aLIGO LHO Logbook

H1 General - Ops EVE Midshift Status

oli.patane@ligo.org — Wed, 15 Oct 2025 20:25:02 -0700

Author: oli.patane@ligo.org

Report ID: 87500

Currrently Observing at 155 Mpc and have been Locked for almost 13.5 hours. We had a 6.3 earthquake from the Drake Passage roll through a bit ago - we had to go to earthquake mode and I dropped Observing to go to ASC Hi Gains, but we rode the earthquake out easily (it also didn't hit us as bad as expected - see three). We've been back in Observing for about 15 minutes now.

Images attached to this report

H1 General - OPS Wednesday DAY shift summary

ryan.crouch@ligo.org — Wed, 15 Oct 2025 16:31:49 -0700

Author: ryan.crouch@ligo.org

Report ID: 87492

TITLE: 10/15 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: We stayed locked the whole shift, over 9.5 hours now.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:36	FAC	Randy	Yarm	N	Beamtube inspection	18:40
19:47	FAC	Randy	Yarm	N	Beamtube inspection	21:49
19:55	PSL	Keita	Optics lab	N	ISS array, Laser Safe	Ongoing
20:13	PSL	Jennie	Optics lab	N	Join Keita	20:57
21:19	PSL	Rahul	Optics lab	N	Join Keita	Ongoing

18:48 - 18:57 UTC We dropped Observing to input some values and load some GRDs in relation to the beam spot, so the next lock aquisition should bring us back to our old spot. alog87495

H1 General - Ops EVE Shift Start

oli.patane@ligo.org — Wed, 15 Oct 2025 16:10:38 -0700

Author: oli.patane@ligo.org

Report ID: 87499

TITLE: 10/15 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 9mph Gusts, 5mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.13 μm/s
QUICK SUMMARY:

Observing at 155 Mpc and have been Locked for over 9 hours. Everything looking good.

LHO FMCS - Cracked Beam Tube Enclosure

tyler.guidry@ligo.org — Wed, 15 Oct 2025 14:39:20 -0700

Author: tyler.guidry@ligo.org

Report ID: 87498

Following our influx of bees, M. Landry ordered an interior inspection of each beam tube enclosure (BTE) interior to document potential areas of ingress. R. Thompson with Apollo Mech is presently tasked with this inspection. During inspection of the X1 enclosure, roughly 5 sections -X of the X arm overpass, Randy observed cracking at the base of the interior of the enclosure. After further investigation he found 4-5 cracks running parallel of one another across the entire section at roughly the 10 & 2 o'clock positions. I was called to come give this section a second look. The cracks were also immediately concerning to me. The first thing I wanted to better understand was the interior width to assess if the section was shifting. With Randy's help, I measured the interior spans of each end of the neighboring tube sections (4 measurements) as well as an additional 4 of the same spans of the tube sections on display outside of the LExC. On average, these spans measure 151" +/- .25". The section in question measures 154" at each end. Moreover, during installation Fred Raab has informed us that grouting was done on the BTE interiors to mitigate a "walking" effect that was causing misalignment between sections. This grouting has clearly separated from the BTE interior which confirms that there is in fact splaying of this section. The current short term "fix" implemented by FAC and VAC has been the erection of scaffolding topped with planking across the 10' area of beam tube at risk of falling debris. This should act as makeshift roof. For the long term, R. McCarthy is currently consulting with structural engineers whom we hope can help us work up a solution to prevent further splaying. Contained in the photos attached are measurements with appropriate labeling of each section (number counted from second door on X1 traveling -X), as well as a "+X" or "-X" which simply denotes if the measurement is on the +X or -X end of the tube section, photos illustrating the separation of the BTE interior from the as-installed BTE grouting, the scaffolding presently in place, the cracking at the footing/mid sections, and a LIGO Yelp review written in welders soapstone (circa ~96') near the splayed tube section. C. Soike, E. Otterman, T. Guidry, G. Moreno, T. Sadecki, J. Vanosky, R. McCarthy

Images attached to this report

X1 SEI - SPI Optomechanics: All 4x IXM Optics Mounts have been converted to Picomotor Actuated Mounts

jeffrey.kissel@ligo.org — Wed, 15 Oct 2025 12:40:23 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 87497

J. Kissel, M. Pirello There are four pico-motor actuated mirrors in the HAM2-3 ISI SPI Pathfinder (or, generically HAM2 = ISI"J" and HAM3= ISI"K"), M_M1, M_C1, M_B4, and M_M2 (see page 3 of D2400108). Those optics have the following mounts: - M_M1 = IXM100.C2L-VC LIGO = 1" optic mount, left-handed. - M_C1 = IXM200.C2-VC LIGO = 2" optic mount, right-handed. - M_B4 = IXM100.C2-VC LIGO = 1" optic mount, right-handed. - M_M2 = IXM100.C2-VC LIGO = 1" optic mount, right-handed. To-date the assembly procedure has been scattered into incomplete pieces, including separated mechanical assembly (D1100362 and E2500163-v1) and electrical assembly (D1400279). As such, I've created an all-inclusive assembly procedure in E2500163-v2, and the DCC file-card now perma-links to a google photo album containing many more photos than even what's in the procedure. So, now I can write this aLOG, which "just" says -- we've completed the assembly for SPI's four pico-actuated mirrors, per E2500163-v2 assembly instructions. It's always challenging to get a photo highlight, so I'll attach the best one I got mid assembly (i.e. the picomotors weren't yet connectorized, nor were the ECR E1400327 range-limiting shafter collars installed). The 2nd, 3rd, and 4th attachment show three photos I got of the completed M_M1 (IXM100.C2L, 1" left-handed) mount.CSWG, ISC, SEI

Images attached to this report

H1 General - Comment to OPS Wednesday DAY shift start

elenna.capote@ligo.org — Wed, 15 Oct 2025 12:11:38 -0700

Author: elenna.capote@ligo.org

Report ID: 87496

Calibration monitoring line at 33 Hz was also 1% worse than yesterday.

Images attached to this report

H1 ISC - Quick drop from observe to correct spot position

elenna.capote@ligo.org — Wed, 15 Oct 2025 12:11:03 -0700

Author: elenna.capote@ligo.org

Report ID: 87495

Jenne allowed us to quickly drop from observing to change the EY camera offsets. Yesterday we updated them 87473 but didn't load the camera servo guardian, so the guardian did not use the correct lscparams file. This meant that the A2L gains (ISC_LOCK controlled) were set for the new spot, but the camera offsets (camera servo guardian controlled) were at the old spot. This was also missed because these values are not monitored in the observe SDF files. We noticed that:

the buildups were even lower than normal, because the camera offsets were wrong
therefore kappa c was at 0.96
the sensitivity was also bad because the A2L and camera offsets were mismatched, causing extra ASC coupling
the calibration monitoring lines showed 3% uncertainty at 33 Hz, this is usually 2%

Many of these are issues are documented in Ryan's shift alog here: 87485.

We dropped out of observing and I set the EY camera offsets to their proper value. This immediately began increasing the PRG and arm power. Then, I loaded the camera servo guardian so that when we relock these values are set properly. Then, I proceeded to monitor all the camera offsets and A2L gains and accept their new values in OBSERVE. This will cause SDF differences if these values change. However, I think these are important enough settings that we should be monitoring them for observing.

Kappa C has increased and the calibration monitoring lines are now back to 2% or less.

Images attached to this report

H1 General - OPS Wednesday DAY shift start

ryan.crouch@ligo.org — Wed, 15 Oct 2025 11:39:00 -0700

Author: ryan.crouch@ligo.org

Report ID: 87485

TITLE: 10/15 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 0mph Gusts, 0mph 3min avg
Primary useism: 0.08 μm/s
Secondary useism: 0.13 μm/s
QUICK SUMMARY:

14:00 UTC Observing
- DCPD window shows something ringup then damp back down in the past 15 minutes, Transient PI? It was smaller than we saw yesterday (added plot at 18:39)
14:17 UTC GRD-Short E610359
Secondary microseism continues to decrease, low winds
Lockloss doesn't seem to be updating, the most recent one isn't showing up
- The web site says: online last update: 1076.1 min ago (2025-10-14 13:42:18.164546)

Images attached to this report

H1 General - Comment to OPS Wednesday DAY shift start

elenna.capote@ligo.org — Wed, 15 Oct 2025 11:26:40 -0700

Author: elenna.capote@ligo.org

Report ID: 87494

We did not load the camera servo guardian yesterday after the changes, so the new camera offsets did not get properly loaded and engaged when the camera servos came on. We are back at the old camera offsets for ETMY, but at new A2L gains based on where we set the camera offsets yesterday. So, the buildups are bad because we're at the wrong beamspot on EY, and the sensitivity is bad because the beam spot is not lined up with the mirror actuation point, so we have extra ASC coupling, as Ryan's plot above shows.

Neither the A2L gains nor the camera offsets are monitored in SDF, so this was not caught until just now.

H1 IOO - Comment to ISS measurements - 10th -14th October

jennifer.wright@ligo.org — Wed, 15 Oct 2025 11:20:48 -0700

Author: jennifer.wright@ligo.org

Report ID: 87471

This morning Rahul recentred the QPD on the input beam (translation stage = 0.4145 inches, allen key - 143mm) and we scanned the translation stage horizontally to measure the calibration of the QPD.

This first scan had too large steps to give a good estimate of the slope for the X coordinate on the QPD near the centre, so I repeated the measurement with smaller steps. Although I thought I set the laser to ~120 mA for both measurements the power on the QPD sum was slightly different between the two, see this plot where the original measurement set is in orange and the second set in blue.

Looking at the plot the QPD has the same slope in Y for both measurements but the second set of Y measurements has lower voltages.

The X data overlaps between the two measurements which makes more sense to me, as we assume the QPD electronics normalise the readout of X and Y by the sum channel to account for power fluctuations.

