Displaying reports 721-740 of 77255.Go to page Start 33 34 35 36 37 38 39 40 41 End
Reports until 05:56, Wednesday 03 July 2024
H1 CDS (OpsInfo, SUS)
oli.patane@LIGO.ORG - posted 05:56, Wednesday 03 July 2024 - last comment - 10:06, Wednesday 03 July 2024(78823)
H1IOPSUSH2A error

Erik, Oli

Got a call from IFO_NOTIFY - there was ground motion that caused the HAM2 ISI (11:56:26 UTC), SEI SW (11:56:28 UTC), and Hepi (11:56:31 UTC) watchdogs to trip. Along with/causing this (or by coincidence?) is an error with H1IOPSUSH2A, and the GDS screen was showing 'LTDS' in red. The front end needs to be either power-cycled, or possibly a card replaced, so Erik will be heading into site in a bit to see about fixing the errors. I manualed ISC_LOCK into IDLE, and either me or the DAY operator will get the ifo back up once the CDS issue is resolved.

Images attached to this report
Comments related to this report
erik.vonreis@LIGO.ORG - 07:46, Wednesday 03 July 2024 (78825)

[Erik, Richard]

The third 18-bit DAC (DAC 2) on h1sush2a failed.  It no longer appeared on the PCI Bus.

Richard replaced the DAC and we restarted the front end.

I originally misdiagnosed the problem as a bad timing card, since the DAC failure caused cascading timing errors on other cards, so we also replaced the timing card with serial number S2101122

erik.vonreis@LIGO.ORG - 09:11, Wednesday 03 July 2024 (78830)

Serial number of the failed DAC is:

101208-06

jim.warner@LIGO.ORG - 10:06, Wednesday 03 July 2024 (78834)

The ground motion plotted here is very unlikely to have caused a seismic watchdog trip. The ham2 trip was almost certainly caused by the sush2a failure.

H1 General (CDS, PSL)
ryan.crouch@LIGO.ORG - posted 01:01, Wednesday 03 July 2024 (78817)
OPS Tuesday EVE shift summary

TITLE: 07/03 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Oli
SHIFT SUMMARY: Spent most of the shift down from the high winds. Currently relocking at DHARD_WFS

Lock 1: Alignments and PRC1 bypass
Lock2: Windy, 42mph Gusts, 33mph 5min avg
General:

LOG:                                                                                                                                  

Start Time System Name Location Lazer_Haz Task Time End
16:08 SAF LVEA LVEA YES LVEA IS LASER HAZARD 10:08
00:58 pem Robert LVEA Y Move a camera to a different view port 01:07
Images attached to this report
H1 General
ryan.crouch@LIGO.ORG - posted 00:02, Wednesday 03 July 2024 (78822)
PRC1/DRMI lockloss trending

I did some trending of the some LSC and ASC signals during the 3 DRMI locklosses from earlier. Here we have the 1st, 2nd, and 3rd lockloss and an example of a good lock from the last long lock before maintenance. I can see that the LSC INMON signals looked maybe twice as strong now compared to before. ASC_PRC1_YAW looks especially different than it did last night, ASC_PRC1_PIT_OUTMON seems to have changed sign to negative from positive. The PRM OSEMS don't look particularly different, a good lock from yesterday, DRMI LL from today.

Images attached to this report
H1 General (Lockloss)
ryan.crouch@LIGO.ORG - posted 19:55, Tuesday 02 July 2024 - last comment - 20:07, Tuesday 02 July 2024(78820)
02:53 UTC lockloss

https://ldas-jobs.ligo-wa.caltech.edu/~lockloss/index.cgi?event=1404010437

The wind has picked up a decent amount since the last lock aquisition so ALS will most likely have trouble staying locked. Gust are  >= 40 mph

Comments related to this report
ryan.crouch@LIGO.ORG - 20:07, Tuesday 02 July 2024 (78821)

From the windy.com forecast, the wind storms at its peak right now and will start to calm down around 07-08UTC / 23-01 PST.

H1 PSL (ISC)
jenne.driggers@LIGO.ORG - posted 17:47, Tuesday 02 July 2024 - last comment - 09:23, Wednesday 03 July 2024(78816)
Alignment of IMC, ISCT1, IFO in response to PMC swap today. PSL -> fiber distribution needs alignment tweak still

[Jenne, Sheila, Tony]

The PMC swap work earlier today (alog 78813) resulted in a slight shift of the alignment of the beams coming out of the PMC. 

