aLIGO LHO Logbook

H1 SUS - ZM4 / ZM5 COILOUTF AntiLP filter updated

oli.patane@ligo.org — Wed, 05 Aug 2026 19:27:10 -0700

Author: oli.patane@ligo.org

Report ID: 91426

Earlier I took ZM4/ZM5 transfer function measurements with the new coil driver chassis but with the old AntiLP coil driver conpensation filters still installed in COILOUTF. I now went and took another set of transfer functions on ZM4 with the new set of coil driver compensation filters (since ZM5 is broke(91425), and it does look like these are giving us the response we want (L,P,Y). There is still a small discrepancy between the magnitudes, but it's about half as much as what it was before. I'll process these new measurements tomorrow.

I've also installed these filters and loaded them in for ZM5 for when we swap out a new modified coil driver tomorrow.

CDS

Images attached to this report

H1 SUS - ECR E2400048 modified preliminary coil driver test results

oli.patane@ligo.org — Wed, 05 Aug 2026 18:56:08 -0700

Author: oli.patane@ligo.org

Report ID: 91418

Here are preliminary pass/fail test results for the modified HAM-A chassis. In 84454 we found out we hadn't done the modifications yet that had been outlined in E2400048.

First I have the results for the newly installed ZM4 and ZM5 coil driver chassis, then the spares, which don't have final results since they aren't assigned to AOSEMs or BOSEMs yet, then the results for the BHD electronics, which aren't being used but have already been installed in the Mechanical Room Mezzanine.

When only one channel is listed as bad, they could actually have an issue or it could just be an error while taking the measurement for that chanel. When multiple channels are bad, that seems more like a chassis problem.

Scripts used to run all of these are in /ligo/svncommon/SusSVN/sus/trunk/electronicstesting/lho_electronics_testing/coildriver/ECR_E2400048/Scripts/, and final results for those who have them are found in /ligo/svncommon/SusSVN/sus/trunk/electronicstesting/lho_electronics_testing/coildriver/ECR_E2400048/Results/.

Rack - Height	SUS Stage OSEMs	S/N	OSEM Type	Date tested	OutImp (kOhm)	Data looking good?	Comments
ZM4, ZM5
SUS-C8, U12	ZM4	S2001194	BOSEM	2026-01-29	0p1	yes
SUS-C8, U11	ZM5	S2001198	BOSEM	2026-01-30	0p1	CH1-4 bad	first pole doesn't get close to 0 phase until we change 0.5 to above 20 Hz

Spares
--	SPARE	S2001202	--	2026-01-29	0p1	yes
--	SPARE	S2001204	--	2026-01-29	0p1	yes
--	SPARE	S2401019	--	2026-01-29	0p1	yes
--	SPARE	S2401020	--	2026-01-29	0p1	yes
--	SPARE	S2001197	--	2026-01-30	0p1	CH2 bad

--	SPARE	S1200609	--	2026-02-02	1p2	all go up above 1000Hz
--	SPARE	S1106046	--	2026-02-09	1p2	all go up above 1000Hz
--	SPARE	S2500410	--	2025-10-02	1p2	yes
--	SPARE	S2500412	--	2025-10-02	1p2	yes
--	SPARE	S2500413	--	2025-10-02	1p2	yes

Installed for BHD
SUS-M2, U42	OM0 M1 F1F2F3SD	S2001203	BOSEM	2026-01-30	0p1	CH1 bad
SUS-M2, U41	OM0 M1 LFRT	S2001201	BOSEM	2026-01-30	0p1	CH1,CH4 bad
SUS-M2, U40	OM0 M3	S2001181	AOSEM	2026-02-02	1p2	CH3 bad

SUS-M2, U38	OBS M1 F1F2F3SD	S2001200	BOSEM	2026-01-30	0p1	yes
SUS-M2, U37	OBS M1 LFRT	S2001199	BOSEM	2026-01-30	0p1	yes

SUS-M2, U35	AM1 M1	S2001179	BOSEM	2026-02-09	1p2	yes
SUS-M2, U34	AM2 M1	S2001178	BOSEM	2026-02-02	1p2	maybe? CH4 bad above 3000Hz

SUS-M2, U32	OMCAB M1 H1V1H2V2	S2001195	AOSEM	2026-01-30	0p1	yes
SUS-M2, U31	OMCAB M1 H3V3	S2001196	AOSEM	2026-01-30	0p1	yes

SUS-M2, U29	OMA1 M1	S2001177	BOSEM	2026-02-09	1p2	yes

SUS-M2, U27	OMB1 M1	S2001176	BOSEM	2026-02-09	1p2	yes

SUS-M2, U24	OMA2 M1	S1200608	BOSEM	2026-02-09	1p2	?? CH1-4 bad above 3000Hz
SUS-M2, U23	OMB2 M1	S1201155	BOSEM	2026-02-02	1p2	?? CH1-4 bad above 3000Hz

SUS-M2, U21	OMA3 M1	S1201162	BOSEM	2026-02-09	1p2	?? CH1-4 bad above 3000Hz

SUS-M2, U19	OMB3 M1	S1201165	BOSEM	2026-02-02	1p2	?? CH1-4 bad above 3000Hz

CDS

Images attached to this report

Non-image files attached to this report

2026-01-29_HAMACoilDriver_D1100687-v1_0p1kOhm_S2001194_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-01-30_HAMACoilDriver_D1100687-v1_0p1kOhm_S2001203_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-01-30_HAMACoilDriver_D1100687-v1_0p1kOhm_S2001201_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-01-30_HAMACoilDriver_D1100687-v1_0p1kOhm_S2001200_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-02_HAMACoilDriver_D1100687-v2_1p2kOhm_S2001181_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-01-30_HAMACoilDriver_D1100687-v1_0p1kOhm_S2001199_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-09_HAMACoilDriver_D1100687-v2_1p2kOhm_S2001179_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-02_HAMACoilDriver_D1100687-v2_1p2kOhm_S2001178_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-01-30_HAMACoilDriver_D1100687-v1_0p1kOhm_S2001195_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-01-30_HAMACoilDriver_D1100687-v1_0p1kOhm_S2001196_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-09_HAMACoilDriver_D1100687-v2_1p2kOhm_S2001177_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-09_HAMACoilDriver_D1100687-v2_1p2kOhm_S2001176_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-09_HAMACoilDriver_D1100687-v2_1p2kOhm_S1200608_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-02_HAMACoilDriver_D1100687-v2_1p2kOhm_S1201155_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-09_HAMACoilDriver_D1100687-v2_1p2kOhm_S1201162_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

2026-02-02_HAMACoilDriver_D1100687-v2_1p2kOhm_S1201165_LPON_20OhmLoad_allresiduals_tailoredfit.pdf

H1 SUS - Comment to ZM4 / ZM5 COILOUTF filter module changes and SUS health checks - pass?

oli.patane@ligo.org — Wed, 05 Aug 2026 18:02:47 -0700

Author: oli.patane@ligo.org

Report ID: 91425

The coil driver on ZM5 (S2001198) is not working correctly. The attached screenshot is how I knew. These traces should both be as close to 1 as possible since we want them to line up with the theoretical model.

Images attached to this report

H1 SEI - Comment to DAS system, tap testing to calibrate distances along fiber

wandaelisabeth.vossius@ligo.org — Wed, 05 Aug 2026 17:40:21 -0700

Author: wandaelisabeth.vossius@ligo.org

Report ID: 91423

I have attached some screenshots which show what the referenced path looks like for the x-arm. Further, it demonstrates how the optical metres of the fibre are now referenced to a certain co-ordinate. With this, we can now correlate any events that we detect to a physical location. In this software, a straight line is drawn between two referenced points. In picture 1, the whole arm is shown. In picture 2, it is zoomed in on the area around the corner station, showing the limitations in our technique as it is relatively rough considering we know the fibre is curving at this point. In picture 3, we see how hovering over the waterfall plot will produce a red point in the refenced fibre showing the location of this channel.

Images attached to this report

H1 IOO - Balancing the JAC Wavefront Sensors

khanh.vu@ligo.org — Wed, 05 Aug 2026 17:18:29 -0700

Author: khanh.vu@ligo.org

Report ID: 91419

Masayuki Nakano, Khanh Vu

This afternoon we worked on balancing the wavefront sensors for JAC. As shown in the plots below, the coupling of the length signal into the pitch and yaw channels of both WFS A and WFS B is significantly reduced after the adjustment, indicating that the balancing was successful.

To measure the length coupling, we injected a 0.1 excitation into the JAC length loop error point at 8 Hz. The 8 Hz peak appeared in both the pitch and yaw channels of WFS A and WFS B, indicating an imbalance among the four quadrants of the wavefront sensors. To reduce this coupling, we modified the WFS input matrices, which convert the four sensor segment signals into pitch and yaw signals. Instead of using equal weights of 1 for every segment, we adjusted each weight based on the measured imbalance.

We first monitored the signals from all four segments of each wavefront sensor and calculated new matrix values. For each sensor, we summed the four segment signals and divided by four to obtain the average signal that each segment should ideally receive. We then calculated the fractional deviation of each segment from this average and used it to determine a correction factor. The new matrix entry for each segment is given by:

New weight = 1 − (Average − Segment)/Average

For example, the measured signals for channel I of WFS A were:

A_I1	A_I2	A_I3	A_I4
10.32	8.39	10.9	11.35

The sum of the four segments is 40.96, giving an average of 10.24. Segment A_I1 is 0.08 above the average, corresponding to a fractional deviation of approximately 0.008 (0.8%). Its new matrix weight therefore becomes approximately 0.992. Since this segment receives slightly more signal than the average, its weight is reduced accordingly. The same calculation was applied to all four segments of both WFS A and WFS B, and the updated matrices were loaded into the system.

The comparison of the pitch and yaw signals for channel I of WFS A and WFS B is shown below. The 8 Hz length coupling is reduced in all cases compared to the original matrices, demonstrating that the new balancing improves the wavefront sensor performance.

IOO

Images attached to this report

H1 AOS - Comment to Summary of JAC ASC Loops Closing

masayuki.nakano@ligo.org — Wed, 05 Aug 2026 17:16:46 -0700

Author: masayuki.nakano@ligo.org

Report ID: 91422

I added the ASC engagement to Guardian. A new ASC_ENGAGING state simply ramps JAC-WFS_GAIN from 0 to 1 over 1 second. It is a minimal implementation.

H1 IOO - Spot position on MC2

elenna.capote@ligo.org — Wed, 05 Aug 2026 17:16:13 -0700

Author: elenna.capote@ligo.org

Report ID: 91420

Keita, Louis, Elenna

Today Louis and I set out to measure the beam spot position on MC2 using A2L. We spent some time doing wrong things to make this measurement, until Keita came along and helped us figure out the correct way to do this.

Here is our correct method:

set up an excitation on the MC2 M3 Dither for either P or Y
We chose 8 Hz, starting with a 10 ct excitation and working up to 100 ct depending on the dof and the A2L gain value
Measure the coupling from MC2 M3 dither to IMC L at 8 Hz, and adjust the MC2 M3 Drivealign A2L gain

We did all of these measurements with IMC ASC engaged, and no offset on MC2 trans QPD, so the beam "should" be centered on MC2.

For both pitch and yaw, we were able to observe a flip in the sign of the MC2 M3 dither/ IMC L transfer function. Because I set up the measurement in that funny way, this actually meant we needed to maximize the transfer function instead of minimize, which is a little confused (I figured this out after having saved several references, sorry). Luckily, we were able to see the sign flip as further proof we were moving through a minimum value.

The results indicate that a P2L gain of -0.85 and a Y2L gain of +0.5 minimized the coupling.

I found this alog I wrote which references several other alogs about measuring the beam position using the A2L gains, 76754. I wrote it about PR2, but MC2 and PR2 are the same suspensions, so the results should be the same.

For a Y2L of 0.5, the alpha factor is 0.0239 (unclear if this should be positive or negative), which means d = 39.28 mm * 0.0239 = 0.94 mm; we are miscentered in yaw by less than 1 mm in some direction.

For a P2L of -0.85, the alpha factor is -0.0405, d = 39.28 mm * -0.0405 = -1.6 mm. Keita and I had a debate about what this could mean. I claim that the P2L gain that matches a centered beam could be different than zero depending on where the suspension wires are attached to the mirror (this is true for the QUADs), but he does not think that should be the case if we are measuring at 8 Hz, above the suspension resonances. Therefore, my claim is that we don't know exactly how miscentered we are in pitch until we figure out how to account for that offset. Keita claims that does not matter. We will reconvene tomorrow to discuss further.

Either way, it it could indicate that MC2 trans QPD is not exactly level with the center of MC2 mirror.

Overall, being less than 1 mm miscentered in yaw is not so bad, and within our tolerances for beam centering while working in chamber.

I attached screenshots of my dtt templates during these injections, labeled by the A2L gains.

