aLIGO LHO Logbook

LHO VE - GV20 Opened

jordan.vanosky@ligo.org — Wed, 30 Sep 2026 18:33:14 -0700

Author: jordan.vanosky@ligo.org

Report ID: 92138

Travis, Gerardo, Jordan, Betsy, Tyler, Richard

This morning we proceeded with the manual opening of GV20. Tyler had made a nice support for the input shaft on the gearbox to stabilize it while rotating the handwheel. This worked great, no additional oil leaked out of the gearbox after installation.

We had left the valve soft closed overnight, so we started raising the valve at 10:41:59 Pacific by turning the handwheel counter clockwise, stopping every 50 turns to check the ballnut/shaft collar gap. No issues found.

At turn 370, we tested to see if the handwheel would be driven backwards by the weight of the gate. No backwheeling was present, so we continued raising the valve stopping every 50 turns to check ballnut/ball screw height. At turn 620 we decided to increase the interval between stoppages to 100 turns. After turn 1520, the top of the ball screw was about even with the top of the clutch body. At 1920, there was enough exposed ball screw to install the safety plate and the locking collars. Locking collars were torqued to 140 in-lbs.

We then continued raising the valve 300 turns (2") at a time, adjusting the lock collars at each interval, until the medm screen showed green.

Final turn count: 7167

Final ball screw height, +37.75" from top of clutch body (open position/green on medm) Note: Height stamped on side actuator body read 37 7/8" for the open position.

The interlock pin was then set, and lock collars were moved to top of safety plate, and torqued to 140 in-lbs. The handwheel was left installed on the gearbox with a clamp on it to prevent rotation.

Full set of compiled notes/details will be posted to the DCC with noises/turn counts/timestamps/ball screw heights/etc.

Images attached to this report

H1 SEI - CRS new Laser Driver installed - CDS TEC loop working

arnaud.pele@ligo.org — Wed, 30 Sep 2026 18:15:53 -0700

Author: arnaud.pele@ligo.org

Report ID: 92137

Jim, Arnaud

wp 13661

We replaced the temporary CRS laser driver with the final version D1500207 (and PCB D1200719-v11) and commissioned the TEC loop. The AC powered Thorlabs TEC is now unplugged from the TCS-R2 rack.

In order of operation:

Took the Laser Chassis hosting the RIO Laser to the EE lab, and added screws and thermal paste between the Laser Diode and the butterfly mount, as recommended in section 7.4.2 of the laser user manual (E2600086).
Reconnected the Laser Chassis and verified we could still get the same power (and noise) with the temporary setup.
Swapped the Laser Driver with the new one, still using the Thorlabs TEC and verified we could get to the same power as with the temporary driver. The knob must now be set at 8.5 to reach the max power.
Turned off the drive to the laser, and commissioned the TEC loop, with the same settings as in 1053. The figure attached (fig1) shows the thermistor readback following the error point request.
After reaching stable temperature, we turned the laser back on and verified the hoqi power and noise was the same as before. Will leave in this state for tonight

To note, the plexiglass key protector was mounted in front of the wrong chassis (Laser Chassis instead of Laser Driver, which controls the state of the laser). We swapped it, so it matches the laser SOP.

Images attached to this report

H1 General - OPS Wednesday eve shift start

ryan.crouch@ligo.org — Wed, 30 Sep 2026 18:14:48 -0700

Author: ryan.crouch@ligo.org

Report ID: 92134

TITLE: 09/30 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 9mph Gusts, 5mph 3min avg
Primary useism: 0.09 μm/s
Secondary useism: 0.15 μm/s
QUICK SUMMARY:

The XARM is open, there is now a full IFO to work with!

23:45 UTC SUSAUXBH234 model restart
23:57 UTC GV20 open
- 00:21 GV19 soft open
- 00:24 UTC GV19 open
I started to run the baffle align GRD states before realizing that the ALS laser was not on...
The MSR racks temperatures have been rising over the past 12 hours

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
16:37	vac	travis.gerardo.jordan.betsy	EX	-	GV20	00:42
23:52	TCS	Camilla	LVEA	N	Take pictures of picomotors at CO2 tables	00:00

H1 General - Updating PCAL Epics entries

anthony.sanchez@ligo.org — Wed, 30 Sep 2026 16:48:49 -0700

Author: anthony.sanchez@ligo.org

Report ID: 92135

Updating the PCAL Epics variables based on the last few End station measurements.

Suggested Epics values for H1:

Channel name	Current value	New Value	Difference
H1:CAL-PCALX_FORCE_COEFF_RHO_T	8300	8301.33	-1.33
H1:CAL-PCALX_FORCE_COEFF_RHO_R	10713.3	10721.3	-8
H1:CAL-PCALX_FORCE_COEFF_TX_PD_ADC_BG	8.81815	-9.46843	18.28658
H1:CAL-PCALX_FORCE_COEFF_RX_PD_ADC_BG	0.56678	-0.574209	1.140989
H1:CAL-PCALX_FORCE_COEFF_TX_OPT_EFF_CORR	0.99331	-0.987685	1.980995
H1:CAL-PCALX_FORCE_COEFF_RX_OPT_EFF_CORR	0.9944	-0.989862	1.984262
H1:CAL-PCALX_XY_COMPARE_CORR_FACT	0.99855	1	-0.00145

H1:CAL-PCALY_FORCE_COEFF_RHO_T	7155.15	7146.49	8.66
H1:CAL-PCALY_FORCE_COEFF_RHO_R	10663.6	10659.1	4.5
H1:CAL-PCALY_FORCE_COEFF_TX_PD_ADC_BG	18.3088	18.5852	-0.2764
H1:CAL-PCALY_FORCE_COEFF_RX_PD_ADC_BG	-0.7353	0.635276	-1.370576
H1:CAL-PCALY_FORCE_COEFF_TX_OPT_EFF_CORR	0.99191	0.983803	0.008107
H1:CAL-PCALY_FORCE_COEFF_RX_OPT_EFF_CORR	0.9931	0.986169	0.006931
H1:CAL-PCALY_XY_COMPARE_CORR_FACT	1.00092	-1	2.00092

caput H1:CAL-PCALX_FORCE_COEFF_RHO_T 8301.33
Old : H1:CAL-PCALX_FORCE_COEFF_RHO_T 8300
New : H1:CAL-PCALX_FORCE_COEFF_RHO_T 8301.33
caput H1:CAL-PCALX_FORCE_COEFF_RHO_R 10721.3
Old : H1:CAL-PCALX_FORCE_COEFF_RHO_R 10713.3
New : H1:CAL-PCALX_FORCE_COEFF_RHO_R 10721.3
caput H1:CAL-PCALX_FORCE_COEFF_TX_PD_ADC_BG 9.46843
Old : H1:CAL-PCALX_FORCE_COEFF_TX_PD_ADC_BG 8.81815
New : H1:CAL-PCALX_FORCE_COEFF_TX_PD_ADC_BG 9.46843
caput H1:CAL-PCALX_FORCE_COEFF_RX_PD_ADC_BG 0.574209
Old : H1:CAL-PCALX_FORCE_COEFF_RX_PD_ADC_BG 0.56678
New : H1:CAL-PCALX_FORCE_COEFF_RX_PD_ADC_BG 0.574209
caput H1:CAL-PCALX_FORCE_COEFF_TX_OPT_EFF_CORR 0.987685
Old : H1:CAL-PCALX_FORCE_COEFF_TX_OPT_EFF_CORR 0.99331
New : H1:CAL-PCALX_FORCE_COEFF_TX_OPT_EFF_CORR 0.987685
caput H1:CAL-PCALX_FORCE_COEFF_RX_OPT_EFF_CORR 0.989862
Old : H1:CAL-PCALX_FORCE_COEFF_RX_OPT_EFF_CORR 0.9944
New : H1:CAL-PCALX_FORCE_COEFF_RX_OPT_EFF_CORR 0.989862
caput H1:CAL-PCALX_XY_COMPARE_CORR_FACT 1
Old : H1:CAL-PCALX_XY_COMPARE_CORR_FACT 0.99855
New : H1:CAL-PCALX_XY_COMPARE_CORR_FACT 1
caput H1:CAL-PCALY_FORCE_COEFF_RHO_T 7146.49
Old : H1:CAL-PCALY_FORCE_COEFF_RHO_T 7155.15
New : H1:CAL-PCALY_FORCE_COEFF_RHO_T 7146.49
caput H1:CAL-PCALY_FORCE_COEFF_RHO_R 10659.1
Old : H1:CAL-PCALY_FORCE_COEFF_RHO_R 10663.6
New : H1:CAL-PCALY_FORCE_COEFF_RHO_R 10659.1
caput H1:CAL-PCALY_FORCE_COEFF_TX_PD_ADC_BG 18.5852
Old : H1:CAL-PCALY_FORCE_COEFF_TX_PD_ADC_BG 18.3088
New : H1:CAL-PCALY_FORCE_COEFF_TX_PD_ADC_BG 18.5852
caput H1:CAL-PCALY_FORCE_COEFF_RX_PD_ADC_BG -0.635276
Old : H1:CAL-PCALY_FORCE_COEFF_RX_PD_ADC_BG -0.7353
New : H1:CAL-PCALY_FORCE_COEFF_RX_PD_ADC_BG -0.635276
caput H1:CAL-PCALY_FORCE_COEFF_TX_OPT_EFF_CORR 0.983803
Old : H1:CAL-PCALY_FORCE_COEFF_TX_OPT_EFF_CORR 0.99191
New : H1:CAL-PCALY_FORCE_COEFF_TX_OPT_EFF_CORR 0.983803
caput H1:CAL-PCALY_FORCE_COEFF_RX_OPT_EFF_CORR 0.986169
Old : H1:CAL-PCALY_FORCE_COEFF_RX_OPT_EFF_CORR 0.9931
New : H1:CAL-PCALY_FORCE_COEFF_RX_OPT_EFF_CORR 0.986169
caput H1:CAL-PCALY_XY_COMPARE_CORR_FACT 1
Old : H1:CAL-PCALY_XY_COMPARE_CORR_FACT 1.00092
New : H1:CAL-PCALY_XY_COMPARE_CORR_FACT 1

CAL

LHO General - Wed DAY Ops Summary

corey.gray@ligo.org — Wed, 30 Sep 2026 16:29:03 -0700

Author: corey.gray@ligo.org

Report ID: 92115

TITLE: 09/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:

GV20 work took place most of the day (and the thought is they may get it open today).