I used the newer measurement to estimate the calibration in the x direction, and the older measurement to estimate the slope in the y-direction, I tried to only use the linear part of the data in my fit and also not use any points with a voltage abive 6 Volts as this is when we expect the QPD to not be linear.

The calibration plot is here with the X calibration line in orange and the Y calibration line in red.

The resultant calibration is 72.0 V/mm in the horizontal direction, at an angle of 7.4 deg with the QPD axis. This is similar to the last calibration we did before several moves of the QPD to recentre it, see alog #87375.

This is worked out by adding the two slopes in quadrature and using atan2(Y_calib/X_calib) to work out the angle of the QPD axis with the horizontal direction of the PZT mirror translation.

Images attached to this report

H1 General - Comment to OPS Wednesday DAY shift start

ryan.crouch@ligo.org — Wed, 15 Oct 2025 11:14:04 -0700

Author: ryan.crouch@ligo.org

Report ID: 87493

I ran the range comparison against a lock last week with better range, lot of extra low frequency noise.

Non-image files attached to this report

compare_darm_1444017256_1444582878.pdf

H1 General - Comment to OPS Wednesday DAY shift start

ryan.crouch@ligo.org — Wed, 15 Oct 2025 10:57:18 -0700

Author: ryan.crouch@ligo.org

Report ID: 87488

The circulating power looks lower than the previous weeks locks, kappa_c also looks lower this lock.

Images attached to this report

LHO VE - Wed CP1 Fill

david.barker@ligo.org — Wed, 15 Oct 2025 10:16:24 -0700

Author: david.barker@ligo.org

Report ID: 87490

Wed Oct 15 10:05:11 2025 INFO: Fill completed in 5min 8secs

Gerardo confirmed a good fill curbside.

Images attached to this report

H1 General - Comment to OPS Wednesday DAY shift start

elenna.capote@ligo.org — Wed, 15 Oct 2025 10:01:41 -0700

Author: elenna.capote@ligo.org

Report ID: 87489

Ryan's data above in consistent with what we saw yesterday too. This makes me think that we should readjust the spot before running the calibration measurement tomorrow.

H1 General - Comment to OPS Wednesday DAY shift start

elenna.capote@ligo.org — Wed, 15 Oct 2025 09:03:11 -0700

Author: elenna.capote@ligo.org

Report ID: 87487

It looks like the same PI that rung up yesterday and almost caused a lockloss is still ringing up, although not as strongly. This suggests, along with other evidence, that we are still not at the right beam position on ETMY. This is on the to-do list to investigate tomorrow, and hopefully we will stop ringing up this PI. See 87473.

LHO FMCS - Mid station chiller plants shut down for the Winter

eric.otterman@ligo.org — Wed, 15 Oct 2025 08:00:03 -0700

Author: eric.otterman@ligo.org

Report ID: 87486

The chilled water plants at the Mid stations have been shut down for the Winter.

H1 General - Ops EVE Shift End

oli.patane@ligo.org — Tue, 14 Oct 2025 22:00:33 -0700

Author: oli.patane@ligo.org

Report ID: 87484

TITLE: 10/15 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Observing at 155 Mpc and have been Locked for about 8.5 hours. Nothing happened during my shift besides a couple of ITMX saturations.
LOG:

23:00UTC Observing and Locked for almost 3 hours
23:34 Left Observing to close beam diverter
23:34 Back into Observing

H1 General - Ops EVE Midshift Status

oli.patane@ligo.org — Tue, 14 Oct 2025 20:24:06 -0700

Author: oli.patane@ligo.org

Report ID: 87483

Still Observing and have been Locked for almost 7 hours. Secondary microseism has continued to drop. Our range has been a bit better than it has been the last couple of days, so that's cool.

Images attached to this report

H1 PSL - ISS array grounding issue (Rahul, Keita)

keita.kawabe@ligo.org — Tue, 14 Oct 2025 17:55:38 -0700

Author: keita.kawabe@ligo.org

Report ID: 87477

First attachment is a screenshot of D1300130 ISS array PD assembly (which is somehow called "PSL PDD MODULE").

Each PD (part #8) is entirely retained in an aluminum cylinder called the PDD main photodiode mount (part #9) and therefore the can of the PD is conductive to the cylinder. However, the cylinder is supposed to be isolated from the ISS array plate (and therefore the entire ISS array structure) by two pieces of kapton insulators (part #10). PCB assembly, which is connected to the PD, is sandwiched between two aluminum clamps (part #2 "PDD clamp" and part #11 "Clamping plate", which I refer to the bottom and the top clamp respectively), but the PCB ground is isolated from the clamps by an insulator ring (part "7?").

This way ground loop is broken even though the can of the PD is connected to the shield of two SMP coax cables on the PCB board (part #1).

Rahul and I checked the continuity between the cylinder and the ISS array cage. (Note that this check could not be done without disconnecting all SMP cables from the preamp first, because the preamp's ground is somehow connected to the optics table, which is connected to the ISS array cage.)

Issues found on the installation spare:

Unfortunately two of the PDs on the first floor (PD 5 and 6 in our notation in the lab, see the 2nd picture for the notation even though that is the picture of the 3IFO unit) didn't pass the check.

We also checked the grounding of the QPD and it was good.

Inspecting 3IFO, finding the same issue, and fixing it:

We quickly checked the 3IFO unit too and found that it also had a grounding issue for one of the PDs (PD 2). In the 2nd attachment, you can see that the space between the top and the bottom clamp of PD2 is smaller than the others.

We removed the top clamp and found no insulator (3rd attachment). We disconnected the PCB from the PD and learned that:

Disconnecting the PCB won't change the PD position. PD is somehow firmly attached to the main photodiode mount, and it won't shift unless we loosen the bottom clamp.
The insulator was found on the other side of the PCB, between the PCB assy and the PEEK pin guide (part #4).
Installing the insulator on the correct side (4th attachment) and reinstalling the top clamp, the grounding was broken.

Fixing the issue on the installation spare:

With the new knowledge about the insulator, we looked at the gap between the top and the bottom clamps of the PDs for the installation spare unit and it looked like PD5, 6, 7 had the insulator on the wrong side of the PCB even though PD7 didn't have the grounding issue.

Sure enough, we removed the top clamp for these problematic PDs, found no insulator for any of these (5th attachment), removed the PCB and found the insulator on the wrong side (6th attachment shows you one example), installed them correctly and the grounding problem was gone.

Electrical test:

Since we have disconnected the PCB and reconnected to the PDs, we reconnected all of the PDs to the preamp again and confirmed that all PDs still respond to the light as they used to.

We haven't measured if any one of these are much noisier than the others, which we'll check later.

Images attached to this report

H1 SUS - Weekly In-Lock SUS Charge Measurement FAMIS

oli.patane@ligo.org — Tue, 14 Oct 2025 17:37:02 -0700

Author: oli.patane@ligo.org

Report ID: 87482

Closes FAMIS#28427, last checked 87380

ITMX had too low of coherence again this week so it didn't run. Everyone else is looking normal.

Images attached to this report

H1 SUS - Comment to Sat Amps Modified: L2 (PUM) Stages for ETMX, ETMY, ITMX, and ITMY

oli.patane@ligo.org — Tue, 14 Oct 2025 17:22:19 -0700

Author: oli.patane@ligo.org

Report ID: 87481

Here's the characterization data and fit results for S1100148, assigned to ITMY L2's ULLLURLR OSEMs.

This sat amp is a UK 4CH sat amp, D0900900 / D0901284. The data was taken per methods described in T080062-v3, using the diagrammatic setup shown on PAGE 1 of the Measurement Diagrams from LHO:86807.

The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/
plotresponse_S1100148_ITMY_L2_ULLLURLR_20250917.m

Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are:

`Optic`	`Stage`	`Serial_Number`	`Channel_Number`	`OSEM_Name`	`Zero_Pole_Hz`	`R_TIA_kOhm`	`Foton_Design`
`ITMY`	`L2`	`S1100148`	`CH1`	`UL`	`0.095:5.19`	`120.5`	`zpk([5.19],[0.095],1,"n")`
			`CH2`	`LL`	`0.0957:5.24`	`120.0`	`zpk([5.24],[0.0957],1,"n")`
			`CH3`	`UR`	`0.0958:5.24`	`120.125`	`zpk([5.24],[0.0958],1,"n")`
			`CH4`	`LR`	`0.0967:5.28`	`120.375`	`zpk([5.28],[0.0967],1,"n")`

The attached plot and machine readable .txt file version of the above table are also found in ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Results/
2025-09-17_UKSatAmp_S1100148_D0901284-v5_fitresults.txt

Per usual, R_TIA_kOhm is not used in the compensation filter -- but after ruling out an adjustment in the zero frequency (by zeroing the phase residual at the lowest few frequency points), Jeff nudged the transimpedance a bit to get the magnitude scale within the ~0.25%, shown in the attached results. Any scaling like this will be accounted for instead with the absolute calibration step, i.e. Side Quest 4 from G2501621, a la what was done for PR3 and SR3 top masses in LHO:86222 and LHO:84531 respectively.

Non-image files attached to this report

2025-09-17_UKSatAmp_S1100148_D0901284-v5.pdf

H1 SUS - Comment to Sat Amps Modified: L2 (PUM) Stages for ETMX, ETMY, ITMX, and ITMY

oli.patane@ligo.org — Tue, 14 Oct 2025 17:21:18 -0700

Author: oli.patane@ligo.org

Report ID: 87479

Here's the characterization data and fit results for S1100127, assigned to ETMY L2's ULLLURLR OSEMs.

This sat amp is a UK 4CH sat amp, D0900900 / D0901284. The data was taken per methods described in T080062-v3, using the diagrammatic setup shown on PAGE 1 of the Measurement Diagrams from LHO:86807.

