aLIGO LHO Logbook

H1 IOO - Comment to Power through JAC is 4-5% less than before EOM swap

elenna.capote@ligo.org — Wed, 16 Sep 2026 18:24:08 -0700

Author: elenna.capote@ligo.org

Report ID: 91947

This issue explains why I was having alignment problems today- "SRY Locked" checks for AS A DC NSUM to be greater than 4000, and with the good alignment I have found we've reached about 3900.

I trended the AS A NSUM for SRY locking and found that with our best alignment, we should be able to achieve 5000 cts on AS_A and 0.06 W on AS_C. However, I have maximized the SRY alignment with the SRM sliders (and also ran SR2 align and AS centering), and the best I can achieve is 3900 ct and 0.047 W, which is considerably less power than the 5% reduction I reported above.

Previous SRY from last week shows what values we expect at AS for SRY

SRY attempt today shows that I have maximized the SRY alignment and achieve the buildups listed above.

ISC

Images attached to this report

LHO VE - Corner Station Vent Activities

gerardo.moreno@ligo.org — Wed, 16 Sep 2026 18:21:38 -0700

Author: gerardo.moreno@ligo.org

Report ID: 91946

(Travis S., Jordan V., Gerardo M.)
Today we were only able to vent the YBM (manifold on the Y-Arm), to do so, we hard closed GV1, GV2, GV5 and GV7. GV5 and GV7 are pneumatic valves, they closed with pressure of 25 psi both, very good pressure. Then we measured the purge air dew point, -42.1 ^oC. One issue that we encountered was that it took a while to vent to atmosphere, the wide range gauge at PT180 is way off indicating 998 torr for a vented to atmosphere volume, should be more like 762 Torr today, we will check on how to reset that value.
Vacuum envelope for the YBM is vented and ready for the viewport work tomorrow. However, the manifold for the X-Arm still under vacuum, no work should take place there until fully vented.

Images attached to this report

LHO VE - EX Pumpdown 9-16-26

jordan.vanosky@ligo.org — Wed, 16 Sep 2026 17:57:16 -0700

Author: jordan.vanosky@ligo.org

Report ID: 91945

After closing up BSC9 yesterday we started pumpdown of the EX volume this morning using the two mobile ISP1000 scroll pumps.

There was minimal overpressure in the system, so I could not get a good dewpoint measurement of the blow down air.

It took ~6 hours to rough the system down from atmosphere to ~500 mtorr, where we start the turbopump.

The cooling water was adjusted on the turbopump stand so that the pump and controller pressures were <= 40C. Once the turbo was at full speed and the inlet pressure ~5e-5 Torr, I switched the backing pump to the dedicated ISP250 on the turbo stand.

Setpoints were adjusted to 5E-2 Torr on Channel 1 (Foreline) and 5E-5 Torr on Channel 2 (Turbo inlet).

We will need to leak check the TMDS port gate valve since it was removed to verify the gate o-ring was in place.

Also, the EX cleanroom was powered off at ~3:10 pm local time.

Images attached to this report

H1 IOO - Comment to JAC Unlocked at 23:39 UTC - Unclear Why

masayuki.nakano@ligo.org — Wed, 16 Sep 2026 17:32:55 -0700

Author: masayuki.nakano@ligo.org

Report ID: 91944

The PZT was railed at that moment. Temperature is changing more from 2days ago, after EOM was swapped. Anything changed in the heater servo?

Images attached to this report

H1 IOO - Power through JAC is 4-5% less than before EOM swap

elenna.capote@ligo.org — Wed, 16 Sep 2026 17:30:39 -0700

Author: elenna.capote@ligo.org

Report ID: 91943

We noticed this today while debugging alignment issues. I compared the powers for 10 W request from PSL.

	Now	Before Swap
H1:IMC-PWR_IN_OUT16	10.0 W	9.96 W
H1:IMC-IM4_TRANS_NSUM_OUT16	8.78 W	9.17 W
H1:IMC-MC2_TRANS_NSUM_OUT16	1491	1559
H1:JAC-TRANS_A_LF_OUT_DQ	30650	32107

All of sensors beyond the JAC agree that there is 4-5% less power now making it to the IMC.