Other work: OMC scans, HAM2 SEI troubleshooting, CRS work, etc.
LOG:

1430-2125 crack sealing on x-arm road (randy)
1522-1800 OMC scans with SQZ beam after OM2 heating (camilla, sheila, ryanS)
1548-1607 technical cleaning @optics lab (kim)
1603 GV20 prep @EX (jordan, gerardo)
1613-1630 Dropping stuff into recycling outside HiBay (christina)
1637 GV20 (travis.betsy)
- Richard also made a trip out there back at 1924
1646 GV20 (tyler)
1738-1747 tcs chiller check (corey)
1750-1858 troubleshoot AI chassis channel for HAM2 SEI (jim.arnaud WP13669)
- 1828 HAM2 ISI tripped
- Overheard Jim tweaking CRS when he got back from CER.
1818 Apollo visitor (contacted bubba to connect with him)
1819-1848 PCal Lab (tony, caroline)
1832-1855 MY parts for storage (ryanC)
2042 Return to GV20 (travis,gerardo,jordan,betsy)
- Saw tyler making a trip to EX at the end of the shift.
2056 CRS work at TCS/CRS rack (jim,arnaud)
2120-2211 SGN group tour in control room and roof
2145 checking on GV20 status at EX (richard)
2158-2210 Checking on LVEA wind sensor (it's busted! Fil will replace it on a future cool morning.) [dave]
2203-2227 CHETA Lab work (camilla.sophie)

H1 CDS - Corner Station Wind Anemometer Support Broken

david.barker@ligo.org — Wed, 30 Sep 2026 15:22:09 -0700

Author: david.barker@ligo.org

Report ID: 92133

Following up on the corner station wind speed going quiet following Friday's wind storm, a quick inspection showed that the anemometer support has broken off and the unit is dangling by its cable at the base of the weather station.

If you look very closely at the photo you can see the swam of flying ants around the weather station which makes working in this area very uncomfortable.

Images attached to this report

H1 SPI - Turned on gains and inputs/output for CPS and GS13 diff channels

jennifer.wright@ligo.org — Wed, 30 Sep 2026 15:01:06 -0700

Author: jennifer.wright@ligo.org

Report ID: 92132

Jennie W

I tried to measure the SPI diff CPS and GS13 monitor channels to compare them to the SPI sensor, I noticed that the GS13 Y and Z DOFs plus the X GS13 and CPS DOFs did not have their gains set to 1 or their outputs were not switched on.

I have fixed this and accepted it in SDF for seiproc.

Images attached to this report

H1 SPI - Comment to SPI optical lever coherence with anti-symmetric port

jeffrey.kissel@ligo.org — Wed, 30 Sep 2026 14:57:24 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 92131

Here's the original time-series that made us realize that the main IFO light was scattering into the SPI's QPDA on HAM2. From that we asked "is it coherent?" and hence all these studies of coherence, and showing the ASDs (less informative). The hope would be that, if coherent, then we could get a linear transfer function to get the *magnitude* of the TF where coherent to have a good estimate of how much power is getting into the SPI. It's 30 seconds of the raw channels in question on 2026-09-22 from 18:00 to 18:05 UTC while the main IFO had corner Michelson aligned and we see exactly the same fringing in QPDA as we do at the IFO AS port. Note that while the coupling is coherent, the time-series on the sum is a +/- 0.001 [V] on a sum of ~35 [V]. While yes, we've shown that even that amount of light can spoil the QPD signal, it may be peanuts amount of light... 35 [V] on QPD A = 28 [mW] of power on QPD A per LHO:92079, so if we calibrate the +/- 0.001 [V] with 28/35 [mW/V] , that's +/0.0008 [mW] = 0.8 [uW]... I also attach the evidence that no PD on HAM3 sees it.

Images attached to this report

H1 SQZ - Grid of SQZ Beam Profiles at Various ZM PSAMS Settings

ryan.short@ligo.org — Wed, 30 Sep 2026 13:29:11 -0700

Author: ryan.short@ligo.org

Report ID: 92103

Yesterday I took several beam profiles of the SQZ beam on SQZT7 using the ThorLabs M² device at various settings for the ZM4 and ZM5 psams as we've done in the past to create a "grid" of values. The psam strain gauge values chosen for this set of measurements was:

ZM4 = [-3.5, -1.5, 0.5, 3.0], ZM5 = [-9.3, -7.0, -5.0, -1.3]

Between Sheila, Camilla, and myself, we were able to produce the attached figures comparing these profile results with the OMC scans taken last week (alog92065) to show the predicted mode mismatch between the SQZ beam and the OMC. The results indicate running on the very low end of the psams range with both ZM4 and ZM5 gives the best mode matching into the OMC with the current ZM2 setting.

EDIT: Fixed some parameters in the code that makes the attached plots so they're more accurate; re-ran and reuploaded here.

Images attached to this report

H1 SEI - Comment to HAM2-3 offline for AI chassis troubleshooting

corey.gray@ligo.org — Wed, 30 Sep 2026 12:19:24 -0700

Author: corey.gray@ligo.org

Report ID: 92130

IMs moved because of this work (Jim warned me). Restored to pointing from 12hrs ago (per Elenna's suggestion). Noticed that IM2, IM3, & IM4 (less so) pitch is cross coupled a little with yaw, but able to get them both back to where they were before this work (see attached screenshot).

SUS

Images attached to this report

H1 SQZ - SQZ to OMC Mode Matching Scans with Hot OM2

camilla.compton@ligo.org — Wed, 30 Sep 2026 11:16:59 -0700

Author: camilla.compton@ligo.org

Report ID: 92124

Ryan S, Sheila, Sophie, Camilla

Repeated SQZ to OMC scans in 92065, now with OM2 hot 92106, thermistor 1 is still changing plot, but the heater has been on for 16 hours has changed from 22deg to 32deg, in the past it has leveled out at 33deg so is >90% of the way there.

Re-touched up OM3/OMC alignment with OMC locked on 00 mode to get misalignment peak <0.5% (plot), saved to /sqz/h1/Templates/dtt/OMC_SCANS/Sept30_2026_OMC_scan.xml

The ran scans with /ligo/gitcommon/squeezing/sqzutils/sqz_to_OMC_mode_matching/omc_scans_sweep_psams.py

PSAM_VALUES_V5 = [-9.3, -7, -5, -1.3]
PSAM_VALUES_V4 = [-3.5, -1.5, 0.5, 3.0]

Interestingly the powers today plot on all diodes in HAM6 a 2-5% higher than last week plot. Unsure if this is caused by OM2 hot or a slightly different FC alignment.

OMC scan plot attached. SQZ to OMC mode matching is worse with hot OM2.

Plots of this with Ryans M2MS data from Monday 92103 propagated with hot OM2 ROC of 1.75m attached. Ryan and Sheila temporarily OM2 ROC edited in it the lho_O4.yaml. Hot 1.75m value from 84255 where cold OM2 ROC is 2.1m.

Scatter Plot
Stem Plot
Contour Plot

We are going to cool of OM2 now.

Images attached to this report

H1 SEI - Comment to Updated SEIPROC Calculations of HAM23 and HAM45 Differential Signals

brian.lantz@ligo.org — Wed, 30 Sep 2026 11:10:23 -0700

Author: brian.lantz@ligo.org

Report ID: 92129

Please, Use the CPS and GS-13 Sensor Differences to Watch the HAM2-3 relative motion, Not the Supersensor Differences

To the extent that the table motion is limited by the noise of the supersensor (and it often is, recall that ground motion though the CPS is equivalent to 'sensor noise', even though we usually track it separately from the CPS readout noise), you can not see that motion in the supersensor. In the past, we've always looked at the CPS or GS-13 signals to estimate the real table motion, and we need to keep doing that.

Questions? I've written this up in T2500279-v2 "Sensor noise coupling to Sensor Output", look at section 7.

One suggestion is to take the sensor difference, filter it, and show that. Do this for both sensors. Do NOT use complementary filters (why would you?). For example, calculate (HAM3 corrected CPS - HAM2 corrected CPS) and filter it with an agressive low-pass filter to keep the part of the spectrum of interest, probably below about 0.5 Hz. For the GS-13 you should probably high pass the difference around 0.1 Hz.

H1 TCS - TCS Chiller Water Level Top-Off (Bi-Weekly, FAMIS #85358)

corey.gray@ligo.org — Wed, 30 Sep 2026 10:54:53 -0700

Author: corey.gray@ligo.org

Report ID: 92122

Addressed TCS Chillers (Wed [sep30] 1038-1047am local time) & CLOSED FAMIS #85358.

For measurements below, measuring from "top" of the red floaty ball.

TCSx Chiller: Had level of 30.5 cm. Added 0mL for 30.5cm.
TCSy Chiller: Had level of 10.6 cm. Added 0mL for 10.6cm.
There was no water in the small cup under the slow leak. (but happened to notice a gooey liquid under the cup).

TCS

H1 SEI - HAM2-3 offline for AI chassis troubleshooting

arnaud.pele@ligo.org — Wed, 30 Sep 2026 10:54:42 -0700

Author: arnaud.pele@ligo.org

Report ID: 92128

offline from 10:53 PT while Jim and Fil troubleshoot AI issues wp 13669, alog 92116

H1 SPI - SPI optical lever coherence with anti-symmetric port

jennifer.wright@ligo.org — Wed, 30 Sep 2026 10:50:06 -0700

Author: jennifer.wright@ligo.org

Report ID: 92127

I redid the measurement of the SPI QPD A that I did in LHO alog #92050. I had been comparing ASC-AS_C_NSUM_OUT_DQ which is calibrated in W at the anit-symmetric port with the individual sum channel of SPI-OL_H23_QPD_A_SUM_OUT_DQ which is in V/V as it is normlaised by the sum of the four segments.

As this measurement is using data from the 22nd, the only DQ'd channels I could compare between the two QPDs are the PIT_OUT_DQ and YAW_OUT_DQ, which are all in V/V.

The measurement shows there is ony coherence between the pitch at the ASC-AS_C QPD and the pitch of SPI QPD A.

The coherence level is 0.6 at 1Hz and drops to near 0 below 0.2 Hz this and above 4Hz.

The transfer function from anti-symmetric port to QPD A has a level of ~7e-6 V/V and a phase of 170 degrees at 1Hz.

This will hopefully have a very small effect on the QPDA and so might not be as much of a problem as I had thought from my previous entry.