ISC

Images attached to this report

H1 ISC - Comment to ASC POP_A and B seem to be connected to the wrong feedthrough

elenna.capote@ligo.org — Wed, 05 Aug 2026 17:14:48 -0700

Author: elenna.capote@ligo.org

Report ID: 91421

As a quick note, now that we see beam on the POP QPDs, I tried to center the beam on the QPDs using the straight shot from IM4. However, I wasn't able to move IM4 in any direction in pitch that didn't cause the NSUMs on both QPDs to start dropping- maybe we are clipping somewhere. I was able to pretty well center the beam in yaw on POP A using IM4 trans though.

LHO General - Wed DAY Ops Summary

corey.gray@ligo.org — Wed, 05 Aug 2026 16:33:06 -0700

Author: corey.gray@ligo.org

Report ID: 91400

TITLE: 08/05 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Oli
SHIFT SUMMARY:

The main detector activities were JAC measurements, SQZ/ZM4, & input alignment. A noisy fan for an EY SEI sent Fil & Tony out to swap the power supply (while out there we lost the SUS front end, so that needed to be restored afterword). Other miscellanea of note: SEI-ITMx has been at DAMPED since Tues morning (Tony noted); SUS-ITMy has been at MISALIGNED since Monday afternoon; & the TCS CO2 lasers are DOWN.

Another very smoky day (AQI close to 180 at end of shift); fire-wise, only one small fire in Pasco noted in the afternoon. Had alarms for the LAB1 Dust Alarm a few times during the shift.

LOG:

1430-1825Asphalt crack sealing along X-Arm's X1 (randy)
1441-1530 LVEA technical cleaning (kim.dawn)
1500 Working on Gate phone (richard)
1550-2004 JAC modematching + high power measurements w/ IMC unlocked (masayuki.khanh)
1627-1646 Checking on AED at the FCES (HAM Shack) [eric]
1642-1653 Pulling chassis for ZM4+5 (fil.camilla)
1655-1934 HAM7 (preceded by quick HAM3 check) SQZ work (sheila.camilla)
1724-1827 EX EY tech cleaning; X-arm crack filling, so switched to EY (kim)
1728-1843 Checking POP electronics and HAM3 electrical feedthru flange (keita)
1748 Let blue truck w/ long flatbed of metal framing thru gate (they tried gate code + gate call, but it did not work)
1801 MC2 misaligned for Keita's work....will realign for Masayuki when he returns to his measurements after SQZ work is done (will need to contact Keita).
- 1956 MC2 misaligned again (keita)
1856-1903 Reseting test measurement s in PCal lab (tony)
1913-1925 TCS chiller check (corey)
1943 EY fan noise check (fil)
1952 cleanroom work with scissor lift (randy)
2034-2135 swapping power supply (noisy-fan) for EY ISI (fil.tony)
- 2056 SEI software WD trip
- Lost the SUS ETMy front end (dave notified us & will restore after power supply work)
- 2129 After WD trips, SEI ETMy back to FULLY ISOLATED
2050-2244 ZM4 in-chamber checks at HAM7 (rahul.camilla)
- 2058 camilla joining
2216 Grabbing 2nd chassis [from CER work this morning] (fil)
Camilla & Rahul chatted with Oli (eve) shift about ZM5 & Oli also connected in the Zoom session with Elenna/Louis for the evening.

H1 SQZ - Comment to ZM4 pre-load on the optics re-adjusted to 60 in-lb

rahul.kumar@ligo.org — Wed, 05 Aug 2026 16:23:00 -0700

Author: rahul.kumar@ligo.org

Report ID: 91417

ZM4 is damping fine.

H1 SQZ - ZM4 pre-load on the optics re-adjusted to 60 in-lb

rahul.kumar@ligo.org — Wed, 05 Aug 2026 16:15:54 -0700

Author: rahul.kumar@ligo.org

Report ID: 91416

Sheila, Camilla, Rahul

The SQZ to OMC mode matching measurement results (posted in alog 91385) had indicated that something is not right with the preload value on ZM4 (s/n 1)- which was recently adjusted from 75in-lb to 65in-lb.

To confirm the preload value on ZM4 we went back to HAM7 and using two torque wrenches we tried to confirm the pre-load value. We increased the torque values in the increments of 20-40-60in-lbs. After 40in-lbs I felt the torque wrench kept going and stopped at 60in-lb - which meant it was indeed less than 60in-lb. Using the two torque wrench I then increased it to 65in-lb, which is when Sheila suggested that we keep it 60in-lb since it will be a better fit.

Hence, ZM4 preload was set to 60in-lb and double checked using the two torque wrench (with 10% error approximately since they didn't behave exactly the same). I should get an analog (gauge dial) torque wrench rather than this springy thing which doesn't work properly sometimes.

After setting the preload, I set the suspension free and re-connected the PSAMS cable and switched ON the chassis.

The transfer function measurements showed that the suspension was healthy (please ignore the magnitude, this maybe due to incorrect filter changes after changing the coil driver impedence from 1200ohms to 100ohms) after all the work was completed in chamber.

SUS

Images attached to this report

H1 ISC - Comment to ASC POP_A and B seem to be connected to the wrong feedthrough

keita.kawabe@ligo.org — Wed, 05 Aug 2026 16:01:22 -0700

Author: keita.kawabe@ligo.org

Report ID: 91415

I connected the illuminator power cable to the illuminator in preparation, but when I checked the POP_A and B QPDs at that point both of them were already seeing the IMC beam.

I didn't use flashlight/laser pointer/illuminator. Illuminator power supply cable was left connected. Be careful, even if you turn it on remotely the light will be blocked by the back of the black glass between the illuminator and the viewport (alog 52184).

Images attached to this report

H1 CDS - End Y Kepco Power Supplies

filiberto.clara@ligo.org — Wed, 05 Aug 2026 15:15:11 -0700

Author: filiberto.clara@ligo.org

Report ID: 91414

WP 13490

The following power supplies were replaced at EY.

July 28 2026
Kepco Power Supply in VDC-C2 Rack, Right Slot U5-7, SEI IO Chassis 24V
Old S1300281
New S1300294

August 5 2026
Kepco Power Supply in VDC-C2 Rack, Left Slot U9-11, +24V SEI-C1
Old S1300293
New S1300274

While working in the VDD rack, the power supply for both SUS IO chassis was powered off. Dave B. restarted models, alog 91413.

F. Clara, D. Barker, T. Sanchez

H1 SUS - ZM4 / ZM5 COILOUTF filter module changes and SUS health checks - pass?

oli.patane@ligo.org — Wed, 05 Aug 2026 14:46:52 -0700

Author: oli.patane@ligo.org

Report ID: 91411

Camilla asked me to take some health check transfer functions on ZM4 and ZM5 since they recently had their coil drivers swapped for modified 100 Ohm output impedance drivers (91407). SQZ team had had to lower the COILOUTF filter bank gains from +/-1 to +/-0.08 due to saturations that they had been seeing after the driver swap.

I moved the COILOUTF gains into FM10 and called them drivercomp (accepted as ON in SDF). I then took health check transfer functions for ZM4 and ZM5 with their previous COILOUTF AntiLP filters on (which I believed to be the wrong filters). ZM4 looked good and was at a similar magnitude as before, but ZM5 is now lower in magnitude - 8% of what it used to be, which does line up exactly with the coil driver and gain change, but we would expect for both ZM4 and ZM5 to have reacted to these changes the same.

Settings
- ISI locked and tripped
- SUS in HEALTH_CHECK
- DAMP OFF
- COILOUTF FM6: zpk([0.9;211.883],[9.99;20.99]) (old, wrong?? compensation)
- COILOUTF FM10: gain(0.08)

ZM4
Data
/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM4/SAGM1/Data/2026-08-05_1900_H1SUSZM4_M1_WhiteNoise_{L,P,Y}_0p02to50Hz.xml
r13101
Results
/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM4/SAGM1/Results/2026-08-05_1900_H1SUSZM4_M1_ALL_TFs.pdf
r13102

ZM5
Data
/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM5/SAGM1/Data/2026-08-05_1940_H1SUSZM5_M1_WhiteNoise_{L,P,Y}_0p02to50Hz.xml
r13103
Results
/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM5/SAGM1/Results/2026-08-05_1940_H1SUSZM5_M1_ALL_TFs.pdf
r13104

Coil driver thoughts

These are actually our first two supensions with the HAM-A 100 Ohm output impedance coil drivers here at LHO (we have had a few with 1.2k Ohm output impedance). We discovered that we hadn't made of the modifications requested in IIET:30349 in 84454. I am pretty sure that the AntiLP filter modules in the COILOUTF filter banks should now go from zpk([0.9;211.883],[9.99;20.99]) to zpk([0.5;3174],[52.32;50.77]) (T2100410), but we don't have any other 100 Ohm CDs here to compare that to, and looking at LLO's filter banks for suspensions they claim have this modification for 100 Ohms, yet they still have the old compensation filters installed.

I did try to install the AntiLP filter that I believed to be the correct one, but doing that with the COILOUTF gains at +/-1 was definitelty not working. When there's some free time I'd like to try reinstalling the zpk([0.5;3174],[52.32;50.77]) filters but with the gain at the 0.08 that it was changed to? I don't see why we would need to do this since the 1.2k Ohm Coil Driver suspensions don't have this factor, but maybe I'm missing something that is specific to the 100 Ohm output impedance drivers.

SQZ

Images attached to this report

Non-image files attached to this report

2026-08-05_1900_H1SUSZM4_M1_ALL_TFs.pdf

2026-08-05_1940_H1SUSZM5_M1_ALL_TFs.pdf

H1 CDS - h1susey and h1susauxey rebooted following DC power supply work

david.barker@ligo.org — Wed, 05 Aug 2026 14:39:49 -0700

Author: david.barker@ligo.org

Report ID: 91413

The EY +24VDC power supply which powers the two SUS IO Chassis went offline. The SWWD in turn tripped the SEI DAC drives.

Fil recovered the IO Chassis and we rebooted h1susey and h1susauxey frontends. All came back with no problems and I untripped the SWWD.

Note that h1omcpi, which receives a 16k IPC channel from h1susetmy, started showing a low receive error rate on its h1ioplsc0 64k receivers. Error rate of 1-6 errors per second, occuring every 5 seconds or so.

H1 SQZ - SQZ Power Measurements using Craning for on OPOS measurements.

camilla.compton@ligo.org — Wed, 05 Aug 2026 13:20:44 -0700

Author: camilla.compton@ligo.org

Report ID: 91410

Sheila, Ryan S, Camilla,

Our SQZ power measurements we've taken so far seem to be unreliable: 91360, 91197. So we made a crane to hold the power meter steady on the OPOS by temporarily removing the OPO SUS EQ stop, see photo of crane before power meter was added. In brackets is the order the measurements were taken.

We seem to get loss both at SFI1 and B:L1 aperture.

(1) Out of OPO before A:DC1: 1.30mW
- 2% loss through SFI1 first pass, expect 1%
(4) After ZM1 1.275mW
- 2% loss through SFI1 second pass, expect 1%
(2)After SFI1 before B:M1: 1.25mW
- 0.8% loss through B:L1 aperture, expect 0%
(3) After B:L1 1.24mW
- 2.5% loss through SFI1 and B:BS1, expect 2%
(5) After ZM4 1.21mW
- Total from OPO to after ZM4 6.9%, expect 4%.

The power then jumped and we took the following set of measurements, but they don't make as much sense so we think the power was drifting.

After SFI1, before A:L2 1.34mW
After A:L2 about 1.34mW
- No loss at A:L2 aperture.
Repeating out of OPO 1.4mW
- 4.5% loss though SFI1 first pass the second time, seems too high.
Repeating after ZM4 1.278mW
- Total 8.7% loss, expect 4%

Yesterday when Ryan and I set up the crane, we measured out of the OPO (1.37mW) and on the SQZT7 HD path after the lens (1.26mW) which is an 8% loss, consistent with today's first measurement.

*Total loss calculated as [1 - (Power after / Power before)]

Images attached to this report

H1 TCS - TCS Chiller Water Level Top-Off (Bi-Weekly, FAMIS #81868)

corey.gray@ligo.org — Wed, 05 Aug 2026 13:12:14 -0700

Author: corey.gray@ligo.org

Report ID: 91412

Addressed TCS Chillers (Wed [aug5] 1213-1225pm local time) & CLOSED FAMIS #81868.

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

TCSx Chiller: Had level of 29.7 cm. Added 50mL for 30.0cm.
TCSy Chiller: Had level of 10.3 cm. Added 30mL for 10.5cm.
There was no water in the small cup under the slow leak.

TCS

H1 ISC - ASC POP_A and B seem to be connected to the wrong feedthrough

keita.kawabe@ligo.org — Wed, 05 Aug 2026 12:44:53 -0700

Author: keita.kawabe@ligo.org

Report ID: 91409

Since POP_A and POP_B QPDs didn't show any signal whatsoever when I scanned the beam going into PR2 (alog 91397), I got suspicious about the electronics.

