aLIGO LHO Logbook

LHO General - Tues EVE Ops Summary

corey.gray@ligo.org — Tue, 04 Nov 2025 21:59:32 -0800

Author: corey.gray@ligo.org

Report ID: 87958

TITLE: 11/05 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

Bit of a rough start to the shift with H1 having issues getting to NLN. Managed to finally get to Observing after a few hours of work (see earlier alogs). Violins were high (but not off the DARM FOM), and have steadily been dropping over the 2+hrs of this lock.

Had a LOW SQZ_PMC voltage, but squeezer lockloss and automatic relock brought the voltage back to a better state (70+ volts).
LOG:

BTE cell phone signal testing (robert, sam)
- Done around 0100utc (and they regaled stories of seeing a herd of elk, lots of fat black widows, and a kitchen knife (all along the x-arm).
0039 Elenna saw 1Hz noise while at ADS TO CAMERAS, so she had me engage "ASC HI GN"....and then continue to INJECT SQUEEZING
0040 Lockloss at CLOSING BEAM DIVERTERS (see Elenna's alog)
Spent a few hours returning to NLN, but it required slowly walking through ISC_LOCK's final states.
0501-0540 First Contact three optic faces in the Optics Lab with RyanS as my Buddy (corey)
0506-0510 SQZ lockloss due to PMC Voltage being low. It automatically relocked and it has made the jump from close to 0V up to 72V (see attached pic) and now we no longer have the LOW Voltage notification for SQZ_PMC.

Images attached to this report

H1 SQZ - H1 Back To Observing: Post Maintenance, Earthquakes, Rising Microseism, Beam Diverter Worries, and LOW SQZ PZT Voltage

corey.gray@ligo.org — Tue, 04 Nov 2025 20:27:44 -0800

Author: corey.gray@ligo.org

Report ID: 87967

At the beginning of the shift H1 had a lockloss during late stages of ISC_LOCK where we slowly stepped through states and found the lockloss occurred at CLOSING BEAM DIVERTERS (see Elenna's alog 87961).

Took a couple of locking attempts for H1 to return to this same point of ISC_LOCK locking. (during this time is when Jenne noticed/addressed the Power Scaling issue (see alog 87965).

While locking chatted with Oli and they mentioned for some of their locklosses, they would go state by state, but ALSO if there was a 1Hz ring-up during these states, they would go to "ASC HiGn" AND then wait there a few minutes until the 1Hz ring up (seen on the PR_GAIN channel on PRMI.sb of nuc30 + ASC-INP1_P_INMON on nuc29).

So for this 2nd attempt of getting through CLOSE BEAM DIVERTERS this shift, went through the states:

0323 LASER NOISE SUPPRESSION --no issues observed
0325 ADS TO CAMERAS--this is where the 1Hz ring up occurred.
0327 ASC HiGn engaged!
- note: have to enter "y" (not "Y")
- Waited about 4min---basically watched the ring up noise disappear and return to quiet levels
0331 ASC Low Noise engaged!
0333 INJECT SQUEEZING
0332 - 0337 Closed the Beam Diverters by hand per Jenne's suggestion---> Able to close all of them (even HAM1's POP shutter which we feared would cause the lockloss).
Then continued through the remaining ISC_LOCK states.

Made it to NLN, but could not go to Observing for (2) (I believe) separate reasons.

1) SQZ_OPO_LR: "CMB EXC is ON" and SDF Diffs (see attachement #1). For the SDF Diffs, I reverted these with no problems.

At this point, I tried to go to OBSERVING, but could not.

2) Then noticed for SQZ_PMC, we had the notification: "PMC PZT volts low". Thought I would address this, but then I was able to take H1 to OBSERVING, so I kicked the can and went to OBSERVING instead of addressing the low voltage. See attachement #2 for PMC Voltage over the last week. Still have the notification for the low pmc voltage.

SQZ

Images attached to this report

H1 ISC - Comment to Close Beam Diverters guardian state causing locklosses

jenne.driggers@ligo.org — Tue, 04 Nov 2025 18:56:11 -0800

Author: jenne.driggers@ligo.org

Report ID: 87962

I double checked that the squeezer wasn't doing anything (just in case waiting longer than 1 min might help disentangle things). The SQZ_MANAGER was hanging out in state 69, where it asks the SQZ_ANG_ADJUST guardian to go to 'ADJUST_SQZ_ANG_ADF'. On the way to that state, the last thing the sqz manager had done was tell the SQZ_ANG_ADJUST guardian to go to WAIT_SQZ_AND_ADF, which just sits and waits for ISC_LOCK to get to NomLowNoise. So, I think I've convinced myself the lockloss is nothing to do with the squeezer.

I plotted several channels (starting from the lockloss 'scope). I'm still not really sure why the test mass L2 channels get a bit fuzzy about one second before the beam diverters close, but I think it's a red herring anyway. The real thing that seems to be interesting is that the HAM1 GS13s see a kick (due to the beam diverter moving) right when DARM sees a kick (the kick that Elenna pointed out).

So, I agree with Elenna and Corey's plan for now, to do the last few locking states slowly, then doing CLOSE_BEAM_DIVERTERS by hand to figure out which beam diverter is causing the problem. I also think it could be interesting to trend the GS13s for HAMs 1 and 6 for other locks (the other one tonight that we lost lock, as well as a few that were successful), to see if the kicks have gotten bigger or if they are the same size as always.

I also think that if closing the beam diverters causes another lockloss, we should just manual past the CLOSE_BEAM_DIVERTERS state, run for the night with them open, and tag DetChar. I'm pretty sure we've shown that they no longer really matter if they are open or closed, so I think we'd rather try to have some data with the beam diverters open than none at all.

Images attached to this report

LHO VE - Kobelco Compressor and Dry Air Skid Functionality Test

gerardo.moreno@ligo.org — Tue, 04 Nov 2025 18:50:26 -0800

Author: gerardo.moreno@ligo.org

Report ID: 87966

I ran the dry air system thru its quarterly test, FAMIS task. The system was started around 8:20 am local time, and turned off by 11:15 am. System achieved a dew point of -50 ^oF, see attached photo taken towards the end of the test. Noted that we may be running low on oil at the Kobelco compressor, checking with vendor on this. Picture of oil level is while system is off.

Images attached to this report

H1 ISC - Laser Power Scaling confused by IM4 response time

jenne.driggers@ligo.org — Tue, 04 Nov 2025 18:47:00 -0800

Author: jenne.driggers@ligo.org

Report ID: 87965

[Corey, Jenne]

We lost lock on the way up (not at all sure why, we hadn't yet gotten to the state we were worried about, but microseism is on an upward trend again), and when the IFO was relocking, the new power scaling (from alog 87806) did something funny.

The guardian is set up to use the IM4 output if the IMC is locked, and the IMC input power otherwise. It looks like this has worked successfully for the whole week since it was implemented, except for right now.

The MC2 Trans Sum was plenty high (but had only just gotten there), correctly indicating that the IMC was locked less than a second before the guardian had to decide whether the IMC was locked, so the Laser power guardian took for the power scaling the IM4 trans output. However, it looks like the laser power guardian read that IM4 value, while IM4 trans was still settling, since it has some whitening / dewhitening.

Once I realized that the power scaling was wonky, I just set the offset to 2, so that we could get back to locking while I investigated, which worked. Since the laser power guardian does reset that value every time there's a change to the laser power, the guardian has already picked it up and put in the more correct value of 1.8.

To prevent this from happening again, I put in a bit of logic to the set_power_scale() function of the LASER_PWR, such that if IM4 trans reads less than 1W, just use the input power as we used to do. We basically never request 1 W or less from the PSL and also are locking the full IFO, so this should be fine.

I tested it by bringing the LASER_PWR guardian to 3W (it used the IM4 trans as it should), and then down to 1W (which ends up as about 0.9W at IM4 trans), and the guardian correctly used the input power for the power scale. So, I think it should work fine.

LHO VE - Comment to CP1 LN2 Fill Line Pump Down

gerardo.moreno@ligo.org — Tue, 04 Nov 2025 18:32:36 -0800

Author: gerardo.moreno@ligo.org

Report ID: 87964

Today all hardware used to pump down the fill line was removed, initial reading was that of 3 microns, but after all the items were removed the reported internal pressure went up to 7 microns. We'll take another reading next Tuesday.

LHO VE - FAMIS Task Completed for Corner Station Turbo Pump Stations

gerardo.moreno@ligo.org — Tue, 04 Nov 2025 18:23:45 -0800

Author: gerardo.moreno@ligo.org

Report ID: 87963

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

Output mode cleaner tube turbo station;
Scroll pump hours: 7284.7
Turbo pump hours: 7306
Crash bearing life is at 100%

X beam manifold turbo station;
Scroll pump hours: 3387.3
Turbo pump hours: 3391
Crash bearing life is at 100%

Y beam manifold turbo station;
Scroll pump hours: 4157.7
Turbo pump hours: 2826
Crash bearing life is at 100%

FAMIS tasks 31339, 31331 and 31347.

H1 ISC - Close Beam Diverters guardian state causing locklosses

elenna.capote@ligo.org — Tue, 04 Nov 2025 16:53:43 -0800

Author: elenna.capote@ligo.org

Report ID: 87961

We have had multiple locklosses right near the end of the locking sequence around CLOSE BEAM DIVERTERS and OMC WHITENING. Today, we held at different states while locking. First, we pasued at MAX POWER while we waited for the R waves of a few different earthquakes to pass. Then, we proceeded successfully through to LASER NOISE SUPPRESSION. There are large glitches in this state, probably because of the CARM loop, so we stayed in the state to wait for the glitches to die down. Then, Corey selected ADS TO CAMERAS. This state proceeded fine, but we saw the 1 Hz starting to ring up. Corey selected the ASC Hi Gain script button on the seismic page to damp the 1 Hz back down. It damped down. We next went to INJECT SQUEEZING, which was fine. We waiting again about a minute after the state finished. Finally, Corey selected CLOSE BEAM DIVERTERS and we lost lock. Here is the guardian log so we can see the timestamps of each step.

We had the same lockloss earlier, it's logged at being from "omc whitening" but usually the beam diverters state is very fast so we are in omc whitening by the time the lockloss happens. Attached is the suspension signals from both locklosses. It looks like something rings up in DARM.

