some work on the reference database file, we now have a template for temporary watchdog implementation for LO1 located here "/cvs/cds/caltech/target/c1susaux/C1_SUS-AUX_LO1.db".
Basically, what I have done is swap the EPICS asyn analog input readout for the COIL and OSEM to accessible medm channels, then write out watchdog
enable/disable to coil filter SW2 switch. Everything else in the file remains the same. I am worried about some of the conversions but the only way to |
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Thu Jan 20 00:26:50 2022, Koji, Update, SUS, Temporary watchdog
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As the new db is made for c1susaux, 1) it needs to be configured to be read by c1susaux 2) it requires restarting c1susaux 3) it needs to be recorded
by FB 4) and restartinbg FB.
(^-Maybe not super exact procedure but conceptually like this) |
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Thu Jan 20 01:48:02 2022, Koji, Update, BHD, PR2 transmission calculation updated
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IMC is not such lossy. IMC output is supposed to be ~1W.
The critical coupling condition is G_PRC = 1/T_PRM = 17.7. If we really have L_arm = 50ppm, we will be very close to the critical coupling. Maybe
we are OK if we have such condition as our testing time would be much longer in PRMI than PRFPMI at the first phase. If the arm loss turned out to be higher, |
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Thu Jan 20 12:10:51 2022, Yehonathan, Update, BHD, AS1 resurrection
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I was wondering whether I should take AS1 down to redo the wire clamping on the side blocks. I decided to take the OpLev spectrum again to be more certain.
Attachments 1,2,3 show 3 spectra taken at different times.
They all show the same peaks 744mHz, 810mHz, 1Hz. So I think something went wrong with yesterday's measurement. I will not take AS1 down |
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Thu Jan 20 16:42:55 2022, Paco, Update, BHD, AS4 OSEMs installation - part 2
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[Paco]
Turns out, the shifting was likely due to the table level. Because I didn't take care the first time to "zero" the level of the
table as I tuned the OSEMs, the installation was b o g u s. So today I took time to, |
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Thu Jan 20 17:21:21 2022, Tega, Update, SUS, Temporary watchdog
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Temp software watchdog now operational for LO1 and the remaining optics!
Koji helped me understand how to write to switches and we tried for a while to only turnoff the output switch of the filters instead of
the writing a zero that resets everything in the filter. |
 Thu Jan 20 17:34:07 2022, Koji, Update, BHD, V6-704/705 Mirror now @Downs
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The PR2 candidate V6-704/705 mirrors (Qty2) are now @Downs. Camille picked them up for the measurements.
To identify the mirrors, I labeled them (on the box) as M1 and M2. Also the HR side was checked to be the side pointed by an arrow mark on the
barrel. e.g. Attachment 1 shows the HR side up |
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Thu Jan 20 18:16:29 2022, Anchal, Update, BHD, AS4 set to trigger free swing test
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AS4 is set to go through a free swinging test at 10 pm tonight. We have used this script (Git/40m/scripts/SUS/InMatCalc/freeSwing.py)
reliably in the past so we expect no issues, it has a error catching block to restore all changes at the end of the test or if something goes wrong.
To access the test, on allegra, type: |
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Fri Jan 21 12:46:31 2022, Tega, Update, CDS, SUS screen debugging
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All done (almost)! I still have not sorted the issue of pitch and yaw gains growing together when modified using ramping time. Image of custom ADC and
DAC panel is attached.
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Fri Jan 21 14:51:00 2022, Koji, Update, BHD, V6-704/705 Mirror now @Downs
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Camille@Downs measured the surface of these M1 and M2 using Zygo.
Result of the ROC measurements:M1: ROC=2076m (convex)M2: ROC=2118m (convex) |
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Fri Jan 21 16:40:10 2022, Anchal, Update, BHD, AS4 Input Matrix Diagonalization performed.
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The free swinging test was successful. I ran the input matrix diagonalization code (/opt/rtcds/caltech/c1/Git/40m/scripts/SUS/InMAtCalc/sus_diagonalization.py)
on the AS4 free-swinging data collected last night. The logfile and results are stored in /opt/rtcds/caltech/c1/Git/40m/scripts/SUS/InMAtCalc/AS4
directory. Attachment 1 shows the power spectral density of the DOF basis data (POS, PIT, YAW, SIDE) before and after the diagonalization. Attachment 2 |
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Mon Jan 24 17:12:27 2022, rana, Update, BHD, AS4 Input Matrix Diagonalization performed.