The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/
plotresponse_S1100127_ETMY_L2_ULLLURLR_20250916.m

Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are:

`Optic`	`Stage`	`Serial_Number`	`Channel_Number`	`OSEM_Name`	`Zero_Pole_Hz`	`R_TIA_kOhm`	`Foton_Design`
`ETMY`	`L2`	`S1100127`	`CH1`	`UL`	`0.0963:5.26`	`121.25`	`zpk([5.26],[0.0963],1,"n")`
			`CH2`	`LL`	`0.0958:5.24`	`121.25`	`zpk([5.24],[0.0958],1,"n")`
			`CH3`	`UR`	`0.0952:5.2`	`121.25`	`zpk([5.2],[0.0952],1,"n")`
			`CH4`	`LR`	`0.0954:5.21`	`121.25`	`zpk([5.21],[0.0954],1,"n")`

Non-image files attached to this report

2025-09-16_UKSatAmp_S1100127_D0901284-v5.pdf

H1 SUS - Comment to Sat Amps Modified: L2 (PUM) Stages for ETMX, ETMY, ITMX, and ITMY

oli.patane@ligo.org — Tue, 14 Oct 2025 17:19:13 -0700

Author: oli.patane@ligo.org

Report ID: 87478

Here's the characterization data and fit results for S1100119, assigned to ETMX L2's ULLLURLR OSEMs.

This sat amp is a UK 4CH sat amp, D0900900 / D0901284. The data was taken per methods described in T080062-v3, using the diagrammatic setup shown on PAGE 1 of the Measurement Diagrams from LHO:86807.

The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/
plotresponse_S1100119_ETMX_L2_ULLLURLR_20250916.m

Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are:

`Optic`	`Stage`	`Serial_Number`	`Channel_Number`	`OSEM_Name`	`Zero_Pole_Hz`	`R_TIA_kOhm`	`Foton_Design`
`ETMX`	`L2`	`S1100119`	`CH1`	`UL`	`0.0949:5.19`	`120`	`zpk([5.19],[0.0949],1,"n")`
			`CH2`	`LL`	`0.0971:5.32`	`120`	`zpk([5.32],[0.0971],1,"n")`
			`CH3`	`UR`	`0.0964:5.27`	`120`	`zpk([5.27],[0.0964],1,"n")`
			`CH4`	`LR`	`0.0957:5.23`	`120`	`zpk([5.23],[0.0957],1,"n")`

Non-image files attached to this report

2025-09-16_UKSatAmp_S1100119_D0901284-v5.pdf

H1 SUS - Comment to Sat Amps Modified: L2 (PUM) Stages for ETMX, ETMY, ITMX, and ITMY

oli.patane@ligo.org — Tue, 14 Oct 2025 17:18:49 -0700

Author: oli.patane@ligo.org

Report ID: 87480

Here's the characterization data and fit results for S1100118, assigned to ITMX L2's ULLLURLR OSEMs.

This sat amp is a UK 4CH sat amp, D0900900 / D0901284. The data was taken per methods described in T080062-v3, using the diagrammatic setup shown on PAGE 1 of the Measurement Diagrams from LHO:86807.

The data was processed and fit using ${SusSVN}/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/
plotresponse_S1100118_ITMX_L2_ULLLURLR_20250916.m

Explicitly, the fit to the whitening stage zero and pole, the transimpedance feedback resistor, and foton design string are:

`Optic`	`Stage`	`Serial_Number`	`Channel_Number`	`OSEM_Name`	`Zero_Pole_Hz`	`R_TIA_kOhm`	`Foton_Design`
`ITMX`	`L2`	`S1100118`	`CH1`	`UL`	`0.0966:5.27`	`120`	`zpk([5.27],[0.0966],1,"n")`
			`CH2`	`LL`	`0.0961:5.25`	`120`	`zpk([5.25],[0.0961],1,"n")`
			`CH3`	`UR`	`0.0963:5.26`	`120`	`zpk([5.26],[0.0963],1,"n")`
			`CH4`	`LR`	`0.097:5.3`	`120`	`zpk([5.3],[0.097],1,"n")`

Non-image files attached to this report

2025-10-14_UKSatAmp_S1100118_D0901284-v5.pdf

H1 ISC - Apparent camera offset change

elenna.capote@ligo.org — Tue, 14 Oct 2025 17:10:25 -0700

Author: elenna.capote@ligo.org

Report ID: 87473

Jenne, Elenna, Oli, Ryan S, Ryan C, Matt

Today the engagement of the camera servos significantly reduced the buildups. The first attachment shows how the PRG, REFL LF and circ power signals dropped as the camera servo guardian engaged the cameras. After reengaging the ADS, we saw that the buildups increased again, although not to the exact same level that they were before the camera engaged. This suggested to us that the camera servos were not going to the same camera set point as before. Oli spoke to the vacuum team that had been doing work at EY and found out that the EY camera cable had been very taut and they tried to loosen it. It's possible they bumped the camera during their work.

While we were considering what to do, we noticed that OMC DCPD sum was increasing rapidly. We realized this was due to a PI ringing up at 10.2 kHz. It's not a PI we usually damp, so there were no PI guardian warnings, and we didn't know how to damp it. Matt thinks this is a PI that we usually see ring up early in the lock, but with a relatively small amplitude, as the Y arm mode passes by. It usually does not need damping. We started getting DCPD saturations warnings, and we were certain we were going to lose lock. We thought perhaps that if we were in a slightly different beam position, that could cause this PI to ring up more than usual. Matt also pointed out that the CO2s had stayed on much longer for commissioning today. I had also held the IFO at 25 W before and after moving spots to perform some ASC measurements. So this was definitely not a normal locking process. However, the PI started to turn around on its own (we think), and we held the lock.

Jenne and I tried engaging the camera servos again, and saw that indeed doing so does reduce the buildups. Our thinking is that if the EY camera got bumped, the digital offset we normally use has probably changed. We also noticed that the low frequency sensitivity was slightly worse than usual, suggesting that wherever the beam was, the A2L decoupling was bad. So, we decided to move the EY camera offsets to see if we could regain the buildups, following the assumption that something had changed at EY. We looked at the camera offset value that was present when the ADS lines were on. We changed the ETMY pitch and yaw offset values. This resulted in a 2 count change for ETMY pitch, from -230 to -228 and a 0.5 ct change in yaw from -349.5 to -349. Changing to these new offsets increased the buildups again. We also saw that the ADS had taken the ETMX camera error signal to a slightly different offset, so we tried changing the ETMX pitch value, but this had no change on the buildups so we reverted.

Even though this whole process was designed to bring us back to the nominal ETMY spot position, it appeared that the low frequency sensitivity was still bad, I ran the A2L script. I watched TJ's A2L script scope and noticed that the A2L starting value for ETMY pitch was very far from zero, so the script never took the A2L value to the minimum. Jenne and I ended up guesstimating what a good A2L value was so that the starting point would be close enough to the minimum that the script steps would go there. This results in a significantly different A2L gain than before for ETMY pitch. I copied the tables below for each A2L script attempt. The nominal ETMY pitch value before was 5.62 and now it is 6.43. According to the a2l lookup script, this is a 3.8 mm change in spot position. The ETMX A2L gains also updated slightly, as you can see below. I did not make any changes to the gains where the diff between final and inital was 0.01 in magnitude.

Now that we have been in NLN for 3.5 hours, the buildups still seem lower than usual. Circulating powers usually read about 382 "kW", but they are currently reading about 374 "kW". Kappa C is also 0.975, and it is usually 0.98. I'm not convinced that the beam is in the correct spot.

Jenne suggested that we could try going back to the old A2L gains, and then adjusting the camera offset until the ADS lines are minimized, which I think is a good idea. However, I do want to point out that our range is currently reading 160 Mpc on sensmon clean.

The new ETMY camera offsets and the updated A2L gains are saved in lscparams and loaded in ISC_LOCK. First try:

Optic	DOF	Initial	Final	Diff
ETMX	P	3.07	3.13	0.06
ETMX	Y	4.79	4.85	0.06
ETMY	P	5.54	5.54	0
ETMY	Y	1.42	1.37	-0.05
ITMX	P	-0.45	-0.46	-0.01
ITMX	Y	3.16	3.15	-0.01
ITMY	P	0.19	0.2	0.01
ITMY	Y	-2.75	-2.75	0

Second try:

Optic	DOF	Initial	Final	Diff
ETMX	P	3.13	3.12	-0.01
ETMX	Y	4.85	4.85	0
ETMY	P	6.3	6.43	0.13
ETMY	Y	1.37	1.37	0
ITMX	P	-0.46	-0.46	0
ITMX	Y	3.15	3.16	0.01
ITMY	P	0.2	0.19	-0.01
ITMY	Y	-2.75	-2.75	0