2025-11-05_00:36:48.787114Z ISC_LOCK [LASER_NOISE_SUPPRESSION.run] ezca: H1:IMC-REFL_SERVO_IN2GAIN => -29 2025-11-05_00:36:48.787719Z ISC_LOCK [LASER_NOISE_SUPPRESSION.run] ezca: H1:IMC-REFL_SERVO_FASTGAIN => -16 2025-11-05_00:37:24.445085Z ISC_LOCK REQUEST: ADS_TO_CAMERAS 2025-11-05_00:37:24.445085Z ISC_LOCK calculating path: LASER_NOISE_SUPPRESSION->ADS_TO_CAMERAS 2025-11-05_00:37:24.446434Z ISC_LOCK new target: ADS_TO_CAMERAS 2025-11-05_00:37:24.501243Z ISC_LOCK EDGE: LASER_NOISE_SUPPRESSION->ADS_TO_CAMERAS 2025-11-05_00:37:24.501532Z ISC_LOCK calculating path: ADS_TO_CAMERAS->ADS_TO_CAMERAS 2025-11-05_00:37:24.505287Z ISC_LOCK executing state: ADS_TO_CAMERAS (578) 2025-11-05_00:37:24.506308Z ISC_LOCK [ADS_TO_CAMERAS.enter] 2025-11-05_00:37:24.532550Z ISC_LOCK [ADS_TO_CAMERAS.main] ezca: H1:GRD-CAMERA_SERVO_REQUEST => CAMERA_SERVO_ON 2025-11-05_00:37:24.533290Z ISC_LOCK [ADS_TO_CAMERAS.main] camera servo guardian state 2025-11-05_00:37:24.533992Z ISC_LOCK [ADS_TO_CAMERAS.main] ezca: H1:ASC-AS_A_RF36_Q_YAW_SW1 => 8 2025-11-05_00:37:24.785056Z ISC_LOCK [ADS_TO_CAMERAS.main] ezca: H1:ASC-AS_A_RF36_Q_YAW => ON: OFFSET 2025-11-05_00:38:24.227696Z ISC_LOCK [ADS_TO_CAMERAS.run] ezca: H1:SUS-ETMX_L2_DRIVEALIGN_P2L_SPOT_GAIN => 3.13 2025-11-05_00:38:24.228345Z ISC_LOCK [ADS_TO_CAMERAS.run] ezca: H1:SUS-ETMY_L2_DRIVEALIGN_P2L_SPOT_GAIN => 4.89 2025-11-05_00:38:24.230162Z ISC_LOCK [ADS_TO_CAMERAS.run] ezca: H1:SUS-ETMX_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 4.85 2025-11-05_00:38:24.230577Z ISC_LOCK [ADS_TO_CAMERAS.run] ezca: H1:SUS-ETMY_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 0.78 2025-11-05_00:39:40.380293Z ISC_LOCK REQUEST: INJECT_SQUEEZING 2025-11-05_00:39:40.383415Z ISC_LOCK calculating path: ADS_TO_CAMERAS->INJECT_SQUEEZING 2025-11-05_00:39:40.386240Z ISC_LOCK new target: INJECT_SQUEEZING 2025-11-05_00:39:40.448133Z ISC_LOCK EDGE: ADS_TO_CAMERAS->INJECT_SQUEEZING 2025-11-05_00:39:40.448133Z ISC_LOCK calculating path: INJECT_SQUEEZING->INJECT_SQUEEZING 2025-11-05_00:39:40.453186Z ISC_LOCK executing state: INJECT_SQUEEZING (580) 2025-11-05_00:39:40.453467Z ISC_LOCK [INJECT_SQUEEZING.enter] 2025-11-05_00:39:40.471153Z ISC_LOCK [INJECT_SQUEEZING.main] ezca: H1:GRD-SQZ_MANAGER_REQUEST => FREQ_DEP_SQZ 2025-11-05_00:39:40.472228Z ISC_LOCK [INJECT_SQUEEZING.main] timer['CheckSqz'] = 90 2025-11-05_00:39:40.473316Z ISC_LOCK [INJECT_SQUEEZING.main] ezca: H1:GRD-SUS_PI_REQUEST => PI_DAMPING 2025-11-05_00:39:40.720211Z ISC_LOCK [INJECT_SQUEEZING.run] USERMSG 0: SQZ_MANAGER: has notification 2025-11-05_00:39:45.281174Z ISC_LOCK [INJECT_SQUEEZING.run] USERMSG 0: SQZ_MANAGER: has notification 2025-11-05_00:40:51.377382Z ISC_LOCK REQUEST: CLOSE_BEAM_DIVERTERS 2025-11-05_00:40:51.378087Z ISC_LOCK calculating path: INJECT_SQUEEZING->CLOSE_BEAM_DIVERTERS 2025-11-05_00:40:51.378087Z ISC_LOCK new target: CLOSE_BEAM_DIVERTERS 2025-11-05_00:40:51.459548Z ISC_LOCK EDGE: INJECT_SQUEEZING->CLOSE_BEAM_DIVERTERS 2025-11-05_00:40:51.459721Z ISC_LOCK calculating path: CLOSE_BEAM_DIVERTERS->CLOSE_BEAM_DIVERTERS 2025-11-05_00:40:51.464167Z ISC_LOCK executing state: CLOSE_BEAM_DIVERTERS (590) 2025-11-05_00:40:51.465760Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.enter] 2025-11-05_00:40:51.475467Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.main] Closing REFL beam diverter 2025-11-05_00:40:51.476845Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.main] ezca: H1:SYS-MOTION_C_BDIV_A_CLOSE => 1 2025-11-05_00:40:51.476939Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.main] Closing AS beam diverter 2025-11-05_00:40:51.478119Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.main] ezca: H1:SYS-MOTION_C_BDIV_D_CLOSE => 1 2025-11-05_00:40:51.478494Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.main] ezca: H1:VID-CAM16_EXP_REQ => 36000 2025-11-05_00:40:51.579758Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.main] ezca: H1:VID-CAM16_EXP_SET => 1 2025-11-05_00:40:51.579758Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.main] Closing POP beam diverter 2025-11-05_00:40:51.580545Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.main] ezca: H1:SYS-MOTION_C_BDIV_B_CLOSE => 1 2025-11-05_00:40:53.156310Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.run] Unstalling IMC_LOCK 2025-11-05_00:40:53.347649Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.run] Unstalling VIOLIN_DAMPING 2025-11-05_00:40:53.521338Z ISC_LOCK JUMP target: LOCKLOSS 2025-11-05_00:40:53.521845Z ISC_LOCK [CLOSE_BEAM_DIVERTERS.exit] 2025-11-05_00:40:53.582367Z ISC_LOCK JUMP: CLOSE_BEAM_DIVERTERS->LOCKLOSS 2025-11-05_00:40:53.582367Z ISC_LOCK calculating path: LOCKLOSS->CLOSE_BEAM_DIVERTERS 2025-11-05_00:40:53.585523Z ISC_LOCK new target: DOWN 2025-11-05_00:40:53.590140Z ISC_LOCK executing state: LOCKLOSS (2)

Lockloss

Images attached to this report

H1 CAL - PCAL EX measurement

anthony.sanchez@ligo.org — Tue, 04 Nov 2025 16:40:37 -0800

Author: anthony.sanchez@ligo.org

Report ID: 87953

Dr. Dripta B. and I went to EX today to do a PCAL End Station measurement with PS4 using the T1500062 ES Power Sensor RR Meas : Procedures & Log.
I took a picture of the beam spots before we started, and after we were done.
We ran Miriam's fantastic shell tool & left her some feed back written in the margins of the 2.2 section of the T1500062 Proc & Log document linked above.

We tried to run the measurement right at the end station but we didn't know that NDS servers were having a problem this week.
I eventually changed the server to be h1daqnds1 port 8088 to get the data instead.

Command Ran:
python generate_measurement_data.py --WS PS4 --date 2025-11-03
Reading in config file from python file in scripts
../../../Common/O4PSparams.yaml
PS4 rho, kappa, u_rel on 2025-11-03 corrected to ES temperature 299.5 K :
-4.7017855975867215 -0.0002694340454223 2.686163396659873e-05
Copying the scripts into tD directory...
Connected to h1daqnds1
martel run
reading data at start_time: 1446313243
reading data at start_time: 1446313659
reading data at start_time: 1446313992
reading data at start_time: 1446314497
reading data at start_time: 1446314910
reading data at start_time: 1446315256
reading data at start_time: 1446315430
reading data at start_time: 1446316080
reading data at start_time: 1446316490
Ratios: -0.46104301054554775 -0.4663040860974578
writing nds2 data to files
finishing writing
Background Values:
bg1 = 9.224674; Background of TX when WS is at TX
bg2 = 4.512480; Background of WS when WS is at TX
bg3 = 9.191238; Background of TX when WS is at RX
bg4 = 4.365167; Background of WS when WS is at RX
bg5 = 9.279967; Background of TX
bg6 = 0.429854; Background of RX

The uncertainty reported below are Relative Standard Deviation in percent

Intermediate Ratios
RatioWS_TX_it = -0.461043;
RatioWS_TX_ot = -0.466304;
RatioWS_TX_ir = -0.455583;
RatioWS_TX_or = -0.461207;
RatioWS_TX_it_unc = 0.084627;
RatioWS_TX_ot_unc = 0.080522;
RatioWS_TX_ir_unc = 0.093808;
RatioWS_TX_or_unc = 0.083107;
Optical Efficiency
OE_Inner_beam = 0.988311;
OE_Outer_beam = 0.989318;
Weighted_Optical_Efficiency = 0.988814;

OE_Inner_beam_unc = 0.058828;
OE_Outer_beam_unc = 0.054324;
Weighted_Optical_Efficiency_unc = 0.080074;

Martel Voltage fit:
Gradient = 1637.051728;
Intercept = 0.515075;

Power Imbalance = 0.988718;

Endstation Power sensors to WS ratios::
Ratio_WS_TX = -1.078345;
Ratio_WS_RX = -1.392858;

Ratio_WS_TX_unc = 0.050215;
Ratio_WS_RX_unc = 0.044908;

=============================================================
============= Values for Force Coefficients =================
=============================================================

Key Pcal Values :
GS = -5.135100; Gold Standard Value in (V/W)
WS = -4.701786; Working Standard Value

costheta = 0.988362; Angle of incidence
c = 299792458.000000; Speed of Light

End Station Values :
TXWS = -1.078345; Tx to WS Rel responsivity (V/V)
sigma_TXWS = 0.000541; Uncertainity of Tx to WS Rel responsivity (V/V)
RXWS = -1.392858; Rx to WS Rel responsivity (V/V)
sigma_RXWS = 0.000626; Uncertainity of Rx to WS Rel responsivity (V/V)

e = 0.988814; Optical Efficiency
sigma_e = 0.000792; Uncertainity in Optical Efficiency

Martel Voltage fit :
Martel_gradient = 1637.051728; Martel to output channel (C/V)
Martel_intercept = 0.515075; Intercept of fit of Martel to output (C/V)

Power Loss Apportion :
beta = 0.998895; Ratio between input and output (Beta)
E_T = 0.993842; TX Optical efficiency
sigma_E_T = 0.000398; Uncertainity in TX Optical efficiency
E_R = 0.994941; RX Optical Efficiency
sigma_E_R = 0.000398; Uncertainity in RX Optical efficiency

Force Coefficients :
FC_TxPD = 7.895132e-13; TxPD Force Coefficient
FC_RxPD = 6.181524e-13; RxPD Force Coefficient
sigma_FC_TxPD = 5.093350e-16; TxPD Force Coefficient
sigma_FC_RxPD = 3.738196e-16; RxPD Force Coefficient
data written to ../../measurements/LHO_EndX/tD20251104/

This produced the following plots:

Martel_Voltage_test.png
WS_at_TX.png
WS_at_RX.png
WS_at_RX_BOTH_BEAMS.png

Running the the Following command makes the Trends plots for the ES measurement:
python pcalPublishReportsV5.py LHO_EndX tD20251104

LHO_EndX_PD_ReportV5.pdf

All of this can be found at the PCAL git lab repo.

CAL

Images attached to this report

Non-image files attached to this report

T1500062Proc&Log.pdf

LHO_EndX_PD_ReportV5.pdf

LHO General - Ops Day Shift End

thomas.shaffer@ligo.org — Tue, 04 Nov 2025 16:32:41 -0800

Author: thomas.shaffer@ligo.org

Report ID: 87959

TITLE: 11/05 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
INCOMING OPERATOR: Corey
SHIFT SUMMARY: Maintenance Tuesday. Relocking hasn't been very successful so far. CO2Y was having IR faulting issues (alog87952), then we had a lock loss that occurred when we got to the Close_Beam_Diverters state, which we saw last week (alog87877). Now we are having a few earthquakes rolling through as we sit in max power. We don't want to advance until the ground stop shaking a bit so we can keep high gain asc on.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
16:06	ISC	Matt	CR	n	IMC 60W meas.	17:01
16:07	SYS	Mitchell, Randy	LVEA	n	Mega cleanroom sock install	17:15
16:10	FAC	Kim, Nellie	LVEA	n	Tech clean	18:03
16:11	VAC	Jordan, Travis, Janos	EY	n	Purge air line install	19:59
16:12	VAC	Gerardo	LVEA, Mech room	n	Run Kobelco, pump CP1 LN2 line, test turbo pumps	20:35
16:12	CDS	Betsy	CER	n	Putting stickers on racks	16:23
16:20	FAC	Tyler, Rays	Site	n	Septic tank inspection and pumping	17:59
16:22	CDS	Fil	EX	n	Connecting fibers to prep for RFM test	17:27
16:31	PCAL	Dripta, Tony	PCAL lab	LOCAL	Check on lab	16:47
16:38	SYS	Betsy	LVEA	n	Check on sock and domes	17:14
16:44	VAC	Norco	CP1	n	LN2 fill	18:49
16:44	FAC	Chirs, pest	LVEA, outbuildings	n	Pest control	17:49
16:49	PCAL	Tony, Dripta	EX	YES	PCAL calibration meas.	19:31
17:07	CDS	Betsy	CER	n	Removing stickers from ISCC3&4	17:16
17:17	VAC	Norco	CP5 MX	n	LN2 fill	19:14
17:31	CDS	Fil	LVEA	n	Cable pull around HAM2/3	20:05
17:34	-	Richard	LVEA	n	Checking on a few things	17:57
17:34	SUS	Oli	CR	n	PRM, SRM estimator measurements	20:08
17:40	PEM	Robert, Sam	LVEA	n	Mounting accel.	18:49
17:45	SYS	Randy	LVEA	n	Taking measurements of HAM3 and BSC2 areas	18:27
17:49	FAC	Chris	LVEA	n	FAMIS checks	18:32
17:49	PSL	Jason	LVEA	n	Walking the PSL chiller lines, FAMIS	18:01
17:57	SQZ	Sheila, Matt	CR	n	OM2 hot OMC meas.	20:08
17:59	FAC	Tyler, Geotech	MY	n	CEBEX surverying	23:24
18:03	FAC	Kim	EX	yes	Tech clean	19:17
18:04	FAC	Nellie	EY	n	Tech clean	19:20
18:05	CDS	Erik	EY, EX	n	Grabbing equipment from EY, doing RFM test at EX	19:18
18:13	CDS	Marc	LVEA	n	Helping Fil with cables at HAM2/3	20:05
18:14	IO	Rahul	Opt Lab	LOCAL	JAC testing	19:07
18:55	PEM	Robert, Sam	LVEA	n	More accelerometer moving	20:28
19:20	FAC	Rana, Mike, Tour	LVEA	n	Tour	20:12
19:41	FAC	Kim	FCES	n	Tech clean	19:42
19:51	FAC	Randy	XTube	n	Filling cracks	23:02
20:47	PCAL	Tony	PCAL lab	LOCAL	Wrapping up meas.	21:32
20:52	TCS	Ryan C	LVEA	n	Turn TCS CO2Y back on	20:53
20:58	PCAL	Rene, Alicia	PCAL lab	LOCAL	Check out lab with Tony	21:44
21:09	TCS	TJ	LVEA	N	Reset CO2Y laser	21:24
22:19	SPI	Corey, Ryan S	Opt Lab	n	Optics cleaning	23:29
23:04	PEM	Robert, Sam	Arms	n	BTE cell phone signal testing	02:04

H1 PSL - PSL Cooling Water pH Test - Monthly

ryan.short@ligo.org — Tue, 04 Nov 2025 16:29:55 -0800

Author: ryan.short@ligo.org

Report ID: 87960

FAMIS 27570

pH of PSL chiller water was measured to be between 10.0 and 10.5 according to the color of the test strip.

LHO General - Tues EVE Ops Transition

corey.gray@ligo.org — Tue, 04 Nov 2025 16:21:44 -0800

Author: corey.gray@ligo.org

Report ID: 87956

TITLE: 11/05 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
SEI_ENV state: EARTHQUAKE
Wind: 10mph Gusts, 6mph 3min avg
Primary useism: 0.52 μm/s
Secondary useism: 0.35 μm/s
QUICK SUMMARY:

Maintenance Day Recovery continues through the hand-off, but H1 locking is also being impacted by strong seismic activity (Russia EQs + microseism also inching back up). Violins look elevated as well, so there has been attention given to them.