H1 IOO - JAC Unlocked at 23:39 UTC - Unclear Why

ryan.short@ligo.org — Wed, 16 Sep 2026 17:19:54 -0700

Author: ryan.short@ligo.org

Report ID: 91942

While at 10W input to JAC and commissioners working on IFO alignment this afternoon, we noticed the output power of JAC and the IMC start to gradually drop until finally JAC unlocked. Anecdotally, some of us have seen this happen at random times before, and JAC has always relocked easily pretty much immediately afterwords, so we haven't given it much thought, but it would be great if JAC didn't do this. I trended several things and can't tell what exactly happened first to cause this, but clearly the length servo and ASC outputs started changing dramatically over about 15 seconds until the cavity unlocked. I've attached short-term and long-term trends leading up to this unlock. I don't have a proposed solution, but mostly wanted to document this happening.

Images attached to this report

H1 General - OPS Wedensday day shift summary

ryan.crouch@ligo.org — Wed, 16 Sep 2026 16:33:30 -0700

Author: ryan.crouch@ligo.org

Report ID: 91935

TITLE: 09/16 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: None
SHIFT SUMMARY: EX is now pumping down, GVs 1, 2, 5, and 7 are closed and the RCG upgrade was completed.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:40	FAC	Kim	EndX	N	Tech clean	15:27
14:40	FAC	Eric	EndX	N	Replace heating element in the mech room	15:05
15:23	VAC	Jordan	EndX	N	Start pumpdown	17:45
15:37	EE/CDS	Jonathan, Fil	CER	Y	Switch work, cameras and LVEA wifi will go down	16:47
16:26	VAC	Gerardo	EndX	N	Join Jordan	17:45
16:31	CDS	Erik, Dave et. all	Office/MSR	N	RCG upgrade, started ~16:30 UTC	19:46
17:05	CDS	Jonathan	CER	Y	Add label, reseat ethernet cables	17:13
17:07	OPS	Oli	LVEA	Y	Check on laser status, might stay to help with TCS work	17:19
17:11	FAC	Kim	MidX	N	Tech Clean	18:00
17:17	CDS	Jonathan	CER/LVE	Y	Check on cameras	19:30
17:21	TCS	TJ, Oli	LVEA	Y	Old TCS infrastructure removal, by YARM term slab	18:56
17:26	SUS	Jennie, Marc	CER	Y	SUS R2 R3, grounding investigation	17:54
17:45	ISC	Betsy	LVEA	Y	Look at some infrastructure	17:51
17:47	EE	Fil	EndY	N	Unplug fibers from unused adnaco cards	18:26
18:15	SEI	Jim, Randy	LVEA	Y	Crane Jims box of parts	18:31
20:00	TCS	TJ	LVEA	Y	Continue removal of old TCS piping	Ongoing
20:34	TCS	Oli	LVEA	Y	Help TJ with TCS piping removal	Ongoing
21:01	VAC	Jordan	EndX	N	Pump down checks	22:40
21:12	SEI	Jim	CR	N	Recenter BRSX	21:33
21:21	VAC	Gerardo, Travis	LVEA	Y	Close GVs for CHETA viewport install, 1&5, and 2&7	Ongoing
21:52	CDS	Jonathan	CER	Y	Power cycle camera switch	22:52
22:02	CDS	Erik	EndX	N	Power cycle BRSX Beckhoff machine and restart SUS_AUX	22:43
22:17	SQZ	Sheila, RyanS, Alex	LVEA	Y	SQZT0 alignment checks	23:11
22:41	VAC	Jordan	LVEA	Y	Join Gerardo/Travis	23:04
23:05	VAC	Jordan	EndX	N	Check on pump down	23:28
23:28	VAC	Jordan	LVEA	Y	Join VAC team, check on GVs	Ongoing

16:30 UTC Erik started the RCG upgrade after I put SUS and SEI into their safe states
~18:35 UTC I recovered the CS, ~18:45 I recovered the end stations
19:15 UTC The SUS slider scopes were unfortunately not SDFed yesterday so Oli, Elenna, Caroline and I brought them back based on top mass osems and OPLEVs when available
21:30 UTC Gate Valves 1 & 5, and 2 & 7 were closed
CDS overview still shows some channel disconnects related to the EX BRS.