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I think our suspension input matrix diagonalization is not so robust usually because we only choose
a inverting matrix which gives the best separation for a single suspension alignment.
i.e. we have seen in the past that adjusting the bias for the alignment makes the matrix inversion not work well. Sometime people turn OFF the |
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Mon Jan 24 17:58:21 2022, Yehonathan, Update, BHD, PR2 Suspension
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I picked up the PR2 mirrors (labeled M1, M2) from Anchel's table and took them to the cleanroom. By inspection, I spotted some dust particles on
M1. I wasn't able to remove them with clean air so I decided to use M2 which looked much cleaner. I wasn't able to discern any wedge angle on the
optic. I inserted the optic into a thin optic adapter. The optic is thicker than I expected so I use long screws for the mirror clamping. I expect that |
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Mon Jan 24 20:48:48 2022, Anchal, Update, BHD, AS4 Input Matrix Diagonalization performed.
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I agree. That's an interesting idea. But does that mean that there is an always working inverse matrix solution or that any solution will be vulnerable
to the alignment biases.
I think we can also calculate the matrix rotation required as a function of dc biases and do that rotation in the simulimk model. |
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Tue Jan 25 18:37:12 2022, TYehonathan, Update, BHD, PR2 Suspension
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PR2's side magnet height was adjusted and its roll was balanced (attachment 1,2). I verified that the OpLev beam is still aligned. The pitch was
balanced: First, using an iris for rough adjustment. Then, with the QPD. I locked the counterweight setscrew.
I turned off the HEPAs, damped PR2, and measured the QPD spectra (attachment 3). Major peaks are at 690mHz, 953mHz, and 1.05Hz. I screwed back |
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Mon Jan 31 10:39:19 2022, Jordan, Update, VAC, TP1 and Manual Gate Valve Removal
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Jordan, Chub
Today, Chub and I removed TP1 and the failed manual gate valve off of the pumping spool.
First, P2 needed to be vented in order to remove TP1. TP1 has a purge valve on the side of the pump which we slowly opened bringing the P2 volume |
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Tue Feb 1 20:16:09 2022, Tega, Update, BHD, PR2 candidate mirror analysis
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git repo: git@git.ligo.org:tega-edo/charmirrormap.git
The analysis code takes in a set of raw images, 10 in our case, for each mirror and calculates the zernike aberration coefficients for
each image, then takes their average. This average value is used to reconstruct the mirror height map. Finally, the residual error between the reconstructed |
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Thu Feb 3 10:25:59 2022, Jordan, Update, VAC, TP1 and Manual Gate Valve Install
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Jordan, Chub
Chub and I installed the new manual gate valve (Nor-Cal GVM-6002-CF-K79) and reinstalled TP1. The new gate valave was placed with the sealing
side towards the main 40m volume, then TP1 was installed on top and the foreline reattched to TP1. |
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Thu Feb 3 14:47:12 2022, Chub, Update, Electronics, new UPS in place
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Received the new 1100VA APC UPS today and placed it at the bottom of the valve rack. I'd connected the battery and plugged the unit into the
AC outlet, but did not turn it on due to the power outage this weekend. |
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Fri Feb 4 10:04:47 2022, Chub, Update, General, dish soap and clean scrub sponges!
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| Bought dish soap and scrub sponges today and placed them under the sink with the other dish supplies. |
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Mon Feb 7 09:00:26 2022, Paco, Update, General, Scheduled power outage recovery
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[Paco]
Started recovering from scheduled (Feb 05) power outage. Basically, time-reversing through this
list. |
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Mon Feb 7 15:32:48 2022, Yehonathan, Update, General, Y End laser controller
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I went to the Y end. The AUX laser was on Standby. I pushed the Standby button. The laser turned on and there was some green light. However, the controller
displayed the message "CABLE?" which according to the manual means that the laser head is powered but there is no control over the laser (e.g.
the control cable is disconnected). I turned off the controller and disconnected both the power and control cables. I put them back and turned the controller |
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Mon Feb 7 16:14:37 2022, Tega, Update, Computers, realtime system reboot problem
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I was looking into plotting temperature sensor data trend and why we currently do not have frame data written to file (on /frames) since Friday, and
noticed that the FE models were not running. So I spoke to Anchal about it and he mentioned that we are currently unable to ssh into the FE machines, therefore
we have been unable to start the models. I recalled the last time we enountered this problem Koji resolved it on Chiara, so I search the elog for Koji's |
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Mon Feb 7 16:53:02 2022, Koji, Update, General, Scheduled power outage recovery
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| I went to the X end and found it was warm. Turned out that not all the A/Cs were on. They were turned on now. |
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Wed Feb 9 11:56:24 2022, Anchal, Update, General, Bringing back CDS
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[Anchal, Paco]
Bringing back CDS took a lot of work yesterday. I'm gonna try to summarize the main points here.
mx_start_stop
For some reason, fb1 was not able to mount mx devices automatically on system boot. This was |
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Wed Feb 9 13:55:05 2022, Koji, Update, General, Bringing back CDS
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Great recovery work and cleaning of the rebooting process.