After Ryan and Jason finished getting the ref cav aligned and locked, the IMC alignment looked poor.  I was able to mostly get it back by hand-moving the sliders for the PZT at the PSL periscope.  I touched MC2 a tiny bit, and then the IMC was able to lock.  I lowered the IMC WFS thresholds (eg  H1:IMC-IMC_TRIGGER_THRESH_ON and _OFF) so that it would take over alignment.  Once the alignment was pretty nearly finished, I used the IMC_LOCK guardian to offload the IMC WFS.  I saved in the safe.snap file for IMCASC the PZT offsets that had been offloaded.

In parallel, Sheila worked on the ALS system.  The initial goal was to check and adjust the PSL pickoff portion of the COMM beatnote, however Sheila noted that the ALS Xarm couldn't lock, since the end station PLLs weren't getting enough light from the PSL.  Sheila lowered the threshold of H1:ALS-C_FIBR_INTERNAL_DC_LOW from 0.05mW to 0.02mW, and also lowered H1:ALS-X_FIBR_LOCK_FIBER_LAUNCHLIM from 0.3 to 0.2 .  After this, the ALS Xarm was able to lock, and Sheila went out to ISCT1 and got the COMM beatnote up to about -1 dBm.  We then convinced ALS Yarm to lock after lowering H1:ALS-Y_FIBR_LOCK_FIBER_LAUNCHLIM from 0.3 to 0.2.  Sheila also changed H1:SQZ-FIBR_TRANS_DC_LOW from 0.2 to 0.05 mW and H1:SQZ-FIBR_LOCK_FIBER_LAUNCHLIM from 0.3 to 0.15, after which she was able to get the squeezer all locked up, so it seems like the squeezer should work fine when we get to that point this evening. 

Attached is the SDF screenshot that Sheila took for the squeezer thresholds.  The other ALS thresholds were also accepted in their safe.snap files.  All of these will need to be accepted in the Observe.snap SDFs in order for us to get to Observing. 

I helped the initial alignment a bit, by moving IM4 and PR2 a bit for the Input_align, and then moving PRM for PRC_align.  After that, initial alignment seemed to finish on its own. 

Particularly since we have been having ALS beatnote issues lately (see alog 78806 for some notes), we will almost certainly want to go into the PSL tomorrow to tweak the alignment of the optic that directs the beam to the fiber for the fiber distribution box, so that we can undo all these threshold changes.  Jason makes the good point that the longest part of doing that tweak will be garbing up for going into the PSL, so it should be quite easy.

Images attached to this report
Comments related to this report
jenne.driggers@LIGO.ORG - 18:09, Tuesday 02 July 2024 (78818)

[RyanC, Jenne]

We lost DRMI lock 3 times in a row at the same place (without losing ALS lock), so it seemed like we had some DRMI alignment issues.  It turns out that we are barely on POP A QPD, which is not at all the same place that the offsets are set to.  For now, it seems to work well to take PRC1 out of the loop.  We'll need to take a look at it in the morning though.

jenne.driggers@LIGO.ORG - 18:17, Tuesday 02 July 2024 (78819)

Our 2W power recycling gain, before full IFO alignment is complete, is already above 60.  Usually in this state it is as high as 58, so this is unusually good.

We are very near the edge of IM4 trans, so dividing by a too-small number, which then makes our PRG artificially high.  That makes more sense, particularly since the arm transmissions aren't higher than usual.

camilla.compton@LIGO.ORG - 09:23, Wednesday 03 July 2024 (78828)

After Tony and I brought alignment sliders from HAM2 WD trip back 78823, the IMC locked and we moved IM3 (alot) to center the beam back on IM4 trans. Plot attached, IM3 sliders moved 450urad in Yaw, 40urad in Pitch. Jaosn is currently in the PSL so temperature changes may mean we need to readjust again later. May need to pico once we're at full lock with good range.

Usually with the IFO down and IMC locked, we have 1.91 on the IM4 trans nsum and centered beam (0.04 P, 0 in Y), plot. After the PSL alignment change yesterday we had 1.69 on the IM4 trans nsum and the beam mis-centered, mainly in yaw (0.3 P, 1 in Y) plot. See overall change here.

Images attached to this comment
H1 PSL (PSL)
ryan.crouch@LIGO.ORG - posted 17:28, Tuesday 02 July 2024 (78815)
Rotation Stage Calibration

After we finished up IA I ran the Rotation stage calibration following alog76890 and ran the python script to generate PSL_rotStageCalib_02July2024.txt (attached) and I accepted the new calibration values in SDF.