Images attached to this report

H1 SEI - Updated SEIPROC Calculations of HAM23 and HAM45 Differential Signals

jeffrey.kissel@ligo.org — Wed, 30 Sep 2026 10:10:27 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 92121

J. Kissel, J. Warner WP:13657 As we starting working through comparisons of SPIH23 with the first instantiation of real-time differential signals computed in the seiproc model with on-board ISIHAM2 and ISIHAM3 sensors, we realized that (a) We should remove a layer of confusion and use the sensor-corrected, "inertial" CPS, rather than the un-corrected CPS. Otherwise, the local "input to the blends" and thus the local super sensor will disagree with the seiproc re-construction as shown in LHO:91990 and LHO:92026; and (b) We're getting greedy in trying to re-create a super-sensor that combines the local GS13s and CPS with a re-production of the blend filters, and then subtracts -- all so we "just" have one trace to compare to SPI signals. However, to reduce computational complexity and signal calibration confusion, we should create a back-up "good enough" solution and do what we did during the SPI conceptual design phase (see LHO:83412). So, yesterday, with the help of Dave (LHO:92104), we installed two changes to the seiproc calculation of (HAM3) - (HAM2) = "H23" and (HAM4) - (HAM5) = "H45" signals. (1) The change that "fixes" (a), we mapped the sensor corrected CPSs from the ISIHAM2, ISIHAM3, ISIHAM4, and ISIHAM5 models to seiproc, rather than the "raw" CPS. (2) We built up parallel infrastructure to the blended super sensor reconstruction that "just" subtracts (HAM{3,4} - HAM{2,5}) GS13s and (HAM{3,4} - HAM{2,5}) GS13s, and (HAM{3,4} - HAM{2,5}) CPS and (HAM{3,4} - HAM{2,5}) CPS. No blends, no calibration, just straight subtraction. The output of the matrix that does the subtraction (2) is fed into filter banks, where -- for now -- only the Y and Z degrees of freedom have an optional "to_nrad" (from [nm]) filter that divides the differential signal by 15.4 [m], i.e. a gain of 0.064935 [1/m]. The MEDM GUI is still under construction, but I've got enough of it functioning that you can see the system: . Screenshot 1 The beginnings of the ISI DIFF overview screen. This is linked from the SITEMAP via the pink SPI menu. On the left is all of the input signals (the seiproc version) from each of the HAMs' CPS (in shades of BLUE) and GS13s (in shades of GREEN). Again, now the incoming CPS are the sensor-corrected CPS. At the top middle is the infrastructure that was already in place to blend the CPS and GS13s together. At the bottom middle, there was only one matrix to subtract the reconstructed super sensor, but now there're two more matrices to subtract the CPSs and GS13s independently, respectively. Finally, again where there was only one set of filters to filter the reconstructed super sensor, now there's two more sets of filter banks to independently calibrate or at least unit convert the differential CPSs and differential GS13s. . Screenshot 2 A shot of the differential CPS matrix, with visual aides drawn on for now (I'll add these labels to the screens themselves in due time). . Screenshot 3 A shot of the differential CPS output filter banks, with the "to_nrad" filter shown turned ON in the Y and Z banks. . Screenshot 4 A shot of the blend filters for the X DOF of HAM2, just to give folks the impression of what's going on here. All of these filters haven't changed since Jim validated that he copied the over from the local ISI models with good fidelity (see LHO:92054). I've turned ON the infrastructure as shown, and accepted those values as "ON" into the SDF system. So -- if you're looking to use these channels, here they are explicitly: (I) Differential CPS (in [nm] or [nrad]): H1:ISI-DIFF_H23_DIFF_CPS_{X,Y,Z,RX,RY,RZ}_OUT_DQ NOTE: This is different and separate from the existing "CPS DIFF" channels, e.g. ISI-DIFF_HAM2_CPS_X -- as these channels are each chamber subracted from *the ISI BS* CPS. Hence the unfortunate new channel "feature" of having DIFF twice in the channel name. (II) Differential GS13 (in inertial sensor units, asymptotes to 1 [nm/s] or 1 [nrad/s]): H1:ISI-DIFF_H23_DIFF_GS13_{X,Y,Z,RX,RY,RZ}_OUT_DQ (III) Pre-subraction, blended, re-constructed super sensor for each chamber (test points, not filter banks; in [nm] or [nrad]): H1:ISI-DIFF_{H2,H3}_BLND_SS_{X,Y,Z,RX,RY,RZ}_DQ (IV) Differential Super Sensor (in [nm] or [nrad]): H1:ISI-DIFF_H23_SS_{X,Y,Z,RX,RY,RZ}_OUT_DQ Again -- for the time being -- the Y and Z channels are calibrated into [nrad] of (differential Y) / L and (differential Z) / L so they can be directly compared with SPI optical lever YAW and PIT signals, respectively, directly. May it all make sense now! #crossesfingers SPI

Images attached to this report

H1 SUS - Comment to QOSEM Noise Hunting - Whitening Gain Comparisons

oli.patane@ligo.org — Wed, 30 Sep 2026 10:05:30 -0700

Author: oli.patane@ligo.org

Report ID: 92126

These results line up with what I had found comparing the two whitening modifications in 92094

LHO VE - Comment to Test Manual Opening of GV20

jon.feicht@ligo.org — Wed, 30 Sep 2026 09:47:17 -0700

Author: jon.feicht@ligo.org

Report ID: 92125

Thanks for the image! I looked up the GV-11 gearbox and it is a F724-30-B7-J so its opposite handed compared to this one. Explains the rotation CCW (GV-20) vs CW (GV-11) to open issue. We need to add the gearbox P/N as part of the valve inspection record. -JRF

LHO VE - Comment to Test Manual Opening of GV20

gerardo.moreno@ligo.org — Wed, 30 Sep 2026 09:39:54 -0700

Author: gerardo.moreno@ligo.org

Report ID: 92123

Photo of name plate for gearbox at GV20. Photo is flipped to accommodate easy reading of the name plate.

Images attached to this report

H1 SEI - CRS damping works - but some issue with AI chassis to solve

arnaud.pele@ligo.org — Wed, 30 Sep 2026 09:27:58 -0700

Author: arnaud.pele@ligo.org

Report ID: 92116

Jim, Arnaud

Following yesterday's installation of the new interface chassis, the CRS capacitive actuators were tested this morning by injecting an impulse voltage to each plate while the CRS was damped. We confirmed that we could ring up the CRS with each injection, see fig1.
We also confirmed the problem with dac0 chan 14 (ai chan 15) from the ham2 hepi AI (U37) as reported here - we see less motion when actuating on that channel (first impulse on fig1) compared to the other channel.

The damping loop was tested and worked with a gain of -2e9 (fig2). This gain was integrated in the dampBP filter, so the damping can be engaged with a gain of +1. We won't measure the Q until the AI chassis is replaced.

Images attached to this report

H1 TCS - TCS Monthly Trends (FAMIS #85474)

corey.gray@ligo.org — Wed, 30 Sep 2026 09:22:16 -0700

Author: corey.gray@ligo.org

Report ID: 92120

Attached are monthly TCS trends for HWS & CO2 lasers. (FAMIS 85474)

Adjusted each of the plots a little bit to see data (or see it a little better); a little laggy, perhaps because of lots of data in the plots?

HWS note: for ITMx & ITMy SLED powermon are both slowly trending down.

TCS

Images attached to this report

H1 AOS - HVAC Fan Vibrometers FAMIS Check (FAMIS 85191)

corey.gray@ligo.org — Wed, 30 Sep 2026 09:01:21 -0700

Author: corey.gray@ligo.org

Report ID: 92119

For FAMIS #85191: All fan trends look fairly flat & normal.

Images attached to this report

LHO VE - Comment to Test Manual Opening of GV20

stephen.appert@ligo.org — Wed, 30 Sep 2026 08:59:21 -0700

Author: stephen.appert@ligo.org

Report ID: 92118

Re: "We confirmed there was only 1 set screw per hole, but they were not brass tipped set screws as expected.

I note that per D1300876-v1, Item 40 (cup point set screw, stainless steel) is used to lock Item 19 (ball nut) in place. In the LGV-11 retrofit, a soft tip set screw was selected, but that does not appear to be the case in the original build. Any expectation of soft tip set screw at the ball nut-drive shaft interface appears to be cross-talk with the LGV-11 retrofit.

H1 PSL - PSL Status Report (FAMIS #85575)

corey.gray@ligo.org — Wed, 30 Sep 2026 08:54:10 -0700

Author: corey.gray@ligo.org

Report ID: 92117

This is for FAMIS #85575.
Laser Status:
NPRO output power is 1.868W
AMP1 output power is 70.75W
AMP2 output power is 139.4W
NPRO watchdog is GREEN
AMP1 watchdog is GREEN
AMP2 watchdog is GREEN
PDWD watchdog is GREEN

PMC:
It has been locked 7 days, 22 hr 41 minutes
Reflected power = 28.68W
Transmitted power = 105.1W
PowerSum = 133.7W

FSS:
It has been locked for 0 days 0 hr and 18 min
TPD[V] = 0.5104V

ISS:
The diffracted power is around 3.6%
Last saturation event was 4 days 17 hours and 39 minutes ago

Possible Issues:
PMC reflected power is high

PSL

LHO General - Wed DAY Ops Transition

corey.gray@ligo.org — Wed, 30 Sep 2026 08:25:46 -0700

Author: corey.gray@ligo.org

Report ID: 92114

TITLE: 09/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 6mph Gusts, 4mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.16 μm/s
QUICK SUMMARY:

GV20 work continues after left in soft-close overnight. ISC LOCK in IDLE overnight. Will unlock front doors.

H1 SUS - QOSEM Noise Hunting - Whitening Gain Comparisons

thomas.roocke@ligo.org — Wed, 30 Sep 2026 07:40:07 -0700

Author: thomas.roocke@ligo.org

Report ID: 92113

Summary: In switching QOSEM whitening gains from the 1st to 2nd modification, there has been a slight increase in noise in the P and Y DOFs, all others uneffected. Whitening gain should be increased again by a factor of 2-3x.

This is one in a series of posts investigating the excess noise seen on the BBSS M1 QOSEMs. In short, at both LHO and LLO, the noisefloor of the QOSEMs appears to be around 8pm/rtHz at 100Hz, quickly increasing to 50pm/rtHz by 1Hz; where we expect the noisefloor to be flat at ~5pm/rtHz across this bandwidth. See more details in LHO alog 91466.