H1 CDS - Comment to H1 Front Ends Upgraded to RCG5.6.6

david.barker@ligo.org — Wed, 16 Sep 2026 16:17:57 -0700

Author: david.barker@ligo.org

Report ID: 91941

Erik has disconnected h1susauxex A4. Unused Adnaco disconnections are now complete.

H1 CDS - Comment to h1brsex restarted

erik.vonreis@ligo.org — Wed, 16 Sep 2026 16:17:02 -0700

Author: erik.vonreis@ligo.org

Report ID: 91940

I've started the EPICS IOC.

H1 SQZ - SQZT0 power measurements

sheila.dwyer@ligo.org — Wed, 16 Sep 2026 16:03:33 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91938

Ryan Short, Sheila Dwyer, Alex Granados

We went to SQZT0 to check on the low green launch powers. We need to realign the AOMs in both the OPO pump and FCGS paths.

SHG power reported by medm: 109 mW
measured with power meter: 84mW before green pump EOM
measured with power meter between EOM and AOM: 88 mW
0V on AOM, 23mW measured after
FCGS path: 24mW before 1st AOM, 8 mW after 2nd AOM

We need to realign these AOMs in laser hazard, but couldn't find a nice power meter mount. We will come back to this when back in laser hazard.

H1 CDS - h1brsex restarted

erik.vonreis@ligo.org — Wed, 16 Sep 2026 15:49:02 -0700

Author: erik.vonreis@ligo.org

Report ID: 91939

h1brsex could not be reached through remotedesktop. Locally, the computer was at the windows log in screen, but when I attempted to log in, the computer got to a loading screen and never got past that point.

I did a gold boot of h1brsex. It spent a long time on a screen saying it was "configuring windows", something that usually only shows up when you log in for the first time. After that boot, remote desktop worked. The epics IOC did not autostart and still needs to be started by hand.

SEI

H1 CDS - WP 13583 replace sw-lvea-aux

jonathan.hanks@ligo.org — Wed, 16 Sep 2026 15:16:26 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91937

Jonathan, Fil,

Per work permit 13583 we replaced sw-lvea-aux with sw-lvea-aux2. This is the camera that provides power and network for most of the cameras in the LVEA. In addition it handles some of the access points. We had seen two failures in the switch.

In order to replace the switch we needed to disconnect connections to both sw-lvea-aux and sw-lvea-aux1. Interestingly enough we had problems with the cameras on sw-lvea-aux1 after this. At around 3:00pm localtime Jonathan power cycled sw-lvea-aux1 and the cameras were restored.

H1 CDS - H1 Front Ends Upgraded to RCG5.6.6

david.barker@ligo.org — Wed, 16 Sep 2026 14:14:05 -0700

Author: david.barker@ligo.org

Report ID: 91936

WP13620 RCG Upgrade

Jonathan, Ryan C, Fil, EJ, Erik, Dave

This morning we successfully upgraded all the front ends from RCG5.6.5 to RCG5.6.6. This required rebooting all the front end computers, plus the two diskless support machines (h1build, h1ecatmon0).

The main reason for the upgrade was to fix the DAC-Flips-Output-Polarity-At-2-Billion-Counts bug, which has been seen as recently as this weekend on H1 SUS systems driving LIGO-DACs (though the bug applies to all types of DACs).

Other fixes are with mixed DAC type mis-mapping, which required LIGO-DACs to follow Gen Std cards on the bus. Also RCG5.6.6 provides full LIGO-ADC support.

We took the opportunity to verify BIOS settings as part of rebooting the front ends. We also disconnected unused Adnacos from the host adapter cards (i.e. Adnaco backplanes with no cards installed on them).

This all went relatively smoothly, with the only surprise being EDC flapping on its DAQ connections on both legs. Erik remembered that a negative wait time is needed, which fixed the issue.

Before today h1omcpi was running a custom RCG to add an IPC delay for the channels it receives from h1ioplsc0. It no longer needs a custom RCG, the new RCG5.6.6 has provision to set the delay via a file.

At the end of the build/install pre-upgrade work done yesterday (Tue 15sep2026) h1crsproc and h1psliss were falsely reporting modifed INI files. We verified these were false and the ini files were byte identical. These was borne out after the reboots, no DAQ restart was required for any of today's work.