 

  Power in (W) D B (Minimum power angle) C (Minimum power)
Old Values 99.253 1.990 -24.830 0.000
New Values 102.488 1.990 -24.801

0.000

Images attached to this report
Non-image files attached to this report
H1 General
anthony.sanchez@LIGO.ORG - posted 16:37, Tuesday 02 July 2024 (78812)
Tuesday Maintance Ops Shift End

TITLE: 07/02 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:

Nitrogen truck came at 15:40 UTC
15:50 UTC  Internet connection to outside networks went down.
16:04 UTC Internet was restored.

Water truck arrived.

PSL team Installed PMC in the PSL enclosure.

Concrete truck left at 19:45 UTC

Ryan S. and Jason come out of the PSL ~ 22:40 UTC.
IMC , PMC and the Rotation Stage Calibration  and alignments must be.
Jenne and Sheila took care of the IMC & PMC and took the IFO to Locking Green arms to do so.
While they were working on X arm I requested Y arm to Increase Flashes to save some time.

To Do before Locking:
We have since started an Initial Alignment and we must wait for that to finish before the Rotation stage Calibration can be done because the IMC needs to be unlocked to make that happen.
To do the Rotation Stage Calibration follow the Bullet points found here:
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=76890

 

LOG:

Start Time System Name Location Lazer_Haz Task Time End
16:08 SAF LVEA LVEA YES LVEA IS LASER HAZARD 10:08
14:59 FAC Karen, Nelly EY N Technical Cleaning 15:40
15:00 FAC Kim EX N Technical Cleaning 16:01
15:05 VAC Gerardo, Isiah LVEA Yes Function test on 3 turbo pumps WP11951 17:40
15:06 PSL Jason, Ryan S PSL YES PSL work 22:39
15:08 eE Fil, Mark MSR No Replacing Server Rack Batteries. 15:41
15:16 FAC Christina & Janos LVEA YES Looking for Vacuum parts 15:39
15:17 PCAL Dripta, Francisco EX YES End X measurement & Beam Spot Move 17:41
15:20 FAC Tyler & Contractors HVAC/VPW, EX&Y, MXY  VEAs No Replacement of Heat Pump 21:20
15:27 FAC Chris Pest LVEA, MS, ES YES Pest control 16:41
15:39 FAC Christina EY, FTCE, EX No Looking for cart 16:24
15:41 EE Marc Fil EX CSR N LD32 Channels 16:11
15:43 FAC Mitchell LVEA YES looking for 3FO parts 15:57
15:48 FAC Karen & Nelly HAM Shaq No Technical Cleaning 16:29
15:58 TCS Camilla LVEA Yes Looking for parts 16:30
16:14 SEI & FAC Jim & Mitchell EX & EY N Checking Dust pumps & Wind Fence. 16:48
16:16 PEM Robert & Co LVEA & Roof YES Checking Sensors 18:12
16:17 EE Fil & Marc LVEA SQZT0 YES Swapping out the Beat note Box 16:33
16:30 ASL/FIT Camilla INSIDE X arm N Running the Inside of the X arm to check the ALS fiber. 17:31
16:31 VAC Janos & Jordan Mid X& Y N Taking measurements 17:12
16:42 FAC Chris LVEA MY & EY Yes Various Famis Tasks around the LVEA 18:25
16:49 EE Fernando LVEA HighBay Yes taking pictures. 17:29
16:53 FAC Nelly, Kim, Karen LVEA Yes Technical Cleaning 18:09
17:15 SAFETY Richard EX N Picking Up Camilla 17:42
17:42 PCAL Emanuel & Francisco PCAL LAB YES PCAL measurements. 18:12
18:19 VAC Janos EY N Vacuum Measurments 19:02
18:44 PSL Jenne PSL Enclosure YES Helping the PSL team 20:13
18:52 CDS Erik & Marc EX N Swapping cables 19:17
21:24 Inventory Christina & Mitchell LVEA Yes Searching for equipment 21:34
21:57 PMC Shiela LVEA ISCT1 Yes PMC alignmnet adjustment 22:57
H1 PSL
jason.oberling@LIGO.ORG - posted 16:30, Tuesday 02 July 2024 (78813)
H1 PSL PMC Swap (WP 11947)

J. Oberling, R. Short, J. Driggers

Summary

I'll get a more detailed alog in tomorrow, right now I am exhausted so a summary it is.