Below in Figure 1, we plot QOSEM readout spectrums when the sat amp was configured with the 1st and 2nd modifications of whitening gain, as described in LHO:91998. The 1st modification dataset was taken from T0:1470725000, during which BBSS M1 damping was on. The 2nd modification dataset was taken from T0:1474137198, during which BBSS M1 damping was off, explaining the additional peaks seen in 2nd modification dataset.

This shows that the reduced whitening gain has not significantly impacted the QOSEM noisefloor, and further rules it out as the source of the excess noise. There is a slight increase in noisefloor in the pitch and yaw DOFs in the 2nd modification whitening, so there is a case that whitening is insufficient and should be increasing by a small margin again, perhaps a factor of 2-3x or so.

SUS

Non-image files attached to this report

figure1_lho_qosem_whitening_comp.pdf

H1 SUS - QOSEM Noise Hunting - ADC noise with new whitening

thomas.roocke@ligo.org — Wed, 30 Sep 2026 06:51:50 -0700

Author: thomas.roocke@ligo.org

Report ID: 92112

Summary: ADC noise is very close to, if not limiting the QOSEM signals. It doesn't seem to be enough to explain the elevated QOSEM noisefloor seen, but whitening gain should not be lowered any futher than it already is.

At both LHO and LLO, changes have been made to the QOSEM sat amp to reduce the whitening gain (see LHO:91853 and LLO:82137), in response to long saturation periods when the BBSS is rung up. In the figures below we plot noise budgets of the LHO BBSS, now including the new whitened ADC noise floor. The expected noisefloor of the GS 16 Bit ADC was taken from T1000322. Keep in mind that the true ADC noise floor often varies from channel to channel and unit to unit. Informally, I've heard they can vary by as much as factors or 2-3, especially towards the lower frequencies, however I dont have any solid reference for this.

Figure 1 shows the raw voltage noise of the QOSEM signals (Sum, XDiff, YDiff) after dewhitening, along with expected shot noise level and ADC noise. During this section of data, the BBSS damping loop was off, and the QOSEM LED sum feedback was turned off (see LHO:92011 for details). Here we see that the ADC noise is very close, if not limiting the QOSEM XDiff and YDiff signals, particularly if we consider true ADC could vary higher than shown. Certainly, whitening gain should not be reduced any futher.

Figure 2 shows an open loop noise budget of the BBSS M1, now with the whitened ADC noise propagated in. Again we see that the ADC noise is very close to, if not limiting, particularly at the high frequencies.

With this said, I'm not convinced we can blame ADC noise for this excess QOSEM noise we've been seeing. In prior budgets (such as LHO:91871), LHO QOSEMs were running with about 10x more whitening gain and the QOSEM noise floor was not sigificantly different. With that said whitening should certainly not be lowered any further.

SUS

Non-image files attached to this report

figure1_lho_qosem_vnoise.pdf

figure2_lho_qosem_nbudget.pdf

LHO VE - Comment to Test Manual Opening of GV20

gerardo.moreno@ligo.org — Tue, 29 Sep 2026 23:13:21 -0700

Author: gerardo.moreno@ligo.org

Report ID: 92111

Measurements of GV19 open and closed, photos attached.

Images attached to this report

LHO VE - Test Manual Opening of GV20

jordan.vanosky@ligo.org — Tue, 29 Sep 2026 18:03:36 -0700

Author: jordan.vanosky@ligo.org

Report ID: 92110

Travis, Gerardo, Jordan, Betsy, Tyler, Richard

This afternoon we began the process for opening GV20, following the procedure outlined in E2600314.

To prep, Tyler machined a 7/8" hole in the 8" diameter handwheel so we could drive the gearbox by hand. We then closed GV19, measuring the distance from the top of the clutch body to the top of the ball screw in the open and closed positions.

Open: +37 9/16" Closed: -10 5/16" (zero is the top of the clutch body)

Moving on to GV20, the motor had been decoupled from the gearbox yesterday, so we again confirmed the measurement from the top of the ball screw to the clutch body with the valve closed.

Closed: -10.125" (zero is the top of the clutch body).

Then we torqued the loose set screws on the top clutch retaining nut. We confirmed there was only 1 set screw per hole, but they were not brass tipped set screws as expected.

We then proceeded to check the set screws on the drive shaft collar/ball nut. We had to rotate the drive shaft in order to access to these set screws, so we began turning the handwheel clockwise, per procedure at 1:48:40 Pacific. There was some increased resistance after~20 turns, and then at turn 31 the clutch popped (1:56pm Pacific). We stopped and called Jon F to discuss. We re-measured the ball screw position and found it at -10 5/16", so the ball screw had been driven down and that's what popped the clutch. We then turned the hand wheel counter clockwise with a scale on the ball screw and confirmed it was indeed raising. After 15 turns, the clutch reset and then at turn 31 (net 0) we stopped and re-measured the ball screw and it had returned to -10 1/8". We then checked the ballnut and confirmed no threads had been exposed.

We then met with the rest of the group on Zoom to discuss before proceeding with the rest of the procedure. We decided to continue raising the valve until we could check the set screws on the drive shaft collar, then raise it 1" past the point where the valve un-cams then set it back down 1" to confirm operation and rotation is as expected.

So we continued raising the valve by turning the handwheel counterclockwise, stopping every 50 turns to inspect the ballnut and measure the height of the ballscrew to confirm it was raising. At turn 171 (3:22 pm) the valve state turned from red to yellow on the medm screen. We used this as the point of "soft close". The ball screw height was exactly -9" at this point. We noticed a small amount of oil dripping from the gearbox during raising. We then continued raising for the 1" test after turn 171 (expected 150 turns per inch, so 321 turns total) again stopping every 50 turns to check the ballnut. When stopping rotation of the handwheel, it rotate slowly backwards (clockwise), but would stop after varying fractions of a turn (maximum was ~1/2 turn, with caveat that I never fully released to wheel, so I could stop rotation if needed).

Once we got to turn 321 (3:37:40 Pacific), we stopped, checked the ballnut and measured the ball screw height of exactly -8". We then lowered the valve by turning the handwheel clockwise back 150 turns (3:49:00 Pacific), where it will remain overnight. By this time more oil had dripped from the gearbox, we put a foil tray underneath to collect any oil that may come out overnight. Pictures below are of the oil at the end of the day, after lowering the valve back to soft close position.

We will meet with the group tomorrow morning to decide the next steps.

Images attached to this report

LHO General - OPS Eve Shift Summary

ibrahim.abouelfettouh@ligo.org — Tue, 29 Sep 2026 17:30:02 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 92109

TITLE: 09/30 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: None
SHIFT SUMMARY:

IFO is in CORRECTIVE MAINTENANCE

VAC Update: GV20 is soft-closed with plans to open it tomorrow pending an investigation (waiting for update alog)

CRS Update: Jim has left HAM3 to damp using the ISI overnight. There was progress today - alog 92108

IFO was left in a single-bounce state in IDLE

OSB Doors were closed after conference

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:34	FAC	Randy	X-arm	N	sealing cracks in beam tube enclosure	19:37
14:35	CDS	Jonathan	MSR	N	Prox mox upgrades	16:35
14:55	FAC	Kim	EY	N	Technical cleanin & resupply	17:17
15:21	FAC	Christina	Woodshop & receiving.	N	Forklifting parts.	16:21
15:24	FAC	Chris	LVEA	N	spot painting the LVEA walls.	17:54
15:50	SUS	Oli	CR	n	BS meas	16:05
16:09	EE	Fil	EX	N	Camera Work	18:16
16:13	Tour	Elenna + 5	LVEA	N	LVEA tour	16:50
16:14	FAC	Kim	LVEA	No	technical Cleaning & Resupply	19:03
16:46	CDS	Dave	Remote	N	Restarting ALL HAM Models except 6	17:31
16:47	PEM	Miranda	Mech room	N	Taking pictes of SEI PEM kits.	16:53
16:48	EE	Marc & Arnaud Jim	LVEA	N	Pulling CRS Cables. Marc out early	19:55
16:49	DetEng	Betsy	CER	N	Getting parts.	16:59
16:54	VAC	Travis & Jordan	LVEA	N	Looking for tools.	17:03
16:57	TCS	Camilla	LVEA	Yes	Working on cheta	18:09
17:32	CDS	Dave	Remote	N	DAQ restarts for SEIPROC ,CRSPROC for HAM6	18:05
17:58	VAC	Gerardo, Travis, Jordan	EX	n	Closing GV19	19:58
18:12	TCS	Camilla & James	LVEA	N	Moving the CHETA table.	18:39
18:37	EE	Fil	EY	N	Camera Work	19:51
18:40	TCS	Camilla	CHETA Lab	yes	plugging in a cheta to the beckhoff.	18:50
19:36	FIT	Noah	X-arm	N	Running X arm	20:15
19:49	FAC	Randy	X-Arm	n	Sealing Beam tube enclosure.	21:41
20:19	VAC	Tyler, Besty, Jordan, Gerardo, Travis	EX	N	working on GV20	23:16
22:40	SEI	Jim & Arnaud	LVEA	N	working on CRS near TCS rack	23:21
23:10	PCAL	Carolyn, Tony	PCAL Lab	Local	Loosening screws to get a better measurement	23:43
23:17	FAC	Tyler	EX	N	Last min EX Vac work	00:17
00:05	VAC	Jordan	EX	N	Grabbing stuff	00:29

H1 SEI - CRS progress - cable pulling and new Interface chassis

arnaud.pele@ligo.org — Tue, 29 Sep 2026 17:17:47 -0700

Author: arnaud.pele@ligo.org

Report ID: 92108

Jim, Marc, Arnaud

wp 13661, CRS wiring D2600186

1- Pulled 2 new, 140ft db25 cables from TCS-R2 to SEI-C1 rack in anticipation of the laser driver swap, which includes new laser monitor channels and TEC driver channels. The cables are labelled CRS LASER 4 and CRS LASER 5 (as per wiring diagram D2600186). There is about 30ft of excess cable on the LVEA side, which was routed on the side of the TCS rack (no cabling left on the floor). See detailled alog from Marc here 92097.

2- Swapped the CRS interface chassis with the final version D2400073. Given the transimpedance amplfiier has a gain of 15.8k [V/A] compared to 4.99k with the previous chassis, we do see an increase of a factor of 3 in the hoqi signal (see fig1).