I first went to the field rack (ISC R4), disconnected the cable (CAB_H1: IO-245) that is supposed to go to HAM3 (and to the POP QPDs) from the front panel of the transimpedance amplifier, connected a breakout board to the cable and checked the diode connection from pin 16 (common cathode for QPD1) to pin 1,2,14, 15 (anode for four segments of QPD1) as well as from pin 19 (common cathode for QPD2) to pin 4,5,17 and 18 (anodes for QPD2) using a DVM. There was no connection.

I moved to the D3 flange of HAM3. The IO-245 cable was connected to D3-F7 and that was correct according to T2400150 as well as the redline version of D1002874.

I disconnected the cable from D3-F7, attached the breakout board to D3-F7 and checked the diode connection. Again, no connection.

I moved the breakout board to D3-F6, which is nominally to be used for "LO1 M1 RTSDxxxx" and I was able to see eight diodes between right pins. pin 16 (cathode) to pin 1, 2, 14 and 15 (all anode) showed about 0.4V only when the current goes from anode to cathode, nothing in reverse direction. Same thing for pin 19 to pin 4, 5, 17 and 18.

We don't have LO1 inside HAM3 (if LO1 means a new suspension for BHD or something) for now, so I'm 100% confident that the POP QPD cable is somehow plugged into D3-F6 instead of D3-F7 inside.

I connected the in-air QPD cable to D3-F6. I'll be testing if the QPD channels respond to flashlight/illuminator/laser pointer.

Images attached to this report

H1 AOS - Comment to Input alignment work

elenna.capote@ligo.org — Wed, 05 Aug 2026 11:03:13 -0700

Author: elenna.capote@ligo.org

Report ID: 91408

The plots I attached to my original alog are kind of impossible to parse, so I remade them comparing each dof at each offset. I also added in the calibration to the xml file, IM4 trans NSUM is calibrated into W and the damp ins of each suspension is ideally calibrated into urad. Now the transfer functions show real units, so they are more physically meaningful.

As a reminder, I drove the exact same excitation strength for each injection, 30 ct, and the line injected was almost 2 orders of magnitude above the noise in each damp inmon. Each measurement was run for 20 averages, 8 s BW with 50% overlap.

If you want to read the exact values in the file, you can find the xml template in my home directory (ligo/home/elenna.capote) as IM4_trans_coupling_calibrated.xml

Images attached to this report

H1 CDS - ZM4 and ZM5 HAM-A Coil Drivers

filiberto.clara@ligo.org — Wed, 05 Aug 2026 10:36:57 -0700

Author: filiberto.clara@ligo.org

Report ID: 91407

WP 13488

The ZM4 & ZM5 HAM-A Coil Drivers were swapped to increase output range. New drivers have an output impedance of 100 ohms. Old drivers were verified to have a 1.2K output impedance.

New Chassis:
S2001194
S2001198

Old Chassis:
S1200611
S1700079

SUS

H1 SQZ - sqz to OMC mode matching with adjusted psams

sheila.dwyer@ligo.org — Wed, 05 Aug 2026 09:52:03 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91385

Ryan S, Camilla, Sheila

Measurements from yesterday and today show that we have improved the SQZ to OMC mode matching, after a long effort by many people.

We see a larger part of the available psams range where we have mode matching better than 2%.
The astigmatism may be slightly improved because of the change in the beam position on ZM2 (91259 and 91197), and we no longer see that our best mode matching is at worse astigmatism points.
Similarly, our best mode matching psams values are now near the lower M2 values, still 1.2, rather than the worst M2 as it was in O4.

The first two plots here show the results of sqz two OMC scans, the first is with the grid described in 91371, the second is a second scan that Camilla did this morning with the same grid as the M^2 measurements in that alog. GPS times for these scans, and the mode matching and misalignments estimated from them, can be found in files in the sqzutils git repo here.

The M2 profiler data that Ryan Short and Camilla took yesterday is attached in the zip file here. A set of scatter plots summarizing all this data is here, which can be compared to attachments to 90902 showing the same measurements taken before the pre-loading changes (and psams repairs). The strain guage ranges are now different, but in both alogs the plots show close to the full range of the psams PZT. The range of M^2 values is similar to before (1.39-1.18) and still shows a dependence on ZM5 psam, which has the larger spot size. The overlaps between vertical and horizontal q parameters seem more uniform over the psams range now, with values of 0.5-0.6% for all the psams values where our mode matching is best.

In the lower right is the results from the OMC scans, since we took two scans with different grids there are some points that have two measurements, with the annotation showing the two different results. The misalignment mode height is shown in parenthesis for each of these, perhaps some of the variation in the results could come from the misalignment. We are hoping that with HAM7 under vacuum we will have an easier time setting the alignment of the sqz beam to the OMC, and it will fluctuate less, so that we can get better alignments and hopefully more consistent mode matching results.

This plot shows the measured q parameters now on an Sw plot at SRM, compared to the measured q parameters before the pre-load change. The contours of OMC mismatch here are from the finesse model, between the datasets taken before and after the pre-loading we now have a lot of measured q parameters and measured mode mismatches that we can use to verify or adjust this part of the finesse model. Our intention with the pre-load change was not to completly move our mode matching area, but to still be able to access the ROCs that we used in O4 (90919). It does look like we missed this, and have overshot compared to what we intended to do.

I reproduced the fitting of ROCs as described in 91013. This plot shows the measured qs propagated back to before ZM4, where all the horizontal and all the vertical values would ideally be the same. This plot shows the measured qs propagated to SRM, along with the qs measured before ZM4 propagated to SRM with the fits to ZM4 and ZM5 ROC. This scatter plot shows the overlap between the measured qs after ZM5 and the measurement from before ZM4 propagated forward with the fit ROCs. Similar to last time I did this fitting, the fitting is limited by something that is not astigmatism, and the fit to horizontal data can do about as good of a job explaining the vertical data as horizontal data, and vice versa. We need to double check if these fits are compatible with expectations based on the applied torques, and I would like to make one fit for horiztonal and vertical data.

ZM4 strain guage [V]	-3.2	-1	1.2	3.4
ROC fit to horizontal data [m]	-31.3	-22.3	-18.2	-14.6
ROC fit to vertical data [m]	-41.5	-29	-21.9	-16.2
physical astigmatism (Dh-Dv) [mD]	-15	-21	-19	-14
total astigmatism Dh/cos(AOI) - Dv*cos(AOI)	-17	-22	-20	-16

ZM5 strain guage	-8	-6.75	-5.5	-4.5	-3.3	-2	-1
ROC fit to horizontal data [m]	4.40	4.50	4.68	4.86	5.09	5.38	5.44
ROC fit to vertical data [m]	4.41	4.57	4.79	4.98	5.19	5.51	5.51
physical astigmatism (Dh-Dv) [mD]	1	7	10	10	7	8	5
total astigmatism Dh/cos(AOI) - Dv*cos(AOI)	2	8	10	10	8	9	5

The script used to make these fits is available here and the first several plots in this alog were made using this script: here

Editing to add a busy version of the Sw plot with the strain guage readings annotated, ZM4 is listed first, then ZM5.

Images attached to this report

Non-image files attached to this report

Aug03_2026.zip

H1 IOO - Summary of JAC ASC Loops Closing

khanh.vu@ligo.org — Wed, 05 Aug 2026 09:50:34 -0700

Author: khanh.vu@ligo.org

Report ID: 91406

Keita Kawabe, Jennie Wright, Masayuki Nakano, Khanh Vu

Below is a summary of how we closed the JAC ASC loops, including our measurements of the sensing and input matrices, the open-loop gain measurements, our work on the IOT1 table, and the final closing of the loops.

We attempted to measure the sensing matrix three times. During the first attempt, we observed strong cross-coupling between the pitch and yaw channels. However, we did not account for this coupling correctly because we inverted the full 4x4 sensing matrix, including the pitch-yaw cross terms, and then extracted the relevant values from the inverted matrix.

The second attempt was more successful. We removed the cross terms and reduced the 4x4 matrix, which would require 16 inputs, into two separate 2x2 matrices for pitch and yaw, requiring only eight inputs in total. We then inverted the two smaller matrices separately. There was also some confusion about the matrix labeling, but Masayuki noticed that the input and output ordering changes when the sensing matrix is inverted, so the rows and columns needed to be labeled accordingly. This proved to be correct. However, the newly calculated matrices were still not good enough because the PZT and JM1 responses in yaw were too similar. This was problematic because we wanted their signals on the two wavefront sensors to be well separated.

Therefore, we went to the IOT1 table to check the alignment. Masayuki made an important observation that the beam was being clipped at the shutter, with approximately half of the beam blocked on the left side. This explained why we were having more trouble with yaw than pitch, since the clipping affected yaw much more strongly.

After aligning the shutter, we measured the sensing matrix for a third time. The result was much better: the PZT and JM1 yaw response vectors were separated by approximately 45 degrees in the WFS basis, while the pitch response vectors were separated by approximately 124 degrees. Although these values are not at the ideal 90-degree separation, we determined that they were good enough and entered the new input matrices.

We then performed open-loop gain measurements and confirmed that all of the loops were behaving properly. Finally, we closed the loops and slowly increased the WFS gains from 0.1 to 1. All four loops closed successfully and worked well.

H1 IOO - Comment to IOT1 Table Work

khanh.vu@ligo.org — Wed, 05 Aug 2026 09:38:01 -0700

Author: khanh.vu@ligo.org

Report ID: 91405

Additional context for the work described above: The motivation for the table work came from the difficulties we had with the sensing and input matrices of the JAC ASC loops. In pitch, the PZT and JM1 signals are well separated, but their responses in yaw are too similar. This is problematic because we need the two wavefront sensors to distinguish between the motions of the two actuators. While identifying a new location for the camera, Masayuki noticed that the shutter was clipping approximately half of the beam on the left side. We suspect that the beam may have been clipped for some time and that this may be related to the yaw issue, since the clipping affects yaw more strongly than pitch.

H1 SQZ - Comment to sqz to OMC mode matching with adjusted psams

camilla.compton@ligo.org — Wed, 05 Aug 2026 09:02:50 -0700

Author: camilla.compton@ligo.org

Report ID: 91404

Following on from 90859.

We have ZM4 SN1 installed now.
- Original data before we changed the preloading (E2100289) had the ROC range -19.3m to -9.0m. With at 0V applied -104mD optical power, with 200V applied -221mD.
- In alog 75677 we increased the preload from 46 in lb to 75 in lb. This is an estimated ROC range of -11.5 to -6.9 meters for strain gauge 1.0 to 8.3V.
- In this vent we reduced the preload from 75 in-lbs to 65in-lbs in 90951. This should be decreased to -174mD + 2.4mD/in lb * 10 in lbs = -150mD mD with 0 V on the PZT, -267mD with 200V on the PZT. This is an estimated ROC range of -13.3m to -7.5m with 0V and 200V on the PZT.
- This disagrees with Sheila's fitted numbers above, her numbers suggest our pre-loading is now at around -30 in-lbs. (-31m ROC = -65mD. -174mD -65mD = 109mD change / 2.4mD/in lb = 45in lb change. 75in lbs - 45 in lbs = 30 in-lbs).

We have ZM5 SN4 installed now.
- Original data before we changed the preloading (E2100297) had the ROC range 3.0m to 3.9m. With at 0V applied 667mD optical power, with 200V applied 508mD.
- In alog 75709 we increased the preload from 20 in lb to 47 in lbs. This is an estimated ROC range of 3.3 to 4.5 meters for strain gauge -5.0 to +2.6V (it's range with 0V and 200V applied).
- In this vent this PSAMs SG broke and after the fix, Camille at Caltech adjusted the preload from 47in lbs to 60in lbs and remeasrured in LIGO-E2100297. This is a measured ROC range of 3.6m to 5m meters with 0V and 200V on the PZT.
- Mostly agrees with Sheila's fitted numbers above.

SUS

H1 CDS - EDC greened up

david.barker@ligo.org — Wed, 05 Aug 2026 08:57:45 -0700

Author: david.barker@ligo.org

Report ID: 91403

Following the FW0 upgrade on Monday h1edc has been running with 51 disconnected old FW0 channels. Until we upgrade FW1 next week and restart the DAQ I have added these obsolete channels to the containerized IOC edc_green_ioc to "green up" the EDC. At this point the only CDS alarm is the reverse osmosis water treatment alarm (which has been bypassed from the cell phone alarms).