I'm just curious: Did you observe that the c1sus2 cards have different numbering order than the previous along with the power outage/cycling? |
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Wed Feb 9 16:43:35 2022, Paco, Update, General, Scheduled power outage recovery - Locking mode cleaner(s)
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[Paco, Anchal]
We went in and measured the power after the power splitting HWP at the PSL table. Almost right before the PSL shutter (which was closed),
when the PMC was locked we saw ~ 598 mW (!!)
Checking back on ESP300, it seems the channel was not enabled even though the right angle was punched |
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Thu Feb 10 15:41:00 2022, Anchal, Update, General, Scheduled power outage recovery - Locking mode cleaner(s)
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I found out that the ESP300 service needs to be run in root mode for it to be able to connect to the USB port of HWP motor controller. While doing this
change, I noticed that the channels hosted by c1psl might have a duplication conflict with some other channel hosting computer, because a lot of them show
the Warning: "Identical process variable names on multiple servers" which is not good. Someone should look into this conflict. |
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Thu Feb 10 17:57:48 2022, Anchal, Update, General, Scheduled power outage recovery - Locking mode cleaner(s)
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Something is wrong with the Video MUX. The system did not turn back on with full functionality. Even though we see the screens as they were before the
power shutdown, we have lost control on switching any of the videos. I went to check the wiki
page about Video MUX which told be we should be able to see the configuration screen on this link, but the page |
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Thu Feb 10 19:03:23 2022, Koji, Update, General, Scheduled power outage recovery - Locking mode cleaner(s)
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I came back to the 40m and started the investigation.
If I ping 192.168.113.92, it responds. But telnet (port 23) was rejected. I somehow tried ssh and it responds! I even could login to the host
using usual password. Here is the prompt. |
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Thu Feb 10 19:46:37 2022, Koji, Update, General, Scheduled power outage recovery - Locking mode cleaner(s)
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== Assign new IP address to c1sus2 ==
cf: [40m ELOG 16398] [40m
ELOG 16396] |
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Thu Feb 10 21:10:43 2022, Koji, Update, General, Video Mux setting reset
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Now the video matrix is responding correctly and the web interface shows up. (Attachment 1)
Also the video buttons respond as usual. I pushed Locking Template button to bring the setting back to nominal. (Attachment 2) |
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Thu Feb 10 21:51:02 2022, Koji, Update, CDS, [Solved] Huge random numbers flowing into ETMX/ETMY ASC PIT/YAW
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Huge random numbers are flowing into ETMX/ETMY ASC PIT/YAW. Because of this, I could not damp the ETMX/ETMY suspension at the beginning during the recovery
from rebooting. (Attachment 1)
By turning off the output of the ASC filters, the mirrors were successfully damped. |
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Fri Feb 11 10:56:38 2022, Anchal, Update, CDS, [Solved] Huge random numbers flowing into ETMX/ETMY ASC PIT/YAW
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Yeah, this is a known issue actually. We go to ASC screen and manually swich off all the outputs after every reboot. We haven't been able to find
a way to set default so that when the model comes online, these outputs remain switched off. We should find a way for this.
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Fri Feb 11 11:17:00 2022, Anchal, Update, General, Scheduled power outage recovery
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I found that two computers are not powering up in the control room, Ottavia and Allegra. Allegra was important for us as it had the current version of
LIGO CDS workstation installed on, providing us with options to use latest packages written by LIGO CDS team. I think the power issue should be resolvable
if someone opens it and knows what thye are doing. Do we have any way of getting fuse repairs on such computers? Both these computers are Dell XPS 420. |
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Fri Feb 11 12:22:19 2022, rana, Update, CDS, [Solved] Huge random numbers flowing into ETMX/ETMY ASC PIT/YAW
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you can hand edit the autoBurt file which the FE uses to set the values after boot up. Just
make a python script that amends all of the OFF or ZERO that are needed to make things safe. This would be the autoBurt snap used on boot up only, and
not the hourly snaps. |
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Fri Feb 11 16:09:11 2022, Anchal, Update, General, Scheduled power outage recovery - Input power increased
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We increased the input power to IMC by replacing the 98% transmission BS by a 10% transmission BS on the detection table (reverse of what mentioned in
40m/16408 see attachment 8-9). We then realigned the BS so that MC RFPD is centered. Then we realigned two steering mirrors to get the beam centered on |
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Fri Feb 11 17:07:19 2022, Anchal, Update, CDS, [Solved] Huge random numbers flowing into ETMX/ETMY ASC PIT/YAW
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The autoBurt file for FE already has the C1:ASC-ETMX_PIT_SW2 (and other channels for ETMY, ITMX, ITMY, BS and for YAW) present, and I checked the last
snapshot file from Feb 7th, 2022, which has 0 for these channels. So I'm not sure why when FE boots up, it does not follow the switch configuration.