The only issue we encountered today is the HEPI AI on SEI-C2 U27 that drives the CRS cap plates has dac0 channel 14 (AI chan15) is not responding as expected (only showing +6.3/-5.5 when requesting +/-10V, see picture attached.

Left to do:

Take pictures of the new cables, and where they are plugged to for posterity
Fix the cts2mW calibration for both hoqi pds
Write down the SN of the chassis installed and the SN of the new cables installed
Finish commissioning the CRS damping
Swap the Laser Driver chassis and commission the TEC loop
Send redlines to Dean on the CRS wiring diagram

Images attached to this report

H1 General - Tuesday Maintenance Day OPS Report

anthony.sanchez@ligo.org — Tue, 29 Sep 2026 16:58:51 -0700

Author: anthony.sanchez@ligo.org

Report ID: 92107

TITLE: 09/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:

Work today:
ISIs on HAMs2 and 3 were both tripped today. But the IMs were trended back using the driftmon scopes found under the slider scopes button on the LSC-->Locking.adl

Dave has an awesome CDS summary link here.

VAC - EX GV 20 Manual open per procedure (will take all day) ----> Still in progress GV19 And GV20 are now both softclosed.
~~Jim - Restart CRSPROC. Some math is missing, add factor 8x that is missing from the contrast calculation for CRS. No daq restart.~~
~~CDS/Jim/Kissel - Restart isiham2-5, seiproc models to switch out which CPS signals are used for reconstructing the ISI DIFF super sensors.~~
~~CDS - isiham6 model restarts to add IPC connections for CRS laser driver~~
~~CDS - Convert all usercode usages of arctan in crsproc~~
~~CDS - observe.snap file updates for 10 models, safe.snap chan updates for: sfc2, susauxb2h34, iopsusb13, calcs~~
~~CDS - virtual machine (proxmox VM) cluster work, hopefully not impacting for if it is, user interfaces will be down for the day~~
Kissel - HAM2-3 driven measurements ???
Fil - Install cable for NN at EY, vac rack to BSC10
~~Fil - install camera at EX in air handler room~~ Kinda..... this one is not working now.
Fil - Investigate 3IFO monitoring signal loss, dust mons offline at times since tied together ---> ?
~~VAC - LN2 delivery CP3 (MY) & CP8 (EX)~~
FAC - Churn test of fire pumps ----> ?

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:34	FAC	Randy	X-arm	N	sealing cracks in beam tube enclosure	19:37
14:35	CDS	Jonathan	MSR	N	Prox mox upgrades	16:35
14:55	FAC	Kim	EY	N	Technical cleanin & resupply	17:17
15:21	FAC	Christina	Woodshop & receiving.	N	Forklifting parts.	16:21
15:24	FAC	Chris	LVEA	N	spot painting the LVEA walls.	17:54
15:50	SUS	Oli	CR	n	BS meas	16:05
16:09	EE	Fil	EX	N	Camera Work	18:16
16:13	Tour	Elenna + 5	LVEA	N	LVEA tour	16:50
16:14	FAC	Kim	LVEA	No	technical Cleaning & Resupply	19:03
16:46	CDS	Dave	Remote	N	Restarting ALL HAM Models except 6	17:31
16:47	PEM	Miranda	Mech room	N	Taking pictes of SEI PEM kits.	16:53
16:48	EE	Marc & Arnaud Jim	LVEA	N	Pulling CRS Cables. Marc out early	19:55
16:49	DetEng	Betsy	CER	N	Getting parts.	16:59
16:54	VAC	Travis & Jordan	LVEA	N	Looking for tools.	17:03
16:57	TCS	Camilla	LVEA	Yes	Working on cheta	18:09
17:32	CDS	Dave	Remote	N	DAQ restarts for SEIPROC ,CRSPROC for HAM6	18:05
17:58	VAC	Gerardo, Travis, Jordan	EX	n	Closing GV19	19:58
18:12	TCS	Camilla & James	LVEA	N	Moving the CHETA table.	18:39
18:37	EE	Fil	EY	N	Camera Work	19:51
18:40	TCS	Camilla	CHETA Lab	yes	plugging in a cheta to the beckhoff.	18:50
19:36	FIT	Noah	X-arm	N	Running X arm	20:15
19:49	FAC	Randy	X-Arm	n	Sealing Beam tube enclosure.	21:41
20:19	VAC	Tyler, Besty, Jordan, Gerardo, Travis	EX	N	working on GV20	23:16
22:40	SEI	Jim & Arnaud	LVEA	N	working on CRS near TCS rack	23:21
23:10	PCAL	Carolyn, Tony	PCAL Lab	Local	Loosening screws to get a better measurement	23:43
23:17	FAC	Tyler	EX	N	Last min EX Vac work	00:17

H1 AWC - OM2 heating overnight

sheila.dwyer@ligo.org — Tue, 29 Sep 2026 16:40:54 -0700

Author: sheila.dwyer@ligo.org

Report ID: 92106

Ryan Short, Sheila

We turned OM2 H1:AWC-OM2_TSAMS_POWER_SET to 4.6W we will let this heat overnight so we can measure squeezer to OMC mode scans tomorow morning.

SQZ

H1 SQZ - adjusted filter cavity green pico's

sheila.dwyer@ligo.org — Tue, 29 Sep 2026 16:38:25 -0700

Author: sheila.dwyer@ligo.org

Report ID: 92101

Sheila, Ryan Short, Camilla

Summary: Following up on 92044, we pico'd the filter cavity green co-alignment with the squeeze beam, we now have 90% of the best green transmission we saw last week at the same time as the IR is aligned to have 5% power in the 1st order HOM and 3% power in the second order HOM.

I moved the H:M1 and H:M2 picos to improve the green flash height in the filter cavity; if we try to move the picos when the filter cavity is locked in green it looses lock. I can see that if I move far enough we start to loose power on the FC refl diode, I have not gone to the table to see if this is clipping on the in air or in vacuum path. I was able to increase the green transmission from 8 counts to 12 counts. Comparing this to a time from thursday when FC1 + FC2 were aligned to maximize green transmission, we had 19.4 counts on FC_TRANS_C for 7.3mW of FC laucnh power, so the filter cavity tranmission is 90% of what it was for that time (19:30 UTC Sept 24 2026) once we take into account the launch power drifting. We don't understand why we needed to adjust these as we checked that the green and red were co-alinged right before we closed HAM7, 91497.

VCO scan after this is attached, misalignment mode 5% of the 00 mode, mode mismatch is about 3%. Ryan realized that we were saturating the FC trans PD with seed in our first scan, and may also have been saturating it in 92044.

Images attached to this report

H1 CDS - Comment to CDS Maintenance Summary: Tuesday 29th September 2026

david.barker@ligo.org — Tue, 29 Sep 2026 16:21:35 -0700

Author: david.barker@ligo.org

Report ID: 92105

MODEL REV UPDATE LIST

diskless)controls@h1build:~$ rtcds rev-update h1crsproc
Changed dependency revisions in new version:
crs/h1/models/h1crsproc.mdl : r36063 --> r36133
isi/common/models/crs_block.mdl : r36011 --> r36134

Removed dependencies in new version:
cds/common/src/ATAN2.c

(diskless)controls@h1build:~$ rtcds rev-update h1isiham1
Changed dependency revisions in new version:
isi/common/models/blend_switch_library.mdl : r31180 --> r33982
isi/common/models/isihammaster_2022.mdl : r31465 --> r36124
isi/h1/models/h1isiham1.mdl : r31300 --> r35402

(diskless)controls@h1build:~$ rtcds rev-update h1isiham2
Changed dependency revisions in new version:
isi/common/models/isiham23_o5.mdl : r35560 --> r36118

(diskless)controls@h1build:~$ rtcds rev-update h1isiham3
Changed dependency revisions in new version:
isi/common/models/isiham23_o5.mdl : r35560 --> r36118

(diskless)controls@h1build:~$ rtcds rev-update h1isiham4
Changed dependency revisions in new version:
isi/common/models/isihammaster_2022.mdl : r35419 --> r36124

(diskless)controls@h1build:~$ rtcds rev-update h1isiham5
Changed dependency revisions in new version:
isi/common/models/isihammaster_2022.mdl : r35419 --> r36124

diskless)controls@h1build:~$ rtcds rev-update h1isiham6
Changed dependency revisions in new version:
isi/common/models/isihammaster_2022.mdl : r31465 --> r36124
isi/h1/models/h1isiham6.mdl : r25380 --> r36130

Changed dependency revisions in new version:
isi/common/models/isihammaster_2022.mdl : r31465 --> r36124
isi/h1/models/h1isiham7.mdl : r25201 --> r35384

diskless)controls@h1build:~$ rtcds rev-update h1isiham8
Changed dependency revisions in new version:
isi/common/models/blend_switch_library.mdl : r25383 --> r33982
isi/common/models/isihammaster_2022.mdl : r26008 --> r36124
isi/common/models/isihammaster_blend_fader.mdl : r26008 --> r36126
isi/h1/models/h1isiham8.mdl : r25201 --> r36125

diskless)controls@h1build:~$ rtcds rev-update h1seiproc
Changed dependency revisions in new version:
isi/h1/models/h1seiproc.mdl : r36047 --> r36129

H1 CDS - CDS Maintenance Summary: Tuesday 29th September 2026

david.barker@ligo.org — Tue, 29 Sep 2026 16:10:51 -0700

Author: david.barker@ligo.org

Report ID: 92104

WP13657 ISI Sensor Correction.

This restart was originally slated for h1isiham[2,3,4,5] with [2,3] changes added to the common isiham23_o5 and the [4,5] with the isihammaster_2022 mdl file. But the latter is also used by h1isiham[1,6,7,8] so we ended up restarting all eight of the ISI HAM models today.

The h1isiham[1,2,3,4,5,7,8] restarts went first, none of these required a DAQ restart. They were restarted between 09:46 and 09:49.

WP13665 Add IPC between h1isiham6 and h1crsproc

Ethernet IPC channels were added to both models, going in both directions. DAQ restart was required.

WP13649 Add gain to h1crsproc

In addition to the above, add a gain to the model.

WP13656 Remove ATAN2.c function call from h1crsproc

In addition to the above, the ATAN2.c function call was replaced with the atan CDS part.

WP13612 h1seiproc model wiring changes.

WP13636 Proxmox Cluster Updates and re-keying

Please see Jonathan's alog from earlier today.