WP13610 Enable PERR/SERR Reporting In BIOS

All front ends now have PERR/SERR PCI bus error reporting where applicable (V4, W22 have these option, W33 do not, we assume it is the default here)

We also verified the BIOS setting to keep the machines powered down following a power distruption when power is returned. This prevents front ends from trying to boot prematurely.

WP13606 Disconnect Unused Adnacos

All done with the exeption of h1susauxex A4.

WP13609 h1oaf0 Adnaco investigation

Erik found the adnaco fibers were dirty and cleaned them. We are waiting to see if this has improved the error rate.

H1 SPI - Ground broken between chamber and rack for QPD

jennifer.wright@ligo.org — Wed, 16 Sep 2026 11:03:42 -0700

Author: jennifer.wright@ligo.org

Report ID: 91934

Jennie W, Fil C, Marc P,

To hopefully fix the intermittent noise on the SPI optical lever QPDs (see alog #91813), Marc and I pulled the ground pin (13) at the input to TIA chassis variant 2 in SUS-R3 rack and variant 1 in SUS-R2 rack, respectively. When the RCG upgrade is over I will run some dark noise measurements to check this noise is gone.

H1 CDS - RCG Upgrade ongoing

david.barker@ligo.org — Wed, 16 Sep 2026 10:24:02 -0700

Author: david.barker@ligo.org

Report ID: 91933

At 09:30 we started the RCG upgrade. All front ends are currently unavailable.

No DAQ restart is anticipated. The EDC was offline for about 20 minutes and is now back up and running.

H1 PSL - PSL Status Report Weekly FAMIS 64008

ryan.crouch@ligo.org — Wed, 16 Sep 2026 08:54:57 -0700

Author: ryan.crouch@ligo.org

Report ID: 91931

Closes FAMIS 64008
Laser Status:
NPRO output power is 1.866W
AMP1 output power is 70.63W
AMP2 output power is 139.1W
NPRO watchdog is GREEN
AMP1 watchdog is GREEN
AMP2 watchdog is GREEN
PDWD watchdog is GREEN

PMC:
It has been locked 0 days, 17 hr 18 minutes
Reflected power = 28.6W
Transmitted power = 105.5W
PowerSum = 134.1W

FSS:
It has been locked for 0 days 17 hr and 17 min
TPD[V] = 0.4165V

ISS:
The diffracted power is around 3.3%
Last saturation event was 0 days 16 hours and 48 minutes ago

Possible Issues:
PMC reflected power is high

Images attached to this report

H1 ISC - PCAL / High-Res Camera Removed from X-arm Adapter Plate.

camilla.compton@ligo.org — Wed, 16 Sep 2026 08:47:18 -0700

Author: camilla.compton@ligo.org

Report ID: 91932

Tony, Camilla. WP 13621

Yesterday we removed the high-res/PCAL camera housing D1500073 from the x-arm adapter plate (A-1C VP2). Approved ECR for this work: LIGO-E2600291.

First we undid the thumb screw and slid off the cover, then we unscrewed the housing. Unplugged cable labeled H1:ITMX_DIGITAL_CAMER_12V photo, will check-in with EE team about this. The ring to keep the housing in place is around the VP, can be removed with VP. It has been covered with a yellow VP cover and a clear plastic guillotine is in place. Currently it's on the floor nearby but we plan to move the assembly to the VAC lab / PCAL lab on top of one of the cabinets.

Images attached to this report

LHO VE - Comment to X-End Station Vacuum Volume Vented

jordan.vanosky@ligo.org — Wed, 16 Sep 2026 08:16:40 -0700

Author: jordan.vanosky@ligo.org

Report ID: 91930

Audio file of the gate valve opening

Non-image files attached to this report

gv20.mp3

H1 General - OPS Wednesday day shift start

ryan.crouch@ligo.org — Wed, 16 Sep 2026 07:47:12 -0700

Author: ryan.crouch@ligo.org

Report ID: 91929

TITLE: 09/16 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 11mph Gusts, 7mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.07 μm/s
QUICK SUMMARY:

Dust, temps look good (EX is a little over the place, but I believe Eric is working on that this morning)
VAC work planned for today, GV1&5, 2&7, and the Cheta VP install (might be tomorrow)
EX is being pumped down
RCG upgrade planned for this morning
Some CER switch work may take down the WIFI