H1 AOS - Comment to conda environment updated

erik.vonreis@ligo.org — Wed, 05 Aug 2026 08:15:06 -0700

Author: erik.vonreis@ligo.org

Report ID: 91401

The read me for the arrakis python module has a quick start

https://git.ligo.org/ngdd/arrakis-python/-/blob/main/README.md?ref_type=heads

Documentation is here:

https://docs.ligo.org/ngdd/arrakis-python/

LHO General - Wed DAY Ops Transition

corey.gray@ligo.org — Wed, 05 Aug 2026 07:40:04 -0700

Author: corey.gray@ligo.org

Report ID: 91399

TITLE: 08/05 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 1mph Gusts, 0mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.07 μm/s
QUICK SUMMARY:

Very smoky day (recent AQI of 170 for UNHEALTHY state); had a Dust Alarm for the Labs for 7amPDT. Potable water supply on site is low (level yesterday morning around ~60" and this morning we are at 46", so please continue water conservation....part needed for fix should arrive today).

A couple earthquakes overnight (M6.3 near New Zealand & M6.3 near Phillipines).

IMC and JAC are locked. ISC Lock is at IDLE.

H1 AOS - conda environment updated

erik.vonreis@ligo.org — Wed, 05 Aug 2026 07:30:03 -0700

Author: erik.vonreis@ligo.org

Report ID: 91398

The CDS conda environment has been updated.

New versions of ndscope and diaggui can connect to an arrakis data source.

Also included is the arrakis-python client library. "include arrakis" to use in your python scripts.

Many packages have been moved up to the versions used in the IGWN environment.

A detailed list of changes can be found here:

https://git.ligo.org/cds/packaging/cds-conda-distribution/-/wikis/Environments#version-2026-08-04-01

You can run a command outside the environment with "noconda "

You can exit conda within a terminal window with "killconda".

You can activate other conda environments with "conda activate " or "conda activate ". Some additional configuration of your account may be needed to get "conda activate" to work.

CDS

H1 AOS - Comment to Input alignment work

keita.kawabe@ligo.org — Wed, 05 Aug 2026 01:10:57 -0700

Author: keita.kawabe@ligo.org

Report ID: 91397

I scanned IM3 (+-200urad, 0.043Hz) and IM4 (+-200urad, 0.053Hz) at the same time in YAW to find beam on POP_A and/or POP_B. With these frequencies, one scan cycle is exactly 1000seconds.

Laser power was increased to 35W. Whitening gain was nominal 12dB without any whitening filters, and there is -12dB gain in the digital to compensate.

PRM transmission is ~3%, PR2 transmission is ~230ppm and there's 90:10 splitter in the POP A/B path that throws away 90% of the power. Each QPD receive roughly half of that, i.e. 35W*3%*230ppm*0.1/2~ 12uW, which is not large but large enough so we can clearly see something if we believe the POP segments calibration (1 ADC count = 0.19 uW with 12db whitening gain and -12dB digital gain).

But I don't see anything, not 12uW, not even 1uW, really nothing. Attached is the trend for 3000 seconds. Are POP QPDs working? Connected?

I lowered the power to 2W and stopped excitation after the scan was done.

Images attached to this report

H1 AOS - Comment to Input alignment work

keita.kawabe@ligo.org — Wed, 05 Aug 2026 00:54:31 -0700

Author: keita.kawabe@ligo.org

Report ID: 91396

> transfer function of IM1 P and Y and IM3 P and Y to the IM4 trans NSUM as a way to quantify possible clipping in the input path. IM1 coupling should indicate clipping somewhere along the IFI, which includes some baffles. IM3 coupling should indicate clipping on the baffle between IM3 and 4.

The point is that IM3 to IM4_TRANS TF excludes the clipping between IM1 and IM3. Of course the TF from IM1 to IM4_TRANS can also show the clipping downstream of IM3 (such as baffles between IM3 and IM4).

> Next, Keita turned off the IMC ASC and moved JM3 to bring the beam to a position on MC2 trans that recreated the beam position he found during the vent.

Turned off the IMC ASC in a hope that MC1/2/3 were all hanging at the same angle as they used to during the in-air work. (Moving JM3 won't change the beam position on MC2 when ASC was not working, it just improves the matching into IMC.) Without ASC, MC2_TRANS YAW was 0.64.

I did this because of my recollection that we intentionally off-centered the MC2 in YAW, but that was wrong, what actually happened was that we did center the beam spot on MC2 because it was initially off in YAW but not in PIT, the only thing was that people including myself were somewhat suspicious about the MC2_TRANS path at the time, so marked the horizontal beam spot position in HAM3 using vertical hard edge put on the ISI surface and then measured the distance from the edge to the neighboring screw holes on the ISI surface.

I trended MC2 TRANS back to the time when Rahul and I finished centering the IM4_TRANS path using IMC flashes (alog 90536). Unfortunately we cannot see fast channels for individual segments but some flashes were long enough (short but lasted for ~3 clock cycles for 2kHz system) to produce meaningful PIT and YAW signals in MC2_TRANS, see Screenshot2026-08-05003532.png. It was 0.68 in YAW, not that different from 0.64.

Anyway I just put an offset of -0.64 to MC2_TRANS YAW and re-engaged IMC ASC to the beam spot on MC2 won't move in YAW.

I also tested the other side of MC2_TRANS.

As Elenna showed, the coupling from IM1/3 dither to IM4_TRANS changed with the MC2_TRANS YAW offset. Positive offset was better than zero offset which was better than negative offset.

As of now I cannot tell if this level of coupling is significant enough or not, we'll need beam propagation math to be able to say anything.

> Since we had found what we believe was a better beam position in HAM2, we checked the REFL alignment. With PRM aligned in this alignment, the beam is on the edge of the ISCT1 refl camera, so not great.

This is not surprising because we caused non-negligible change in the beam going into PRM and the beam was not retro-reflecting. On top of that, since IMC alignment change will change the alignment of the IFO REFL beam going into HAM1 even if PRM retroreflects.

However, with zero offset in MC2 YAW, without much care/attention to IMs,

the IFO refl beam makes it to the ISCT1, and
we can center ASC REFL A and B using RMs without railing them.

That's already a sign of reasonable alignment. If we'll have to do a major rework of HAM2 to accomodate MC2_TRANS YAW offset, that seems to be a sign that the IMC is all in all different from where it was in-air desipite the MC2_TRANS YAW position of in-air flashes.

As a side project, I'll let Elenna and/or Louis measure the MC2 beam position offset by a2l without MC2_TRANS YAW offset as the intent was to center MC2.

Images attached to this report

H1 AOS - Input alignment work

elenna.capote@ligo.org — Tue, 04 Aug 2026 21:49:21 -0700

Author: elenna.capote@ligo.org

Report ID: 91395

Keita, Louis, Elenna

Today, we proceeded to look for the input alignment, given all the changes that occurred in HAM2 during the ISS install, 90545. Although we have been able to lock PRX, we have not yet seen any beam on ASC-POP_A or B QPDs (they capture the forward POP beam).

To start, we locked the JAC and IMC, and aligned PRM. We could see the usual beam on the ISCT1 REFL camera. We noted that the beam position on IM4 trans QPD was far from center, about 0.26 in pitch and 0.66 in yaw. The IM4 trans NSUM was about 1.825 W, which is similar to a pre-vent value of 1.842. At this time the IM3 sliders were P: 40.3 and Y: 655.6. We confirmed that the IM sliders were where we expected them to be set due to the vent work.

I moved IM3 sliders to center the beam on IM4 trans QPD, so new slider values were P: 103.3 and Y:472.6. Then, following Keita's direction, I proceeded to measure a transfer function of IM1 P and Y and IM3 P and Y to the IM4 trans NSUM as a way to quantify possible clipping in the input path. IM1 coupling should indicate clipping somewhere along the IFI, which includes some baffles. IM3 coupling should indicate clipping on the baffle between IM3 and 4.

The first four screenshots show those results, which I obtained by driving a 30 ct excitation from the test bank of each suspension dof at 8 Hz. IM1 P, IM1 Y, IM3 P, IM3 Y

Next, Keita turned off the IMC ASC and moved JM3 to bring the beam to a position on MC2 trans that recreated the beam position he found during the vent. He set a yaw offset of -0.64 on MC2 trans and then re-engaged the IMC ASC. After the ASC converged, I recentered the beam on IM4 trans using IM3 again. We confirmed that the NSUM on IM4 trans returned to 1.825. I reran the same coupling test above and we saw that for all four dofs, the coupling to IM4 trans NSUM increased. This is evident in both increased coherence and coupling value at 8 Hz. IM1 P, IM1 Y, IM3 P, IM3 Y

Then, Keita flipped the sign of the yaw offset to +0.64, since there is some confusion about which way the sign goes on that QPD. I recentered the beam again on IM4 trans, confirmed the NSUM came back to 1.825 , and reran the coupling measurement. The results show that for all four dofs, the coupling is decreased to below the starting value, shown in both the coherence and coupling value. IM1 P, IM1 Y, IM3 P, IM3 Y

It's possible that we are confused about the sign on MC2 trans, so that the first offset Keita tried actually went to the wrong position.

Another confusing point is that we see coupling in both pitch and yaw, and beam movement in both pitch and yaw. However, the beam translation we did was yaw only, to relieve yaw clipping.

Since we had found what we believe was a better beam position in HAM2, we checked the REFL alignment. With PRM aligned in this alignment, the beam is on the edge of the ISCT1 refl camera, so not great. There was also very little beam on the REFL WFS, and trying to run the REFL WFS centering servos rails RM2. We are now concerned about the REFL path and possible clipping on the REFL baffle in HAM2 as well.

To finish, Keita turned off the MC2 trans offset, and I reverted the IM3 sliders to the start position. However, the final screenshot here shows the final IM3 position we found where we think we had very little clipping in the input alignment.

None of theae alignments helped us find the beam on ASC POP A, but that's not surprising since we didn't make any IM4 moves. As we finished, Keita set up a long raster of IM3 and IM4 to look for a beam on those QPDs.

Images attached to this report

H1 CAL - PCAL EY End Station Measurement

anthony.sanchez@ligo.org — Tue, 04 Aug 2026 17:08:19 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91393

Ibrahim and I went to End Y with the PS4 Working Standard to do a PCAL End Station measurement. We followed T1500062-V21 to complete the measurment suite with out any issues.
Here are the obligitory Before Beam spot pics.
Martel plots for ADC conversion.

Working standard at TX module with only One beam.

Working standard at the RX module with only One beam.

Working standard at RX module with Both beams.

Post measurement beam spots!

anthony.sanchez@cdsws25: python generate_measurement_data.py --WS PS4 --date 2026-07-16
Reading in config file from python file in scripts
../../../Common/O4PSparams.yaml
PS4 rho, kappa, u_rel on 2026-07-16 corrected to ES temperature 299.6 K :
-4.698647654693516 -0.0002694340454223 0.000750622815531554
Copying the scripts into tD directory...
Connected to h1daqnds1
martel run
reading data at start_time: 1469911700
reading data at start_time: 1469912270
reading data at start_time: 1469912670
reading data at start_time: 1469913100
reading data at start_time: 1469913500
reading data at start_time: 1469913900
reading data at start_time: 1469914560
reading data at start_time: 1469915320
reading data at start_time: 1469915650
Ratios: -0.5339859682199335 -0.543765733929218
writing nds2 data to files
finishing writing
Background Values:
bg1 = 18.671164; Background of TX when WS is at TX
bg2 = 5.156755; Background of WS when WS is at TX
bg3 = 18.605483; Background of TX when WS is at RX
bg4 = 5.281252; Background of WS when WS is at RX
bg5 = 18.674174; Background of TX
bg6 = -1.117857; Background of RX

The uncertainty reported below are Relative Standard Deviation in percent

Intermediate Ratios
RatioWS_TX_it = -0.533986;
RatioWS_TX_ot = -0.543766;
RatioWS_TX_ir = -0.526609;
RatioWS_TX_or = -0.535095;
RatioWS_TX_it_unc = 0.059001;
RatioWS_TX_ot_unc = 0.057064;
RatioWS_TX_ir_unc = 0.061781;
RatioWS_TX_or_unc = 0.063032;
Optical Efficiency
OE_Inner_beam = 0.985936;
OE_Outer_beam = 0.983757;
Weighted_Optical_Efficiency = 0.984846;

OE_Inner_beam_unc = 0.046465;
OE_Outer_beam_unc = 0.047412;
Weighted_Optical_Efficiency_unc = 0.066385;

Martel Voltage fit:
Gradient = 1637.889101;
Intercept = 0.085727;

Power Imbalance = 0.982015;

Endstation Power sensors to WS ratios::
Ratio_WS_TX = -0.927858;
Ratio_WS_RX = -1.383422;

Ratio_WS_TX_unc = 0.047658;
Ratio_WS_RX_unc = 0.041564;

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

Key Pcal Values :
GS = -5.135100; Gold Standard Value in (V/W)
WS = -4.698648; Working Standard Value

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

End Station Values :
TXWS = -0.927858; Tx to WS Rel responsivity (V/V)
sigma_TXWS = 0.000442; Uncertainity of Tx to WS Rel responsivity (V/V)
RXWS = -1.383422; Rx to WS Rel responsivity (V/V)
sigma_RXWS = 0.000575; Uncertainity of Rx to WS Rel responsivity (V/V)

e = 0.984846; Optical Efficiency
sigma_e = 0.000654; Uncertainity in Optical Efficiency

Martel Voltage fit :
Martel_gradient = 1637.889101; Martel to output channel (C/V)
Martel_intercept = 0.085727; Intercept of fit of Martel to output (C/V)

Power Loss Apportion :
beta = 0.998844; Ratio between input and output (Beta)
E_T = 0.991820; TX Optical efficiency
sigma_E_T = 0.000329; Uncertainity in TX Optical efficiency
E_R = 0.992968; RX Optical Efficiency
sigma_E_R = 0.000330; Uncertainity in RX Optical efficiency

Force Coefficients :
FC_TxPD = 9.158396e-13; TxPD Force Coefficient
FC_RxPD = 6.237025e-13; RxPD Force Coefficient
sigma_FC_TxPD = 4.417816e-24; TxPD Force Coefficient
sigma_FC_RxPD = 2.847865e-24; RxPD Force Coefficient
data written to ../../measurements/LHO_EndY/tD20260804/

Images attached to this report

Non-image files attached to this report

LHO_EndY_PD_ReportV6.pdf

H1 CDS - Replace Adnaco with bad slot h1seiey

david.barker@ligo.org — Tue, 04 Aug 2026 17:00:47 -0700

Author: david.barker@ligo.org

Report ID: 91394

WP13482

Jim, Erik, Dave:

h1seiey was powered down: computer, IO Chassis and AI chassis.