Hand-Offs from TJ:

wifi is ON at EX, EY, MSR for Tony, so will need to turn OFF before OBSERVING
CO2y laser tripped earlier today, and TJ hopes it will be fine, but just mentioned it.
Currently taking H1 to LASER NOISE SUPPRESSION and Elenna wants to walk through the states to NLN slowly to watch for reasons for locklosses.

H1 TCS - Comment to CO2Y IR sensor in and out of fault, resat cable

thomas.shaffer@ligo.org — Tue, 04 Nov 2025 16:13:59 -0800

Author: thomas.shaffer@ligo.org

Report ID: 87957

Picture of the box with me touching the cable I moved around.

Images attached to this report

X1 SUS - BRDs Installed Further Away - Modes Measured

ibrahim.abouelfettouh@ligo.org — Tue, 04 Nov 2025 16:07:44 -0800

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87954

Ibrahim, Rahul

Rahul tuned BRDs to previously found B/R modes of B = 19.55Hz and R = 31.67 Hz (alog 83461)
On 10/12, measurements were taken that found mechanical modes to be at B = 19.72Hz and R = 31.85Hz (changes made to BBSS were wire coatings and the mass of BRD itself being simulated). Screenshots are attached.
BRDs were installed, but there was a clearance issue that required a new part to extend the BRD out. This part was made and is currently in clean and bake. In the meantime, we used washers to extend the BRDs out using a mount hole. Pictures are attached.
BRD measurements were then re-taken to see whether the Bounce and Roll modes were truly damped. It seems as though they were.
- Note: We will likley require another round of retuning to the 10/12 values. As of now, the tuning is ~0.5% off for Roll and ~0.9% off for Bounce (and indeed, it seems Bounce is less damped than Roll).
Rahul and I are planning to re-tune and re-install and re-measure with up-to-date mode measurements next week.

In short, it appears that BRD damping is working.

SUS

Images attached to this report

H1 General - OMC scan with SQZ beam and hot OM2-- 20251104

matthewrichard.todd@ligo.org — Tue, 04 Nov 2025 16:04:10 -0800

Author: matthewrichard.todd@ligo.org

Report ID: 87955

M. Todd, S. Dwyer

We wanted to heat up OM2 and retake an OMC scan to get another measurement to compare against our models, as Sheila had the idea to use the SQZ beam which we know well at ZM5 and measure the overlap to the OMC. We were able to take some data at the very end of the maintanence period but we were having issues for a long time and gave up on having the OM2 hot for the measurement and let it cool down so that relocking could be on time today.

We did all the usual steps of turning the DC centering loops on for the OMs and put the OMC ASC on to center on the QPDs. In the future, here's what we should do.

Step 0 -- Turn on OM2 1hr45min before measurement

Go to IFO_OUT > OM2 and in the input box below "POWER_SET" in the bottom panel, set the power to 4.6. Wait 1hr45min.

Step 1 -- SQZ guardian to LOCKED_SEED_DITHER

Also make sure that there is no IFO power when you go to take your measurement.

Make sure the beam diverter is closed and that the seed launch power is around 75 (if not you may have to pico the half wave plate by going to SQZT0 and clicking on the lambda/2 near "Seed Launch"). Then take the SQZ manager to LOCKED_SEED_DITHER and make sure that OPO locks. You should also take the FC to misaligned, as this was causing flashes in our DCPDs we did not want and were confusing us.

Step 2 -- Open beam diverter and close DC centering

By opening the beam diverter and the fast shutter you should be able to get light on the AS_A and AS_B QPDs so that you can close the DC3 and DC3 centering loops. Then you can take the OMC guardian to OMC ASC and make sure the beam is centered on the OMC QPDs. The NSUM values we saw with the SQZ beam was around 0.001, so there isn't a ton of light on them.

--- You should be able to measure an OMC scan now ---
If the HG10 peak is really high compared to the OM2 you may try closing the OMC LSC loop and waiting for things to settle before unlocking and remeasuring.

The OMC scans from today were not very good as the HG10 modes were much too high and don't make a good quadratic estimate of the mode-mismatch.

Images attached to this report

H1 TCS - CO2Y IR sensor in and out of fault, resat cable

thomas.shaffer@ligo.org — Tue, 04 Nov 2025 14:00:38 -0800

Author: thomas.shaffer@ligo.org

Report ID: 87952

The IR sensor for CO2Y was intermittently going into fault. I resat the connector on the sat box and it seems to be okay now.

Today during maintenance the CO2Y laser tripped off 3 times. The first one we figured was due to cable pulling activity in the area, the second was a bit more of a mystery, and the third made us think there was definitely something wrong. Ryan C restarted the first two at the control box, needing to power cycle it at least once each time. The third time I went out there and noticed the IR fault light going on and off. I touched the cable that goes to the IR sensor itself and the lights on the IR satellite box went red. Simply placing my finger on the cable near the connector on the box was enough to bring it into fault. I checked the connector there and it had some play in it, so I tried to seat it a bit better and then it seemed to not be as sensitive to me touching it. I turned the key off and on again and it was good to go.

Because this last trip happened while we were powering up to 25W, there was about 20 minutes or so when CO2X was on at its nominal annular power, but CO2Y was off (~2107-2131UTC). Perhaps this is an interesting bit of time for someone to look at?

We ended up losing lock when powering up to 60W. Perhaps I should have waited longer after CO2Y was back to let it "catch up" to ITMX's thermal state.

H1 SUS - Comment to H1SUSPRM M3, M2, and M1 Drive to M1 Response TFs to inform Estimator Models

oli.patane@ligo.org — Tue, 04 Nov 2025 13:45:42 -0800

Author: oli.patane@ligo.org

Report ID: 87951

Took some more of the meaurements for PRM estimator here: 87950

Those four M1 to M1 with DAMP Y at 20% for V R P and Y are still needed

H1 SUS - Most of the rest of the measurements for H1SUSPRM for Estimator

oli.patane@ligo.org — Tue, 04 Nov 2025 13:41:10 -0800

Author: oli.patane@ligo.org

Report ID: 87950

Last week (87801) Jeff took a bunch of transfer function measurements for PRM for the PRM L, P, and Y estimators. There were some he wasn't able to take:

- H1ISIHAM2 to H1SUSPRM M1 for all dofs with DAMP L, P, and Y all with 20% gain

- H1ISIHAM2 to H1SUSPRM M1 for all dofs with DAMP Y at 20% gain

- H1SUSPRM M1 to M1 for V, R, P, Y with DAMP Y at 20% gain

Today I was able to get the first two bullet points done

Measurements:

First, I made sure the SUSPOINT matrix had the correct values for driving PRM, which it did.

First set (L P Y DAMP gain at 20%):

L, P and Y DAMP gains were set to 20% of their nominal values, so they were set to -0.1, and T, V, and R were left at their nominal -0.5 gain values.

Measurements can be found in

/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/Common/Data/2025-11-04_1800_H1ISIHAM2_ST1_PRMSusPoint_M1LPYDampingGain0p1_WhiteNoise_*_0p02to50Hz.xml r12766

Second set (Y DAMP gain at 20%):

After those measurements were taken, I set the L and P DAMP gains back to their nominal values of -0.5 and took another set of SUSPOINT measurements with only the Y gain at 20%.

Those measurements can be found in

/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/Common/Data/2025-11-04_1930_H1ISIHAM2_ST1_PRMSusPoint_M1YawDampingGain0p1_WhiteNoise_*_0p02to50Hz.xml r12767

I ran out of time and wasn't able to finish the four M1 to M1 dofs that were left for the reduced Y damping, so we'll have to get those next week.

I also wasn't able to get in any measurements for SRM, but that's okay since we're not in a rush.

H1 SUS - Comment to Investigation of problematic violin mode, ETMX mode 1 and 6

jenne.driggers@ligo.org — Tue, 04 Nov 2025 12:22:45 -0800

Author: jenne.driggers@ligo.org

Report ID: 87947

And, here is a version of the spectrum over time. Probably the 'true' ETMX mode 1 is the one closer to 511.3 Hz, which is consistent with the filters as well as Rahul's violin mode identification spreadsheet, and the 511.269 Hz that we've had trouble with today is something else that is outside the width of the monitor filter, but inside the width of the damping filter. As Elenna's alog shows, it's not really clear what the filters are picking up to drive at 511.269 Hz, but probably the damping filter was set up for 511.3 Hz and so when being applied to something at 511.269 Hz it just feeds nonsense.

In the attachment, I show strain spectra from 3 different times when the alog has mentioned violin modes at around 511 Hz. Green is today (after we were saturating, hence the elevated background), brown is this Oct 2025, and pink is Aug 2023. All of the times have a small peak at 511.302 Hz (which is not so far from the ETMX mode1 monitor and damping filter central frequecy of 511.299 Hz), so that's probably the true violin mode. Oct and Nov have also this much larger peak at 511.269 Hz, which is this new confusing peak. I haven't looked at any times other than these 3, so it's possible that the 511.269 Hz has come and gone before Oct 2025.

Also shown is the ETMX mode 1 monitor and damping filters, showing that as Elenna said the monitor filter seems to only catch the 'true' mode, while the damping filter is broad enough for both of these frequencies.

Images attached to this report

H1 General - LVEA Swept

ryan.crouch@ligo.org — Tue, 04 Nov 2025 12:21:44 -0800

Author: ryan.crouch@ligo.org

Report ID: 87949

The LVEA has been swept, I unplugged an extension cords that were not connected to anything, and the genie lift near the west bay.

H1 SUS - Comment to Investigation of problematic violin mode, ETMX mode 1

elenna.capote@ligo.org — Tue, 04 Nov 2025 12:20:40 -0800

Author: elenna.capote@ligo.org

Report ID: 87946

Here is a follow up on the mode frequency that is very confusing! The ETMX mode 1 and mode 6 damping was disengaged about 20 minutes before our last lockloss. If I plot the strain spectrum in the 20 minutes before the damping was off and then the 20 minutes after, I see the expected ETMX mode 1 and 6 peaks at 511.18 Hz and 511.2993 Hz Hz. Only in the spectrum with the damping on do I see a large peak at 511.27 Hz. Jenne and I don't understand that yet, but are thinking about it. Plotted in diaggui_test with fft length 512 seconds, 2 averages with 50% overlap in each measurement.

The attached plot shows ETMX mode 1 and 6 damping ON in red and ETMX mode 1 and 6 damping OFF in blue.

However, the mode 1 filter is more likely to be the culprit, since it actually covers 511.27 Hz whereas the mode 6 filter does not, filter screenshot.

Images attached to this report

H1 CDS - 4K ethernet testing moved to EX

erik.vonreis@ligo.org — Tue, 04 Nov 2025 12:18:43 -0800

Author: erik.vonreis@ligo.org

Report ID: 87948

The test system for 4k Ethernet was moved from EY to EX, ending the test at EY.

The link was tested between the MSR and EX at 100G for a short itme. The link tested at 80G, the maximum the software can test.

The link is now being tested long-term at 25G. So far, no issues.

Earlier log entry about test at EY https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=87811

H1 DetChar - Intermodulation lines and β estimation in H1:OMC-DCPD_SUM_OUT_DQ

alicia.calafat@ligo.org — Tue, 04 Nov 2025 11:49:52 -0800

Author: alicia.calafat@ligo.org

Report ID: 87923

[Alicia Calafat, Joan-Rene Merou, Sheila Dwyer, Robert Schofield, Jenne Driggers]

Scope

We analyze violin harmonics and their intermodulation products in H1:OMC-DCPD_SUM_OUT_DQ, and estimate the quadratic mixing coefficient β for those products. Peak detection and confirmation use an Ansel-inspired adaptive-threshold approach on a stabilized series, combined with simple height floors. We then confirm analytically expected intermodulation frequencies and compute beta from amplitude products of paired parent lines and their intermodulation. Calibration tones near 15.6, 16.4, 17.1, and 17.6 Hz serve as fixed frequency references. The full-band ASD (about 10 to 1610 Hz) shows violin harmonics near 500 Hz (v), about 1000 Hz (2v), and about 1500 Hz (3v), together with the labeled calibration tones. This context motivates the intermodulation search at violin plus/minus calibration, and at violin-violin sums and differences across the band.

Problem and physical context

Small-signal readout model (mA domain, OUT):
  y(t) = alpha * s(t) + beta * s(t)^2 + n(t)

where
  s(t)  ~ mA  (photocurrent at DCPD SUM),
  alpha ~ linear gain,
  beta  ~ weak quadratic nonlinearity coefficient (1/mA),
  n(t)  ~ noise.

Single violin tone at f_v and calibration tone at f_cal:
  s(t) = X * sin(2*pi*f_v*t) + Z * sin(2*pi*f_cal*t)

Square s(t):
  s(t)^2 = X^2 * sin^2(2*pi*f_v*t)
         + Z^2 * sin^2(2*pi*f_cal*t)
         + 2*X*Z * sin(2*pi*f_v*t) * sin(2*pi*f_cal*t)

Use identities:
  sin^2(u) = (1 - cos(2u))/2
  2*sin(a)*sin(b) = cos(a - b) - cos(a + b)

Decomposition:
- Self terms:
    X^2 * sin^2(2*pi*f_v*t) -> DC and a line at 2*f_v
    Z^2 * sin^2(2*pi*f_cal*t) -> DC and a line at 2*f_cal

  In our beta workflow:
    * We ignore DC (0 Hz).
    * The 2*f_v component IS used inside the violin-violin families as the
      i=j "sum" case (often labeled vv_h2). Its estimator is
        beta_self(v) = A_2v_bin / ( A_v_bin * A_v_bin ).
    * The 2*f_cal component is not used for beta (we do not define a "cal-cal"
      family here), though it may be visible.