LHO General - Tues DAY Ops Summary

corey.gray@ligo.org — Tue, 15 Sep 2026 16:31:23 -0700

Author: corey.gray@ligo.org

Report ID: 91922

TITLE: 09/15 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: None
SHIFT SUMMARY:

LOG:

2000 Covering Afternoon DAY shift (from TJ)
1945 JAC modematching post eom-install (masayuki)

2005-2050 Checking on VAC crew @ EX (gerardo)
- 2015 Travis joining
- 2025 Tony & Randy out
2042-2223 TCS plumbing clean-up (removing old piping and cutting pipe...soldering possibly tomorrow [tj]
- opened vestibule Exit near the Y-Beam Manifold for old tcs pipes (no access alarm yet)
- 2107 oli joining
- 2227 clean-up & trash removal (tj)
2106-2109 returning equip to Cleaning Room area (travis)
2119-2251 PSL lens adjustment from masayuki's mode matching (jason.ryanS)
2149-2305 leak detector to EX & continue pumping annulus (jordan,gerardo.travis)
2150-2228 checking vea camera install options at EY (fil)
2221-2244 LVEA & optics lab trip to gather viewport installation parts (camilla)
2252 jac mode matching mesurements at 62W post-lens-moves from jason/ryanS (masayuki)
2300-2326 Local Laser Hazard for Squeezer (sheila)
2326 LVEA to Laser HAZARD (camilla)

H1 SQZ - Comment to quick look at recovering squeezer

sheila.dwyer@ligo.org — Tue, 15 Sep 2026 16:31:14 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91928

Camilla and I had another look at the filter cavity alignment this afternoon. We see green flashes of 7.1 counts, where we would expect about 30 counts based on the launch power and O4 FC transmission. These slider values are in the attached screenshot. Went to SQZT7 to align the beam onto FCGS refl diode, didn't see any signal in the DC readback of that diode. However, now there are mini locks of the filter cavity on the 00 mode, so this looks like the diode is working.

Images attached to this report

H1 IOO - Comment to JAC Mode Matching After EOM Swap (WP 13586)

ryan.short@ligo.org — Tue, 15 Sep 2026 16:20:08 -0700

Author: ryan.short@ligo.org

Report ID: 91926

See attached for pictures of the lens configuration before and after our change (where the two lenses are much closer together after).

Images attached to this report

H1 PSL - Comment to Swapping JAC EOM in PSL

jason.oberling@ligo.org — Tue, 15 Sep 2026 16:19:59 -0700

Author: jason.oberling@ligo.org

Report ID: 91927

The "new" EOM is aLIGO #4, which was operated in the PSL from aLIGO install until the swap to the 4f version in 2018. EOM crystal serial number is 10252005 (unchanged from previous use).

Images attached to this report

H1 IOO - JAC Mode Matching After EOM Swap (WP 13586)

jason.oberling@ligo.org — Tue, 15 Sep 2026 16:15:51 -0700

Author: jason.oberling@ligo.org

Report ID: 91925

R. Short, J. Oberling, M. Nakano (remote)

This morning Masayuki ran an assessment of the JAC mode matching after our EOM swap yesterday and came up with new lens positions for the mobile JAC mode matching lenses (IO_MB_L1 and IO_MB_L2). The result we were given:

SITE INSTRUCTION -- two-lens solution (IO_MB_L1 + IO_MB_L2):

move IO_MB_L1 by 2.0 mm DOWNSTREAM (toward JAC) (dz_L1 = +2.0 mm)

move IO_MB_L2 by 34.6 mm UPSTREAM (toward the PMC) (dz_L2 = -34.6 mm)

(decomposition: common -16.3 mm = waist position, differential +18.3 mm = waist size)

L1-L2 gap: 60 mm -> 23 mm

Moving IO_MB_L1 went smoothly with no change to the beam alignment. However, we were not able to move IO_MB_L2 the full requested amount due to interference between the lens mounts. Instead of the requested 23mm separation between the lenses, the best we could get was ~26.5 mm. To get any better than this we would have to completely change the mounting setup for the lenses. After moving IO_MB_L2 we had to yaw it a little to recover the beam alignment onto our irises. While the irises looked good in the PSL enclosure, when we tried to lock JAC it wouldn't lock; Masayuki had to do some alignment tweaks to get the JAC to lock. This isn't entirely surprising given that our alignment irises are several meters away from the JAC in HAM1, so what looks good on the irises isn't necessarily good enough to lock the cavity. Once the cavity was locked, Masayuki began tuning things up and we left the enclosure. He's running his mode matching assessment code now, so we'll see what the results show (preliminary report: "The mode matching seems better." -M. Nakano).