The IO Chassis A2 Adnaco backplane was replaced with a spare. The original backplane's slot3 failed during O4 (Oct 2025) and back then we shifted the cards left by one slot to avoid it.

old backplane with broken slot3 (removed)	C8610513
spare backplane (installed)	C8610832

I was then able to put the cards back into their original slots, making h1seiey identical to h1seiex. This meant A3 now had no cards installed, so I disconnected the A3 fibers from the rear of h1seiey.

For backplane testing we stopped the models from running to verify all the cards are seen. Auto start was turned back on, the system was powered up, the models started and lastly I powered the AI chassis back on.

LHO General - Comment to OPS Day Shift Summary

ibrahim.abouelfettouh@ligo.org — Tue, 04 Aug 2026 16:43:23 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91392

It is also worth nothing that as of 16:30 PT, there are no active fires in Benton or Franklin county per Watch Duty.

H1 AOS - JAC ASC Loops Closed

khanh.vu@ligo.org — Tue, 04 Aug 2026 16:41:19 -0700

Author: khanh.vu@ligo.org

Report ID: 91391

Masayuki Nakano, Khanh Vu We successfully closed all of the JAC ASC loops. Attached below are the outputs from the two wavefront sensors. All of the signals converge to zero within approximately 30 seconds, indicating that the loops are working beautifully. More details will be reported tomorrow.

Images attached to this report

LHO General - OPS Day Shift Summary

ibrahim.abouelfettouh@ligo.org — Tue, 04 Aug 2026 16:33:07 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91389

TITLE: 08/04 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

Slow day due to ongoing FAC water and outdoor air quality issues but the following was done:

HAM7 Power measurements
JAC Beam profiling at IOT1 and power measurements and IOT2L
Scissor lift work
Gate phone work
PCAL EY Measurement
Seismic work (Jim) on HAM2 electronics and ITMX

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:45	FAC	Kim	LVEA	Local	Technical Cleaning	15:18
15:21	SQZ	Camilla	LVEA	Local	Taking Viewport covers off HAM5	16:13
15:31	FAC	Kim	LVEA	Local	Technical Cleaning	16:15
16:11	ISC	Jennie	Optics Lab	Local	Looking for parts	16:13
16:17	JAC	Jennie, Masayuki	LVEA	YES	IOT1 beam profiling, then IOT2L beam pwr meas.	19:17
16:21	FAC	Chris	LVEA	YES	FAMIS Tasks	17:21
16:31	JAC	Khanh	LVEA	YES	Joining JAC Team	20:02
16:37	SEI	Jim	LVEA HAM2	yes	Chcking signal paths	17:58
17:16	VAC	Jordan	LVEA GV6	y	Getting parts.	17:25
18:30	CDS	Dave	EY	N	SEI Chassis work	20:02
18:40	SQZ	Camilla	LVEA	YES	HAM7 power measurements	19:34
18:42	SQZ	Ryan S	LVEA	YES	HAM7 Power measurements	19:34
19:33	PCAL	Tony	PCAL Lab	Local	Staging parts	19:53
19:39	FAC	Randy	LVEA	Y	Scissor Lift Work	20:39
19:54	CAL	Tony, Ibrahim	EY & Lab\\	Y	PCal measurement	22:18
20:50	SQZ	Camilla	LVEA	-	Covering HAM5/7 viewport	21:16
21:44	SQZ	Camilla	LVEA	Y	HAM7 power budget	00:44
22:01	SQZ	Ryan S	LVEA	Y	HAM7 power budget	23:13
23:31	SQZ	Sheila	LVEA	Y	HAM7 power budget	01:31
23:31	CDS	Dave	EY	N	Chassis work	23:32

H1 SQZ - Comment to SQZ OMC Scans and M^2 Measurements with new ZM4 ZM5 PSAMS Preloadings

eric.oelker@ligo.org — Tue, 04 Aug 2026 16:27:21 -0700

Author: eric.oelker@ligo.org

Report ID: 91390

Below I calculate the astigmatism based Ryan's grid of M^2 measurements.

I compute the 1D overlap between the x and y directions using the q values from the M^2 measurements

eta_1D = 4*zRx*zRy / ( (z0x - z0y)^2 + (zRx + zRy)^2 ) where z0 is the waist position and zR is the rayliegh length = pi * w /(M^2*lambda)

The astigmatism, which i express as 1 - eta_1D is tabulated below in %

ZM5 \ ZM4	-3.2	-1	1.2	3.4
-8	0.52	0.52	0.55	0.59
-6.75	0.51	0.48	0.60	0.64
-5.5	0.56	0.55	0.62	0.50
-4.5	0.57	0.56	0.55	0.36
-3.3	0.52	0.50	0.40	0.29
-2	0.42	0.50
-1	0.56	0.78	0.62	0.15

The dependance is pretty weak over much of the grid, but things get a bit squirly in the lower right corner near the positive end of the range for both PSAMS. We're not as sensitive to the strain gauge setting as ZM2 (91185), but there's clearly a noticible dependence.

Non-image files attached to this report

Aug03_2026.zip

H1 AOS - Comment to IOT1 Table Work

masayuki.nakano@ligo.org — Tue, 04 Aug 2026 14:56:43 -0700

Author: masayuki.nakano@ligo.org

Report ID: 91388

The beam profile between the beamsplitter and the JAC WFS was measured. Here I fit a Gaussian beam to those measured beam sizes and convert the WFS locations into Gouy phase.

Fit

The measured beam diameters were fit independently in x and y with the standard Gaussian beam model, w(z) = w0 * sqrt(1 + ((z - z0)/zR)^2) with zR = pi * w0^2 / lambda and lambda = 1064 nm:

	w0 [um]	z0 [m from JACR_BS4]	zR [cm]
x	141.2	0.377	5.89
y	151.9	0.370	6.81

The beam is slightly astigmatic, so x and y are treated separately throughout.

WFS positions and Gouy phase

The positions of WFS A and WFS B were measured with a ruler from the same reference as the profile scan: WFS A at z = 0.325 m, WFS B at z = 0.410 m. The corresponding Gouy phases, psi(z) = arctan((z - z0)/zR), are:

	WFS A [deg]	WFS B [deg]	Separation [deg]
x	-41.3	+29.5	70.8
y	-33.5	+30.4	63.9

Assessment

The separation is 71 deg in x and 64 deg in y, not the optimal 90 deg. This is not optimal, but it is not terrible either: the two WFS remain well separated in Gouy phase and the sensing matrix would not be close to degenerate. Given the time available we did not optimize the layout.

If we want to optimize it later, the fix is straightforward: moving WFS A upstream (toward the BS) by about 5 cm in x / 7 cm in y, i.e. from z = 0.325 m to roughly z = 0.27 m, brings the separation to 90 deg. WFS B does not need to move.

Images attached to this report

H1 IOO - IOT1 Table Work

khanh.vu@ligo.org — Tue, 04 Aug 2026 14:32:40 -0700

Author: khanh.vu@ligo.org

Report ID: 91386

Jennie Wright, Masayuki Nakano, Khanh Vu This morning we worked on several tasks on the IOT1 table, including installing the camera and shutter, profiling the beam, and calibrating the DC power. We identified a new location for the camera using the beam transmitted through JACR_M5. During this process, Masayuki noticed that the beam was being clipped by the shutter. We suspect that the beam may have been clipped for some time. We then installed the camera in its new location, and Masayuki aligned the shutter on the table. Next, we profiled the beam for the wavefront sensors. We found that the Gouy phase separation between the two WFSs is approximately 70 degrees. We decided to leave the current configuration as it is since the separation is good enough. Masayuki will make a plot and perform a more detailed calculation later. We also maximized the laser power in the REFL path by optimizing the waveplate angle. When JAC is unlocked, the measured power on the RFPD is 5.1 mW, and the trigger PD voltage is 0.28 V. When JAC is locked, the measured power decreases to 0.4 mW, and the trigger PD voltage is 0.02 V. Since the beam is split evenly, each WFS receives approximately 2.55 mW of optical power. Finally, we calibrated the DC readout of RFPD by converting counts to mW. Before performing the calibration, Masayuki checked the alignment and recentered the RFPD. He then recorded two sets of measurements, each averaged over 10 seconds: Measurement #1 * JAC_REFL_A_LF_INMON: 1072.3966186523437 counts * DC power: 4.4 mW Measurement #2 * JAC_REFL_A_LF_INMON: 1073.5228637 counts * DC power: 4.5 mW After the calibration, we updated filter number 10 with the new coefficients. IOO

H1 ISC - Comment to SRY locked with different BS alignment

elenna.capote@ligo.org — Tue, 04 Aug 2026 13:34:59 -0700

Author: elenna.capote@ligo.org

Report ID: 91387

After discussion this morning, I put the ITMX sliders back to the O4 alignment position: pitch = -113 and yaw = 104.6

H1 SEI - Comment to BS ISI health check

jim.warner@ligo.org — Tue, 04 Aug 2026 10:36:57 -0700

Author: jim.warner@ligo.org

Report ID: 91384

Finally had a chance to repeat the test swapping st2 h1 v1 cps. Still no change, as I have seen when I did this test before. The excess low freq noise follows the in-air to feedthru and in-vac cables, so the problem is not from the satellite chassis or the CER rack. I can try to swap the cable from the feedthru to the satellite rack, but the work platform, crossbeam and feedthru protection make access to that difficult from pretty much any direction.

Attached spectra compare the nominal H1 V1 asds and the asds with the white in-air cables at satellite rack for st2 H1&V1 swapped. Dashed is nominal, solid is the swapped configuration. Red is the H1 channel, blue is the V1 channel.

Images attached to this report

H1 ISC - Comment to SRY locked with different BS alignment

keita.kawabe@ligo.org — Tue, 04 Aug 2026 10:33:35 -0700

Author: keita.kawabe@ligo.org

Report ID: 91383

Attached is a not-to-scale, super-simplified cartoon so people understand what happened. As of now, ITMY is unchanged (because I reverted the changes temporarily made to ITMY), BS is angled in PIT, ITMX was angled mostly in PIT to follow the BS motion.

Initial state is in the top cartoon. The symptom that the two beams (single bounce and reflection of SRM reflected back by ITMY) didn't interfere well only meant that the beam was not retro-reflecting on ITMY.

This could be remedied by many different ways. At first I moved ITMY just to confirm that something like this was going on, and we did confirm that (because we were able to make the SRY fringe deeper).

Once we confirmed this was actually the case, I reverted the ITMY back, moved BS, and refined SRM using SRY fringe. The bottom cartoon represents this final state.

Though it's not captured in the cartoon, this of course made the MICH fringe wrong, so we moved ITMX, too.

Using BS or ITMY (or a combination of them) is not the only way though, you can change the angle of the beam from PR3 hitting the BS and refine SRM alignment to recover a good SRY fringe depth. As long as the beam is still on ITMs it will work. I haven't done that bacause it was late and I wanted to see the beam on POP_A or B, but we should.

Note that, ultimately, the good alignment of the ITMs, BS and PR3 won't be known until we open the arms. There's no magic in the current alignment we have (or even after using PR3 instead of BS to regain SRY fringes).

The main purpose of this excercise is just to confirm that nothing terrible is going on in the SRC chain. Because of the things described in Elenna's alog above, we already know that nothing terrible is going on. The rest is just an effort to gradually, maybe, approach the good alignment (on a belief that we already know the good angles for ITMs).