- Cross term (interaction):
    2*X*Z*sin(2*pi*f_v*t)*sin(2*pi*f_cal*t)
      = X*Z * [ cos(2*pi*(f_v - f_cal)*t) - cos(2*pi*(f_v + f_cal)*t) ]
    -> mixing lines at f_v - f_cal and f_v + f_cal
       with amplitudes proportional to beta * X * Z.

Spectral amplitudes from PSD (same convention for all lines):
  PSD has units mA^2/Hz. Let Delta_f be the bin width. For a narrow line,
  area ~ amplitude^2, so we use
    A_bin(f) = sqrt( PSD(f) * Delta_f ) = ASD(f) * sqrt(Delta_f)   [mA]
  For robustness we integrate +/- 1 bin around the peak index:
    A_bin ~= sqrt( (PSD[i-1] + PSD[i] + PSD[i+1]) * Delta_f )

Quadratic mixing scaling used for the estimator:
  A_mix ~ beta * A_L * A_R   (same amplitude convention for all lines)

Per-line beta estimators used here:
  - Violin +/- calibration:
      beta = A_v+/-cal_bin / ( A_v_bin * A_cal_bin )   [1/mA]
  - Violin self-mix (i=j) at 2*f_v (vv_h2):
      beta_self(v) = A_2v_bin / ( A_v_bin * A_v_bin )  [1/mA]
  - General violin-violin (i != j) sums/diffs:
      beta = A_fi+/-fj_bin / ( A_fi_bin * A_fj_bin )   [1/mA]

How the scripts work

Intermodulation explorer: input long spectrum (f, PSD); derive ASD; estimate band medians; detect violin peaks with an adaptive threshold on a stabilized series plus simple height floors; propose and confirm intermods at violin +/- calibration and violin-violin sums/diffs; export plots and a JSON summary.
Beta estimator: read the JSON and the same spectrum; reconstruct A_left, A_right, A_mix via +/- 1-bin PSD integration; compute beta_hat = A_mix_bin / (A_left_bin * A_right_bin); summarize by families and produce plots.

Current intermodulation detections

These are the retained detections after applying our thresholds and pairing rules. They are the inputs used downstream to compute and summarize beta by family.

Detected violin peaks kept: v = 20, approx 2v = 25, approx 3v = 30.
Intermod candidates before pairing: v plus/minus cal total = 154; violin-violin (sums and differences) total = 761.
Paired intermods kept for beta: v plus/minus cal = 22; 2v plus/minus cal = 18; 3v plus/minus cal = 18; vv(fund) = 386; vv(2v) = 247; vv(3v) = 128.

Beta results (paired families)

Family	Paired count	beta median [1/mA]
v +/- cal	22	0.638
2v +/- cal	18	0.450
3v +/- cal	18	0.286
vv (fund)	386	10.824
vv (2v)	247	1.586
vv (3v)	128	13.329

Plots

1) Calibration-violin explorer

Calibration tones align as symmetric sidebands around violin harmonics at the predicted offsets (v +/- f_cal). This validates the pairing rules used for beta estimation and shows that v +/- cal families are present at v, 2v, and 3v.

2) Violin-violin explorer

Sums and differences of violin peaks form dense loci at the predicted frequencies. Violin-violin intermods are abundant in all three bands.

3) Violin and intermods (zoom panels with thresholds)

Zooms around about 500, about 1000, and about 1490 Hz show violin peaks, calibration sidebands, and violin-violin intermods. Thresholds used (representative):

Band medians (ASD): about 9.29e-08 (v), 8.12e-08 (2v), 8.38e-08 (3v).
Violin peak floor (ASD): about 5.3e-06.
Intermod minimum height (ASD): about 1.3e-07.

Adaptive selection tracks local noise; loosening/tightening these settings trades recall vs precision. The chosen values recover the strong violins and yield a physically plausible intermod count for stable beta.

4) Beta histograms by family

Violin-violin families peak at larger beta than calibration mixes, as expected for a quadratic mechanism scaling with the product of parent amplitudes. Broader tails appear near thresholds and in crowded regions.

5) Beta by intermodulation family

The hierarchy is clear: vv(fund) and vv(3v) give the largest medians; vv(2v) is smaller but still above all calibration mixes. This is consistent with larger and cleaner A_left * A_right for violin-violin pairs than for violin +/- calibration.

6) beta(+cal) versus beta(-cal)

v and 2v show near-diagonal symmetry; 3v is imbalanced, consistent with leakage or pairing sensitivity at the third harmonic.

7) A_mix versus (A_L * A_R) - quadratic check

Largest deviations sit near thresholds and in crowded sub-bands.

8) beta versus A_mix with thresholds

Scatter grows as A_mix approaches thresholds.

Next steps

Repeat the analysis in the ADC domain (counts) for H1:OMC-DCPD_SUM_IN. Use the OMC_DCPD filter magnitude file (cols: freq, DCPD A mag, DCPD B mag) to convert counts<->mA and recompute beta. Comparing OUT (mA) and IN (counts) will test for any domain-dependent bias in beta.

DetChar

Images attached to this report

H1 PSL - Quarterly Inspection of PSL Chiller Lines (FAMIS 27545)

jason.oberling@ligo.org — Tue, 04 Nov 2025 11:46:56 -0800

Author: jason.oberling@ligo.org

Report ID: 87945

I inspected the PSL chiller lines external to the PSL enclosure this morning and found no issues or anomalies. This closes FAMIS 27545.

H1 SEI - Comment to OPS Monday EVE shift summary

thomas.shaffer@ligo.org — Tue, 04 Nov 2025 11:29:07 -0800

Author: thomas.shaffer@ligo.org

Report ID: 87944

SEI_ENV went to high gain ASC state on its own here for 15 minutes before we lost lock.

Images attached to this report

H1 SUS - Investigation of problematic violin mode, ETMX mode 1 and 6

elenna.capote@ligo.org — Tue, 04 Nov 2025 11:22:51 -0800

Author: elenna.capote@ligo.org

Report ID: 87941

[Jenne, TJ, Elenna]

The last three locks saw a violin mode ring up (see 87933), which managed to saturate the DCPDs and cause a large amount of excess noise, see this screenshot of DARM near the time of lockloss. I am assuming that all of the extra noise is a result of some crazy nonlinearity due to the saturation DCPDs.

Jenne and I have concluded that the mode that rung up must be ETMX mode 1, which the violin mode monitor screen reports is at f = 511.2993 Hz. However, we have looked at GDS calib strain when the mode has rung up using both diaggui_test and with exported data in python at double precision with fft length of 4096 and 1024 seconds respectively and find that the mode is at 511.269 Hz, DTT screenshot, matplotlib screenshot.

Jenne has plotted both the damping filter and the monitor filters here. We can see that the damping filter is broad enough to cover this frequency, but the monitor filter is not. The violin mode guardian is supposed to track the modes via the monitor filters and disengage damping if the mode is ringing up. However, we think the monitor filter might be missing this frequency and this is why the damping did not turn off.

The attached timeseries also shows that the DCPDs were railed for some time, the suspension drive on ETMX L2 was very nearly saturated, and the monitor filter level was low overall, near 3.5. Jenne has included channel H1:FEC-88_ACCUM_OVERFLOW, maybe this is a useful channel for us to monitor.

I just want to add that I am being specific about how we measured the mode frequency above because we have been confused by insufficient precision before. I think we have sufficient precision to measure this frequency accurately, but the results show a shift of 0.02 Hz from the previously reported value.

ISC

Images attached to this report

H1 SEI - Nov Wind fence survey famis 27576

jim.warner@ligo.org — Tue, 04 Nov 2025 11:22:17 -0800

Author: jim.warner@ligo.org

Report ID: 87943

I had to do this check a week ago, but no damage was observed at either end.

Images attached to this report

H1 SEI - H1 ISI CPS Sensor Noise Spectra Check - Weekly FAMIS 27396

ibrahim.abouelfettouh@ligo.org — Tue, 04 Nov 2025 11:13:09 -0800

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 87942

Closes FAMIS 27396. Last checked in alog 87787

Plots look fine compared to last week but BSC High-Freq noise is elevated for these sensors:

ITMX_ST1_CPSINF_H1
ITMX_ST1_CPSINF_V1
ITMX_ST2_CPSINF_V1

Note - it is Tues Maint. so there are people in the LVEA.

There was a 7.5Hz peak in TJ's last-week check that is now gone. It was most prominent in HAM1 it seems.

Pdf Attached.

SEI

Non-image files attached to this report

CPS_spectra_11:03-11_04_2025.pdf

LHO VE - Tue CP1 Fill

david.barker@ligo.org — Tue, 04 Nov 2025 10:45:48 -0800

Author: david.barker@ligo.org

Report ID: 87940

Tue Nov 04 10:05:35 2025 INFO: Fill completed in 5min 31secs

Gerardo confirmed a good fill curbside.

Images attached to this report

H1 General - New Cleanroom ceiling for Mega Cleanroom installed.

mitchell.robinson@ligo.org — Tue, 04 Nov 2025 09:54:20 -0800

Author: mitchell.robinson@ligo.org

Report ID: 87939

Randy and I installed new CR ceiling.

Betsy had a local company fabricate a C3 ceiling for our Mega Cleanroom. This ceiling has velcro opening to allow access for Septum removal. Opening extends to end of CR opening on the -X side and ends just short of the +X opening.

SYS

Images attached to this report

LHO General - Comment to Ops Day Shift Start

ryan.crouch@ligo.org — Tue, 04 Nov 2025 09:41:10 -0800

Author: ryan.crouch@ligo.org

Report ID: 87938

I've set the gain of ETMX mode 1 to zero in lscparams for now.

SUS

H1 GRD - Comment to IM1-4 & MC1 Guardian nodes Misaligned state removed

thomas.shaffer@ligo.org — Tue, 04 Nov 2025 09:12:11 -0800

Author: thomas.shaffer@ligo.org

Report ID: 87937

Sheila, TJ

We also added the OMs, OPO, and OFI to the list. This brings the total list of sus nodes without misaligned states to:

IM1-4
MC1
OM1-3
OPO
OFI

OpsInfo, SUS

H1 GRD - IM1-4 & MC1 Guardian nodes Misaligned state removed

thomas.shaffer@ligo.org — Tue, 04 Nov 2025 08:24:10 -0800

Author: thomas.shaffer@ligo.org

Report ID: 87936

I've removed the Misaligned states and their associated edges for the IMs and MC1 nodes to avoid a similar mishap from last week (alog87793) of going up to 60W but misaliging optics that should not be moved at that power.

To do this I needed to make h1 versions of these nodes. Most other sus nodes are common, and these do use the common SUS.py file, but we redefine the edges and removed the misaligned and misaligning states.

SUS

Images attached to this report

LHO FMCS - Quarterly Corner Station chiller maintenance finished

eric.otterman@ligo.org — Tue, 04 Nov 2025 08:18:54 -0800

Author: eric.otterman@ligo.org

Report ID: 87935

The quarterly maintenance of Chiller 3 and pump at the Corner Station has been done. Additionally, all chillers site-wide have been rotated.

LHO General - Comment to Ops Day Shift Start

thomas.shaffer@ligo.org — Tue, 04 Nov 2025 07:55:00 -0800

Author: thomas.shaffer@ligo.org

Report ID: 87934

Looks like this happened to Ryan C last night as well - alog87930. I did just as he did and turned off the damping to violin ETMX modes 1&6, and the saturations went away and DARM looked better. The 500Hz line in DARM is still very elevated, but the harmonics are much lower and the DCPDs are no longer saturating.

Now that the gains are off, the monitors are making more sense for those modes. They immediately went up when the gain was turned off.

SUS in lock charge is running and should be good, at least for the latter half of the measurements.

SUS

Images attached to this report

LHO General - Ops Day Shift Start

thomas.shaffer@ligo.org — Tue, 04 Nov 2025 07:38:42 -0800

Author: thomas.shaffer@ligo.org

Report ID: 87933

TITLE: 11/04 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 8mph Gusts, 5mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.29 μm/s
QUICK SUMMARY: Violin modes are very rung up, although our violin monitors dont agree with that. Our range has been very low for the past 2 hours, as if the squeezer isn't squeezing. While the magnetic injections are running right now, I don't think they are getting anything useful. Still trying to figure out what's going on.

Maintenance day today.

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 04 Nov 2025 07:01:51 -0800

Author: erik.vonreis@ligo.org

Report ID: 87932

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

H1 AOS - OPS Monday EVE shift summary

ryan.crouch@ligo.org — Mon, 03 Nov 2025 22:00:27 -0800

Author: ryan.crouch@ligo.org

Report ID: 87930

TITLE: 11/04 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Aligning
INCOMING OPERATOR: Oli
SHIFT SUMMARY: One lockloss, we are relocking at MAX_POWER.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
23:50	CAL	Tony	PCAL lab	LOCAL	Prep for end station meas tomorrow	00:35
00:49	CAL	Rick	Receiving	N	Pick up PSL parts	01:25
00:52	OPS	Ryan	Optics lab	N	Check on dust monitor	00:58

03:45 UTC Something started to ring up in the DCPDs and the 500Hz line looked large on DARM. None of the vioins were ringing up though, I eventually found that both ETMY and ETMX (mostly ETMX) mode1/6's drive was ringing up and once I turned off the damping the DCPDs came back down and so did the line on DARM. (tagging SUS). I then put the nominal gain back into ETMX mode6 and it started to damp back down.