PSL

LHO VE - Install of BSC9 +Y Door

jordan.vanosky@ligo.org — Tue, 15 Sep 2026 14:29:06 -0700

Author: jordan.vanosky@ligo.org

Report ID: 91924

Randy, Tony, Travis, Gerardo, Jordan

Once we got the go ahead for re-installing the BSC door, Randy, Tony and I re-installed the +Y door without any issues. There was some particulate/viton pieces at 12 and 3 o'clock on the flange, but we were able to remove them using IPA wipes.

Bolts were torqued, then Travis and Gerardo set up the turbo and aux cart to pump on the annulus volume. Annulus pumping in progress.

H1 SUS - ETMX QUAD Vertical Sensor 15 year story

betsy.weaver@ligo.org — Tue, 15 Sep 2026 14:04:15 -0700

Author: betsy.weaver@ligo.org

Report ID: 91921

While looking at the ETMX for it's rubbing issue of late, we have been doing some data mining to understand why the ETMx Main and Reaction chain vertical BOSEMs (M0 and R0 LF and RT) are not where I would have assumed to leave them when we installed the "new" ETM test mass and rebuilt the suspension in 2018. Today, these vertical sensors are all ~6-8k counts when they should be closer to 11k per the open light voltage counts we determined in 2018 alog 41937.

I worried about temp and slow drift which could be also contributing to the rubbing, but in fact, it seems like something happened immediately at closeout in 2018 that put these vertical sensors off the nominal centered 11k value. (sigh)

In the end, hunting for an event or evolution which could have lead to the L1 LL rubbing of late has not been fruitful.

Anywho, since I waded through the deep water of everything-ETMX-SUS via temp change hunts, etc, I will post it here for the next time we wonder about what the longer history of the EX VEA temp has been doing:

Dec 2014 - CR excursions turned back down from 68 to 65

Jan 6, 2015 - 15883 - John turns temp “back to 65F (down from 67F)” - likely after a vent?

2015-2016 - No one writes actual temp values just things like “seasonal change so I turned a heater on”

May 2017 - 36271 - Upgrade to HVAC controls everywhere, EX week of ~May 15-18th, Kissel alog on calibration discrepancy 64 is actually 68…

May 22, 2017 - 36331 - Jeff/Bubba request to increase from 64 to 66 degC

May 30, 2017 - 36536 - Bubba changes which sensors are in-loop at EX

June 14, 2017 - 36894 - Bubba changes which sensors are in-loop at EX

Jan 23, 2018 - 40233 - Bubba/Hugh banter about where sensors in EX are mounted

Feb-Jun 2018 - Vented, warm with Cleanrooms on, new ETM/AERM installed

________________________________________

June 1, 2018 - 42283 - Chamber closeout TFs ETMx

Vertical sensors get “bumped” or set from nom 11k to ~8k somehow.

June 6, 2018 - 42351 - Bubba puts temp back down to 65degF after chamber closeout

June 26, 2018 - 42664, 42686 - Chandra asks to put temp up to 68defF to aid in outgassing/pumpdown, Kissel/Chandra banter about temp increase. Chandra states that 65degF is more energy efficient than 68degF

June 29, 2018 - 42722 - Bubba puts temp back down to 65degF

Jan 27, 2022 - 61472 - Bubba/Fil move some sensors/cables, “The temperature at the end stations by request of Jeff Kissel several years ago was maintained at 65 degrees F.” - Probably need to go back to fact check this since originally Kissel suggested 66 per logs found above. 0.5degF change but Vert’s see -2k OLV change, weird.

Mar16 ’23-Jun 22 - EX "Rubbing" and 11Hz issues, offsets put on, then later turned off because not an issue “anymore” (68034, 68121, 63766) - So, in hind sight, could have had the L1 LL flag close and maybe brushing in 2022 then it kinda alleviated itself.