Images attached to this report

H1 General - OPS Tuesday Day shift summary

ryan.crouch@ligo.org — Tue, 14 Oct 2025 16:29:17 -0700

Author: ryan.crouch@ligo.org

Report ID: 87459

TITLE: 10/14 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: We ran into some issues after relocking following maintenance, but everything is stable currently. Is it in the best setup/orientation? Maybe not.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
22:52	SAF	Laser HAZARD	LVEA	YES	LVEA is Laser HAZARD \u0d26\u0d4d\u0d26\u0d3f(\u239a_\u239a)	15:51
14:34	FAC	Eric	Mech room	N	FAC checks	14:55
14:35	FAC	Randy	Yarm	N	Beam tube inspection, midy to corner	18:39
15:08	SUS	Jeff	CR	N	ETMX measurements, prep for satamp swap	16:08
15:08	SUS	Matt	CR	N	ITM measurements	15:25
15:12	TCS	Matt	LVEA	Y	Turn off sidebands	15:25
15:18	FAC	Chris	Out buildings	N	FAMIS checks	16:59
15:24	FAC	Kim	EndX	N	Tech clean	16:39
15:24	FAC	Nellie	EndX	N	Tech clean	16:38
15:25	VAC	Gerardo, Jordan	EY	N	Purge air	17:15
15:28	FAC	Tyler	Yarm	N	Termination slab checks	19:04
15:31	EE	Fil	CER	Y	ITM work	16:11
15:35	OPS	RyanS	LVEA	Y -> N	HAZARD TRANSITION, to safe	15:51
16:04	FAC	Richard	LVEA	N	Safety checks	16:25
16:05	VAC	Anna	LVEA	N	Join RGA team	17:15
16:06	VAC	Travis	MidX	N	Emergency pump checks	17:11
16:13	SUS	Jeff	CR	N	ETMY measurement	16:51
16:14	EE	Fil	Ends, X -> Y	N	Satamp swap, EY at 16:38 UTC	17:22
16:32	ISC	Sam	LVEA	N	Measure stuff	17:13
16:33		Keita, Alicia, Joan-Rene	LVEA	N	Tour, take pictures	17:14
16:42	PSL	Rahul, Jennie	Optics lab	LOCAL	ISS PD array	18:23
16:43	FAC	Nellie, Kim	LVEA	N	Tech clean	18:21
16:51	SUS	Jeff	LVEA	N	ITMX SAT amp measurement	17:03
17:00	FAC	Chris	LVEA	N	FAMIS checks	17:25
17:22	EE	Marc, Fil	LVEA HAM5	N	SUS R7 rack work, chassis installations	18:59
17:04	SUS	Jeff	LVEA	N	SR75 measurement in the Biergarten ITMX	18:05
17:11	VAC	Travis	MidY	N	Emergency pump checks	17:42
17:31	FAC	Richard, Alicia, Joan-Rene	OSB roof	N	Admire the view	17:47
17:33	VAC	Janos, Anna	LVEA	N	Move parts	18:01
17:35	VAC	Jordan	LVEA	N	1000 amu RGA	18:01
17:48	IMC	Matt	CR	N	IMC injections	17:54
17:56	IMC	Matt	LVEA	N	Sidebands back on	17:58
18:00	TCS	Matt	LVEA	N	Turn back on TCS Y	18:10
18:27	VAC	Jordan, Anna	LVEA	N	YARM manifold rga	19:02
19:00	TCS	Matt	LVEA	N	Reset both CO2 lasers	19:04
19:03	OPS	RyanS	LVEA	N	LVEA sweep	19:14
19:24	ASC	Elenna	CR	N	Soft ASC loops measurement	21:06
19:49	PSL	Rahul, Keita	Optics lab	N	ISS Array work, laser safe	21:46
19:50	FAC	Randy	Yarm beamtube	N	Beamtube inspection	21:46
20:42	EE	Fil	MidY	N	Grab electronics parts	21:42
21:56		Matt	Vac prep lab	N	Grab a part	22:06
21:56	PSL	Jennie	Optics lab	N	Double check something	22:11

15:32 UTC SUS PR3 and SR3 model restarts
15:47 UTC GRD reboot alog87463
16:00 UTC SAT amp swaps, QUADs L2 (ITMY, ITMX, ETMX, ETMY) alog87469
16:43 UTC Norco arrived at the gate, CP2
18:00 UTC TCS CO2Y trips off IR alarm
18:08 UTC Back to regular locking
- 18:19 UTC IA
18:54 UTC CO2 X & Y OUTPUT OFF "Power too low"
- 2 seconds before there was a HAM7 cps glitch that tripped the ISI
19:18 UTC I followed the wiki and minimized the SHG_FIBER_REJECTED_DC as we relocked
20:24 UTC we finished up the ASC loop measurements
20:46 UTC GRB-Short E610126
20:50 UTC While we were investigating the buildups dropping once the camera servo turned on a PI started to ring up around ~10.2k
22:08 UTC Observing

Images attached to this report

H1 General - Ops EVE Shift Start

oli.patane@ligo.org — Tue, 14 Oct 2025 16:17:09 -0700

Author: oli.patane@ligo.org

Report ID: 87476

TITLE: 10/14 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 12mph Gusts, 7mph 3min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.18 μm/s
QUICK SUMMARY:

Observing at 155Mpc and have been locked for almost three hours. Everything looking good.

H1 CDS - Comment to CDS Maintenance Summary: Tuesday 14th October 2025

david.barker@ligo.org — Tue, 14 Oct 2025 15:24:37 -0700

Author: david.barker@ligo.org

Report ID: 87475

Tue14Oct2025
LOC TIME HOSTNAME MODEL/REBOOT
08:32:35 h1sush2a h1suspr3 <<< model restarts
08:33:06 h1sush56 h1sussr3

08:34:52 h1daqdc0 [DAQ] <<< 0-leg restart
08:35:05 h1daqfw0 [DAQ]
08:35:05 h1daqtw0 [DAQ]
08:35:06 h1daqnds0 [DAQ]
08:35:13 h1daqgds0 [DAQ]
08:36:17 h1daqgds0 [DAQ] <<< GDS0 needed 2nd restart
08:41:11 h1daqdc1 [DAQ] <<< 1-leg restart
08:41:20 h1daqfw1 [DAQ]
08:41:21 h1daqtw1 [DAQ]
08:41:24 h1daqnds1 [DAQ]
08:41:30 h1daqgds1 [DAQ]
08:52:28 h1daqfw1 [DAQ] <<< FW1 spontaneously restarted itself

H1 CDS - CDS Maintenance Summary: Tuesday 14th October 2025

david.barker@ligo.org — Tue, 14 Oct 2025 15:16:18 -0700

Author: david.barker@ligo.org

Report ID: 87474

WP12827 SUS HLTS Estimator

Jeff, Oli, Brian L, Edgard, Dave, Ryan C:

New h1suspr3 and h1sussr3 models were installed. Slow channels had been renamed and therefore a DAQ restart was required.

WP12835 h1guardian1 reboot

TJ:

h1guardian1 was rebooted, all nodes now have the latest userapps files and changes will be tracked by GRD-CFC.

DAQ Restart

Dave, Jonathan:

The DAQ was restarted for the model changes. GDS0 needed a second restart. FW1 spontaneously restarted itself soon after the 1-leg restart.

H1 IOO - ISS measurements - 10th -14th October

jennifer.wright@ligo.org — Tue, 14 Oct 2025 14:00:41 -0700

Author: jennifer.wright@ligo.org

Report ID: 87466

Jennie W, Keita, Rahul

On Friday, Keita and Rahul and I tried moving PDs 2 and 6 to align them better with the others. As can be seen from the scans we did of the DC voltage of the diodes as we moved the input alignemnt in horizontal translation and yaw from alog #87290, 2 and 6 have a range of alignment that is shifted relative to the other 6.

We also checked this with a IR sensitive camera with a zoom lens.

One person used the camera with a zoom lens to check the spot on the PDs as another person loosened the screws from behind the array and the third person held the barrel of the PD assembly to stop it moving or rotating in an undesired direction.

There is not a lot of space as 2 and 6 are in a column and are very close to diodes 1 and 5 on the right.

The horizontal scan we took after these moves showed we had made things worse, see this image.

Later that afternoon, Keita moved the PD 2 back and checked the alignment and it looks better.

The alignment as of yesterday (Monday) was 143mm in pitch (as read out by the allen key in the PZT mirror pitch actuator wheel) and 0.4145 inches in horizontal translation as read out by the translation stage the PZT mirror sits on.

Keita measured the coupling (after finding an error in my code from the previous coupling measurement I plotted last Thursday (alog #87400)).

The coupling in both vertical and horizontal is below 10, so this should be good enough for install if all else checks out.

Yesterday afternoon, Rahul and I did the vertical scan (slightly off from the horizontal reference position of 0.4145 inches that Keita had aligned to). The data in this graph was collected at a horizontal translation stage reading of 0.4162 inches.

We had to redo the horizontal scan today as I missed out some scan values yesterday. The data was collected with the pitch indicator at 143mm (the allen key on the pitch wheel actuator).

ISC, PSL

Images attached to this report

H1 SEI - Comment to SEI_ENV node testing with High ASC gain testing

ryan.crouch@ligo.org — Tue, 14 Oct 2025 13:23:31 -0700

Author: ryan.crouch@ligo.org

Report ID: 87470

It looks like we lost it from a big DHARD_P oscillation and it corresponds to CHARD_P gain increasing back to nominal right as the P filters are reset? I also made plots of the filter bits from Oli's filter history right click tool.

Images attached to this report

H1 SUS - Sat Amps Modified: L2 (PUM) Stages for ETMX, ETMY, ITMX, and ITMY

filiberto.clara@ligo.org — Tue, 14 Oct 2025 13:11:40 -0700

Author: filiberto.clara@ligo.org

Report ID: 87469

WP 12836
ECR E2400330
Modified List T2500232

The following SUS SAT Amps were upgraded per ECR E2400330. Modification improves the whitening stage to reduce ADC noise from 0.05 to 10 Hz.

Suspension	Old	New	OSEM
ETMX L2 (PUM)	S1100146	S1100119	ULLLURLR
ETMY L2 (PUM)	S1100137	S1100127	ULLLURLR
ITMX L2 (PUM)	S1100135	S1100118	ULLLURLR
ITMY L2 (PUM)	S1000277	S1100148	ULLLURLR

F. Clara, J. Kissel, O. Patane

H1 PEM - Comment to H1 & L1 Down Due to M7.6 EQ (+also some high-ish winds)

ryan.crouch@ligo.org — Tue, 14 Oct 2025 13:05:29 -0700

Author: ryan.crouch@ligo.org

Report ID: 87468

We lost lock ~3 seconds after CHARD_Y filters bits are changed, there's also a big jump in ground motion at the same time, and it was gusting >30mph at the corner station.

Images attached to this report

H1 General - LVEA Swept Post-Maintenance

ryan.short@ligo.org — Tue, 14 Oct 2025 12:51:14 -0700

Author: ryan.short@ligo.org

Report ID: 87467

After maintenance wrapped up this morning, I swept through the LVEA to prep for observing. I unplugged an unused extension cord near the PSL racks and the scissor lift in the vertex/west bay area. Everything else looked okay.

Jeff also mentioned that he moved an SR785 from the PSL racks into the Biergarten for his work this morning, but it's unplugged (in case someone goes looking for it later).