04:03 UTC We dropped observing, I brought us to Hi gain ASC as a semi large earthquake from Eastern Russia was hitting us (6.0)

04:19 UTC lockloss from the Earthquake

04:55 UTC MC2 M3 tripped as the IMC was trying to relock after a lockloss from FIND_IR, a look at some of the OSEMs

04:56 UTC IA, after INPUT_ALIGN it took the IMC 6 minutes to relock itself

SUS

Images attached to this report

H1 General - 04:19 UTC lockloss

ryan.crouch@ligo.org — Mon, 03 Nov 2025 20:20:16 -0800

Author: ryan.crouch@ligo.org

Report ID: 87931

04:19 UTC lockloss from a 6.0 from Eastern Russia, we were in the Hi gain ASC state at the time trying to ride it out.

Lockloss

H1 General - November 3rd ISS Injection Measurement

matthewrichard.todd@ligo.org — Mon, 03 Nov 2025 18:29:05 -0800

Author: matthewrichard.todd@ligo.org

Report ID: 87922

M. Todd

I ran ISS injections in several bands during commissioning today (1-20 Hz) until about 9:30 PT. I am still struggling to get coherence below about 4 Hz, but the measurements of the transfer functions match relatively well with models of the ISS couplings to different ports in the IFO, except for POP. This could be sideband dominated dynamics, but more thought is needed.

Images attached to this report

Non-image files attached to this report

all_plots_input_rin_to_asundc_tf_during_thermalized_nln___november_3_2025___bw_0_05_hz.pdf

all_plots_input_rin_to_popa_tf_during_thermalized_nln___november_3_2025___bw_0_05_hz.pdf

all_plots_input_rin_to_refla_tf_during_thermalized_nln___november_3_2025___bw_0_05_hz.pdf

all_plots_input_rin_to_trxa_tf_during_thermalized_nln___november_3_2025___bw_0_05_hz.pdf

H1 General - Moday Ops Day shift & Lockloss

anthony.sanchez@ligo.org — Mon, 03 Nov 2025 16:55:04 -0800

Author: anthony.sanchez@ligo.org

Report ID: 87929

TITLE: 11/04 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
INCOMING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 6mph Gusts, 4mph 3min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.36 μm/s
SHIFT SUMMARY:

Lockloss from NLN , Lockloss tool failed again.

Thefirst channel that I was able to see deviate from its nominal operation was ETMX L3 channels.
screen shot attatched.

Relocking notes:
Relocked after another IA that unlocked and faulted the IMC after Saturating MC2. Doing a manual IA does not cause this issue.
Once passed DRMI, it locked without issue until NLN where the 1 hz ring up happened on the ASC-INP1-P. Elenna had me use the ASC high gain button for about a minute.
Once that had properly damped the oscillation and used the ASC Low gain button we were able to do some Observing.
Observing reached at 00:15:01 UTC

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:50	FAC	Randy	Mid X	No	Sealing the Beam tube	21:59
16:31	PEM	Robert	LVEA	N	Setting up for Shaker injections, & now shutting down shakers	19:16
16:32	iss	Matt	Control Rm	N	ISS injections.	17:16
16:33	FAC	Nellie	Mid Y	N	Technical Cleaning	17:33
16:33	FAC	Kim	Mid Y	N	Technical cleaning	17:25
18:29	CDS	Erik	EY	N	swapping fibers at the racks.	20:29
23:50	CAL	Tony	PCAL lab	LOCAL	Prep for end station meas tomorrow	00:35
00:49	CAL	Rick	Receiving	N	Pick up PSL parts	01:49
00:52	OPS	Ryan	Optics lab	N	Check on dust monitor	01:02

Lockloss

Images attached to this report

H1 General - OPS Monday EVE shift start

ryan.crouch@ligo.org — Mon, 03 Nov 2025 16:28:46 -0800

Author: ryan.crouch@ligo.org

Report ID: 87928

TITLE: 11/04 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 147Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 3mph Gusts, 1mph 3min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.44 μm/s
QUICK SUMMARY:

Secondary microseism has decreased over the past 12 hours
We've been locked for ~ 20minutes
00:15 UTC Observing

H1 CDS - Fiber pair swapped for Corner Stateion to EY test

erik.vonreis@ligo.org — Mon, 03 Nov 2025 15:10:37 -0800

Author: erik.vonreis@ligo.org

Report ID: 87927

At about 1100 PST I swapped the fiber pair for Ethernet IPC testing from the MSR in the corner station to EY. The new 4k pair is connected via patch fiber 24 at EY, replacing patch fiber 33.

H1 PSL - PSL 10-Day Trends

ryan.short@ligo.org — Mon, 03 Nov 2025 14:29:32 -0800

Author: ryan.short@ligo.org

Report ID: 87926

FAMIS 31110

The PSL was restarted on Thursday following an interlock trip and the PS3 pump current was increased (alog87866). Since then, AMP2 power has been very slightly lower, but so has PMC reflected power. ISS diffrected power has been low the past couple of days as well.

Images attached to this report

H1 General - Comissioning Lockloss & relockign notes.

anthony.sanchez@ligo.org — Mon, 03 Nov 2025 14:22:41 -0800

Author: anthony.sanchez@ligo.org

Report ID: 87925

Lockloss at 18:37 UTC Lockloss tool seemed to failed.
There was an unknown lockloss during commissioning.
Related Lockloss scopes attached.

Relocking notes:
Initial_Alignment railed MC2 in PRC aligning again today, twice. This perhaps is the start of a trend?
I just ran a manual IA.
After that relocking was pretty fast.
I accecpted some SQZr SDF changes to get back into Observing. Tagging SQZ.

Got back to Observing at 20:39:50
Superevent candidate S251103f

Lockloss, SQZ

Images attached to this report

H1 CDS - Comment to ETMX HWWD showing activity again, closely correlated to IFO lock state

ryan.crouch@ligo.org — Mon, 03 Nov 2025 13:55:35 -0800

Author: ryan.crouch@ligo.org

Report ID: 87924

Looking at several aquisitions this HWWD switching always starts around the LOWNOISE states such as LOWNOISE_ESD_ETMX, LOWNOISE_ASC, LOWNOISE_LENGTH_CONTROL, and I also saw it start at TRANSITION_FROM_ETMX..

Images attached to this report

LHO VE - Mon CP1 Fill

david.barker@ligo.org — Mon, 03 Nov 2025 10:36:19 -0800

Author: david.barker@ligo.org

Report ID: 87921

Mon Nov 03 10:11:37 2025 INFO: Fill completed in 11min 33secs

Gerardo confirmed a good fill curbside.

Images attached to this report

H1 CDS - Comment to Replace bad ADC in h1seiey, +24V Power Supply tripped, laser interlock tripped taking PSL down

david.barker@ligo.org — Mon, 03 Nov 2025 08:34:16 -0800

Author: david.barker@ligo.org

Report ID: 87919

FRS35819

H1 General - Monday OPS morning shift report.

anthony.sanchez@ligo.org — Mon, 03 Nov 2025 08:00:40 -0800

Author: anthony.sanchez@ligo.org

Report ID: 87918

TITLE: 11/03 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
SEI_ENV state: USEISM
Wind: 17mph Gusts, 12mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.47 μm/s
QUICK SUMMARY:

This morning the secondary u-seism has dropped enough to lock!
Oli was woken up and had suspected some Fast shutter errors, But was able to get H1 relocked!
When I walked in Oli had H1 in OMC_Whitening already!
H1 went back to Observing at 15:41 UTC.
The wind forecast to the next 24 hours looks fantastic for Observing.

H1 CDS - ETMX HWWD showing activity again, closely correlated to IFO lock state

david.barker@ligo.org — Mon, 03 Nov 2025 07:30:00 -0800

Author: david.barker@ligo.org

Report ID: 87917

The ETMX Hardware Watchdog started showing activity again around Wed 20oct2025. This does not appear to be related to any maintenance or Satellite Amp work. As the plot shows, its activity is very closely correlated to the IFO lock state, this was not the case earlier this year before it went quiet.

Images attached to this report

H1 General - Comment to Ops OWL Intervention: Fast Shutter Issues

oli.patane@ligo.org — Mon, 03 Nov 2025 06:50:17 -0800

Author: oli.patane@ligo.org

Report ID: 87916

Jenne, Fil, Oli

I INITed ISC_LOCK and decided to try CHECK_AS_SHUTTERS a third time. This time, everything worked correctly (fast shutter closed&opened) and the test passed (ndscope). I checked with Fil, who said it might have just been a logic mix-up, and Jenne, who confirmed that we should be good to power up now that the test passed. We are heading up!

Images attached to this report

H1 General - Ops OWL Intervention: Fast Shutter Issues

oli.patane@ligo.org — Mon, 03 Nov 2025 06:09:17 -0800

Author: oli.patane@ligo.org

Report ID: 87915

Got called by H1 Manager due to the fast shutter check during CHECK_AS_SHUTTERS failing. I've been looking at the trigger power and various SYS-PROTECTION channels (medm, ndscope), and it looks like to me that the fast shutter test failed only because we lost lock right as it was checking?? You can see the trigger power oscillating along with DRMI as DRMI is right about to fail. However, It does look like the fast shutter did not fire for this test.

So it looked like just a bad coincidence to me, BUT when I went to try opening the shutter manually via the shutter controller, it wouldn't open. I ended up using the FORCE OPEN button, which did work, and after that I was ableto open and close it fine normally.

Looking back further it looks like it doesn't close&open it every time?Looking back on ndscope, it looks like the few times we got up to CHECK_AS_SHUTTERS from the past day, during that state, the fast shutter did not close/open for the test(I thought it was supposed to get opened and closed every relock during CHECK_AS_SHUTTERS??). At 11/02 14:59 UTC it had functioned correctly, but then at the next CHECK_AS_SHUTTERS, it didn't.

I wanted to go just to CHECK_AS_SHUTTERS to see if I could confirm that maybe the failure was just coincidental and based on a lockloss during the test, so I got up to CHECK_AS_SHUTTERS, and it did run the test by itself, but as it closed, it caused a lockloss(ndscope). After this test though, all of the issues on the AS_PORT_PROTECTION screen had cleared, so I went up again. I did accidentally leave the FAST_SHUTTER guardian in SHUTTER_FAILURE though(last time it got reset by my INITing), so that probably affected the next test that I tried on the next CHECK_AS_SHUTTERS. When we got there, it didn't run the test. I realilzed the FAST_SHUTTER guardian was in the wrong state and corrected it, but the test still didn't run, but the ISC_LOCK state marked itself as finished. I manually ran the test from the AS PORT PROTECTION screen, and it caused a lockloss. The test failed and the AS PORT PROTECTION screen is back to having lots of red, with the fault this time saying 'NotReopening'.

Now that it's after 6am Pacific, I'll call Fil or Marc because it definitely seems like something is wrong with the fast shutter, but I'm still a bit confused as to what it is.

P.S. MC2 watchdog just tripped while trying to relock the IMC, but it's okay now

Images attached to this report

H1 General - OPS Sunday EVE shift summary

ryan.crouch@ligo.org — Sun, 02 Nov 2025 22:00:23 -0800

Author: ryan.crouch@ligo.org

Report ID: 87914

TITLE: 11/03 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Microseism
INCOMING OPERATOR: Oli
SHIFT SUMMARY: The lockloss tool does not seem to be working. I was able to lock DRMI and PRMI a few times tonight, I got as high as MAX_POWER. We are in DRMI with the flashes looking decent at the end of the shift.
LOG: No log.

03:00 UTC IA

DRMI locked within 30 seconds now

04:01 UTC lockloss at MAX_POWER, after it had finished the state

04:27 UTC DRMI_LOCKED_CHECK_ASC lockloss

Lockloss

H1 General - Sun day Ops Shift report

anthony.sanchez@ligo.org — Sun, 02 Nov 2025 16:31:57 -0800

Author: anthony.sanchez@ligo.org

Report ID: 87913

TITLE: 11/03 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Microseism
INCOMING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
SEI_ENV state: USEISM
Wind: 4mph Gusts, 2mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.72 μm/s
QUICK SUMMARY:
Once again microseism has been elevated all day. There was a very slight drop in the microsiesm earlier in the day where I was able to get up to locklock loss from Check_AS_SHUTTERS @ 19:49 UTC.
Since then I have gotten past DRMI only once.
LOG:
No log

H1 AOS - Explosions from east side of Yakima Training Center coupling strongly to DARM by exciting EX cryobaffle

robert.schofield@ligo.org — Sun, 02 Nov 2025 16:16:26 -0800

Author: robert.schofield@ligo.org

Report ID: 87912

Robert, Tony

My beating shaker data from Thursday commissioning was ruined by large scattering glitches in DARM. We also saw these glitches on Friday. I found that they were coincident with brief seismic and microphone signals (Figure 1). The coupling site has to be EX because the signals appear in DARM before they reach any other station (Figure 2). I was able to determine that they could be coming from the direction of one crater-marked site on the east side of YTC, but not a more central location that Tony and I had found. The propagation velocity of the 5-20Hz signal is the same for both seismic and acoustic sensors and about 337 m/s indicating that the dominant propagation is through the air not the ground, though it couples to the ground locally. The linear attenuation in the ground at these frequencies is much greater than it is in the air.

The scattering noise produced at EX in DARM has harmonics of about 10 Hz (Figure 1, page 2). This is about the frequency of one of the worst resonances of the cryobaffles (9.7 Hz here: 56857 ). This is a reminder that we did not reduce the light reflected back into the interferometer from the cryobaffles, we just reduced their usual velocity by damping them. The explosions apparently kick the EX one pretty hard. It would be interesting if Detchar could keep track of the YTC glitches and also see if they ever knock us out of lock.