Aug 28, 2023 - 72497 - Kissel nice blog analysis of temp on EY, FWIW

Sept 14-15, 2026 - Rubbing issues on ETMX - L1 LL flag brushing. Vented, moved LL BOSEM over away from flag. See that ETM M0/R0 V BOSEMs have been at ~6-8k instead of nominal ~15k for many many many years (SUS is “UP” which correlates to “COLD”).

Sept 15, 2026 - 91912 - Richard raising EX from 65F to 67F as read out by HVAC chans. (This should drop the suspension and more center the V BOSEMs, but likely not an actual problem.)

Images attached to this report

H1 SUS - ETMX not rubbing anymore

oli.patane@ligo.org — Tue, 15 Sep 2026 13:59:21 -0700

Author: oli.patane@ligo.org

Report ID: 91923

After various ETMX transfer functions and offset tests, it looks like ETMX isn't rubbing anymore!

I did these tests this morning and wasn't able to get any rubbing. For everthing I did, L1 LL (and everyone else) moved as expected and no one got stuck anywhere. The offset tests that I did involved putting offsets in the L1 COILOUTF banks, M0 TEST banks, and R0 TEST banks and making sure L1 osems were all responding how we expected them to.

We noticed that L1 UL has been a little more jaggedly compared to the other L1 osems since we went to air, but the osem spectra looked good (comparing to its brethren) and putting a drive in M0 to move L1 around shows that UL is moving and behaving normally. We think it's probably just related to its current flag vs osem position as we put air in the chamber.

Transfer Functions
Settings:
- HEALTH_CHECK
- OPTICALIGN OFFSETS ON
- DAMP OFF
- ISI in ISI_DAMPED_HEPI_OFFLINE

M0
Data:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Data/2026-09-15_1540_H1SUSETMX_M0_WhiteNoise_{L,P,Y}_0p02to50Hz.xml
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Data/2026-09-15_1540_H1SUSETMX_M0_WhiteNoise_{T,V,R}_0p03to50Hz.xml
r13152
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Results/SAGM0/Results/2026-09-15_1540_H1SUSETMX_M0_ALL_TFs.pdf
r13153

R0
Data:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGR0/Data/2026-09-15_1615_H1SUSETMX_R0_WhiteNoise_{L,T,V,R,P,Y}_0p03to50Hz.xml
r13148
Results:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGR0/Results/2026-09-15_1615_H1SUSETMX_R0_ALL_TFs.pdf
r13150

Spectra:
L1
Data:
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGL1/Data/2026-09-15_H1SUSETMX_L1_OSEMINF_spectra_invac_vs_inair.xml
r13149

Images attached to this report

Non-image files attached to this report

2026-09-15_1540_H1SUSETMX_M0_ALL_TFs.pdf

2026-09-15_1615_H1SUSETMX_R0_ALL_TFs.pdf

H1 CDS - Realtime model freeze going into RCG upgrade

erik.vonreis@ligo.org — Tue, 15 Sep 2026 12:33:22 -0700

Author: erik.vonreis@ligo.org

Report ID: 91920

Please do not make any changes to real time models with simulink or foton until after the RCG upgrade.

H1 IOO - JAC servo

daniel.sigg@ligo.org — Tue, 15 Sep 2026 11:33:08 -0700

Author: daniel.sigg@ligo.org

Report ID: 91919

Quickly checked the ugf of the JAC servo. At a filter gain of 0.8, the nominal gain was 300Hz. This seems the same as before, indicating the modulation index didn't change much with the EOM swap. The attached plot shows the ugf at 400Hz with a gain of 1.0.

Non-image files attached to this report

jac_ugf_260915_A.pdf

H1 SEI - Comment to HAM2 dead cps after whitening measurement

jim.warner@ligo.org — Tue, 15 Sep 2026 11:20:23 -0700

Author: jim.warner@ligo.org

Report ID: 91918

It turns out, the cabling at the HAM2 rack is kind of confusing and I was inadvertently swapping the cables for corner2 and corner1&3. Apparently when we had to swap cables around during install to make room for the PSL, we plugged the cable marked CPS2 into interface chassis 1 and vice versa. Confusingly, we did not do this swap with the power cables, so power cable 1 is coupled with CPS cable 2. Fil says he thinks we can probably straighten this out at the chamber, but we are running out of time today, so we will come back to this. FRS is : https://services1.ligo-la.caltech.edu/FRS/show_bug.cgi?id=39086

H1 CDS - Comment to PicketFence updated

erik.vonreis@ligo.org — Tue, 15 Sep 2026 10:57:26 -0700

Author: erik.vonreis@ligo.org

Report ID: 91917

Picket Fence fixed and working. Display now shows latency for each station.