Images attached to this report

LHO General - OPS Day Shift Start

ibrahim.abouelfettouh@ligo.org — Tue, 04 Aug 2026 07:41:34 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91382

TITLE: 08/04 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 4mph Gusts, 1mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.08 μm/s
QUICK SUMMARY:

IFO is in IDLE for MAINTENANCE

Today, we anticipate some Ion Pump work from Vacuum and some comissioning work after Tues Maintenance

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 04 Aug 2026 06:01:13 -0700

Author: erik.vonreis@ligo.org

Report ID: 91381

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

LHO VE - Comment to Seal Replacement on GV6 Air Cylinder

jordan.vanosky@ligo.org — Mon, 03 Aug 2026 17:45:39 -0700

Author: jordan.vanosky@ligo.org

Report ID: 91378

8/3/2026

Travis, Gerardo, Jordan

Today we again disassembled the GV6 air cylinder with the valve soft closed to try and see what may have been causing the air blow-by which prevented us from fully opening the valve last week.

We did not find anything immediately obvious such as a seal that had jumped out of the groove, so we measured the ID of the original air cylinder, which was re-used, and found that it was ~0.01" larger than the ID of the spare cylinder (original ID ~8.015", spare ID ~8.005"). We then elected to use the spare cylinder instead to make sure there is good sealing contact with the cylinder wall, so we re-distributed the grease on the new cylinder and attempted to install over the piston, but the tube seemed to be slightly out of round and would not fit over the piston. So we flipped the tube 180 degrees and measured that side of the tube and found it was better. We again added grease to that side of the cylinder and installed it over the piston, ensuring the seals and wear band stayed in place, Then we re-installed the threaded rods, torqued the nuts, installed the reed switches and installed the air lines.

To verify all the new joints/connections were ok, we put ~10 psi to the top of the cylinder and then to the bottom to see if there were any leaks. There were none so we started to open the valve by increasing air pressure at the regulator, once we got to ~25 psi we could hear and feel air coming out of the bottom plate/adapter flange below the cylinder assembly, see picture below the area where air is coming out of is circled in red, at which point we stopped trying to open the valve and closed the quarter turn isolation valve to the air line.

We spoke with a GNB rep who advised we try to to open at a higher pressure and see if the bottom seals, so we then tried to open the valve again. This time we started at 20 psi and followed our normal opening procedure with the exception of increasing by 5 psi instead of 10 and waiting 3 minutes between increases. At ~35 psi, air stopped leaking out of the bottom flange, there was no air blow-by in the cylinder and we could hear the carriage starting to move. The gate fully opened at ~48 psi and Gerardo was able to take a video where you can hear the piston incrementally move up the cylinder. We increased the holding pressure to 58 psi and verified the MEDM screen showed the valve status as green.

Images attached to this report

H1 PSL - PSL 10-Day Trends

ryan.short@ligo.org — Mon, 03 Aug 2026 17:25:49 -0700

Author: ryan.short@ligo.org

Report ID: 91377

FAMIS 63910

Last Tuesday's interlock work and brief time in the enclosure are clearly seen on many trends, and essentially everything came back as expected. One item of note is the PMC, which relocked at a slightly higher temperature, which seems to have caused the transmitted power to be a bit lower while the reflected power is a bit higher.

Images attached to this report

H1 ISC - SRY locked with different BS alignment

elenna.capote@ligo.org — Mon, 03 Aug 2026 16:58:30 -0700

Author: elenna.capote@ligo.org

Report ID: 91376

[Keita, Elenna]

Sheila and I struggled to lock SRY last Friday, 91360. Keita and I revisited today.

To start, I ran the usual SR2 alignment, which centers the beam on AS_C, and the AS centering which centers OM1,2 on AS A and B.

Then, we could see a large beam at the center of the AS AIR camera, and a strange fringing beam at the top edge of the camera. We swept SRM in both pitch and yaw to both edges and saw the beam disappear. This convinced us that we were seeing the two beams we needed to overlap in SRY, however, there was not an SRM alignment that could overlap the two beams.

Keita first moved ITMY 10 urad in pitch, and was able to overlap the two beams. He then undid that alignment and moved the beamsplitter instead. We were able to achieve the SRY fringing and then lock SRY with the guardian. The resulting beam ended up on the top edge of th AS AIR camera view.

Using that beamsplitter alignment, we then relocked MICH dark, which required a large movement of ITMX, since we had decided to maintain the beamsplitter and ITMY alignment. ITMX is now at P: -135 and Y: 113.1 on the sliders. This means it has been moved relative to where it should be according to a previous arm alignment we achieved.

We can still see the MICH fringes on the ISCT1 refl camera with this alignment.

We can also lock PRX, with a movement of PRM. We still see no beam on POP A or B, so Keita is scanning the input alignment.

The attached screenshot shows the alignment sliders after we locked SRY, MICH, and PRX.

I'm not sure if we are happy with this alignment overall, since we're not sure if this is where we want the ITMs.

Images attached to this report

H1 DAQ - Comment to WP 13472 - new frame writer software on h1daqfw0 + OS upgrade

jonathan.hanks@ligo.org — Mon, 03 Aug 2026 16:46:53 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91375

As the new framewriter is a different piece of software, we track different metrics. So we will need an updated edc capture list and a daqd restart.

A note about what this system brings in.

* It automatically changes its configuration when there is a channel list. It is a step towards not having daqd restarts (those don't go away while we have the daqd in other places).

* When we restart the daqd we usually have a gap of several frames. We hide this from the outside world by having two frame writers and only restarting one at a time. This reconfigures the channel list and does not have gaps unless you actually restart the program.

* It is also being used in the ngdd work to write derived frame data, so that we have a common frame writer (we just change the input type).

H1 DAQ - WP 13472 - new frame writer software on h1daqfw0 + OS upgrade

jonathan.hanks@ligo.org — Mon, 03 Aug 2026 16:37:37 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91374

Per WP 13472 updated h1daqfw0 to use the new auto-reconfiguring frame writer. This is the same code has been running on h1daqfw2 for months in a test mode.

I also did an inplace upgrade of h1daqfw0 to Debian 12, which is what h1daqfw2 is running and what we have tested as.

Erik helped with package wrangling for Debian 12. I had been running h1daqfw2 from the experimental repository (which is a snapshot of the continous integration system). We were able to move this from using the experimental repository to the unstable repository. We will move it up to production later. We don't have a full Debian 12 release of advligorts as we are not planning on supporting the rcg and real time code on Debian 12.

Dave and I will be watching the timings and checksums to make sure everything looks good. The IO setup is a bit different between h1daqfw2 and h1daqfw0 (fw2 writes to local disk, fw0 to a NAS).

H1 General - Ops Monday report

anthony.sanchez@ligo.org — Mon, 03 Aug 2026 16:35:47 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91373

TITLE: 08/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 11mph Gusts, 7mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.07 μm/s
QUICK SUMMARY:
The well pump was not working today due to some electrical issue. Last I heard FAC had a contractor on site to check on the well. So there is limited amounts of water here. Many folks were asked to work from home if they can.

GRB-Short E644098 @ 17:29 UTC

Jonathan started working on the FrameWrite0 today, installing Deb12 OS.

End stations were misaligned today to some tests that Camilla was doing.

ITMX ISI Stage 1 & 2 WD tripped twice today. Jim went out to the CER today to fix this.

Vac Team did some work on the GV6 Gate Valve today and GV6 is currently Open on the Y arm, But GV5 is still closed so the corner volume is still not open to the Arms yet.

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:10	FAC	Kim	LVEA	y	Technical cleaning & resupply	17:00
15:41	CDS	EJ	Remote	N	Test on OAF	15:42
15:43	FAC	Tyler, Eric, & contractors	EY	N	Working on the well	20:39
15:48	SQZ	Camilla	LVEA HAM5	YES	Opening ViewPort on HAM5	15:55
16:10	FAC	Kim	Mid X	N	Tecnical Clkeaning & resupply	17:01
16:11	SEI	Jim	LVEA	n	working on SEI near BSC2	18:08
16:41	VAC	Jordan & Travis	LVEA GV6	N	Working on the Gate Valve	18:39
17:20	SEI	Jim	remote CER	N	Tests on HAM2 & looking at Wiring	18:22
17:25	VAC	Gerardo	LVEA	N	Checking on GV6 work	19:25
17:45	CDS	Partick	MSR	N	CDS work?	18:06
18:39	FAC	Kim	HAM Shaq	N	technical Cleaning & Resupply	19:07
19:05	CDS	Jonathon	Remote	N	Re-imaging FW0	22:04
19:59	SEI	Jim	Remote	N	Tests on HAM3	21:25
20:03	VAC	Jordan	LVEA	N	Getting pics of GV6	20:07
20:51	VAC	Travis & Gerardo	End Y	N	Using the pump cart for Anulus work.	21:28
21:10	SQZ	Camilla & Ryan S	LVEA HAM7	YES	Beam Profiling with M2**2 profiler. Ryan Out early	23:10
21:12	SEI	Jim	CER	N	troubleshooting ITMX ISI WD trips.	21:24
21:43	VAC	Jordan	LVEA GV6	N	Checking on GV6 status	22:28
22:41	VAC	Jordan & Gerardo	LVEA GV6	N	Opening GV6	00:11
22:46	SQZ	Sheila	LVEA HAM7	YES	Working on the Power budget	00:16

H1 ISC - Dark offsets run

elenna.capote@ligo.org — Mon, 03 Aug 2026 16:15:01 -0700

Author: elenna.capote@ligo.org

Report ID: 91372

Keita and I took an opportunity while JAC was offline to run all the dark offsets. I ran the usual dark_offsets_exe.py from userapps isc/h1/scripts/dark_offsets

I did not visually check all of them but the ones I compared before and after in SDF looked reasonable.

Some of the whitening gain settings have been set strangely for the vent, so this should help fix that now that we have reset the proper settings.

SDFed, see screenshots.

After we ran, Keita and I realized the whitening settings for POP B were still wrong, so I corrected them and reran the offset for the POP B segments. Added screenshot.

Images attached to this report

H1 SQZ - SQZ OMC Scans and M^2 Measurements with new ZM4 ZM5 PSAMS Preloadings

camilla.compton@ligo.org — Mon, 03 Aug 2026 15:44:46 -0700

Author: camilla.compton@ligo.org

Report ID: 91371

Sheila, Ryan S, Camilla

We spent the morning repeating 90783, now that ZM4 preloading has been adjusted (90951) and ZM5 has been swapped and now has a different preloading than our O4 ZM5 (91292):

Using SQZ ASC with ZM4 and ZM5 to get ASC_A and ASC_B centered, we needed to move SRM to stop saturating ZM4/5,
then locking OMC on 00 touching up OMC and OM3 alignment to maximize 00 peak,
then putting these ASC-OMC offsets into H1:OMC-ASC_QPD_A/B_PIT/YAW_OFFSET so that the OMC ASC will put us in this good location.

Sheila then used her script to run OMC scans at a grid (below) of PSAMS locations. These initially look great, showing sqz to omc mode mismatch is as good as 1%. with some alignment fluctuations. Ndscope of data taking attached.

PSAM_VALUES_V5 = [-8, -5.5, -3.3, -1]

PSAM_VALUES_V4 = [-3.2, -1, 1.2, 3.4]

Ryan then took M^2 measurements on SQZT7 of a slightly different grid:

PSAM_VALUES_V5 = [-8, -6.75, -5.5, -4.5, -3.3, -1]

PSAM_VALUES_V4 = [-3.2, -1, 1.2, 3.4]

Images attached to this report

H1 ISC - BBSS model with MICH ASC

elenna.capote@ligo.org — Mon, 03 Aug 2026 10:44:11 -0700

Author: elenna.capote@ligo.org

Report ID: 91368

Following a similar process for the length control as in 91028, I used both the BSFM and BBSS model to construct a model of the MICH ASC and check the crossover frequencies.

The most recent ASC OLG measurements of MICH P and Y are in userapps asc/h1/templates/MICH. MICH P UGF is roughly 2 Hz, MICH Y is roughly 0.7 Hz. Using the BSFM model and this information, I once again assumed the optical gain of the MICH ASC would be the same and calculated a rad/ct calibration factor to use with the BBSS model. Note that these UGFs are from full power lock, so I'm not certain what the MICH ASC OLGs look like in DRMI lock.

The BSFM model also says that both P and Y have a 22 mHz crossover between M1 and M2.

Using these calibration factors show that we might have some trouble running with the exact same MICH ASC design with BBSS. I think this is because the MICH ASC design contains a pretty extreme BSFM plant inversion. We could replace it with a BBSS inversion, or use this opportunity to move to a slightly different design principle that doesn't require precise plant inversion.

The model also suggests that the yaw crossover from M1 to M2 will be about 22 mHz as before, but shows the pitch crossover would now be 8.5 mHz. I need to confirm I am using the correct lever arms for the calibration to make sure I haven't made a mistake there. Either way, we can confirm the crossover with an injection.