DetChar

Non-image files attached to this report

Fig1-Coincident-DARM-seismic-glitches-10Hz-Harmonics.pdf

Fig2-Propagation-delays.pdf

H1 General - OPS Sunday EVE shift summary

ryan.crouch@ligo.org — Sun, 02 Nov 2025 15:52:07 -0800

Author: ryan.crouch@ligo.org

Report ID: 87911

TITLE: 11/02 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Microseism
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
SEI_ENV state: SEISMON_ALERT_USEISM
Wind: 3mph Gusts, 1mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.77 μm/s, 3 min avg of 1.036 μm/s from a script I have going
QUICK SUMMARY:

The secondary microseism has decreased a slight bit but its still quite high, over the 90th percentile
- Locking is still a struggle
The wind is low

LHO VE - Sun CP1 Fill

david.barker@ligo.org — Sun, 02 Nov 2025 10:20:53 -0800

Author: david.barker@ligo.org

Report ID: 87910

Sun Nov 02 10:11:30 2025 INFO: Fill completed in 11min 26secs

Images attached to this report

H1 General - Sunday Ops Morning shift report

anthony.sanchez@ligo.org — Sun, 02 Nov 2025 07:49:17 -0800

Author: anthony.sanchez@ligo.org

Report ID: 87909

TITLE: 11/02 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
SEI_ENV state: USEISM
Wind: 7mph Gusts, 5mph 3min avg
Primary useism: 0.05 μm/s
Secondary useism: 0.59 μm/s
QUICK SUMMARY:

Walking in to the Control Room, H1 was locking DRMI _1F.
I took the Observing mode back to Microseism after taking control of H1.

H1 has been unlocked for atleast the past 24 hours.
Oli's owl shift was looking pretty rough last night.

But the 2ndairy useism looks to have fallen over the last 12 hours AND the wind forecast is looking great.
So there is some hope we can get locked today!

H1 General - Comment to OPS OWL Intervention pt 2: please go down secondary microseism

oli.patane@ligo.org — Sun, 02 Nov 2025 06:00:35 -0800

Author: oli.patane@ligo.org

Report ID: 87908

Still no luck with getting past DRMI_LOCKED_CHECK_ASC, but secondary microseism levels look to be at a similar level to what we relocked with last time, so I'll let it keep trying. It has been catching multiple times, but it can't stay locked more than a few seconds most times. The length of DRMI locks and places in the code were it loses lock are different every tme, so I don't think it's a different issue?

Going to keep letting the IFO try relocking.

H1 General - Comment to OPS OWL Intervention pt 2: please go down secondary microseism

oli.patane@ligo.org — Sun, 02 Nov 2025 03:23:51 -0800

Author: oli.patane@ligo.org

Report ID: 87907

Time to try relocking again. Going to give this a couple hours to try getting past DRMI, and if it can't I'll put the detector in IDLE for the rest of the night.

H1 General - OPS OWL Intervention pt 2: please go down secondary microseism

oli.patane@ligo.org — Sun, 02 Nov 2025 01:10:53 -0700

Author: oli.patane@ligo.org

Report ID: 87906

Got called again because we can't get past OFFLOAD_DRMI_ASC due to excessively high secondary microseism. We've had three DRMI catches in the last hour, all three of which died before finishing offloading DRMI ASC. Locklosses were from TRANSITION_DRMI_TO_3F, TURN_ON_BS_STAGE2, and DRMI_LOCKED_CHECK_ASC. It definitely looks like the issue is the high secondary microseism. The secondary microseism isn't as bad as it was earlier today, but it's still pretty high (nuc5). Looking at the secondary microseism channels in the Z direction (since that's where it's moving us the most), it looks like the level of microseism that we're seeing right now is the level that we last lost lock at (although we didn't lose lock because of the high microseism - there was some weird wiggle).

So since the secondary microseism looks to be heading downward, if this current DRMI can't catch and we lose lock, I'm going to put the detector in DOWN for now and come back in a couple hours to try again. Hopefully by then the secondary microseism will have gone down a bit further and we'll be able to lock.

Images attached to this report

H1 SEI - OPS OWL Quick Call

oli.patane@ligo.org — Sat, 01 Nov 2025 22:21:43 -0700

Author: oli.patane@ligo.org

Report ID: 87905

Got called 6 minutes into my OWL shift due to the BSC2 ST2 ISI stages tripping during MICH_BRIGHT_LOCKED (in INITAL_ALIGNMENT). The rest of the inital alignment finished fine, so we're attempting to lock now, although I know the very high microseism has been making that really hard today.

H1 General - OPS Saturday EVE shift summary

ryan.crouch@ligo.org — Sat, 01 Nov 2025 22:00:49 -0700

Author: ryan.crouch@ligo.org

Report ID: 87904

TITLE: 11/02 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Microseism
INCOMING OPERATOR: Oli
SHIFT SUMMARY: The secondary microseism is at about the same level as the start of the shift but the wind is much lower. We have not been able to lock DRMI or PRMI for more than a few seconds this shift. The alignment keeps running away, we get stuck in a loop of PRMI to CHECK_MICH. I also adjusted the SQZ SHG_FIBR_REJ power while we we're trying to get DRMI.
LOG: No log.

00:02 UTC IA

After going into CHECK_MICH then back to PRMI it looks worse

02:08 UTC IA

04:50 UTC IA

H1 General - Ops Day shift report.

anthony.sanchez@ligo.org — Sat, 01 Nov 2025 16:33:30 -0700

Author: anthony.sanchez@ligo.org

Report ID: 87903

TITLE: 11/01 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Microseism
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:
H1 has been locked and Observing for 0 hours all day due to High microseism & High wind speeds.
Microseism seems to be slowly coming down.
No calibration was done today.
LOG:
No Log

H1 PSL - PSL Status Report - Weekly

anthony.sanchez@ligo.org — Sat, 01 Nov 2025 16:30:06 -0700

Author: anthony.sanchez@ligo.org

Report ID: 87902

FAMIS 27401 PSL Status Report - Weekly
Laser Status:
NPRO output power is 1.836W
AMP1 output power is 70.51W
AMP2 output power is 139.2W
NPRO watchdog is GREEN
AMP1 watchdog is GREEN
AMP2 watchdog is GREEN
PDWD watchdog is GREEN

PMC:
It has been locked 2 days, 1 hr 40 minutes
Reflected power = 24.68W
Transmitted power = 107.0W
PowerSum = 131.7W

FSS:
It has been locked for 0 days 0 hr and 42 min
TPD[V] = 0.5318V

ISS:
The diffracted power is around 3.4%
Last saturation event was 0 days 4 hours and 37 minutes ago

Possible Issues:
PMC reflected power is high

H1 General - OPS Saturday EVE shift start

ryan.crouch@ligo.org — Sat, 01 Nov 2025 15:37:43 -0700

Author: ryan.crouch@ligo.org

Report ID: 87901

TITLE: 11/01 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Microseism
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
SEI_ENV state: USEISM
Wind: 24mph Gusts, 16mph 3min avg
Primary useism: 0.08 μm/s
Secondary useism: 0.83 μm/s
QUICK SUMMARY:

We haven't been able to relock following the earlier lockloss
Secondary microseism is very high, the wind is high as well

H1 General - Mid shift update

anthony.sanchez@ligo.org — Sat, 01 Nov 2025 13:56:51 -0700

Author: anthony.sanchez@ligo.org

Report ID: 87900

TITLE: 11/01 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Microseism
CURRENT ENVIRONMENT:
SEI_ENV state: USEISM
Wind: 39mph Gusts, 30mph 3min avg
Primary useism: 0.11 μm/s
Secondary useism: 0.77 μm/s
QUICK SUMMARY:

No calibration was done due to, being unlocked.
H1 hasn't been able to get past DRMI all morning.
Secondard microseism has fallen a little bit.... but the wind has picked up the slack. :(
The wind's forcast is not looking great either.

LHO VE - Sat CP1 Fill

david.barker@ligo.org — Sat, 01 Nov 2025 10:35:28 -0700

Author: david.barker@ligo.org

Report ID: 87899

Sat Nov 01 10:08:48 2025 INFO: Fill completed in 8min 44secs

Images attached to this report

H1 General - Sat Morning Ops Shift Report.

anthony.sanchez@ligo.org — Sat, 01 Nov 2025 08:08:23 -0700

Author: anthony.sanchez@ligo.org

Report ID: 87898

TITLE: 11/01 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: USEISM
Wind: 3mph Gusts, 1mph 3min avg
Primary useism: 0.07 μm/s
Secondary useism: 0.87 μm/s
QUICK SUMMARY:

Walking in H1 was unlocked and had been for a while.
Looks like it was a H1 called the Ryan S and gave him a rough 2ndairy useism night for the Owl Shift last night.

I took OPS_Observatory mode back to Microseism since the useism is still elevated unfortunately. I was however able to lock DRMI for a short stint before a lock loss.
We have a 28ft waves in the Gulf of Alaska, and 17ft waves off the coast of WA. Let's see what sort of locking we can do.
But on the bright side.... the STS BLRMS dont look as bad, the wind is low, and I can get DRMI to lock! Maybe we can get locked and stay locked throughout this.

Images attached to this report

H1 General - Comment to Ops Owl Assistance

ryan.short@ligo.org — Sat, 01 Nov 2025 04:09:38 -0700

Author: ryan.short@ligo.org

Report ID: 87897

Not having much luck. Had a couple more unsuccessful attempts at DRMI before running an initial alignment, which doesn't seem to be helping much. I've set H1_MANAGER to try relocking again on its own and I'll check back again in abit.

H1 General - Ops Owl Assistance

ryan.short@ligo.org — Sat, 01 Nov 2025 02:48:34 -0700

Author: ryan.short@ligo.org

Report ID: 87896

H1 called for assistance at 08:20 UTC as it was struggling to relock. Understandable, as the secondary microseism has been rising today and is now to the point where all STS BLRMS are well into the red. After 90 minutes, I finally got H1 to lock DRMI despite good-looking alignment, but it fell apart as it was checking ASC. I'll keep at it for a while, but if the microseism doesn't improve, I may leave H1 down for the night.

Images attached to this report

H1 General - OPS Friday EVE shift summary

ryan.crouch@ligo.org — Fri, 31 Oct 2025 22:00:29 -0700

Author: ryan.crouch@ligo.org

Report ID: 87894

TITLE: 11/01 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: One lockloss with an easy relock, I've left damping off for EX mode1. We've been locked for just over 2 hours.
LOG:

01:29 UTC lockloss

03:41 While in ADS_TO_CAMERAs I saw the 1Hz start so I brought us to ASC Hi Gn and sat for a few minutes before reverting, I slowly stepped through states above LASER_NOISE

03:48 UTC Observing

04:20 UTC The DARM fom started to timeout and lose connection and would stop displaying the data periodically

04:55 UTC Restarted NUC25 to try to revive pimon which I noticed was not running, running just the launch.sh gave an error for it. (The restart did not work either)

H1 AOS - Comment to 01:29 UTC lockloss

ryan.crouch@ligo.org — Fri, 31 Oct 2025 20:50:38 -0700

Author: ryan.crouch@ligo.org

Report ID: 87895

03:48 UTC Observing

H1 AOS - 01:29 UTC lockloss

ryan.crouch@ligo.org — Fri, 31 Oct 2025 18:31:03 -0700

Author: ryan.crouch@ligo.org

Report ID: 87893

01:29 UTC lockloss, there was a wiggle in PR_GAIN right before the LL. Lockloss tool looks to be offline for the last hour.

Lockloss

H1 General - Spooky Halloween Ops Day Shift Report.

anthony.sanchez@ligo.org — Fri, 31 Oct 2025 16:40:38 -0700

Author: anthony.sanchez@ligo.org

Report ID: 87892

TITLE: 10/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:
H1 stayed locked througout the entire shift But there was some DARM commotion from 20 ~40 Hz today
The "Control Room Collectived" decided, warrantlessly, to blame the person slowly driving the boom lift down the length of the beam tube sealing cracks in the top of the beam tube.
We got him on the phone, and the PEM expert asked him to ~~dance~~ do a Seismic injection [18:08 UTC] while we watched him from the roof cameras.
Turns out the 20-40 Hz noise was not from the boom lift & may have been from the artillery range west of here.

18:59 Superevent Candidate S251031cq !!

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:01	FAC'	Randy	MidX	N	Caulking Beam tube & Robert's Seismic Injection test	20:05
18:06	FAC	Kim	Receiving	N	Lifting receiving door	18:11
20:04	SPI	Ryan S	Optics lab	N	Cleaning opitcs	20:50
22:38	OPS	RyanC	Optics lab	N	Swap dust monitors for huddle test	22:47

H1 General - OPS Friday EVE shift start

ryan.crouch@ligo.org — Fri, 31 Oct 2025 15:55:14 -0700

Author: ryan.crouch@ligo.org

Report ID: 87891

TITLE: 10/31 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 8mph Gusts, 6mph 3min avg
Primary useism: 0.11 μm/s
Secondary useism: 0.48 μm/s
QUICK SUMMARY:

Secondary microseism is elevated, just below the 90th percentile
- The range has been slowly dropping over the long lock
We've been locked for over 22 hours
Wind is low
Some violin damping settings are not in as GRD won't let me
- If we drop OBS I'll fix this, the main method od DAMP_FULL_POWER needs to run again

Images attached to this report

H1 General - POP measurements vs model

matthewrichard.todd@ligo.org — Fri, 31 Oct 2025 15:12:49 -0700

Author: matthewrichard.todd@ligo.org

Report ID: 87890

M. Todd, S. Dwyer

Overall Summary: we cannot learn enough from the POP measurements in HAM1 to constrain the values of PR2 and PR3.