H1 CDS - Guardian Pending Source File System (GRD-CFC)

david.barker@ligo.org — Tue, 14 Oct 2025 12:22:04 -0700

Author: david.barker@ligo.org

Report ID: 87465

I have created an EPICS IOC which reports any Guardian nodes which use source file(s) which have been modified in userapps but have not been loaded into the nodes. On the next restart of such nodes (e.g. guardian reboot) the new code will be automatically loaded, and so this system permits us to load new code in a scheduled and orderly way, for example by the code-author/node-manager during Tuesday maintenance.

This is similar to the front-end filter-module configuration file change (CFC) system, so I've called this GRD-CFC.

The CDS Overview MEDM has a "GRD CFC" button at the bottom showing the GRD-CFC status as GREEN/YELLOW. Pressing this button opens the H1CDS_GUARDIAN_CFC.adl MEDM (attached).

This MEDM has three main areas:

Top is the system overview. the magenta box encompasses the CFC summary (it will be yellow if one of more nodes are in need of reloading), the STATUS shows the IOC status
Middle is the main Guardian nodes table. The grey boxes will turn yellow if any node has one or more source files which need to be loaded
Bottom is the IOC details section. the yellow box encompassing server start and runtime information. The red box encompasses the database files' validity.

If any nodes are reporting pending changes, you can get pending file details by running the shell command:

guardian_modified_not_loaded

The output from this command provides information on how to list the line differences between pending files and what is running.

Images attached to this report

LHO VE - Tue CP1 Fill

david.barker@ligo.org — Tue, 14 Oct 2025 10:14:44 -0700

Author: david.barker@ligo.org

Report ID: 87464

Tue Oct 14 10:08:10 2025 INFO: Fill completed in 8min 7secs

Images attached to this report

H1 GRD - h1guardian1 machine rebooted

thomas.shaffer@ligo.org — Tue, 14 Oct 2025 08:55:40 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87463

Rebooted h1guardian1 at 1547UTC so that we could start with fresh fresh and it would become easier to manage any file differences with help from some of Dave's new screens and scripts.

All nodes started up on their own, and Ryan C helped me recover them all back to a maintenance state.

CDS

H1 SEI - SEI_ENV node testing with High ASC gain testing

thomas.shaffer@ligo.org — Tue, 14 Oct 2025 08:47:19 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87462

I went to test the high gain ASC states I made for SEI_ENV this morning while we were still locked this morning. The good news is that there were no errors in the code and it did exactly what I asked of it. The bad news is that we lost lock while transitioning back to a low gain state. This wasn't a great test though because I had a brain fart and forgot to change the thresholds for the test. The high gains were turned on, then immediately turned back. So I'm not entirely sure if the lock loss was from the transition back, or just the fact that we quickly flipped it back and forth.

The major change between what SEI_ENV does and what the script the operators use right now is that the sleep timers between engaging/disengaging each loop are almost completly gone. At minimum for the next test it seems that we need some for the return back to low gain, or maybe increased tramps.

On the bright side, it looks like the structure of the node and the code seems to work, just need to tune it a bit. For now I've returned this node back to its normal operation, without the high asc states.

GRD, ISC

Images attached to this report

H1 General - OMC scans -- 2025-10-14

matthewrichard.todd@ligo.org — Tue, 14 Oct 2025 08:42:42 -0700

Author: matthewrichard.todd@ligo.org

Report ID: 87461

M. Todd

Today I ran another OMC scan (following last week's instructions alog 87316 and 87342) after the morning lockloss to see if could a better measurement of the hot state overlaps.

I was still limited to about 12 minutes after the lockloss, so we expect some amount of difference in the full hot state.

I've plotted the results on top of last week's scans, in yellow. Analysis of this will follow in a comment.

Images attached to this report

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 14 Oct 2025 08:35:14 -0700

Author: erik.vonreis@ligo.org

Report ID: 87460

Workstations were updated and rebooted. This was an OS packages update. Conda packages were not updated.

LHO FMCS - LVEA Zone 3B temperature control

eric.otterman@ligo.org — Tue, 14 Oct 2025 08:07:38 -0700

Author: eric.otterman@ligo.org

Report ID: 87458

The second stage heating contactor had burned up, reducing heating capacity. This is why the zone had difficulty maintaining set point on 10/13. I replaced the ruined contactor and checked functionality.

H1 General - Comment to Ops Tuesday day shift start

ryan.crouch@ligo.org — Tue, 14 Oct 2025 07:59:04 -0700

Author: ryan.crouch@ligo.org

Report ID: 87457

SQZ_OPO reports "pump fiber rej power in ham7 high" so I get to try adjusting that today.

SQZ

H1 General - Comment to Ops Tuesday day shift start

ryan.crouch@ligo.org — Tue, 14 Oct 2025 07:41:52 -0700

Author: ryan.crouch@ligo.org

Report ID: 87456

There was a small typo in inj_params in fm_dict that I found and fixed and reloaded.

H1 General - Ops Tuesday day shift start

ryan.crouch@ligo.org — Tue, 14 Oct 2025 07:33:39 -0700

Author: ryan.crouch@ligo.org

Report ID: 87455

TITLE: 10/14 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 15mph Gusts, 10mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.26 μm/s
QUICK SUMMARY:

Secondary microseism looks to be rebounding after increasing into the night
We've been locked for ~19 hours
- PEM_MAG_INJ node is in error (Key error 'freq_low')
- The operator WS was stuck at "failed to unmount" when I arrived
11:33 UTC Superevent S251014cn

LHO General - OPS Eve Shift Summary

ibrahim.abouelfettouh@ligo.org — Mon, 13 Oct 2025 22:04:36 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87454

TITLE: 10/14 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY:

IFO is in NLN and OBSERVING (~10 hr lock)

2:53 - SQZ Dropped

4:10 - SQZ recovered, back to OBS

Mostly quiet shift except for the SQZ dropping due to FC lockloss.

The Squeezer FC lost lock due to FC2 alignment walking away from a lockable GR_LOCKED configuration. As per the wiki, I trended the last time we had a stable lock and reset values for FC1, FC2 and ZM3 (P/Y). Then, I tuned FC2 a bit more to maximize GR_TRANS output. This worked.

Interestingly, I first tried an alignment from a few days ago but this didn't work. I did this because FC2 has been increasing quite a bit in the last few days (screenshots) - probably worth looking into. The values I set FC suspensions to (using opticalign sliders)

FC2 P: 1558, FC2 Y: 109.6

FC1 P: -899.6, FC1 Y: -74

ZM3 P: -66.25 ZM3 Y: -463

I hope this issue doesn't happen again during OWL shift though the trend below from a few days ago shows FC2 P going up for the last few days seemingly with SQZ compensating in its alignment. Anecdotally, it seems related to the temperature since there's a diurnal breathing day to day (lows at night, highs in the day). Tagging SQZ to look at FC2 and FC.

LOG:

SQZ

Images attached to this report

LHO General - Ops Day Shift End

thomas.shaffer@ligo.org — Mon, 13 Oct 2025 16:25:21 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87436

TITLE: 10/13 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Locked for 4 hours. We had one lock loss during commissioning time today, though it does not seem to be caused by any commissioning activites. useism is on its way up, and the wind is gusting above 30mph at times.
LOG:

1543 Commissioning start
1740 GRB short E609775
- Since we were already commissioning we will not stand down
1747 Lock loss
1817 GRB short E609786
- Relocking, no stand down
1917 Observing

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
22:52	SAF	Laser HAZARD	LVEA	YES	LVEA is Laser HAZARD	13:52
14:36	FAC	Randy	Yarm	n	Y arm bte checks	18:36
14:46	FAC	Kim	Opt Lab	n	Tech clean	15:10
14:59	FAC	Nelly	MY	n	Tech clean	15:50
15:11	FAC	Kim	MX	n	Tech clean	16:05
15:33	ISC	Matt	Prep lab	n	Cheeta table prep	15:46
16:38	FAC	Kim	Prep lab	n	Table clean	17:09
16:50	ISC	Keita	Opt Lab	YES	ISS array work	20:54
17:01	SYS	Mitchell	MY	n	Checking out equipment	17:49
17:56	ISC	Matt	Prep lab	n	More measurements	18:13
18:03	VAC	Janos	EY, EX	n	Parts locate	18:33
18:07	FAC	Tyler	Xarm	n	Checkng on X1 bte	18:37
20:21	VAC	Travis	Mids	n	Measurement and prep for tomorrow	20:50
20:54	ISC	Rahul, Jennie	Opt Lab	YES	ISS array work	23:08

H1 ISC - Optical gain before and after power outage

elenna.capote@ligo.org — Mon, 13 Oct 2025 16:21:44 -0700

Author: elenna.capote@ligo.org

Report ID: 87453

In 86964 I ran a side by side comparison of the powers at various ports before and after the power outage so we could determine what, if anything had changed. Although it generally seemed like we had regained or even increased the powers everywhere, kappa C has indicated that the optical gain reduced. Our current kappa C has been consistently near 0.98 since the outage.

However, I calculated the full optical gain value today from the most recent calibration report (20251012T200500Z) and the current exported report on August 23 (20250823T183838Z). Each report lists H_c in ct/m. I also chose a time just before each report was measured to calculate the OMC-DCPD_SUM/LSC-DARM_IN1 transfer function that provides the mA/ct calibration value.

Date	OMC-DCPD_SUM/LSC-DARM_IN1 [mA/ct]	H_c [ct/m]	Optical gain [mA/pm]
10/12	2505448	3.423e6	8.576
8/23	2465012	3.478e8	8.573

It seems like our optical gain between these two times has actually stayed the same to much less than a percent. I'm not sure what to make of this with regards to the calibration, given that the calibration report suggests an overall magnitude change in the sensing function (that we are correcting in the TDCFs), but in actuality the magnitude of the sensing function has remained constant.