We swaped our in-service PMC, SN 007, with our spare, SN 004, to correct what appeared to be a very slow build up of loss in the PMC (time scale of several months).  The swap itself went well with no issues (some very slight yaw alignment required to lock the new PMC), but we ran into a problem upon PMC recovery.  The new PMC was presenting the exact same issue as the old PMC, in that we were measuring a high visibility but a markedly lower power throughput.  We could find no cause for this: control loop looked fine, PMC optics were clean (had 1 optic that had to be cleaned pre-install, but all looked great afterwards), our locked voltage on the locking PD was well above the PD's dark voltage.  After much investigation and deliberation, we decided to continue recovering the new PMC so we could get the IFO back up and running.  We carefully upped the power incident on the PMC in stages until we had reached full power (measured with our water cooled power meter at 128.1 W).  At this point we were measuring a visibility of 89.6% and a power throughput of only 82% (105.1 W transmitted with the ISS OFF).  Our locking PD locked voltage is roughly -0.061 V and its unlocked voltage is roughly -0.453 V; the dark voltage on this PD is -0.015 V.  The UGF is ~1.1 kHz with a phase margin of ~53.9 deg.

We then found we could not lock the FSS RefCav, and upon inspecting that path found the alignment to be off.  So the PMC's mounting scheme did not exactly maintain the post-PMC alignment.  Already being almost 3 hours past the end of maintenance we did a quick recovery of the FSS while Jenne and Sheila worked to recover the IMC and the beam alignment on ISCT1 (since the post-PMC alignment shifted slightly this changed the beam alignment into the IMC and on ISCT1, which are both many meters downstream of the PMC).  The FSS will have to be tuned up next week, as we were only able to get a RefCav TPD of just over 0.7 V.  We forgot to check the ALS/SQZ pickoff before leaving the enclosure, but found it was reading too low once we were out; as a quick fix Sheila lowered the thresholds for locking both ALS and SQZ, and I will go back into the enclosure in the morning to correct the beam alignment into the pickoff.

There is still optimization to do on this new PMC, but it's up and running for now.  We will watch the PMC Refl signal over the next week to see if it exhibits the same behavior; if it does then the problem likely lies elsewhere, we'll see what happens over the next week.  Regardless, we will have to go into the enclosure next week to do some PMC optimization, re-tune the FSS path, and see if we can figure out what the root issue here is.  More to come (including a more detailed alog of today's work).

 

H1 General
ryan.crouch@LIGO.ORG - posted 16:00, Tuesday 02 July 2024 (78811)
OPS Tuesday EVE shift start

TITLE: 07/02 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 9mph Gusts, 5mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.06 μm/s
QUICK SUMMARY:

H1 CAL
francisco.llamas@LIGO.ORG - posted 15:10, Tuesday 02 July 2024 - last comment - 11:19, Tuesday 09 July 2024(78810)
Pcal XY comparison investigation - seventh movement, inner beam centered

DriptaB, FranciscoL

After one week of having the inner beam up on the Rx sensor (alog 78807), on July 2, we moved the beam from up to center.

The last page of EndStationLog.pdf lists the voltage values after each significant step of procedure T2400163. The steps represent writing down a voltage value after a particular change to the beam position. Some highlights from the recorded values:

The 'Initial' measurement is *equal* to the last voltage measurement from the previous movement, done on June 25 (alog 78807). The initial and final voltage measurement during today procedure did not change.

Images attached to this report
Non-image files attached to this report
Comments related to this report
francisco.llamas@LIGO.ORG - 11:19, Tuesday 09 July 2024 (78961)

Title should be "eight", not "seventh". This movement was a week after the seventh move, which was moved up (alog 78807).

H1 CAL
francisco.llamas@LIGO.ORG - posted 14:53, Tuesday 02 July 2024 (78807)
Pcal XY comparison investigation - seventh movement, inner beam up

RickS, FranciscoL

After one week of having the inner beam centered on the Rx sensor (alog 78514), on June 25, we moved the beam from center to up.

The last page of EndStationLog.pdf shows a diagram of the movements that have been done and, on dashed lines, the move that were left to do. The previous to last page on file lists the voltage values after each significant step of procedure T2400163. The steps represent writing down a voltage value after a particular change to the beam position. Some highlights from the recorded values.

The 'Initial' measurement changed by 11% from the last voltage measurement from the previous movement, done on June 18 (alog 78514). The initial and final voltage measurement during today procedure changed by 0.03%.

Images attached to this report
Non-image files attached to this report
LHO VE (VE)
gerardo.moreno@LIGO.ORG - posted 14:24, Tuesday 02 July 2024 (78808)
Corner Station FAMIS Task for Turbo Pumps

(Isaiah V., Gerardo M.)