Restart Summary

Full list of models restarted today:

h1isiham[1,2,3,4,5,6,7,8] h1crsproc, h1seiproc.

DAQ Restart

The DAQ was restarted for the models h1isiham6, h1crsproc and h1seiproc.

There were no issues with the DAQ restart.

CHETA chassis move to LVEA and swap in Optics Lab.

In February 2026 the CHETA ITMX chassis was installed in the Optics Lab and it was connected to the MSR Slow Controls Bechhoff Chassis in the MSR via a long ethernet link which ran via Rm163, the computer users room and from there underfloor to the MSR.

Today Camilla moved the ITMX chassis into its permanant location in the LVEA. This will be connected to the Beckhoff network at a later stage. In the Optics Lab, the ITMY chassis was connected to the MSR chassis.

So at this time the ITMX chassis is not being read out, and the ITMY chassis is being read as ITMX.

When it comes time to connect ITMX LVEA chassis to Beckhoff, the ITMX channels will be redirected to it and a new ITMY set will be created for the Optics Lab chassis.

While this swap was ongoing this morning the DEV1 Beckhoff unit's slave count dropped from 19 to 7.

H1 OpsInfo - Arm Baffle Alignment Code Moved into ALS_ARM Guardian Nodes

ryan.short@ligo.org — Tue, 29 Sep 2026 14:55:09 -0700

Author: ryan.short@ligo.org

Report ID: 92098

I have adapted the code from "the baffle/dither align scripts" into new Guardian states in the ALS_XARM and ALS_YARM nodes called BAFFLE_ALIGN_TMS, BAFFLE_ALIGN_ITM, and BAFFLE_ALIGN_ETM.

Previously, the baffle alignment scripts for each arm were run via a button on the INIT_ALIGN.adl screen. All of the code used was spread across multiple functions in three separate files in the /userapps/asc/h1/scripts/ directory: ditherAlign.py, baffleAlign.py, and slowDemod.py. Since this process was just a user running a script, there was no logging of what was done, it wasn't clear when these scripts were run if someone wanted to trend back that information, and multiple users could mistakenly run these at the same time.

Now, there are states in the ALS_XARM and ALS_YARM Guardian nodes that will appropriately mis/align optics as necessary and run through the baffle alignment process for the desired suspension. To do this, I created a new file called baffle_align_params.py that lives in /userapps/als/h1/guardian/ which contains the parameters and functions called by the new baffle align states. Functionally these states work the same as the scripts did, but it's now more clear when these are running and we have a record of what happens in the process that can be looked back on. These states are all branched off of the UNLOCKED state so that an arm can't accidentally be locked while the baffle alignments are running, and they are protected states so that the process can't be interrupted partway through (except for switching the node's operating mode to "manual" and moving to another state, which would require manually reverting alignment changes and closing any open excitations).

I tested the functionality of the new states this morning and have appropriately committed everything to svn.

GRD, ISC, OpsInfo

H1 SUS - BBSS M1 OLGs: (M1 damping ON) vs( M1 and M3->M2 damping ON)

oli.patane@ligo.org — Tue, 29 Sep 2026 14:40:08 -0700

Author: oli.patane@ligo.org

Report ID: 92095

On Friday I took two sets of BBSS M1 OLG measurements - the first measurement (blue (/cyan)) had damping ON for M1, but damping OFF for M2 and M3 (aka M3->M2 damping OFF, aka no actuation on M2 or M3). The second measurement (red (/pink)) had damping ON for M1 as well as damping ON for M3->M2 (aka actuation on M2, aka nominal in ALIGNED).

The only difference I really see between the two sets of measurements is in Yaw. Without the M3->M2 damping, there is an extra peak 0.4 - 0.6 Hz, but turning M3->M2 damping ON completely removes that.

Settings:
- In HEALTH_CHECK
- M1 DAMP ON
- SEI_BS FULLY_ISOLATED
- SEI_ENV CALM

M1 DAMP ON, M3->M2 DAMP OFF
(2026-09-25 ~17:30 UTC)
Data:
/ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Data/2026-09-25_1730_H1SUSBS_M1_CDBIOState1_WhiteNoise_{L,T,V,R,P,Y}_0p02to50Hz_OLGTF.xml
r13182

M1 DAMP ON, M3->M2 DAMP ON
(2026-09-25 ~18:25 UTC)
Additional Settings:
- M3->M2 DAMP ON
- M3 OSEM signals go up to M2 and M2 is actuated on to damp
- 'OLDAMP' bank
Data:
/ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Data/2026-09-25_1825_H1SUSBS_M1_CDBIOState1_M3toM2dampON_WhiteNoise_{L,T,V,R,P,Y}_0p02to50Hz_OLGTF.xml
r13184

Images attached to this report

H1 SEI - Installation of Newtonian Noise Power Cable - EY

filiberto.clara@ligo.org — Tue, 29 Sep 2026 13:51:55 -0700

Author: filiberto.clara@ligo.org

Report ID: 92100

WP 13663

In preparation for the installation of the Newtonian Noise Array, a power cable was installed from the vacuum rack to BSC10. A power distribution box will be installed near BSC10.

H1 General - PZT Camera Installed at EX

filiberto.clara@ligo.org — Tue, 29 Sep 2026 13:46:53 -0700

Author: filiberto.clara@ligo.org

Report ID: 92099

WP 13666

A PZT camera was installed in the EX VEA. It is mounted on the cable tray entering the VEA. A PoE injector is powering the camera. Camera is connected to the network via the access switch in the air handler room.

CDS

H1 SEI - Complete the permanent CRS electronics installation in anticipation of IR1

marc.pirello@ligo.org — Tue, 29 Sep 2026 13:20:38 -0700

Author: marc.pirello@ligo.org

Report ID: 92097

WP13661

We finished step 3 of this WP, pulling two of the 140ft DB25 cables from TCS-R2 to the SUS-C1 in the CER.

We started by laying out the cables, wiping them down, and testing them to for continuity. As expected pin 13 is connected to shield on one end of the cables, keep this in mind for future, these are reused cables, so the shield connected end may not be the end of choice. There was plenty of extra cable length left, this was pulled to the TCS rack side. The CER end of the cable has enough slack to be moved over to Beckhoff if this is required in the future.

A. Pele, M. Pirello, J. Warner

H1 CDS - WP 13636 Proxmox VM updates with a CephX rekeying

jonathan.hanks@ligo.org — Tue, 29 Sep 2026 11:01:46 -0700

Author: jonathan.hanks@ligo.org

Report ID: 92096

As per WP 13636 the VM cluster was updated. This is normally a routine activity. It was elevated to a work permit due to extra steps required. To address CVE-2025-30156 the Ceph layer (which manages the shared file storage for the virtual machines) needed to have authentication methods updated and new keys issued.

As part of the prep work I removed some disks that had been put in with the goal of making them a local zfs store for each node. The issue was they had been used as ceph test disks and not completely cleaned up. So I pulled the disks so that the update scripts did not see those and cause errors. Another part of the upgrade prep was verifying the backup and restore process.

There was no user/host downtime for this work. There were no issues when the update was done. The local proxmox documentation is good, it provided the workflow that was used.

The work steps:

Do updates as normal.
- The ceph system will mark itself in an error state. The system is functional, it is alerting us to the fact that the ceph layer needed to be re-keyed. This is part of the reason this operation was not done earlier. We did not want do the upgrade until we were ready to re-key and had time to respond to problems if any came up. Updating w/o re-keying leaves your storage layer in an error state and makes it easy to miss a failed disk or problem OSD.
Then on one box only do the following:
- Sanity check the migration plan for rotating cluster keys, look for blockers by running:
  - /usr/share/pve-manager/migrations/pve-cephx-rotate-service-keys --rotate-cluster-keys
- Apply the first stages of migration
  - /usr/share/pve-manager/migrations/pve-cephx-rotate-service-keys --rotate-cluster-keys --apply
- At this point ceph health moves from ERR to WARNING
- Check the next step, rotating user keys
  - /usr/share/pve-manager/migrations/pve-cephx-rotate-service-keys --rotate-all-storage-keys --rotate-admin-key
- Apply if no blockers
  - /usr/share/pve-manager/migrations/pve-cephx-rotate-service-keys --rotate-all-storage-keys --rotate-admin-key --apply
- At this point we need to live-migrate everything that is running, so that the active clients pick up the new ceph keys. Livemigration, stop/start will do it, a quick restart will not.
- Do a final check of the system
  - /usr/share/pve-manager/migrations/pve-cephx-rotate-service-keys
- This directs to do:
  - /usr/share/pve-manager/migrations/pve-cephx-rotate-service-keys --apply --confirm-all-clients-refreshed --restrict-ciphers

H1 SUS - BBSS M1 satamp comparison between 1st and 2nd whitening modifications

oli.patane@ligo.org — Tue, 29 Sep 2026 10:13:08 -0700

Author: oli.patane@ligo.org

Report ID: 92094

I've made a comparison of the 1st vs the 2nd BBSS M1 satamp whitening modifications(see 92051 for timeline). Unfortunately there is a small difference (besides the whitening of course) between the environmental configurations - the second time (for the 2nd mod configuration) was during a time when SEI_ENV was in MAINTENANCE, which slightly raises the noise we see at lower frequencies. Eventually we'll be able to get the correct adc configurations on these plots so we can see where those would lie. Hopefully by then we will also have a better second time where we are in nominal SE_ENV conditions.

I had to get two different sets of loop suppression for each whitening configuration. The OLG measurement dates used for each measurement are listed and shown in the individual plots.

Results:
/ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Results/2026-09-29_allDampRegressCompare_H1SUSBS_M1_NoiseComparison_1469227619vs1473639115-1200.pdf
r13183

Data:
/ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Data/2026-07-27_dampRegress_H1SUSBS_M1_1469227619_1200.mat
/ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Data/2026-09-17_dampRegress_H1SUSBS_M1_1473639115_1200.mat
r13182

Non-image files attached to this report

2026-09-29_allDampRegressCompare_H1SUSBS_M1_NoiseComparison_1469227619vs1473639115-1200.pdf

LHO FMCS - HVAC Fan Vibrometers FAMIS Check #85190

ryan.crouch@ligo.org — Tue, 29 Sep 2026 08:54:46 -0700

Author: ryan.crouch@ligo.org

Report ID: 92029

Closes FAMIS85190, last checked in alog91956.

All the fans look the same as they did in the last check. No changes.