CAL, IOO

LHO General - OPS Eve Shift Start

ibrahim.abouelfettouh@ligo.org — Mon, 13 Oct 2025 16:20:41 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87452

TITLE: 10/13 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 19mph Gusts, 14mph 3min avg
Primary useism: 0.05 μm/s
Secondary useism: 0.31 μm/s
QUICK SUMMARY:

IFO is in NLN and OBSERVING (4 hr lock)

Wind is pickign up. Secondary microseism is picking up. Hoping to stay quiet and locked for the shift.

H1 SUS - SatAmp Swap Auto Alog

oli.patane@ligo.org — Mon, 13 Oct 2025 16:01:20 -0700

Author: oli.patane@ligo.org

Report ID: 87448

When we're doing the satamp swaps, we always need to write alog comments for each serial number that was updated. The alogs have repetitive text but have multiple values that need to be changed, and it's time-consuming and easy to miss changing something. I've written a script that automatically grabs the info and copies it to your clipboard so you can paste it into an alog.

The script that I made for auto-generating the satamp swap alog is here as r12693:

/ligo/svncommon/SusSVN/sus/trunk/electronicstesting/lho_electronics_testing/satamp/ECR_E2400330/Scripts/satampalog.py

You can run it by entering the serial number of the satamp and using one of the following flags: --uk4ch, --us4ch, or --us8ch for the satamp type.

Example:

$ python3 satampalog_4Jeff.py S1100147 --uk4ch

Alog for S1100147 is copied to clipboard. CRTL+V into alog and 'Preview' or 'Save to Draft' to fix formatting.

Pasting into an alog initially, it'll look like this

Click 'Save to Draft' to fix the formatting. It'll then look like this

Images attached to this report

H1 SUS - Comment to H1SUSITMY L2DAMP P and R Open Loop Gain TFs

jeffrey.kissel@ligo.org — Mon, 13 Oct 2025 14:30:20 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 87447

FYI, we also took ITMX data for these loops as well. /ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ITMX/SAGR0/Data 2025-07-08_2240UTC_H1SUSITMX_R0_WhiteNoise_0p02to50Hz_L2DAMP_OLGTF_P.xml 2025-07-08_2240UTC_H1SUSITMX_R0_WhiteNoise_0p02to50Hz_L2DAMP_OLGTF_R.xml

Images attached to this report

H1 SUS - Comment to SR3 P Estimator Blend filter swapped (back)

brian.lantz@ligo.org — Mon, 13 Oct 2025 13:44:29 -0700

Author: brian.lantz@ligo.org

Report ID: 87445

Oli - Thanks for doing this test, I'm looking forward to learning what happens. I think the question here is "how well does it work" and "what do we see" rather than "does it work". I'm hoping this will reduce the RMS a bit, although the analysis is complicated by the cross-coupling w/ length.

H1 SUS - SR3 P Estimator Blend filter swapped (back)

oli.patane@ligo.org — Mon, 13 Oct 2025 13:22:58 -0700

Author: oli.patane@ligo.org

Report ID: 87444

For the SR3 P estimator, we had initially developed and installed blend filters (in H1:SUS-SR3_M1_EST_P_FUSION_MEAS_BP and H1:SUS-SR3_M1_EST_P_FUSION_MODL_BP filter banks), named pit_v1, that blended between the OSEMs on-resonance, and the estimator everywhere else (86452). After a bit, Brian Lantz made a pit_v2 that included OSEM damping at two extra frequencies because we were having issues with extra resonances at 0.65 and 0.75 Hz that weren't being damped (86510)(filter comparisons).
Eventually we realized the reason why those two peaks weren't being damped was because we had forgotten to include the model contribution to P from L, and we installed those needed filters(86567). However, we didn't swap the blend filters back to pit_v1 at the time.
So during relocking today (2025/10/13 19:05:00 UTC), I swapped us back to pit_v1. We will run with this until at least tomorrow morning and then verify that we don't see a difference in the damping of those two peaks.

SEI

Images attached to this report

H1 General - Comment to Lock loss 1747 UTC

thomas.shaffer@ligo.org — Mon, 13 Oct 2025 12:23:14 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87443

Back to observing at 1917 UTC. Ran initial alignment, but I didn't have to do anything.

H1 ISC - Comment to Camera spot calibration

elenna.capote@ligo.org — Mon, 13 Oct 2025 11:57:21 -0700

Author: elenna.capote@ligo.org

Report ID: 87442

I reran the ITMX beam spot calibration following the same method described above, but this time I checked how the beam spot moved on both ITMX and ITMY when I changed the BS camera offset. Turns out, they give the same answer, so that's good.

Camera Offset

A2L gain

Conversion

ITMX P (ITMY P)

start: -230 ct, end: -231 ct

start: -0.45 (0.19), end: -0.55 (0.09)

(6.41 mm - 5.96 mm)/-1 ct

= -0.45 mm/ct

ITMX Y (ITMY Y)

start: -236 ct, end: -237 ct

start: 3.18 (-2.75), end: 3.06 (-2.63)

(11.26 mm - 11.70 mm)/ -1ct

= 0.44 mm/ct (-0.44 mm/ct for ITMY)

H1 General - Lock loss 1747 UTC

thomas.shaffer@ligo.org — Mon, 13 Oct 2025 11:08:50 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87441

Lock loss 1444412849

While it was during commissioning, it seems like it wasn't any of the activities going on at the time. Looks very much like the most recent lock losses we have that very quickly go.

H1 ISC - Changing OFI temperature test

elenna.capote@ligo.org — Mon, 13 Oct 2025 10:41:32 -0700

Author: elenna.capote@ligo.org

Report ID: 87439

Jennie W, Elenna

Today we changed the OFI temperature and monitored the OFI PD A power. At each temperature change, we reran Sheila's OMC fringe wrapping injection to replicate the measurement Sheila and Naoki did in alog 78942.

Results: we did not see a very significant change in the OFI PD A power when we changed the OFI temperature from 37.5 C to 25.5 C. We see a smaller scattering shelf at 25.5 C than we do at 37.5 C.

I saved Sheila's template over into my own directory as /ligo/home/elenna.capote/OFI/OMC_fringe_wrapping.xml

She had old references in that template (different from the alog) that were taken in Sept 2024. Those references indicated that an OFI temperature of 37.5 C had the smallest scattering shelf. Today, Jennie and I saw very little difference between the scattering shelves generated at 37.5 C (nominal temperature), 34.5 C and 30.5 C. Only when we measured at 25.5 C did we see the scatter shelf reduce slightly (plot).

In this plot, I added in Sheila's old references that show the exact opposite result a year ago. Specifically, the 25.5 C measurement from now is very close to the old 37.5 C measurement from a year ago.

At first, I didn't think there was much of a change in the power on OFI PD A. However, looking at the second trend, it looks like maybe the power dropped by a small amount. I might have needed to slow down this test more than I realized (plot). I saved this ndscope template in /ligo/home/elenna.capote/OFI/OFI_TEC.yaml

Images attached to this report

LHO VE - Mon CP1 Fill

david.barker@ligo.org — Mon, 13 Oct 2025 10:34:04 -0700

Author: david.barker@ligo.org

Report ID: 87440

Mon Oct 13 10:07:35 2025 INFO: Fill completed in 7min 32secs

Images attached to this report

H1 PSL - PSL 10-Day Trends

ryan.short@ligo.org — Mon, 13 Oct 2025 10:02:36 -0700

Author: ryan.short@ligo.org

Report ID: 87438

FAMIS 31107

The main changes that can be seen this week are a result of our amplifier pump diode current adjustments on Tuesday (alog87338). Otherwise, no major events this week.

Images attached to this report

LHO General - Ops Day Shift Start

thomas.shaffer@ligo.org — Mon, 13 Oct 2025 07:38:18 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87435

TITLE: 10/13 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 17mph Gusts, 12mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.22 μm/s
QUICK SUMMARY: Locked for 21.5 hours. No alarms, two GRB shorts overnight.

0804 GRB short E609675
0825 GRB short E609680

LHO General - OPS Eve Shift Summary

ibrahim.abouelfettouh@ligo.org — Sun, 12 Oct 2025 22:00:14 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87434

TITLE: 10/13 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

IFO is in NLN and OBSERVING (12 hr lock)

We were locked for the entirety of shift.

The range came back over the course of the shiftso did not have to leave OBSERVING to touch up the squeezer.

Wind and ground motion look good

LOG:

LHO General - Ops Day Shift End

thomas.shaffer@ligo.org — Sun, 12 Oct 2025 16:30:35 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87427

TITLE: 10/12 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 147Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: One lock loss that only needed initial alignment but full auto. After we thermalized I ran a calibration sweep in coordination with LLO. The range for this most recent lock looks to be trending down slightly. The SQZ blrms see it, but Ibrahim will keep an eye on things.
LOG:

1515 Lock loss
1659 Observing
1958 Out of observing for a calibration measurement
2029 Observing

LHO General - OPS Eve Shift Start

ibrahim.abouelfettouh@ligo.org — Sun, 12 Oct 2025 16:02:24 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87433

TITLE: 10/12 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 147Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 27mph Gusts, 21mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.22 μm/s
QUICK SUMMARY:

IFO is in NLN and OBSERVING (6 hr lock).

Range is slowly going down seemingly due to SQZ. Wind is also picking up. If range continues to degrade, will re-tune the squeezer.

H1 TCS - TCS Chiller Water Level Top-Off - Biweekly

thomas.shaffer@ligo.org — Sun, 12 Oct 2025 15:47:11 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87432

FAMIS27825

No water added, values all looked good and were recorded into the sheet T2200289 sheet.

I somehow missed this and its a week late, next one should run next week.