Functionality test for the corner station turbo pumps, see notes below:

Output mode cleaner tube turbo station;
Scroll pump hours: 5908.3
Turbo pump hours: 5970
Crash bearing life is at 100%

X beam manifold turbo station;
Scroll pump hours: 1950.8
Turbo pump hours: 1955
Crash bearing life is at 100%

Y beam manifold turbo station;
Scroll pump hours: 2283.6
Turbo pump hours: 956
Crash bearing life is at 100%

Note for the output mode cleaner tube system, the scroll pump is making a little of extra noise when active, noise comes and it goes, the scroll pump did not made that noise during last FAMIS task.

FAMIS tasks 23532, 23604 and 23652.

H1 CAL
francisco.llamas@LIGO.ORG - posted 14:19, Tuesday 02 July 2024 (78514)
Pcal XY comparison investigation - sixth movement, inner beam centered

TonyS, FranciscoL, [Remote: RickS]

After one week of having the inner beam left by 5mm on the Rx sensor (alog 78373), on June 18, we moved the beam from left to center.

It is very important to note that this procedure had a different order than the movements done previously. The purpose of the procedure - move the inner beam 5 mm to investigate sources of systematic uncertainties on the pcal system - is not affected by this change. The intention of changing the steps of the procedure is to see more clearly any unexpected changes introduced by moving the beam, especially in the optical efficiency.

For the previous movements, the target would always remain in the Rx_PS. During this procedure, the outer beam is blocked before placing the target.

AlignedTarget.jpg shows the alignment with the beam height gauge. The file EndStationLog.pdf lists the voltage values after each significant step of procedure T2400163. The steps represent writing down a voltage value after a particular change to the beam position. Some highlights from the recorded values.

The 'Initial' measurement is *equal* to the last voltage measurement from the previous movement, done on June 11 (alog 78373). The initial and final voltage measurement during today procedure changed by 0.17%.

Images attached to this report
Non-image files attached to this report
H1 ISC
sheila.dwyer@LIGO.ORG - posted 12:10, Tuesday 02 July 2024 (78806)
some signals related to ALS beatnotes

Camilla, Sheila

We looked at some signals related to the ALS X beatnote, relating to the problems described in 78703 and 78691

This morning the PSL is down so there is no light coming out of the X end or Y end fiber.  For the Y arm, the beatnote PD gets about 0.2mW from the fiber; the X arm beatnote PD doesn't show a noticable step down when the PSL went offline, indicating that there is much less light coming from the fiber reaching the X beatnote PD than the Y.   This has been the case at least since last Novemeber, when the PLL seemed to be working fine. 

The total power on the two beatnote PDs are similar, both just over 2mW. When we aren't having these temperature dependent changes in the X beatnote, the two beatnotes have similar sizes according to H1:ALS-X_FIBR_A_DEMOD_RFMON.  As long as the amplification at the two end stations are the same, this means that the beatnote alignment and mode matching at end X must be better than at EY, to get the same beatnote strength with much less light from the PSL.

Without light from the PSL, the ALS X beatnote noise floor is -32dBm, ALS Y beatnote noise floor is -41dBm.  This means that when TJ saw an X beatnote of of around -30dBm, 78745 , there was effectively no beatnote.  Camilla and I toggled the noise eater for both lasers, shown in the third attachment here.  The X laser has a larger increase in noise than the Y laser, but both beatnotes returned to their previous values after we turned the noise eaters back on.

The last attachment shows a trend of the beatnote strengths over the last few weeks.  Although the problem had come and gone a few times in the past, it doens't seem to be resolving itself now.

Images attached to this report
H1 CDS (CDS, VE)
patrick.thomas@LIGO.ORG - posted 12:04, Tuesday 02 July 2024 (78805)
Updated PLC code on h0vacmr for MKS 937 gauge controller calibration
Closes WP 11957.

Gerardo M., Patrick T.

From the WP:
Update and restart the PLC code on h0vacmr to repurpose the voltage and torr channels from the IP 8 gamma ion pump controller for the readout of a MKS 937 gauge controller. The channel names will remain the same, but the value of the pressure in torr will use a different calibration. This will take the MR CDS vacuum system down for the duration of the work. No DAQ restart should be needed.