Fr safety, I changed all the gains of these filter modules, named like C1:ASC-XXXX_YYY_GAIN (where XXXX is ETMX, ETMY, ITMX, ITMY, or BS , and YYY is PIT |
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Mon Feb 14 18:31:50 2022, Paco, Update, General, Scheduled power outage recovery - IMC recovery progress
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[Paco, Anchal, Tega]
We have been realigning the IMC as of last Friday (02/11). Today we made some significant progress (still at high input power), but the IMC autolocker
is unable to engage a stable mode lock. We have made some changes to reach this point, including re-centering of the MC1 REFL beam on the ccd, centering |
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Mon Feb 14 21:03:25 2022, Koji, Update, General, Scheduled power outage recovery
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I opened the boxes. Allegra has obvious vent of at least 4 caps. And the power supply did not respond even a paper clip test was performed. https://www.silverstonetek.com/downloads/QA/PSU/PSU-Paper%20Clip-EN.pdf
(Paper Clip Test)
=> The mother board and the PSU are dead. |
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Tue Feb 15 19:32:50 2022, Koji, Update, General, Scheduled power outage recovery - IMC recovery progress
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Reduced the IMC power to 100mW
Setup: The power meter was placed right before the final aperture (Attachment 1)
Before the adjustment: Initial position of the HWP was 37.29deg and the input power was 987mW (Attachments 2/3) |
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Tue Feb 15 19:40:02 2022, Koji, Update, General, IMC locking
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IMC is locking now. There was nothing wrong: just a careful alignment + proper gain adj
=== Primary Alignment ===
- I used WFS error signals as the indicator of the PDH error signals. Checked C1:IOO-WFS1_(I/Q)n_ERR and ended up C1:IOO-WFS1_I4_ERR |
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Wed Feb 16 15:19:41 2022, Anchal, Update, General, Reconfigured MC reflection path for low power
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I reconfigured the MC reflection path for low power. This meant the following changes:
Replaced the 10% reflection BS by 98% reflection beam splitter
Realigned the BS angle to get maximum on C1:IOO-MC_RFPD_DCMON
when cavity is unlocked.
Then realigned the steering mirrors for WFS1 and WFS2.
I tried to align the light for MC reflection CCD |
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Tue Feb 22 18:47:51 2022, Ian MacMillan, Update, SUS, ETMY SUS Electronics Replacement
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[Ian, Koji]
In preparation for the replacement of the suspension electronics that control the ETMY, I took measurments of the system excluding the CDS System.
I took transfer functions from the input to the coil drivers to the output of the OSEMs for each sensor: UL, UR, LL, LR, and SIDE. These graphs are |
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Wed Feb 23 15:08:57 2022, Anchal, Update, General, Removed extra beamsplitter in MC WFS path
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| As discussed in the meeting, I removed the extra beam splitter that dumps most of the beam going towards WFS photodiodes. This beam splitter needs to be placed back in position before increasing the input power to IMC at nominal level. This is to get sufficient light on the WFS photodiodes so that we can keep IMC locked for more than 3 days. Currently IMC is unlocked |
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Thu Feb 24 14:32:57 2022, Anchal, Update, General, MC RFPD DCMON channel got stuck to 0
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I found a peculiar issue today. The C1:IOO-MC_RFPD_DCMON remains constantly 0. I wonder if the RFPF output is being read properly. I opened the table
and used an oscilloscope to confirm that the DC output from the MC REFL photodiode is coming consistently but our EPICs channel is not reading it. I tried
restarting the modbusIOC service but that did not affect anything. I power cycled the acromag chassis while keeping the modbusIOC service off, and then |
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Thu Feb 24 18:05:58 2022, Yehonathan, Update, BHD, Re-susspension of AS1
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{Yehonathan, Anchal, Paco}
Yesterday, Anchal and Paco removed AS1 from the vacuum chamber and moved it into the cleanroom. The suspension wires were cut and the AS1 optic
was put on the table. |
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Thu Feb 24 19:26:32 2022, Anchal, Update, General, IMC Locking
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I think I have aligned the cavity, including MC1 such that we are seeing flashing of fundamental mode and significant transmission sum value as well.However,
I'm unable to catch lock following Koji's method in 40m/16673. Autolocker could not
catch lock either. Maybe I am doing something wrong, I'll pickup again tomorrow, hopefully the cavity won't drift too much in this time. |