H1 CAL - Calibration Sweep 1958 UTC

thomas.shaffer@ligo.org — Sun, 12 Oct 2025 14:04:29 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87431

Coordinated a calibration measurement with LLO since we couldn't get it done yesterday. Back into observing 2029UTC

Simulines start:

PDT: 2025-10-12 13:04:59.811759 PDT
UTC: 2025-10-12 20:04:59.811759 UTC
GPS: 1444334717.811759

Simulines end:

PDT: 2025-10-12 13:28:25.449920 PDT
UTC: 2025-10-12 20:28:25.449920 UTC
GPS: 1444336123.449920

Files:

2025-10-12 20:28:25,294 | INFO | File written out to: /ligo/groups/cal/H1/measurements/DARMOLG_
SS/DARMOLG_SS_20251012T200500Z.hdf5
2025-10-12 20:28:25,302 | INFO | File written out to: /ligo/groups/cal/H1/measurements/PCALY2DA
RM_SS/PCALY2DARM_SS_20251012T200500Z.hdf5
2025-10-12 20:28:25,308 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_
L1_SS/SUSETMX_L1_SS_20251012T200500Z.hdf5
2025-10-12 20:28:25,312 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_
L2_SS/SUSETMX_L2_SS_20251012T200500Z.hdf5
2025-10-12 20:28:25,317 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_
L3_SS/SUSETMX_L3_SS_20251012T200500Z.hdf5

Images attached to this report

Non-image files attached to this report

H1_calibration_report_20251012T200500Z.pdf

LHO VE - Sun CP1 Fill

david.barker@ligo.org — Sun, 12 Oct 2025 10:25:16 -0700

Author: david.barker@ligo.org

Report ID: 87430

Sun Oct 12 10:08:26 2025 INFO: Fill completed in 8min 22secs

Images attached to this report

H1 General - Comment to Lock loss 1515 UTC

thomas.shaffer@ligo.org — Sun, 12 Oct 2025 10:00:17 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87429

1659 Observing. Needed an initial alignment, but all auto.

H1 SUS - SRM watchdog trip thresholds updated

thomas.shaffer@ligo.org — Sun, 12 Oct 2025 09:57:26 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87428

We've recently been having some issues with SRM tripping during initial alignment and during DRMI acquisition, alog87370 for example. After consulting with Jeff K, I've bumped up the trip thresholds as listed below. This was based off of the last few trips, so hopefully it has enough of a buffer now. Saved in the safe and observe sdfs.

	Old	New
M1	150	250
M2	200	350
M3	225	400

Images attached to this report

H1 General - Lock loss 1515 UTC

thomas.shaffer@ligo.org — Sun, 12 Oct 2025 08:31:41 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87426

Lock loss 1444317365

No obvious cause, ended a 29.5hour lock.

LHO General - Ops Day Shift Start

thomas.shaffer@ligo.org — Sun, 12 Oct 2025 07:27:18 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87425

TITLE: 10/12 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 9mph Gusts, 5mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.28 μm/s
QUICK SUMMARY: Locked for 28.7 hours, range is stable, no alarms, no alerts overnight.

LHO General - OPS Eve Shift Summary

ibrahim.abouelfettouh@ligo.org — Sat, 11 Oct 2025 22:00:14 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87424

TITLE: 10/12 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

IFO is in NLN and OBSERVING (19 hr lock!)

Range is stable. Environment is stable. Locked for the whole shift.

LOG:

None

LHO General - OPS Eve Shift Start

ibrahim.abouelfettouh@ligo.org — Sat, 11 Oct 2025 16:34:16 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87423

TITLE: 10/11 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 15mph Gusts, 8mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.20 μm/s
QUICK SUMMARY:

IFO is in NLN and OBSERVING

Calibration sweep was not run this morning due to LLO not being thermalized. TJ plans on running it tomorrow with LLO.

Otherwise, LHO has been quietyl observing for ~14 hours!

LHO General - Ops Day Shift End

thomas.shaffer@ligo.org — Sat, 11 Oct 2025 16:31:25 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87422

TITLE: 10/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Locked for almost 14hours. Range has been stable. Public tours came through, but it's been a very quiet shift.
LOG:

2212 GRB short E609151

LHO General - Ops Day Mid Shift Report

thomas.shaffer@ligo.org — Sat, 11 Oct 2025 12:19:57 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87421

Locked and observing for 9.5 hours. H1 and L1 have moved the calibration sweep to tomorrow since we could not get a coordinated time in today.

LHO VE - Sat CP1 Fill

david.barker@ligo.org — Sat, 11 Oct 2025 10:21:38 -0700

Author: david.barker@ligo.org

Report ID: 87420

Sat Oct 11 10:08:39 2025 INFO: Fill completed in 8min 36secs

Images attached to this report

LHO General - Ops Day Shift Start

thomas.shaffer@ligo.org — Sat, 11 Oct 2025 07:34:28 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87419

TITLE: 10/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 6mph Gusts, 2mph 3min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.18 μm/s
QUICK SUMMARY: Locked for almost 5 hours, no alarms, calm environment. Af ew GRB alerts and one lock loss over the night.

0342 GRB short E608872
0709 GRB short E608943
0709 GRB short E608942
0801 Lock loss
0944 Observing

LHO General - OPS Eve Shift Summary

ibrahim.abouelfettouh@ligo.org — Fri, 10 Oct 2025 22:00:06 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87418

TITLE: 10/11 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

IFO is in NLN and OBSERVING as of 00:38 UTC

After the initial alignment at the start of the shift, IFO locked fully automatically. The wind has also since calmed down.

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
22:52	SAF	Laser HAZARD	LVEA	YES	LVEA is Laser HAZARD \u0d26\u0d4d\u0d26\u0d3f(\u239a_\u239a)	13:52
15:05	fac	randy	y-arm	-	Y2 BTE inspection	22:53
16:38	cheta	matt	CHETA.JAC	-	parts checks	17:02
17:02	psl	keita.jenny	opticslab	YES	ISS PD Array	00:28
17:47	pem	mitch	sitewide	-	dustmon famis	18:40

LHO FMCS - Checking HVAC Fans - Weekly FAMIS 27427

ibrahim.abouelfettouh@ligo.org — Fri, 10 Oct 2025 16:55:56 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87417

Closes FAMIS 27427, Last checked in alog 87284

Corner Station looks good - nothing of note

Outstations look good too except for EX, which had a peak on Tuesday. This isn't a problem and is corroborated by Eric's alog 87343, reporting a fan bearing replacement on this fan. Everything has looked quiet since.

Screenshots attached.

Images attached to this report

LHO General - Fri Ops DAY Shift Summary

corey.gray@ligo.org — Fri, 10 Oct 2025 16:32:03 -0700

Author: corey.gray@ligo.org

Report ID: 87405

TITLE: 10/10 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:

Started day with high winds peaking at under 40mph at 10amPDT but they never really died. And then in the early afternoon a huge M7.6 EQ beteween Argentina/Antartica took over most of the afternoon. Ended the shift starting an Initial Alignment for the hand off to Ibrahim (EQ is steadily dropping, but it's still windy).
LOG:

1430-2100 Y-Arm BTE iinspection continues for Y2 (between EY & MY) [randy]
1527 Grabbing cardboard & open/close Reciving Door (nellie, kim)
1600-1615 optics lab cleaning (nellie)
1614-1702 Parts checks in Cheta lab (matt)
1701 ISS PD Array (keita,jenny,rahul)
- 1937 lunch break
- 2124 Returning to lab
1747-1840 Dust Mon FAMIS check on-site (mitch)
2049 LOCKLOSS due to M7.6 (see alog 87415)
2302 Started an Initial Alignment, but Y-arm has been strugglign to complete....but finally got past Green Arms and on PRC ALIGN!

H1 CAL - Checking in on the calibration- it's fine, actually

elenna.capote@ligo.org — Fri, 10 Oct 2025 16:20:40 -0700

Author: elenna.capote@ligo.org

Report ID: 87409

Ibrahim ran a calibration measurement last night, report attached to this alog (again, the weird bug happened where it pulled the wrong report reference so I had to regenerate). Just from the first page, we can see that the PCAL/GDS transfer function, as measured by both PCAL X and Y, show the uncertainty to be around 1% again. We can see that the modeled actuation strength matches up very well with the current model that has been running since 8/28, indicating that I corrected the drivealign gain properly (ignoring all the mistakes I made in the middle).

The difference in the sensing function is mostly due to the loss of optical gain, this came with the power outage. There might be some small change in the spring, but it is very minimal, and that lines up with the fact that trying to adjust the SRCL offset yesterday only made things worse.

Comparing the GDS/PCAL broadband with previous measurements, we can see that this broadband (in red, Oct 10) is almost exactly the same at the broadband taken on Aug 28 (gray reference) when we pushed this particular calibration. There are small differences at low frequency, perhaps due to some change in the spring behavior of the sensing function, and at high frequency, which I don't have a good immediate reason for.

Given that correcting the TST actuation strength brought the calibration almost exactly back to the model, I spoke with Joe to understand then what the "mysterious" large deviation in the calibration was on Oct 4 (green trace). In the process, I also made a plot comparing the same measurement times, but instead looking at CAL DELTA L/PCAL, so examining what our calibration would look like without TDCFs (I matched the colors with teh GDS/PCAL plot). We determined that by comparing the CAL DELTAL measurement to the GDS measurement, indeed the TDCFs are doing something correctly; without them on Oct 4, our uncertainty woyld be over 6%. However, they are clearly not doing a perfect job of correcting us back to model. Joe thinks that this is because the TCDF correction process may not completely account for the effect of the DARM OLG between each of the actuation TDCF measurement points. We trended what happened to kappa UIM and kappa PUM when I adjusted the L3 drivealign gain to bring kappa TST back to 1 and we see that kappa UIM dropped by 0.9% and kappa PUM by 0.4%. This is happening because the DARM OLG is changing as we adjust kappa TST, and kappa UIM and kappa PUM are seeing some frequency dependent change, but their calculation is assuming that the DARM OLG is not changing.

In summary, the increase calibration uncertainty on Oct 4 is exactly due to the increase in kappa TST, even though the TDCFs were correcting GDS. We can can see by comparing the broadbands from Sept 27 (purple trace) and Oct 4 that at both times the TCDFs were doing an imperfect job of correcting GDS, and that scales with how large the deviation from 1 is; on Sept 27 kappa TST was about 1.02. Now that the actuation strength has been corrected, there is no need to update the calibration at this time.