We double checked all the distances reported from alog 84307 and the distances of the POP lens in the model, and we found a 3(ish) cm discrepancy. We corrected this discrepancy before doing any fitting or analysis. We use the portion of the measurements in front of the POP lens (towards the POP LSC diode), as they contain enough information at each Gouy phase region in the beam evolution, to fit for a q-parameter in front of the POP lens. We can propagate this to where the other measurements are behind the POP lens to get an understanding of the focal length of the POP lens. Figure 1 shows a plot of the fitted q from the portion of measurements compared to the ones not used.

We saw that this q-parameter was not well collimated behind the POP lens, making us think that the focal length may not be exactly what is in the model/reported. We adjusted the focal length by +2% (reducing lensing power) as is listed in the tolerance of the optic (see D1300313), and found much better agreement with the un-fitted measurements. This is shown in Figure 2, which shows that the overlap with the measurements before the POP lens is better, but the overlap with the model q-parameter is not as good as we would like.

We then increased the radius of curvature of ROM RH3 mirror (in HAM3) by +1%, and saw that the model beam becomes well overlapped with the fitted q-parameter fromt the measurements. This is shown in Figure 3.

Overall, I think this tells us that because we can tweak the parameters of the lenses in the POP path within their specs to give us the overlap we want with the Input mode through the PRC, we cannot use these measurements as a constraint on the values of the PRC telescope optics. It would be great if we could get a few beam profile measurements in transmission of PR2, without the POP lens or RH3 mirror but getting the IMC locked while HAM3 is vented seems unlikely.

Images attached to this report

H1 DetChar - Correlation between ITMX and ITMY ESD bias settings and near-30 Hz near-100 Hz line amplitudes

joan-rene.merou@ligo.org — Fri, 31 Oct 2025 15:03:54 -0700

Author: joan-rene.merou@ligo.org

Report ID: 87889

[Joan-Rene Merou, Alicia Calafat, Sheila Dwyer, Robert Schofield] We have analyzed the evolution of the near-30 Hz and near-100 Hz comb amplitudes, continuing with the work on aLOG 87414. In that alog was shown how there appeared to be a correlation between the ITMY ESD bias and the amplitude of the near-30 Hz and near-100 Hz combs. In this study, we first listed all time intervals between ITMX and ITMY bias changes from the study Robert Schofield did and reported on aLOG 78925 and the associated entries. Robert changed the biases in a number of occasions "for determining the ITM biases that minimize coupling of electronics ground noise". We wanted to see if this was also true for minimizing the amplitude of lines in DARM. The full list of constant-bias segments in-between changes is shown in the following table, which defines the start and end GPS times, along with the corresponding ITMX and ITMY bias values. We have added a few data points in between the ones shown in the related Robert aLOGs.

const_start_gps	const_end_gps	ITMX_bias	ITMY_bias
1403650000	1403651100	0	0
1403651220	1403653448	0	-39
1403653569	1403655679	0	170
1403655799	1403657640	0	-222
1403657760	1403804070	0	0
1403804192	1403804365	0	77
1403804489	1403807629	0	-80
1403807751	1403809555	0	-20
1403809816	1403812204	-40	-40
1403812324	1403816907	36	-40
1403817127	1403820880	36	0
1403821000	1403912193	0	0
1403912517	1403914518	20	-20
1403914684	1403917205	-19	19
1403917405	1404317823	0	0
1404317979	1404319278	-20	-22
1404319453	1404320829	20	-20
1404320940	1404341414	0	0
1404341526	1404342991	0	-20
1404343117	1404344533	0	-40
1404344655	1404346187	40	-40
1404346300	1404413221	0	0
1404413147	1404416077	0	-40
1404416200	1404417200	0	0

For each of these intervals, we performed custom Fscan analyses using DARM and the 5-26 ADC channel as input data with 128 s Tsft. Each Fscan job covered one of the constant-bias segments, allowing us to investigate whether higher ITM biases corresponded to larger spectral peaks in the resulting spectra. The attached plots show the relative amplitude of the first harmonic for the two strongest combs identified near 30 Hz and 100 Hz. In these color scatter plots the X and Y axes represent the ITMX and ITMY bias voltages, respectively. The color scale encodes the relative amplitude ratio (or signal-to-noise ratio) of the selected comb harmonic. These plots correspond to DARM (GDS-CALIB-STRAIN-CLEAN). From the visual inspection, there appears to be a consistent trend where higher absolute ITMY bias values correspond to larger peak amplitudes, the same could be true for ITMX values, but the data does not appear to be conclusive. It would be interesting to get data points with much higher absolute values of ITMX bias. Here is one example for the first harmonic of the highest near-30 Hz combs: Although these results currently refer only to the first harmonic of each comb, this correlation already suggests a relationship between ITMY bias magnitude and the peak amplitude. We also generated the same set of plots for the H1:PEM-CS_ADC_5_26_2K_OUT_DQ ADC channel, to test whether the observed trend in DARM is also visible in the ground current monitor. From these additional plots, the correlation appears less clear. For the near-30 Hz comb. It appears that changing ITM bias values does not change the comb amplitude in the ground monitor. Showing an example for the same comb as before: The current analysis only considers a single harmonic per comb. The next steps are to extend the study to higher harmonics of these combs and check whether the same behavior is observed in other comb families beyond the 30 Hz and 100 Hz series. DetChar

Images attached to this report

Non-image files attached to this report

comb_29969514_offset_0000000_bias_color_correlation_constant.pdf

comb_99998457_offset_0000000_bias_color_correlation_constant.pdf

comb_99998650_offset_0000000_bias_color_correlation_constant.pdf

5_26_comb_29969514_offset_0000000_bias_color_correlation_constant.pdf

5_26_comb_99998457_offset_0000000_bias_color_correlation_constant.pdf

5_26_comb_99998650_offset_0000000_bias_color_correlation_constant.pdf

H1 ISC - Comment to HAM1 POP path beam profile and distance measurements

sheila.dwyer@ligo.org — Fri, 31 Oct 2025 12:02:55 -0700

Author: sheila.dwyer@ligo.org

Report ID: 87888

Here is the layout to reference optic numbers listed above: D1000313-v20

And here are Corey's chamber close out photos: 84561

H1 CDS - FMCS LVEA/VEA fans off for a few minutes between 05:10 and 05:15 early Thursday morning

david.barker@ligo.org — Fri, 31 Oct 2025 11:00:53 -0700

Author: david.barker@ligo.org

Report ID: 87887

Eric, Dave:

Following up on the end station VEA temperature excursions yesterday morning, Eric noticed that the fan accelerometer channels looked strange just prior to that time.

The attached plot shows that most, but not all, of the LVEA/VEA fans were turned off for about 1min40sec each, with the turn off times not coincident, but over a period of several minutes.

FAN	Turn Off	Turn On	Duration
EY	05:13:10	05:14:44	1min34
EX	05:12:32	05:14:13	1min41
MY	05:12:24	05:14:10	1min46
MX	05:11:41	05:13:19	1min38
LVEA-FAN1	05:12:28	05:14:10	1min42
LVEA-FAN2	05:12:31	05:14:12	1min40
LVEA-FAN3	05:10:57	05:12:30	1min33

LVEA-FAN4 is always zero. FAN5 and FAM6 have a signal but no change around this time.

Images attached to this report

LHO VE - Fri CP1 Fill

david.barker@ligo.org — Fri, 31 Oct 2025 10:54:16 -0700

Author: david.barker@ligo.org

Report ID: 87886

Fri Oct 31 10:08:00 2025 INFO: Fill completed in 7min 56secs

Jordan confirmed a good fill curbside.

Images attached to this report

H1 General - Comparing model and measurements of the corner cavities

matthewrichard.todd@ligo.org — Fri, 31 Oct 2025 10:27:49 -0700

Author: matthewrichard.todd@ligo.org

Report ID: 87885

M. Todd, S. Dwyer

Sheila had the idea to use the measurements that Leo and Camilla took of the SQZ beam and OMC scans to constrain the values of some of the output optics (OM1 and OM2 especially), as they are under scrutiny in our work as well.

Leo, Camilla, and Jennie performed OMC scans with the SQZ seed beam to estimate the mode matching of the SQZ beam to the OMC. The mismatch they estimated was between 2.2 and 2.9%. See alogs 86445, 85775.

Using the finesse model, we can propagate the q-parameter that was estimated from beam profiles (see alog 85917) to the OMC and check its mismatch with the OMC eigenmode. The path is summarized: ZM5->ZM6->OFI->SRM->OFI->OM1->OM2->OM3->OMC_IC.

The model estimates that this q-parameter measurement propagated from ZM5 to the OMC input coupler has a 2.3% mismatch with the OMC eigenmode. This gives us a lot more confidence in the radius of curvature of OM2, which was previously one of the optics we believed to have a different RoC compared to the reported value. Especially given that if we use the value of OM2 that would remedy the discrepencies in other measurements vs. models (see alog 87872), this would make the modeled mismatch of the SQZ beam to the OMC around 8.6%, which is far from measurements.

H1 CDS - Comment to Replace bad ADC in h1seiey, +24V Power Supply tripped, laser interlock tripped taking PSL down

david.barker@ligo.org — Fri, 31 Oct 2025 08:35:38 -0700

Author: david.barker@ligo.org

Report ID: 87884

Testing of ADC 110204-18

After Marc replaced the cracked capacitor he discovered, this ADC (pulled from h1seiey) was tested on the DTS Thursday 30oct2025.

x7eetest1 IO Chassis was used. The ADC was installed into A3 by itself, no interface card or ribbon was attached. The chassis powered up with no problems. The ADC was not visible on the PCI bus (lspci and showcards).

Looks like this card is broken and not usable.

H1 CDS - EY environment monitor went offline again 04:30 Fri 31oct2025 PDT

david.barker@ligo.org — Fri, 31 Oct 2025 08:29:28 -0700

Author: david.barker@ligo.org

Report ID: 87883

While I was at EY yesterday for h1seiey recovery I took the opportunity to look at the Geist Watchdog 1250 Environment Monitor (env-ey-1) which at the time was not pingable. I verifed that the unit was updating its front panel display (put my finger over the light sensor). I reseated the ethernet cable (no indication of a problem there) and then power cycled the unit. After restarting the EPICS IOC (cds_env_ey.service on cdsioc0) the EPIC channels came back to life.

At 04:30 this morning the unit went offline again (for the third time). The plot certainly suggests this unit's ethernet port goes offline when the room temperature drops into the mid-70s degF. I will schedule a unit replacement.

Images attached to this report

H1 CDS - Comment to Replace bad ADC in h1seiey, +24V Power Supply tripped, laser interlock tripped taking PSL down

david.barker@ligo.org — Fri, 31 Oct 2025 08:17:47 -0700

Author: david.barker@ligo.org

Report ID: 87882

Here is the +24VDC power supply after we got everything going again. It is drawing about 3.5A

Images attached to this report

H1 General - Spooky Halloween Ops Morning Shift Report.

anthony.sanchez@ligo.org — Fri, 31 Oct 2025 08:12:07 -0700

Author: anthony.sanchez@ligo.org

Report ID: 87881

TITLE: 10/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: USEISM
Wind: 5mph Gusts, 4mph 3min avg
Primary useism: 0.05 μm/s
Secondary useism: 0.45 μm/s
QUICK SUMMARY:

The tree leaves have fallen on to the rocks, while the IFO has been locked.
For 14 hours now, we've been observing, what's out in the universe? What's a swirling?
Waiting for a pair of big monsterous Black Holes to spiral out of control. Into the center of something bigger than Sol.
I hope your day is spooky and you get a sweet treat for your costume
Happy Halloween from LHO Control Room.

H1 SUS - Comment to Violin damping - ETMX mode 6 (beating with ETMX mode1)

rahul.kumar@ligo.org — Thu, 30 Oct 2025 22:13:19 -0700

Author: rahul.kumar@ligo.org

Report ID: 87880

Ryan Short has now put us back into Observing.

H1 SUS - Violin damping - ETMX mode 6 (beating with ETMX mode1)

rahul.kumar@ligo.org — Thu, 30 Oct 2025 22:10:40 -0700

Author: rahul.kumar@ligo.org

Report ID: 87879

ETMX mode 6 was rung up when Oli gave me a phone call. After trying few settings unsuccessfully, I noticed that ETMX mode 1 was beating with mode 6 (they sit closely).

I have turned off the damping for ETMX mode 1 and then started damping ETMX mode 6 with nominal setting and this seems to be working fine.

Ryan Short also confirmed that the DCPD is now looking great (was increasing earlier due to the rung up modes).