Images attached to this report

H1 General - Tuesday Morning OPS report

anthony.sanchez@ligo.org — Tue, 29 Sep 2026 08:17:06 -0700

Author: anthony.sanchez@ligo.org

Report ID: 92093

TITLE: 09/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 16mph Gusts, 11mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.23 μm/s
QUICK SUMMARY:
Lovely fall morning today.
SUS charge Guardians did not run today.

CDS team hit the ground runnin this mornin! Jonathan is already working on ProxMox, Dave is building models, and Erik has alread rebooted workstations.
I just took ALL SEI_HAM Gaurdians have been taken to ISI_Damped_HEPI_OFFLINE in preperation for restarts.
The IMC_LOCK Guardian has been taken to OFFLINE already.

Notes for Dust mons:
H1:PEM-CS_DUST_LVEA5 Error: data set contains 'not-a-number' (NaN) entries

Expected work today:

VAC - EX GV 20 Manual open per procedure (will take all day)
Jim - Restart CRSPROC. Some math is missing, add factor 8x that is missing from the contrast calculation for CRS. No daq restart.
CDS/Jim/Kissel - Restart isiham2-5, seiproc models to switch out which CPS signals are used for reconstructing the ISI DIFF super sensors.
CDS - isiham6 model restarts to add IPC connections for CRS laser driver
CDS - Convert all usercode usages of arctan in crsproc
CDS - observe.snap file updates for 10 models, safe.snap chan updates for: sfc2, susauxb2h34, iopsusb13, calcs
CDS - virtual machine (proxmox VM) cluster work, hopefully not impacting for if it is, user interfaces will be down for the day
Kissel - HAM2-3 driven measurements
Fil - Install cable for NN at EY, vac rack to BSC10
Fil - install camera at EX in air handler room
Fil - Investigate 3IFO monitoring signal loss, dust mons offline at times since tied together
VAC - LN2 delivery CP3 (MY) & CP8 (EX)
FAC - Churn test of fire pumps

PEM

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 29 Sep 2026 07:42:14 -0700

Author: erik.vonreis@ligo.org

Report ID: 92092

Workstations were updated. This was an OS packages update and a conda packages update.

The conda update includes:

This environment updates ndscope to 0.22.3. This changes ndscope to use the ARRAKIS_SERVER environment variable to connect to an Arrakis server. Add "--arrakis" at the command line to select ARRAKIS_SERVER. "--arrakis-server <arrakis-url>" will use a the specified URL.

diaggui has been updated to 4.2.3. It also now uses the ARRAKIS_SERVER variable to populate the Arrakis URL box on the input tab.

diag 4.2.3 now has its own "--arrakis" option to connect to ARRAKIS_SERVER when the "open" command is given.

emacs has been added in an attempt to get newer emacs on to CDS workstations.

A large number packages aimed at ldas analysis pipelines have been dropped because of incompatibilities.

Full list of changes to the conda environment here:
https://git.ligo.org/cds/packaging/cds-conda-distribution/-/wikis/Environments#version-2026-09-28-01

CDS

H1 IOO - JAC Heater stable

jennifer.wright@ligo.org — Mon, 28 Sep 2026 18:16:19 -0700

Author: jennifer.wright@ligo.org

Report ID: 92089

Jennie W

I still have some work to do on the JAC heater but it has stayed locked for 3 days, since Friday when we took the JAC down for an unrelated reason.

There is still some oscillation around the set point but the PZT length fb is staying within a 77V range.

We might need to check this again once we are at 62W for long periods as this will increase the heat load.

We have gone to 10W for periods less than an hour and can see no difference in the PZT length fb over this time.

This is too short a test to say how the cavity will respond to an increased heat load.

The last time I switched the heater off (first cursor) after I reverted some guardian changes on Wednesday that rang up the temperature servo, the system took 2.5 hours to cool down by 0.1 degree C (second cursor), this was the minimum temperature it reached before I switched the heater back on 6 hours later.

Aftyer switching the heater back on with the controller running the temperature took 19 hours roughly to reach equilibrium.

I'm still trying to calculate what frequency to put my lead compensation filter at to speed this up.

Summary: JAC heater working well and staying locked for multiple days at 2W and 10W input power but more tests needed at higher power. The step reponse time is still on the order of 1 day for the system while under control so some more filter changes are neccessary.

Images attached to this report

LHO VE - Corner Station Vacuum Envelope Open To The Arms

gerardo.moreno@ligo.org — Mon, 28 Sep 2026 18:05:25 -0700

Author: gerardo.moreno@ligo.org

Report ID: 92091

(Jordan, Travis, Gerardo)
Today we opened GV5 and GV7, no issues opening both gate valves. Instrument air pressure to open the gate valves was 45 psi, and both of them were set at 55 psi to remain open. The turbo pumps that were on, YBM and XBM main turbo pumps, were stopped, they'll be powered off tomorrow, they need time to stop spinning. After, the purge air compressor and dryer tower was turned off and powered off. The corner station vacuum envelope is back to nominal.

H1 SEI - Comment to CRS engaged on HAM3 now that the weather is cooperating

arnaud.pele@ligo.org — Mon, 28 Sep 2026 17:52:49 -0700

Author: arnaud.pele@ligo.org

Report ID: 92090

The CRS was only in loop for about 2 hours during those times (it was automatically reverted by a guardian after an earthquake)

09/25 - 19:04 UTC / 12:04 PT
09/25 - 21:36 UTC / 14:36 PT

H1 IOO - Comment to Offloaded JAC WFS

jennifer.wright@ligo.org — Mon, 28 Sep 2026 17:45:37 -0700

Author: jennifer.wright@ligo.org

Report ID: 92088

Images attached to this report

LHO General - OPS Eve Shift Summary

ibrahim.abouelfettouh@ligo.org — Mon, 28 Sep 2026 17:44:31 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 92087

TITLE: 09/29 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: None
SHIFT SUMMARY:

IFO is in CORRECTIVE MAINTENANCE

Calm evening where I helped Tony and Elenna with their ALSY WFS stuff (alog 92085)

Oli transitioned the LVEA back to SAFE in prep for VAC work in the morning.

I secured the two OSB doors that were unlocked for the conference.

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:12	FAC	Kim	EX MX	N	Technical cleaning & Resupply	16:58
16:16	VAC	Jordan	LVEA	N	Isolating the Turbo pumps.	16:25
16:59	Laser Transition	Camilla	LVEA	N	Transitioning to Laser Hazard	17:16
17:16	SQZ	Camilla & Ryan C	LVEA SQZT0	YES	Aligning beams and AOMs on SQZT0	18:32
17:30	SEI	Jim & Arno	Mid Y	N	Looking for Cables	18:11
17:52	FAC	Kim	MY	No	Technical Cleanin	17:51
18:10	SEI	Jim & Arno	CER	y	Checking ports on AA chassis.	18:34
20:28	SQZ	Camilla & Ryan	SQZT0	YES	AOM Alignment & M^2 measurements, Camilla out	22:29
20:28	FAC	Randy	X-arm	N	Sealing the Beam tube.	23:58
20:29	FAC	Mitchell	Mid X&Y	No	Looking for supplies.	20:44
22:00	VAC	Travis Gerardo Jordan	EX	N	Gate Valve 20 prep!	00:43
22:31	SEI	Jim & Arno	LVEA near TCS racks	y	Working on CRS racks.	00:33
22:35	TCS	Camilla	CHETA Lab	yes	Cheta lab work	23:23
23:22	EE	Fil	EX	N	Helping with GV20 work	00:43
00:17	OPS	Oli	LVEA	Y	Transitioning to Laser SAFE	00:43

H1 IOO - Offloaded JAC WFS

jennifer.wright@ligo.org — Mon, 28 Sep 2026 17:42:51 -0700

Author: jennifer.wright@ligo.org

Report ID: 92086

Jennie W

Elenna asked me to offload the JM1 and PZT alignment offsets in case they get affected in the model restart tomorrow. I will have to add a state for this. Its more annoying to do as the integrators are in the SUS LOCK filter banks for JM1 and in the ASC filter banks for the PZT mirror.

H1 ISC - Baffle Alignment Scripts Ran for TMSY and ITMY

ibrahim.abouelfettouh@ligo.org — Mon, 28 Sep 2026 17:24:48 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 92085

Ibrahim, Oli, Tony

For Yarm script, IY was misaligned.

For TMSY script, TMSY was misaligned

Tony ran the TMSY baffle alignment and the Oli and I ran the ITMY/Yarm baffle Alignment. We can confirm that there are now new offsets. We then ran through ALSY alignment with WFS (and then offloaded them) successfully. In prep for tomorrow's DAQ restart, we have offloaded MCWFS.

H1 General - Dither align scripts. AKA Baffle Align scripts.

anthony.sanchez@ligo.org — Mon, 28 Sep 2026 16:47:00 -0700

Author: anthony.sanchez@ligo.org

Report ID: 92084

TITLE: 09/28 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:

Gate Valve 5 & Gate Valve 7 are now open! Gate Valve 20 is still closed, BUT.... the VAC team is preparing to open it tomorrow.
IFO beam tube enclosures are being sealed at the cracks between the enclosure.

Dither aka Baffle scripts were ran:
ITMY: MissAligned.
ETMY: MissAligned
Then ran TMSY dither script.

Once finished I then Aligned ITMY then ran the ITMY dither script.

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:12	FAC	Kim	EX MX	N	Technical cleaning & Resupply	16:58
16:16	VAC	Jordan	LVEA	N	Isolating the Turbo pumps.	16:25
16:59	Laser Transition	Camilla	LVEA	N	Transitioning to Laser Hazard	17:16
17:16	SQZ	Camilla & Ryan C	LVEA SQZT0	YES	Aligning beams and AOMs on SQZT0	18:32
17:30	SEI	Jim & Arno	Mid Y	N	Looking for Cables	18:11
17:52	FAC	Kim	MY	No	Technical Cleanin	17:51
18:10	SEI	Jim & Arno	CER	y	Checking ports on AA chassis.	18:34
20:28	SQZ	Camilla & Ryan	SQZT0	YES	AOM Alignment & M^2 measurements, Camilla out	22:29
20:28	FAC	Randy	X-arm	N	Sealing the Beam tube.	23:58
20:29	FAC	Mitchell	Mid X&Y	No	Looking for supplies.	20:44
22:00	VAC	Travis Gerardo Jordan	EX	N	Gate Valve 20 prep!	01:00
22:31	SEI	Jim & Arno	LVEA near TCS racks	y	Working on CRS racks.	00:20
22:35	TCS	Camilla	CHETA Lab	yes	Cheta lab work	23:23
23:22	EE	Fil	EX	N	Helping with GV20 work	01:22

H1 SQZ - SQZT0 Green Pump Path Alignment Improvement

camilla.compton@ligo.org — Mon, 28 Sep 2026 15:19:15 -0700

Author: camilla.compton@ligo.org

Report ID: 92080

Ryan S, Camilla, Sheila. Followed 82881. WP 13645.