This has been completed. The channel reading the MKS 937 is H0:VAC-MR_IP8_VI168_PRESS_TORR. There were a couple of issues generating the TwinCAT 3 solution from the updated powershell script. The first was an error that I did not completely catch, but did not repeat itself on subsequent runs. Twice when I ran it I got a message that the computer was low on memory, and I restarted the computer each time in response. Everything appears to be running now. The code is using git commit b977513795e0827c974ebab238a1cef219ad9840.
H1 SUS (ISC)
jim.warner@LIGO.ORG - posted 11:06, Tuesday 02 July 2024 - last comment - 11:11, Tuesday 02 July 2024(78803)
SRM M1 Lock boost tested, seem good

Follow up to the previous SRM M1 boost test, I tested the new boost yesterday, druing commissioning with the IFO in NLN. Seems like it works pretty good, I have added it to the ISC_DRMI guardian. Attached asds were taken yesterday, the refs are with the boost on, the live traces are with the boost off. Top plot are SRCL and SRM M3 drives, they are both reduced up to almost 10x around 50mhz, with very little gain peaking around .25 hz. I think the extra high frequency SRCL noise is from a measurement RobertS was doing. Bottom plot are the OAF SRCL length using the ISI gs13 suspoint motions, showing the table motions were very similar between the two measurements.  Hopefully this will help with staying locked during earthquakes and other low frequency motion.

Images attached to this report
Comments related to this report
jim.warner@LIGO.ORG - 11:11, Tuesday 02 July 2024 (78804)ISC

I added FM5 to the list of filter modules getting turned on at line 1278 in the ISC_DRMI guardian. If we have problems with locking DRMI, reverting this change will just require removing FM5 from this list. There will also be an Observe sdf diff created by this that will have to be accepted.

H1 ISC
jennifer.wright@LIGO.ORG - posted 10:54, Monday 01 July 2024 - last comment - 14:33, Tuesday 02 July 2024(78776)
Improving f_CC with SRM moves

Sheila, Jennie W

We lost some range with the hot OM2 so we thought to see if we could move SRM and raise the coupled cavity pole to regain this range as we did before in this entry.

Took 5 minutes no squeeze time.

Opened POP beam diverter to monitor POPAIR

Following the procedure in this entry we opened the SRC1 ASC loops by turning off input and offsets simultaneously after changing ramp to 0.1s.

Set the ramp to 10s, turn gain to 0, clear history, gain back to 4.

Then we started to move SRM alignment sliders.

The starting alignment sliders are here.

started yaw steps down on SRM, wrong way as f_cc avg went down, changed to up in  yaw, then noticed POPAIR_RF18 was going down so switched to pitch steps down. Found a poitn at which it no longer chnaged fcc, went back to maximum found for f_cc. The trends can be seen here where the first vertical cursor is when we opened the beam diverter and the second is when we thought we had the highest coupled cavity pole (middle bottom trace). So we put the SRM sliders to their values for this time after finishing.

I then changed offsets in SRC1 ASC to -0.0417 for ASC-SRC1_P_OFFSET and 0.0977 for ASC-SRC1_Y_OFFSET but didn't turn them on while we grabbed 5 minutes no squeeze time.

17:05:30 UTC closed loops and switched on new offsets.

Sheila used the second period of no squeeze time to plot the how the range compares to June 24th when we had a cold OM2. This plot shows the DARM comparison on the top plot (Yellow is cold OM2, blue is hot OM2) and the range difference on the bottom. This plot shows the cumulative range comparison on the top (yellow is cold OM2, blue is hot OM2) with the same difference in range plotted on the bottom. From the bottom plot it looks like with hot OM2 we gain range between 25 and 40Hz, don't gain between 40 and 90 Hz and lose range for hot OM2 above this point.


So summary is, we didn't completely recover the range by raising the coupled cavity pole. Hot OM2 is good for low frequency range but not for high frequency. We still need to do some PSAMS tuning today so this might regain us range at higher frequencies.

Images attached to this report
Comments related to this report
jennifer.wright@LIGO.ORG - 11:23, Monday 01 July 2024 (78779)ISC

I changed the values (ASC_AS72_P and ASC_AS72_Y) in line 551 and 552 of lscparams.py to match the new offsets and reloaded ISC_LOCK guardian.

Then I accepted these offset values in sdf after changing the ramps back to their setpoint which was 5s.

Images attached to this comment
sheila.dwyer@LIGO.ORG - 14:33, Tuesday 02 July 2024 (78809)

The no sqz time for reference:

With OM2 hot, and SRM alignment adjusted as Jennie described above, we took no sqz time from 16:58- 17:05 UTC on July 1st.

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