Just as with length, we would need to slightly adjust the locking filter design if we want to move to M1 and M3 actuation, but in principle I don't see any issue with driving from M3 instead of M2 for ASC as well. This would be in line with how we drive all other triple sus for ASC.

First attachment shows the MICH ASC in the BSFM model, second in the BBSS model.

SUS

Images attached to this report

H1 CDS - Greened up h1iopomc0 timing card status on CDS Overview

david.barker@ligo.org — Mon, 03 Aug 2026 10:42:38 -0700

Author: david.barker@ligo.org

Report ID: 91370

Post upgrade the CDS Overview was showing an issue with h1iopomc0's timing card. On further investigation we found that this timing card is a very early rollout of the V5 firmware, upgraded back in Feb 2025 for DT-frequency changes. The actual issue is that RCG5.65 is more accurately calculating the duotone crossing for h1omc0's low-noise ADCs. This value was +0.1uS pre-upgrade and now is -5.625uS with only nano-second variation. The CDS overview was using the DT crossing time as an indicator of timing card firmware version. V3 had DTs between +7uS and +8uS, V5's are in the -1uS to +1uS range.

I've changed the CDS Overview to extend the lower limit of acceptible DT timings to -6uS. No further action is required.

H1 CAL - O4b DARM Loop Design Comparisons and Critiques

rachel.langgin@ligo.org — Mon, 03 Aug 2026 10:16:40 -0700

Author: rachel.langgin@ligo.org

Report ID: 91369

Rachel and Elenna:

The goal of this project is to better understand the DARM loop design that was used during O4b and evaluate how well it performed. By identifying where the design worked well and where we observe limitations, we can gain insight into potential improvements for future DARM loop designs.

To do this, I recreated the pydarm.plot.critique() function using valid O4b calibration reports (H1: 20250111T193645Z and L1: 20250102T163026Z). I then broke the DARM loop down into its individual components to understand how each stage contributes to the overall control performance.

The analysis includes comparisons of the open-loop gain (OLG, (G)), the suppression function (1/(1+G)), the digital_out_to_displacement actuation transfer functions, the lock_in_to_displacement actuation transfer functions, annotated crossover frequencies, and the frequency ranges over which each actuation stage dominates.

Several notable differences emerge between the H1 and L1 DARM loops. H1 has a lower unity gain frequency (72.2 Hz vs. 86.0 Hz), a lower low-frequency OLG magnitude, and substantially less phase margin (22.5º vs. 34.3º). The reduced phase margin is also reflected in the larger gain peaking observed in the suppression function. Regardless of how future DARM loops are offloaded, increasing the available phase margin should be a primary design objective.

The actuator comparisons show that the overall stage hierarchy is similar between the detectors, with the UIM dominating at low frequencies before the TST becomes dominant above approximately 17 Hz. However, the lock_in_to_displacement transfer functions reveal more complicated interactions between the UIM, PUM, and TST at low frequencies than are apparent from the digital_out_to_displacement transfer functions alone.

See: LIGO-G2601606 for slides.

CAL

H1 IOO - Comment to JAC heater and HAM1 pressure

keita.kawabe@ligo.org — Mon, 03 Aug 2026 10:15:31 -0700

Author: keita.kawabe@ligo.org

Report ID: 91366

Actually I turned the heater back on shortly after I turned it off on Friday because the pressure rise that some were worried about looked like diurnal change to us and it was already peaking at the time.

I monitored the pressure on Friday evening and it was good, it was good on Saturday too so I kept the heater ON over the weekend. No need to turn it off from this point on.

Images attached to this report

H1 General - Monday Ops Morning report

anthony.sanchez@ligo.org — Mon, 03 Aug 2026 08:09:34 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91365

IFO status: Currently Unlocked. Both GV5 and GV7 are shut..... for now.
Corner pump down continues.
Spool cameras work to reinstall IR cameras.
More Distributed acoustic sensing DAS system.

H1 CDS - Comment to no h1sush12 IPC errors since fiber/SFP swap

david.barker@ligo.org — Sat, 01 Aug 2026 09:59:05 -0700

Author: david.barker@ligo.org

Report ID: 91364

h1syscsauxsdf had gotten stuck, I restarted it on h1ecatmon0.

H1 CDS - no h1sush12 IPC errors since fiber/SFP swap

david.barker@ligo.org — Sat, 01 Aug 2026 08:12:15 -0700

Author: david.barker@ligo.org

Report ID: 91363

Following yesterday's swap of h1sush12's IPC fiber and switch-SFP (port3) 23 hours ago there have been no IPC errors from this frontend. Also the 25GE switch (sw-msr-ipc0 port3) shows zero packet errors.

H1 SQZ - Comment to HAM7 Squeezer beam alingment work, power budget estimation and beam injected into HAM5.

sheila.dwyer@ligo.org — Fri, 31 Jul 2026 17:39:09 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91360

Power budget: We measured 1.35mW out of the OPO, and 1.2mW on SQZT7. we struggled as usual with the reliablity of the power meter measurements, but it seems like the return beam through SFI1 has higher loss than it should, and there also seems to be power missing between the beam leaving the VIP and the beam arriving on SQZT7. If we believe this measurement we have too much loss, with 12% measured loss in HAM7 where we should have 4-5%.

I did walk the alignment of ZM1/2/3 a little bit, we could try this more to see if we can fix clipping that way. Screenshot of where I left the sliders is attached.

Elenna and I put SR3 back to where it was in O3, aligned SR2 to center on AS_C, and ran the AS centering + offloaded. We then tried to align SRY, but could not get the fringes as high as they should be. We paused on SRY alignment to inject sqz into HAM6.

The sqz beam was on the HAM6 QPDs, we ran the AS WFS to ZM4+5 loops descirbed in 90742. This is close to saturating ZM4 + 5 but is within the range. (We would like to increase the range on these as was done at LLO to make things easier).

We set the OMC PZT offset to 0, decided to scan the psams through strain gauge values of

PSAM_VALUES_V5 = [-8, -5.5, -3.3, -1]

PSAM_VALUES_V4 = [-3.2, -1, 1.2, 3.4]

and engaged the strain gauge servos. I did not tune the OMC ASC offsets carefully as described in 90783, perhaps that needs to be done to get a good estimation of the mode matching.

A set of OMC scans for different psams is running now.

Images attached to this report

H1 IOO - JAC heater and HAM1 pressure

sheila.dwyer@ligo.org — Fri, 31 Jul 2026 17:36:36 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91361

Keita turned on the JAC heater this afternoon. Attached plot has the first cursor at the time of 91296, the second cursor at the time when Keita turned on the heater, they both happened at the same point in the diurnal pattern where the termperature rises.

Keita has now turned the heater off before people leave for the weekend, because we can't say it's not causing the pressure to rise. Let's repeat this earlier in the day on Monday.

Images attached to this report

LHO General - Ops Day Shift End

thomas.shaffer@ligo.org — Fri, 31 Jul 2026 16:31:59 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91359

TITLE: 07/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
SHIFT SUMMARY: The final bits of the CDS upgrade continued today, as well as some SQZ and michelson commissioning. The LVEA is currently in Operations SAFE.

The corner station continues to be pumped down, pressures are around 4e-7torr. The HAM1 pressure has been a concern when using the JAC heater this week, but I think we may have been scaring ourselves. The HAM1 pressure changes diurnally regardless of whether the heater is on or off. We have seen a pressure response from turning on the heater, but this diurnal effect might be the dominating factor. Looking at LVEA temps around HAM1 it tracks well with the local temperature.

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
13:33	DAS	Jenne, Wanda, Shoshana, Gizem	Yarm, Xarm inside	N	Hitting things with hammer	17:09
16:05	CDS	Jonathan	MSR	n	Troubleshooting iopsush12	16:13
16:12	FAC	Kim	LVEA	n	Tech clean	17:13
16:21	SUS	Ryan C	CR (Ends)	n	EX & EY sus charge meas.	18:03
16:38	SQZ	Sheila, Rahul	LVEA	LOCAL	SQZ alignment with refurb ZM5	19:38
17:37	VAC	Gerardo, Travis	EY	n	BSC6 annulus work	18:25
17:39	VAC	Gerardo	LVEA	n	Grabbing lifting hardware for EY	17:49
17:57	ENG	Betsy	Opt Lab	n	Parts	18:03
18:01	SAF	Ryan C	LVEA	N -> n	Transition LVEA from Upgrade laser safe to Operations lasre safe, open light pipe	18:31
18:08	DAS	Wanda	EX, vertex	n	Looking for glasses	18:31
18:20	SQZ	Daniel	LVEA	LOCAL	Look at ZM4 electronics	18:49
19:31	FAC	Randy	LVEA	n	Measuring around BSC1	19:58
19:37	SEI	Shoshana	LVEA	n	Turning on CRS laser	19:41
20:43	VAC	Gerardo, Travis	LVEA	n	Checking on HAM2 pumps, disconnecting	20:56
20:45	SQZ	Sheila, Rahul	LVEA	LOCAL	Open HAM7 to HAM5, check alignment	21:45
20:52	CDS	Dave	CER, CUR	n	iopsush34 troubleshooting	21:50
21:34	CDS	Richard	CER	n	Checking in on iopsush34 work	21:35

Images attached to this report

H1 SQZ - HAM7 Squeezer beam alingment work, power budget estimation and beam injected into HAM5.

rahul.kumar@ligo.org — Fri, 31 Jul 2026 15:51:44 -0700

Author: rahul.kumar@ligo.org

Report ID: 91358

Sheila, Rahul

We got back into HAM7 for beam alignment work after ZM5 was repaired and, up & running. Listed below are the things we did to check and improve the alignment in HAM7 chamber and also on the SQZT7 irises.

1. Checked the incoming beam on ZM5 from ZM4, found it to be off in yaw by few mm - hence we translated ZM5 (pushing it in the direction towards SQZT7 table) to center the beam on the PSAMS.

2. Checked the reflected beam from ZM5 on the iris (which Camilla had set last week) - it was off in Yaw and was too high as well. Hence, I mechanically adjusted the pitch and yawed the suspension cage to center the beam on the iris. Sheila then checked the beam on the two irises in SQZT7. Using sliders we were able to center it nicely on the two irises, however several times while doing so we were eating up on DAC output. Hence iteratively we were using sliders and mechanically offloading Pitch/Yaw by adjusting the pitch adjuster or yawing the suspension cage.

3. Sheila also used ZM4 sliders to fine tune the alignment on the irises on the table.

Current status - we have centered the beam on the two irises in SQZT7 but we might have to mechanically offload ZM5 or perhaps ZM4 as well. ZM5 has all four dog clamps attached and baffle installed as well.

We removed the yellow viewport cover (and guillotine) from HAM5, removed the foil and opened the gate valve on HAM7 viewport (going towards HAM5) and then confirmed that the beam is injected into HAM5.

Sheila, is fine tuning the IFO alignment before aligning the two beams (IFO and squeezer) in HAM6 photodiode.

We also did some power measurements in HAM7 chamber, mainly on the OPO and then compared it against SQZT7 table. Sheila will posting the numbers later on.

SUS

H1 CDS - fix h1susb2h34 DAC MEDM and verify correct drive of DACs

david.barker@ligo.org — Fri, 31 Jul 2026 15:16:11 -0700

Author: david.barker@ligo.org

Report ID: 91357

WP13479 Move last ADC in h1susb2h34 in front of the LIGO-DACs

Erik, Jonathan, EJ, TJ, Dave:

The 3rd ADC, which was after the LIGO-DACs on the PCI bus, was moved to be before the LIGO-DACs. EJ found that if a General Standards card followed the LIGO DACs, and there are other General Standard DACs in the chassis, then the DAC mapping became ambiguous. This was first discovered by TJ when he noticed that the LIGO-DAC card temperatures was being reported as -1C (not being read). We then found that model's LIGO-DAC drive counts were being reported by h1iopsusb2h34 on the wrong DAC MEDM.

A quick fix as to move the ADC inside the IO Chassis from after to before the LIGO-DACs

The original card layout (BIO not shown):

empty

***ADC2***

LIGO-DAC1

LIGO-DAC0

20bit-DAC1

ADC1

20bit-DAC0

ADC0

empty

Timing

A3-4

A3-3

A3-2

A3-1

A2-4

A2-3

A2-2

A2-1

A1-4

A1-3

A1-2

A1-1

The new card layout (BIO not shown):

empty

LIGO_DAC1

LIGO-DAC0

empty

***ADC2***

20bit-DAC1

ADC1

20bit-DAC0

ADC0

empty

Timing

A3-4

A3-3

A3-2

A3-1

A2-4

A2-3

A2-2

A2-1

A1-4

A1-3

A1-2

A1-1

I was able to shuffle the cards without disconnecting any rear cables except ADC2 (SUS_HAM_209) and the MTP. The cables had enough slack to pull the chassis out to access the card screws. At the rear I was able to push the h1susauxb2h34 chassis forward to access the interface cards.