We touched up alignment in SQZT0 Green Pump path.

Starting:
- Into EOM: 70mW
- Out of EOM: 66mW (94% throughput)
- Out of AOM (0V): 16mW (24% throughput)
We touched up EOM alignment and then AOM alignment with 0V on DRIVE_ALIGN:
- Into EOM: 95mW
- Out of EOM: 92mW (97% EOM throughput)
- Out of AOM (0V): 88mW (95% throughput). With this AOM alignment the first order beam (5V on DRIVE_ALIGN) was very dim.
Final:
- Out of AOM (0V): 68mW (77% AOM throughput)
  - 9mW in first order beam as we've aimed for in the past 87233.

Ryan and I then reduced the power going into the fiber to 25mW with the waveplate and touched up the alignment into the fiber. Starting 0.2mW, ending 3.3mW which seems around typical O4 level.

Before we did this, we noticed the beam was high and clipping on the OPO-REFL diode so we adjusted the steering mirror MG4 and checked the beam was centered on the REJECTED diode with MG5 (D2000242).

H1 TCS - ITMX ring heater set to 0.44 W/segment

elenna.capote@ligo.org — Mon, 28 Sep 2026 15:10:35 -0700

Author: elenna.capote@ligo.org

Report ID: 92083

I set ITMX ring heater back to nominal 0.44 W per segment just after 15:00 today local time.

I also set SR3 disk heater to 0 W at this time, it had been set to 4 W at 11:10 today local time for gouy phase measurements.

H1 SUS - ETMX still looking gooooood

oli.patane@ligo.org — Mon, 28 Sep 2026 14:37:44 -0700

Author: oli.patane@ligo.org

Report ID: 92082

Took transfer functions again on Friday (sept 25) as another verification of ETMX L1 LL still no longer rubbing (and entire suspension still being healthy). Measurements are still looking good.

Settings:
- SEI nominal
- HEALTH_CHECK
- DAMP OFF
- alignment offsets ON

M0
Data:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Data/2026-09-25_1730_H1SUSETMX_M0_WhiteNoise_{L,T,V,R,P,Y}_0p02to50Hz.xml
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Results/2026-09-25_1730_H1SUSETMX_M0_ALL_TFs.pdf
r13181

R0
Data:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGR0/Data/2026-09-25_1800_H1SUSETMX_R0_WhiteNoise_{L,T,V,R,P,Y}_0p02to50Hz.xml
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGR0/Results/2026-09-25_1800_H1SUSETMX_R0_ALL_TFs.pdf
r13180

Images attached to this report

H1 General - Monthly Hanford Systems test

anthony.sanchez@ligo.org — Mon, 28 Sep 2026 13:00:06 -0700

Author: anthony.sanchez@ligo.org

Report ID: 92081

Hanford called to tell us:
Alarms, sirens, and tones will sound today at 20:15 UTC (1:15 local time) at Hanford for 20 seconds for their monthly test.

PEM

H1 SPI - H1SPIH23 Sees 35% Increase in Input Power after EOM Swap / PMC Power Increase; SPI Prep Chassis input now (modeled to be) 240 [mW]

jeffrey.kissel@ligo.org — Mon, 28 Sep 2026 11:58:07 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 92079

J. Kissel On Sep 14 and Sep 15 2026 (see LHO:91891 and LHO:91925, respectively), the PSL team swapped out the primary RF EOM in the PSL from "former, damaged by a dust storm in the PSL" to "refurbished spare." After the dust EOM was discovered to cause mode-matching issues in the IFO due to thermal distortions caused by the dust, we re-allocated the power through the PSL, such that there was less power going through the EOM. This was done by throttling the power out of the PMC. After replacing the EOM, they restored the "nominal" power allocation through the PSL, re-increasing the power output of the PMC. That power increase out of the PMC means the the ALS / SQZ / SPI pick-off path now has more power, and thus the SPI. According to various optical power monitor channels, there's 35% more power in the SPI system. see first attachment 1-month trend, where the vertical bar time cursor highlights the EOM swap / powr increase. Assuming nothing else changed, that changes our power budget to as follows (just taking the values from LHO:90627 and increasing them by 35%): Former [mW] New Power [mW] PSL IN port of SPI prep 178.0 240.75 MEAS Fiber output at HAM3 D4-1J1 64.0 86.56 REF Fiber output at HAM3 D4-1J2 18.3 24.75 Output of MEAS Fiber Collimator 64.0 86.56 Output of REF Fiber 15.0 20.29 In front of FBR_PWRIN_MEAS 1.0 1.35 In front of FBR_PWRIN_REF 1.1 1.49 Launched to HAM2/QPDA 42.0 56.81 (putting the power on QPDA behind 50R:50T M_C1 at 28.4 [mW]) Returned from HAM2 21.4 28.94 (putting the power on QPDB behind 50R:50T M_B4 at 14.5 [mW]) (c.f. designed power budget E2400441, and optical layout D2400108). Thankfully, no ADC channels of photodiodes are saturating at this increased power level; see proof in short timeseries of IFO PDs, QPDs, and FBR_PWRIN PDs. We should review these new power levels along the signal chain and consider throttling the SPI pick-off path input. My biggest point of concern is power through the long optical fiber run between the PSL and the SPI prep chassis. The second biggest concern is the total power in the QPDs.PSL

Images attached to this report

H1 CDS - How to :: Replacing CDS Function Call version of atan2.c with CDS_PARTS atan2 function block -- one-to-one drop-in replacement

jeffrey.kissel@ligo.org — Mon, 28 Sep 2026 10:29:25 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 92078

J. Kissel for the CDS Team IIET:32407 ECR:E2400394 EXECUTIVE SUMMARY: When replacing the cdsFunctionCall to the user-code atan2.c function with the CDS_PARTS cdsAtan2 block per IIET:32407 / ECR:E2400394, reconnect the inputs exactly as you found them, treating the numerator "y" and denominator "x" as the first and second inputs, respectively, in order to achievethe desired mathematical expression theta = atan2(y/x). Supporting Details The above referenced ECR demands that users replace any cdsFunctionCall use of ${CDS_SRC} = /opt/rtcds/userapps/release/cds/common/src ${CDS_SRC}/ATAN2.c rev 24024 with the now-integrated cdsAtan2 gui interface block that lives in the simLinkParts block of /opt/rtcds/rtscore/advLigoRTS-5.5.2/src/epics/sinLink/ CDS_PARTS.mdl library. Because the former cdsFunctionCall block relies on the poorly-documented c-code to determine the number and order of inputs, and the code itself -- quoted below void ATAN(double *argin, int nargin, double *argout, int nargout) { argout[0]=latan2(argin[0],argin[1]); } -- points to a built-in CDS sub-function latan2 which I couldn't find a description of (maybe it's some custom CDS version of atan2l, for "atan2 long double?"), I wasn't 100% confident in which order we should stick the previous inputs when using the cdsFunctionCall into the new CDS_PARTS version. EDIT: I was able to retro-actively find and confirm that latan2 is after Line 123 of tagged release 5.5.2 (git commit hash 4b167593) of the git.ligo.org/CDS/software/advLigoRTS/ repository. Though it's not commented, the input variables are defined clearly as latan2( double __y, double __x ) So, here I show what builds my confidence enough to say the input order for this user function is the same as the CDS_PARTS block -- by showing successful examples of the *old* block that have already been upgraded to the *new* block. Thankfully, it seems like there's some industry standard for atan functions, in which the first input is the numerator "y", and the second input is the denominator, "x", within the mathematical definition, / y \ / input[0] \ theta = atan2 | --- | = atan2 | ---------- | \ x / \ input[1] / and both versions within CDS follow that convention. So, here, I attach (1) BEFORE Screenshot 1: /opt/rtcds/userapps/release/cal/common/models/CAL_LINE_MONITOR_MASTER.mdl rev r35945 The MAGNITUDE_PHASE library block when it still used the cdsFunctionCall to ${CDS_SRC}/ATAN2.c (2) AFTER Screenshot 2: /opt/rtcds/userapps/release/cal/common/models/CAL_LINE_MONITOR_MASTER.mdl rev r36124 The same MAGNITUDE_PHASE library block after being updated by Joe Betzwieser on 2026-08-27 (installed at LHO on 2026-09-02; see LHO:91779) (3) WHERE TO FIND cdsAtan2 Screenshot 3: /opt/rtcds/rtscore/advLigoRTS-5.5.2/src/epics/sinLink/CDS_PARTS.mdl The simulinkParts library within the latest release of CDS_PARTSCAL, CDS, ISC, SEI, SPI, SQZ

Images attached to this report

H1 PSL - PSL 10-Day Trends

ryan.short@ligo.org — Mon, 28 Sep 2026 09:47:51 -0700

Author: ryan.short@ligo.org

Report ID: 92077

FAMIS 63918

There was a brief incursion into the PSL to check diode alignments last Tuesday and is clearly seen on several trends as expected. Jason also touched up the RefCav alignment and adjusted the ISS RefSignal on Friday. No other major events of note this week.

Images attached to this report

H1 General - Monday OPS morning report

anthony.sanchez@ligo.org — Mon, 28 Sep 2026 08:25:32 -0700

Author: anthony.sanchez@ligo.org

Report ID: 92076

TITLE: 09/28 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 5mph Gusts, 3mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.22 μm/s
QUICK SUMMARY:

Seems like there has been some close seismic activity in the last 12 hours.
I noticed today when walking in : We have a standby notice query failure.

Gate Valve 20 Is still closed.

ITMX ring heater still off.

Ops Mode is Corrective Maintenance.
ISC_LOCK : IDLE.
LASER_PWR: Power_2W
All other Locking Nodes are in Down.

H1 TCS - ITMX Ringheater set to 0W

louis.dartez@ligo.org — Sat, 26 Sep 2026 21:15:01 -0700

Author: louis.dartez@ligo.org

Report ID: 92075

I set the ITMX ring heater to 0W today at 1474517448 to match the ITMY RH.