Images attached to this report

Non-image files attached to this report

H1_calibration_report_20251010T002302Z.pdf

LHO General - OPS Eve Shift Start

ibrahim.abouelfettouh@ligo.org — Fri, 10 Oct 2025 16:15:11 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87416

TITLE: 10/10 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Earthquake
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
SEI_ENV state: EARTHQUAKE
Wind: 31mph Gusts, 22mph 3min avg
Primary useism: 0.92 μm/s
Secondary useism: 0.16 μm/s
QUICK SUMMARY:

IFO is in INITIAL_ALIGNMENT

Recovering from an M7.6 EQ in the Drake Passage ( gap between Argentina and Antarctica). Ground motion is looking good - wind is looking meh.

Plan is to lock, observe and stay that way.

H1 PEM - H1 & L1 Down Due to M7.6 EQ (+also some high-ish winds)

corey.gray@ligo.org — Fri, 10 Oct 2025 14:10:20 -0700

Author: corey.gray@ligo.org

Report ID: 87415

Another big EQ rolling through. This one is down near Antartica! Debated when to transition to "ASC Hi Gn", since R-wave was going to be 45-60min. But S&P waves triggered EQ Mode + saw a yellow Picket Fence---Clicked on ASC Hi Gn button, but during the transition H1 lost lock. This might have been too big for ASC Hi Gn regardless, but kinda wished I clicked it earlier.

Winds were peaking just under 40mph around the lockloss as well.

Will be hanging out here for a few hours.

2040 Notification of a M7.6 EQ down near Antartica at the Drake Passage
- R-wave due to arrive in ~1hr and is in the yellow/red area on EQ Response plot (see attached)
2043 Start seeing Picket Fence activity (no colors tho)
2045 L1 goes down
2045 Start seeing S&P Wave spikes on 0.03-0.1Hz Band on nuc5
2048 EQ Mode Activated and also get get yellow Picket Fence
2049 Turned on Hi Gain ASC
2049 H1-LOCKLOSS
2050 Keeping ISC LOCK at READY while riding out EQ.
2059 Red Picket Fences -AND- SEI_ENV to LARGE_EQ -AND- SEI_CONF goes to LARGE_EQ_NOBRSXY
2101 V1 goes down
2125 Saw some light BLUE Picket Fences! (which most likely corresponds with the R-Wave arrival)
2135 R-Wave peak (Same or a little bigger than the big Philippines last night).

Now we wait for R-wave which is probably due to arrive around 2135-ish utc.

PEM, SEI

Images attached to this report

H1 DetChar - Witness channels of the set of near-30Hz and near-100Hz combs at LHO

joan-rene.merou@ligo.org — Fri, 10 Oct 2025 13:51:57 -0700

Author: joan-rene.merou@ligo.org

Report ID: 87414

[Joan-Rene Merou, Alicia Calafat, Anamaria Effler, Sheila Dwyer, Robert Schofield, Jenne Driggers] We have looked at the near-30 Hz and near-100 Hz combs (Detchar issue 340) in all of LHO Fscan channels (Full 148 channels list can be found in O4_H1_Fscan_ch_info.yml) to find witnesses and also channels where the amplitude and coherence change at the same dates as DARM. The list of combs is the following one:

spacing (Hz)	offset (Hz)
29.9695138888	0
99.99845486125	70.02888889
99.99845679	0
99.99846	29.9694
99.9984722225	89.90847222
99.99865	0
99.99845	10.08992
29.96952	520.17208
29.9695211	589.9007589
29.96951374	760.22840625

As reported by Xuanye Fan in Detchar issue 296, "it can be determined that the high-order harmonics disappeared on April 8, 2024, and reappeared on July 7, 2024". Hence, we have compared coherence with DARM in all the channels and the difference between July 1st and July 7th 2024. Following the findings by Xuanye, we have redone the comb time-evolution plots for all of these combs in order to check for dates where their amplitude changed. As can be seen in the plots below, there are two clear dates where changes in the behavior of the combs took place, April ~4th 2024 and July ~7th 2024. The attached plots to this post are similar to the ones generated by Fscan using FscanFineToothPlot plots, however, they have two differences: They use data from the non-normalized spectras instead of from the time average plots. Additionally, they compute the relative harmonic amplitude with respect to the median of the surrounding 1 Hz spectrogram. The attached plots confirm that there is a significant change in comb amplitude between April 4th and July 7th 2024. One clear example is shown here: We list here the channels that do show most of these Combs. These same channels do show changes in coherence between July 1st and July 7th 2024, but do not show changes in the amplitude of the combs. - H1_IMC-F_OUT_DQ - H1_LSC-MCL_IN1_DQ - H1_LSC-MICH_IN1_DQ - H1_LSC-SRCL_IN1_DQ - H1_PEM-CS_MAG_EBAY_LSCRACK_X_DQ - H1_PEM-CS_MAG_EBAY_LSCRACK_Y_DQ - H1_PEM-CS_MAG_EBAY_LSCRACK_Z_DQ - H1_PEM-CS_MAG_LVEA_INPUTOPTICS_X_DQ - H1_PEM-CS_MAG_LVEA_INPUTOPTICS_Y_DQ - H1_PEM-CS_MAG_LVEA_INPUTOPTICS_Z_DQ In most channels, the comb amplitude tends to get quite low after ~1500 Hz. The following sets of channels show differences between X, Y and Z: - H1_PEM-CS_MAG_EBAY_SUSRACK_X_DQ (Higher amplitudes and towards higher frequencies) - H1_PEM-CS_MAG_EBAY_SUSRACK_Y_DQ (Lower comb amplitudes) - H1_PEM-CS_MAG_EBAY_SUSRACK_Y_DQ (Lower comb amplitudes) Regarding CS_MAG_LVEA_OUTPUTOPTICS, these combs can be seen best in X, weaker in Y and almost non-existent in Z. (In CS_MAG_LVEA_INPUTOPTICS they look roughly the same height) - H1_PEM-CS_MAG_LVEA_OUTPUTOPTICS_X_DQ (Strongest) - H1_PEM-CS_MAG_LVEA_OUTPUTOPTICS_Y_DQ (Weaker lines) - H1_PEM-CS_MAG_LVEA_OUTPUTOPTICS_Z_DQ (Almost no lines) Same behavior at: - H1_PEM-CS_MAG_LVEA_VERTEX_X_DQ (Strongest lines) - H1_PEM-CS_MAG_LVEA_VERTEX_Y_DQ (Weaker lines) - H1_PEM-CS_MAG_LVEA_VERTEX_Z_DQ (Almost no lines) We can see that these combs mostly appear in the corner station. The combs do not appear in neither EX nor EY channels. However, comb 99.99865 Hz offset 0.000 appears in many EX, EY channels and does become more coherent after July 7th. However, it is very close to 100 Hz so it may be influenced by other round-number combs (?) DetChar

Images attached to this report

LHO VE - Fri CP1 Fill

david.barker@ligo.org — Fri, 10 Oct 2025 10:23:24 -0700

Author: david.barker@ligo.org

Report ID: 87408

Fri Oct 10 10:07:47 2025 INFO: Fill completed in 7min 43secs

Gerardo confirmed a good fill curbside.

Images attached to this report

H1 CAL - Comment to Some attempts to fix the calibration

elenna.capote@ligo.org — Fri, 10 Oct 2025 09:31:19 -0700

Author: elenna.capote@ligo.org

Report ID: 87407

I also did revert the gain change in the pydarm_ini file, but forgot to mention it earlier.

H1 PSL - PSL Status Report (FAMIS #27398)

corey.gray@ligo.org — Fri, 10 Oct 2025 08:17:33 -0700

Author: corey.gray@ligo.org

Report ID: 87406

This is for FAMIS #27398.
Laser Status:
NPRO output power is 1.857W
AMP1 output power is 70.67W
AMP2 output power is 140.3W
NPRO watchdog is GREEN
AMP1 watchdog is GREEN
AMP2 watchdog is GREEN
PDWD watchdog is GREEN

PMC:
It has been locked 16 days, 21 hr 4 minutes
Reflected power = 24.26W
Transmitted power = 106.6W
PowerSum = 130.8W

FSS:
It has been locked for 0 days 1 hr and 35 min
TPD[V] = 0.538V

ISS:
The diffracted power is around 3.9%
Last saturation event was 0 days 3 hours and 40 minutes ago

Possible Issues:
PMC reflected power is high

PSL

LHO General - Fri Ops Day Transition

corey.gray@ligo.org — Fri, 10 Oct 2025 08:00:38 -0700

Author: corey.gray@ligo.org

Report ID: 87404

TITLE: 10/10 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 22mph Gusts, 13mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.14 μm/s
QUICK SUMMARY:

Looked like the spooky shaky night continued with another Phillipines EQ of M6.7 3hrs ago. But continuing from Ibrahim's summary, after his alignment, H1 automatically made it back to NLN to observe for under 2hrs until the next lockloss (no EQ tag tho); then a brief SQZ drop (see below). Finally the EQ 3+hr ago which took down H1/L1. There were no Wake-Up calls last night.

Environmentally: watch for EQs! AND winds have been picking up over the last 90min with winds just under 30mph currently.

Overnight ISSUES:

1104-1108 SQZ Unlocked due to "LO Railing":

2025-10-10_09:47:27.819286Z SQZ_MANAGER executing state: FREQ_DEP_SQZ (100)
2025-10-10_11:04:43.645262Z SQZ_MANAGER [FREQ_DEP_SQZ.run] Unstalling SQZ_PMC
2025-10-10_11:04:43.839754Z SQZ_MANAGER [FREQ_DEP_SQZ.run] USERMSG 0: LO railing!
2025-10-10_11:04:43.839754Z SQZ_MANAGER [FREQ_DEP_SQZ.run] LO unlocked

SQZ

Images attached to this report