SUS

H1 General - Comment to Ops EVE Midshift Status

oli.patane@ligo.org — Thu, 30 Oct 2025 22:07:24 -0700

Author: oli.patane@ligo.org

Report ID: 87878

Looks liek we lost lock in the same placeas one of yesterday's relocking locklosses

Lockloss

Images attached to this report

H1 General - Ops EVE Shift End

oli.patane@ligo.org — Thu, 30 Oct 2025 22:06:33 -0700

Author: oli.patane@ligo.org

Report ID: 87877

TITLE: 10/31 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 147Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: Locked at 147 Mpc and have been Locked for 4.5 hours. Relocking today took a while due to a lockloss right after CLOSE_BEAM_DIVERTERS/beginning of OMC_WHITENING (87873). Coming back up was fine - I just went state-by-state from LASER_NOISE_SUPPRESSION onwards, and we were fine.
2.5 hours in is where it got interesting (87876). I noticed the DCPDs diverging. Since this happened yesterday (87842) and had been due to violin mode ETMX mode 6, I first turned the damping off for that mode since trying to damp the mode more yesterday made it ring up more. This clearly didn't help since the DCPDs started diverging at a faster rate, so I slowly upped the gain from its nominal of 5 up to 13. It seemed to work for a while - the DCPDs levelled out, but then the ETMX damp mode output started increasing again, this time parabolically, and the DCPD MIN and MAX's started wiggling. At this point I turned the gain back down to 9, but then the DCPDs started diverging again so I turned them back to 13. I tried no gain as well as nominal gain again, but DCPDs immediately start diverging. Here's a look at the relationship I was seeing with the damp gain, the damp output, and the DCPDs. I called Rahul. Eventually he decided to try turning off drive for ETMX mode 1 since it is at a similar freuqnecy, and that immediately fixed the problem. Currently he is looking into better settings, but otherwise he will leave damping off for both of them. So what happened yesterday ws probably that the guardian turned off ETMX mode 1, and that solved the problem.

LOG:

23:30UTC Relocking and in ADS_TO_CAMERAS
- Had to turn on Hi ASC gain due to 1 Hz ringup
- Lockloss after CLOSE_BEAM_DIVERTERS/start of OMC_WHITENING
- Got up to LASER_NOISE_SUPPRESSION, waited
- ADS_TO_CAMERAS, waited, turned on Hi ASC gain due to 1 Hz ringup, waited, went back to regular ASC gains
- Stepped through each state individually and waited a few moments, nothing happened
00:38 NOMINAL_LOW_NOISE
- 00:38 Observing
- ~2.5 hours into the lock, DCPDs start divergingg
- 04:49 Out of Observing to try and find better damping settings for ETMX mode 6
- 04:58 Back into Observing
- 04:59 Out of Observing to try and find better damping settings for ETMX mode 6/ 1

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
23:42	PCAL	Tony	PCAL Lab	y(local)	Putting covers on the spheres	23:47

Images attached to this report

H1 General - Ops EVE Midshift Status

oli.patane@ligo.org — Thu, 30 Oct 2025 20:52:24 -0700

Author: oli.patane@ligo.org

Report ID: 87876

Observing at 150 Mpc and have been Locked for almost 3 hours. About 2.5 hours into the lock I noticed that the DCPDs were diverging. Since this happened yesterday (87842) and had been due to violin mode ETMX mode 6, I first turned the damping off for that mode since yesterday trying to damp the mode more made it ring up more (but also brought the DCPDs back together??). This clearly didn't help since the DCPDs started diverging at a faster rate, so I've slowly been upping the gain from its nominal gain of 5, to now 11, which seems to be damping it. I'll probably bump the gain up a bit more to get the DCPDs to start converging.

As expected, the time from finishing the MAX_POWER state to when the DCPDs visibly start diverging yesterday's lock vs today's is about the same, 2hr 37mins-ish (yesterday's lock, this lock)

SUS

Images attached to this report

H1 General - Comment to Ops EVE Shift Start

oli.patane@ligo.org — Thu, 30 Oct 2025 17:40:55 -0700

Author: oli.patane@ligo.org

Report ID: 87875

00:38 UTC Back to Observing. I stepped one-by-one through the states above LASER_NOISE_SUPPRESSION, pausing in between each state and turning the Hi ASC gains on/off as needed, and we were fine and didn't lose lock.

X1 SUS - BBSS model physical d4 value reverted to OG FDR value

oli.patane@ligo.org — Thu, 30 Oct 2025 16:41:02 -0700

Author: oli.patane@ligo.org

Report ID: 87871

Jeff, Oli

Back in 85674 we updated the model paramenter set for the BBSS, bbssopt.m, to better line up with what we were seeing in our measurements at LHO X1 and LLO X2. We ended up adjusting the value of (physical) d4 down by 1mm, so the original FDR physical d4 value of 2.6775 mm was changed in the model to a value of 1.6775mm.

After confirming that LHO's physical d4 value on the dummy mass is currently actually measured to be 2.73mm above the dummy centerline (87767), and that LLO's physical d4 value on the dummy mass is currently measured to be 2.5715mm above the centerline. In 87781 I showed that a +/- 3mm error in the primary prism's location compared to the original FDR-designated physical d4 location would only shift the frequency of that peak by +/- 0.1 Hz, so we don't need to worry about anything with the placement of the primary prisms.

As Jeff said in an email:

"The plots [in 87781] (and specifically pages 1&7 for longitudinal and 5 & 11) show:

(1) where the value of d4 ends up — even +/- 3.0 [mm] from the FDR +4.0 [mm] effective d4 or +2.67 [mm] physical d4 only moves the first pitch mode up or down by 0.1 Hz. We’re talking about only a +/-1 [mm] range around the FDR value.

- Unimpactful for seismic isolation

- Unimpactful for ISC control, and

- Easily accounted for in the top mass damping loop design.

(2) The data that drove us to *think* that (i.e. fit) the physical d4 of 1.67 [mm] on the dummy masses was “in between” a physical d of 1.67 [mm] and 2.67 [mm]. This was *the only* reason 1.67 [mm] was ever brought up instead of 2.67 [mm].

- There was tons of confusion early on about d4, given

:: the confusion about physical vs. effective ds (hopefully now cleared up) and

:: the error in dummy mass being installed / built upside down, and

:: the site-to-site confusion about what to measure,

but all of that is resolved now, and we’re confident that both dummy masses were built “correctly” and the install teams measure, consistently, on the dummy metal build, a physical d4 of 2.67 [mm].

In conclusion — the jig is designed to land the BBSS M3 stage prism on the real optic at a physical d4 of +2.67 [mm], or effective d4 of +4.0 [mm]. That is a totally fine value for d4, and is we’ll call it “ the correct” value, as that’s what the value was in the FDR."

Thus, we are going to revert the physical d4 value in our bbssopt.m model back to what it was originally, d4 = 2.6775 mm, since that's closer to the actual physical measurements that we are seeing, has a very small effect on the resonances, and was the original intended physical d4 value.

The bbssopt.m file has been updated in /ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/TripleModel_Production/bbssopt.m, r12764. It has also been updated in T2000599 (v5).

H1 General - Ops EVE Shift Start

oli.patane@ligo.org — Thu, 30 Oct 2025 16:35:51 -0700

Author: oli.patane@ligo.org

Report ID: 87873

TITLE: 10/30 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 10mph Gusts, 6mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.43 μm/s
QUICK SUMMARY:

Right up about to get back to NLN, had to turn the Hi gains on, we were doing well but then just lost lock right after CLOSE_BEAM_DIVERTERS, suspiciously like what was happening on Tuesday (87826).

LHO General - Ops Day Shift End

thomas.shaffer@ligo.org — Thu, 30 Oct 2025 16:31:25 -0700

Author: thomas.shaffer@ligo.org

Report ID: 87849

TITLE: 10/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Oli
SHIFT SUMMARY: 3 lock losses during my shift today, the first two looked vaguely similar, but we haven't come to any conclusion as to what the cause was. The last one was due to a ADC card failure at SEI EY. During troubleshooting of this the interlocked was tripped and we had to recover all of the site lasers after the ADC card was fixed. We ran an initial alignment and we are now back to NLN. For both of the relocks in the morning the 1Hz ringup didn't show up, but we just saw it come up for this lock. Oli pressed the new high ASC button.
LOG:

1540 Lock loss - 87848
1738 Lock loss - 87856
1913 Observing
2006 Lock loss
- h1iopseiey ADC card error
- Interlocked tripped during EY troubleshooting
- More info for ADC card failure - alog87867
- PSL recovery - alog87866

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:43	FAC	Randy	Xarm	n	BTE sealing, starting at EX	18:43
15:32	PEM	Robert	LVEA	n	Measurement setup	17:32
16:01	IO	Rahul	Opt Lab	LOCAL	JAC optics	17:56
20:25	CDS	Dave, Fil	EY	n	h1iopseiey troubleshoot	21:42
21:07	-	Jeff S	Arms	n	Running arms	22:09
21:11	FAC	Tyler & APEX contractor	Mid Y	N	Contractors doing work in Mid Y	23:11
21:22	Safe T	Danny	Mid X	N	Inspecting Harnesses	23:22
21:24	-	Oli, Tony	LVEA	n	Turning lasers back on	21:44
21:25	-	Fil	EX	n	Turning on ALS laser	21:45
22:01	IO	Keita	Opt Lab	LOCAL	JAC optics	22:38

H1 General - Comparing model and measurements of the corner cavities

matthewrichard.todd@ligo.org — Thu, 30 Oct 2025 16:17:57 -0700

Author: matthewrichard.todd@ligo.org

Report ID: 87872

M. Todd, E. Capote, J. Wright, S. Dwyer

We are attempting to understand discrepancies between model estimates and measurements of various parameters in the corner cavities. In particular, we have measurements of the PRC and SRC Gouy phase [alog 66215, alog 66211], along with input mode (IMC) overlap with the OMC mode from OMC scans [alog 87342], and beam profile measurments at the REFL and POP port in single bounce, with ITMY misaligned [alog 84307].

Using the LHO O4 yaml file in the modeling repo, we can model what we expect these values to be given our understanding of the optics geometries and lengths between optics. We've already identified a few issues with the model as several estimates disagree with the measurements. The first example of this was the SR2 position relative to the SRM and SR3. It was discovered that the model had not accounted for a 5mm shift of the SR2 towards the BS, adding roughly 5mm to each of the corrresponding lengths in the model.

This does not explain all of the discrepancies with measurements, however, so we are exploring how uncertainty in optic geometries can affect the model. Below is a table summarizing this effort so far.

The PR3/SR3 uncertainty in the RoC is +/- 6mm. The PR3 LIGO reported RoC is 36.021, the vendor reports 36.006 mm. The SR3 LIGO reported RoC is 36.013, the vendor reports 36.00. At each bound of these uncertainties, we analyze the beam overlap between the Input mode propagated to the POP port with the q-parameter fit from the measurements. We also analyze the mode overlap between the Input mode and the OMC mode, with ITMX misaligned (this was measured to be 91.7%).

PR3 RoC [m]	SR3 RoC [m]	POP Measurements Overlap [%]	Input Mode to OMC Overlap with ITMX misaligned [%]	PRC Gouy (x, y) [deg]	SRC Gouy (x, y) [deg]
36.015	36.013	70.86	87.03	23.80, 24.17	16.97, 17.86
36.021 (LIGO nominal)	36.013	65.92	85.05	23.16, 23.50	16.97, 17.86
36.027	36.013	61.27	82.69	22.60, 22.90	16.97, 17.86
36.015	36.007	70.86	89.47	23.80, 24.17	19.36, 20.16
36.021	36.007	65.92	87.31	23.16, 23.50	19.36, 20.16
36.006 (vendor report)	36.013	78.23	92.44	24.89, 25.34	19.36, 20.16
(from measurements)		100	91.7	20.5 +/- 0.2	19.5 +/- 0.4

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

matthewrichard.todd@ligo.org — Thu, 30 Oct 2025 16:02:12 -0700

Author: matthewrichard.todd@ligo.org

Report ID: 87870

Adding mode overlap estimates.

Images attached to this report

H1 CDS - Comment to Replace bad ADC in h1seiey, +24V Power Supply tripped, laser interlock tripped taking PSL down

david.barker@ligo.org — Thu, 30 Oct 2025 15:39:57 -0700

Author: david.barker@ligo.org

Report ID: 87869

Updated as-built drawing for h1seiey IO Chassis

Images attached to this report

H1 CDS - Comment to Replace bad ADC in h1seiey, +24V Power Supply tripped, laser interlock tripped taking PSL down

david.barker@ligo.org — Thu, 30 Oct 2025 15:26:36 -0700

Author: david.barker@ligo.org

Report ID: 87868

Tripped power supply location:

Images attached to this report

H1 CDS - Replace bad ADC in h1seiey, +24V Power Supply tripped, laser interlock tripped taking PSL down

david.barker@ligo.org — Thu, 30 Oct 2025 15:15:10 -0700

Author: david.barker@ligo.org

Report ID: 87867

After remotely rebooting h1seiey and seeing that the 4th ADC is now completely absent from the PCI bus, the next test was a power cycle of the IO Chassis.

Procedure was:

Stop h1seiey models, fence from Dolphin and power down the computer.

Dave (@EY):

power down the IO Chassis (front switch, then rear switch)

Power down the 16bit-DAC AI Chassis (prevent overvoltage when IO Chassis is power up)

Power up the IO Chassis (rear switch, then front switch).

The chassis did not power up. Tracking it back, the +24V-DC power strip was unpowered, the laser interlock chassis which is also plugged into this was powered down. This tripped all the lasers.

Fil came out to EY with a spare ADC

Dave & Fil (@EY):

We opened the IO Chassis and removed the 4th ADC. With this slot empty Fil powered up the DC power supply with the IO Chassis on, it did not trip.

We powered down the IO Chassis to install a new ADC. We are skipping the slot the old ADC was in, because it could be a bad slot.

The second DAC was moved from A2-slot4 to A3-slot1, the new ADC was installed in A2-slot4, leaving the suspect A2-slot3 empty.

We powered the IO Chassis on with no problems, then we powered up the h1seiey computer. The models started with no issues, I was able to reset the SWWD.

The chassis was buttoned up, pushed into the rack, and the AI Chassis were powered back up.

Marc is fixing a cracked cap on the old ADC so we can test it offline.

ADCs:

old ADC (Removed)	110204-18
new ADC (Installed)	210128-28