Internally only ADC2's ribbon cable needed to be disconnected.

TJ methodically started driving the top stages for MC2, PR2 and BS. We verified the model's and IOP's MEDM reported the correct channels being driven.

I trended the ADC2 channels from before and after its move to verify it is connected correctly.

H1 ISC - DIAG_MAIN whitening checks updated

thomas.shaffer@ligo.org — Fri, 31 Jul 2026 15:08:29 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91355

Keita pointed out that the normal DIAG_MAIN whitening check doesn't currently cover the OMC DCPD external analog whitening (state of which can be seen on H1:OMC-DCPD_{A,B}_GAINVAL, 0=high 1=low), and the corresponding digital antiwhitening for it at FM2 on H1:OMC-DCPD_{A,B}0. This is now in DIAG_MAIN's whitening test.

While I was looking at this test, I noticed it was quite out of date with the whitening overview screen. I pull all of the names from that screen and made a new list for the DAIG_MAIN test. There were only additions from the old list, so I don't think we dropped any sensors. I commented out some BHD sensors until they are fully ready.

OpsInfo

LHO VE - Comment to HAM2 Annulus Ion Pump Work

gerardo.moreno@ligo.org — Fri, 31 Jul 2026 14:46:20 -0700

Author: gerardo.moreno@ligo.org

Report ID: 91356

(Travis S., Jordan V., Gerardo M.)
HAM2 annulus system pumpdown is done, Jordan Isolated the system earlier on the week from the aux-cart, ion pump took over the pumping with no issues. Today, taking advantage of a computer reboot, Travis and I removed the flex hoses and can turbo from the annulus system. Aux-cart and components were moved away and stored away from the chambers. BTW, this time we only used one aux-cart for the pumpdown process. HAM2 annulus system is back to nominal.

Images attached to this report

H1 SEI - DAS system, tap testing to calibrate distances along fiber

jenne.driggers@ligo.org — Fri, 31 Jul 2026 13:30:53 -0700

Author: jenne.driggers@ligo.org

Report ID: 91353

Jenne, Wanda, Shoshana, Gizem

We started very early this morning to beat the heat, and performed 'tap tests' at various points along the length of the arms to identify positions along the length of the fiber (according to DAS) with GPS positions (according to Wanda's phone).

Spreadsheet attachment is information about where along the fiber Shoshana and Gizem identified our tapping in the data, and associated time stamps. I've also copied the spreadsheet data to a google sheet, so that we can add to it.

We tried to do more dense taps on the 'inside of the vertex' side of the arms, where the fiber actually is. This required some walking out in the sand along the arms, so we had sun hats and knee-high boots and plenty of water. We also did a few taps along the road during our drive back, to get some more coarse information along the length of the arms. At the Xend station, there were too many tumbleweeds for us to walk along the inside-vertex side of the arm, so there at EX we did our more dense taps along the road side, with the exception of the EX vault location.

In the attached photos, you can see some examples of our tap test method. Gerardo provided us with a scrap piece of steel that we used as a strike plate. We also borrowed a sledgehammer from the mechanical / vacuum parts lab. For most of the Yarm, we only did 3 heavy strikes and Gizem and Shoshana chose the strongest signal from that as our time. Once we were on the road-side of Yarm, and then for all of Xarm, we added some light tapping that seems to have helped identify which distance bin (called a "channel" in DAS terminology) we were closest to. The photos are also labeled with X/Yarm, and position number, which corresponds to the position numbers in the google sheet - I tried to capture features in the photo to help identify where exactly the strike plate was.

Wanda has added to the google sheet the GPS locations that she identified while we were at each tap point.

The last photo shows our used (but can be used again in the future!) strike plate.

Images attached to this report

Non-image files attached to this report

DAS_Fiber_Test_July_31_2026.xlsx

H1 SUS - OPLEV charge measurement, ETMX & ETMY

ryan.crouch@ligo.org — Fri, 31 Jul 2026 12:22:47 -0700

Author: ryan.crouch@ligo.org

Report ID: 91350

I ran the charge measurements for both ETMs this morning. Unfortunately a medium (5.2 from Mexico) earthquake rumbled through from 16:38 to 16:58 UTC, but it didn't seem to effect the errors and coherences noticeably enough for me to restart the measurement.

For ETMX:

I was consistently getting low coherence for LL in Yaw, the charge appears to have plateaued or seen small increases (the error bars from the last measurement overlap with this one on all DOF/quadrants) on most DOFs/quadrants. The charge is above +\-50[V] on UR_P and LR_P, LR is still slowly trending to zero. ETMX is also quite misaligned as seen by its OPLEV.

For ETMY:

I was also seeing the worst coherence and largest errors on LL, both P and Y. The charge appears stable, there's not much difference from this measurement to the second to last (most recent one has large errors so it's not as valuable of a comparison). The charge is above +\-50[V] on LL P and Y, and UL_Y, there were some small increase of charge on LL as well.

SUS

Images attached to this report

H1 SEI - Distributed acoustic sensing (DAS) setup, day 4

jenne.driggers@ligo.org — Fri, 31 Jul 2026 10:44:54 -0700

Author: jenne.driggers@ligo.org

Report ID: 91351

Late post for DAS setup work on Thursday yesterday. Jenne, Wanda, Gizem, with Jonathan and Nyath helping get our remote access set up.

* EX, Fil connected a patch cable between fiber chassis and our termination fiber. This patch cable was FC-APC on the end that was connected to the fiber chassis, and FC-UPC connected to the FC-UPC termination cable. We were trying this mismatch between the FC-UPC of the chassis to a patch cable, in hopes that that would reduce any etalon effect between the UPC-UPC connectors. It didn't seem to help much.

* Xarm, Did a test for a while where Fil connected both our DAS channels to 2 fibers (#23 and #24) on the Xarm, to see if that made any difference in the noise; no impact, so eventually went back to just using #24 on X and #24 on Y.

Eventually we realized that the reason the data looked noisier is that we had changed some acquisition settings (effectively, changing our averaging). So, nothing actually changed in the overall performance of the system, which is good (we had thought that somehow we made it much worse between Mon and Wed).

We started an overnight data set using 500 Hz sample rate, to see that hopefully this is an okay balance between big file sizes and going up to high enough frequency to be useful. Xarm was connected to the Febus instrument, and Yarm to the Sintela instrument.

Also in the afternoon we got the remote connectivity working for both the Sintela and the Febus instruments.

Febus is the IP adress that ends in xxx.xxx.xxx.xx3
Sintela is the IP address that ends in xxx.xxx.xxx.xx4

H1 CDS - Comment to h1sush12 IPC ethernet fiber and switch SFP swap

david.barker@ligo.org — Fri, 31 Jul 2026 09:16:30 -0700

Author: david.barker@ligo.org

Report ID: 91348

Replacement completed. I have unbypassed the SWWD for SEI HAM1 and HAM2.

Jonathan replaced the original fiber FMM-02M-1120 and installed FMM-02M-1111. sw-msr-ipc0 port3 SFP was replaced.

H1 CDS - Comment to h1sush12 IPC ethernet fiber and switch SFP swap

david.barker@ligo.org — Fri, 31 Jul 2026 09:12:40 -0700

Author: david.barker@ligo.org

Report ID: 91347

Here is the CDS overview while h1sush12's fiber/SFP are being swapped out.

Images attached to this report

H1 CDS - h1sush12 IPC ethernet fiber and switch SFP swap

david.barker@ligo.org — Fri, 31 Jul 2026 09:04:35 -0700

Author: david.barker@ligo.org

Report ID: 91346

Jonathan, EJ, Erik, Dave:

The first step in fixing h1sush12's IPC errors is to replace the fiber and switch SFP. I've put SEI SWWD for HAM1 and HAM2 into bypass mode in preparation for this.

Jonathan will perform the swap in the MSR.

This will be a hot-swap, no models need to be fenced, stopped or computers rebooted. Very different from the "Dolphin crash" days.

H1 CDS - Comment to extremely large coil output in the user model will flip the DAC output from positive to negative rail

keita.kawabe@ligo.org — Fri, 31 Jul 2026 08:55:35 -0700

Author: keita.kawabe@ligo.org

Report ID: 91345

Erik made a new git issue here: https://git.ligo.org/cds/software/advligorts/-/work_items/748

H1 CDS - Comment to h1sush12 low level send errors following the link restart Thursday 16:55

david.barker@ligo.org — Fri, 31 Jul 2026 08:53:01 -0700

Author: david.barker@ligo.org

Report ID: 91344

h1sush12 is connected to port 3 of sw-msr-ipc0. Looking at the port stats shows errors on port3 which are not seen on any other port (port2 shown for comparison).

h1susb2h34 Port2:

sw-msr-ipc0#show interfaces ethernet2
Ethernet2 is up, line protocol is up (connected)
Hardware is Ethernet, address is 4c09.9737.14bb (bia 4c09.9737.14bb)
Description: "h1susb2h34 | FMM-02M-1122"
Ethernet MTU 9214 bytes, BW 25000000 kbit
Full-duplex, 25Gb/s, auto negotiation: off, uni-link: n/a
Up 2 days, 16 hours, 31 minutes, 54 seconds
Loopback Mode : None
6 link status changes since last clear
Last clearing of "show interface" counters 2 days, 19:10:45 ago
5 minutes input rate 44.4 Mbps (0.2% with framing overhead), 34811 packets/sec
5 minutes output rate 937 Mbps (4.1% with framing overhead), 534449 packets/sec
6036140558 packets input, 962213865558 bytes
Received 84764 broadcasts, 6036055766 multicast
0 runts, 0 giants
0 input errors, 0 CRC, 0 alignment, 0 symbol, 0 input discards
0 PAUSE input
90864581964 packets output, 19842295883609 bytes
Sent 1569974 broadcasts, 90863012607 multicast
0 output errors, 0 collisions
0 late collision, 0 deferred, 0 output discards
0 PAUSE output

h1sush12 port3:

sw-msr-ipc0#show interfaces ethernet3
Ethernet3 is up, line protocol is up (connected)
Hardware is Ethernet, address is 4c09.9737.14bc (bia 4c09.9737.14bc)
Description: "h1sush12 | FMM-02M-1120"
Ethernet MTU 9214 bytes, BW 25000000 kbit
Full-duplex, 25Gb/s, auto negotiation: off, uni-link: n/a
Up 15 hours, 49 minutes, 3 seconds
Loopback Mode : None
6 link status changes since last clear
Last clearing of "show interface" counters 2 days, 19:10:47 ago
5 minutes input rate 19.4 Mbps (0.1% with framing overhead), 18429 packets/sec
5 minutes output rate 962 Mbps (4.2% with framing overhead), 550830 packets/sec
3187368940 packets input, 418602501888 bytes
Received 96260 broadcasts, 3187272674 multicast
50 runts, 0 giants
57 input errors, 7 CRC, 0 alignment, 38 symbol, 0 input discards
0 PAUSE input
93703371906 packets output, 20383690243959 bytes
Sent 1558417 broadcasts, 93701815262 multicast
0 output errors, 0 collisions
0 late collision, 0 deferred, 0 output discards
0 PAUSE output

H1 CDS - h1sush12 low level send errors following the link restart Thursday 16:55

david.barker@ligo.org — Fri, 31 Jul 2026 07:37:43 -0700

Author: david.barker@ligo.org

Report ID: 91343

At 16:55 the IPC-ETH link on h1sush12 went offline for about 5 seconds, stopping all IPC traffic into and out of this front end. Since that time we have had a low rate of send errors from models running on h1sush12, but no receive errors.

Two models on h1sush12 send IPCs to remote models:

chan	send model	rate	receive model
H1:IOP-SUS_H12_RM1RM2PM1_WDIPC	h1iopsush12	2k	h1iopseih16
H1:IOP-SUS_H12_MC1MC3PRMPR3_WDIPC	h1iopsush12	2k	h1iopseih23
H1:SUS-PRM_M1_LOCK_L	h1susprm	16k	h1seiproc

Note that the SWWD IPC send at 2k even though the models run at 64k.

The receivers on h1iopseih16, h1iopseih23 and h1seiproc reported a low level of receive errors overnight. Each time these were one error in the second. Most of the time the IOP error times were not the same as the PRM times, except for the last one (see trend)

In the past 14 hours, IOP had 5 errors and PRM 9 errors.

EJ recommends as a first step to replace h1sush12's ethernet fiber and the switch SFP (not replacing h12 Mellanox SFP at this time).

Images attached to this report

LHO General - Ops Day Shift Start

thomas.shaffer@ligo.org — Fri, 31 Jul 2026 07:33:18 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91342

TITLE: 07/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 2mph Gusts, 0mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.08 μm/s
QUICK SUMMARY: SEI BS is in ISI_DAMPED_HEPI_OFFLINE, CDS overview is Green, Temps and dust look good.