H1 IOO - IMC refl power now

elenna.capote@ligo.org — Tue, 15 Sep 2026 10:24:36 -0700

Author: elenna.capote@ligo.org

Report ID: 91916

Reminder: we attenuated the power by half to the IMC refl diode and IMC WFS after a power outage during O4, 86884, using a half wave plate along the refl path in IOT2L.

The attenuation was such that we maintained the desired power on IMC refl and the WFS by reducing the refl path power by 2, 86989, in other words, whatever the power outage did to the upstream mode matching, it was such that the power reflected off the IMC when locked had doubled.

To summarize, our nominal power to IMC refl when locked with ~60 W input is 18.5 mW. The WFS nominal is 0.95 and 0.76 mW respectively.

Now we have JAC, so I checked the powers at IMC REFL. Looks like the JAC team turned up the input power to the IFO to 60 W recently. For 60 W input with IMC locked (guardian state 100), we now have 1.57 mW on IMC REFL, 0.079 and 0.064 mW on WFS A and B. I think this indicates we should adjust the half wave plate to increase power to IMC REFL. I'm not sure if we can get back to nominal since the powers are more than an order of magnitude lower than before, but we should be able to at least double it.

Reminder that the "IMC PWR IN" diode is actually reporting the power into JAC. We have a JAC trans diode, but it still has a funny calibration, so I did not include it here because the number it says is totally wrong.

ISC

Images attached to this report

H1 CDS - Comment to PicketFence updated

erik.vonreis@ligo.org — Tue, 15 Sep 2026 10:15:56 -0700

Author: erik.vonreis@ligo.org

Report ID: 91915

IOC is not updating server status. Results are being updated, so the PicketFence is talking to the IOC.

H1 ISC - Photos of EX Transmon Mirrors - coating looks good on all mirrors, some dust.

camilla.compton@ligo.org — Tue, 15 Sep 2026 09:46:39 -0700

Author: camilla.compton@ligo.org

Report ID: 91908

Betsy, Oli, Tony, Camilla

Yesterday when Betsy, Oli and Tony were inside the ETMX BSC (WBSC9) they took some photos of the transmon mirrors,

with the illuminators on
with the illuminators off and an eye-safe Ozoptics green laser injected via the HWS path

Reason for this is that we've had issues with both the ALS 91306 and HWS 91248 beams at EX.

Full telescope assembly is D1002460. The optics on the transmon table are in D1201457. The mirrors are called from transmon towards ETM: M2 , F2, F1, M1. D1102361 and Madi's cartoon, attached from G2500646 shows this.

Betsy notes that the optics with the side HR facing -X (F2 and M1) appear to have considerably more dust on the those facing +X. Is purge air or similar causing this? The dusty side is direction ETMX faces. All the mirrors coating looks intact.

Transmon - photo a, b, Green QPD A, M12 mirror, again.
LPM - photo with beam
M2 (TMS telescope Secondary mirror - parabolic) - photo, with beam
F2 (Folding Mirror 2 - flat) - photo, with beam, wide
F1 (Folding Mirror 1 - flat) - photo
M1 (TMS telescope primary mirror - parabolic) - photo a, b, c , with beam

The HWS path green beam made it though the transmon and retroreflected off ETMX and back onto the HWS CCD, but the alignment isn't perfect as the return beam looks clipped, photo.

SUS

Images attached to this report

H1 ISC - Comment to Noticed BS PIT Moved while locking and then drifts in NLN: not new, happened end of O3b but not 1 year ago.

jenne.driggers@ligo.org — Tue, 15 Sep 2026 09:37:24 -0700

Author: jenne.driggers@ligo.org

Report ID: 91914

With the new BBSS, Elenna has removed the 'slow let-go' of the pitch top mass. See alog 91910.

H1 CDS - PicketFence updated

erik.vonreis@ligo.org — Tue, 15 Sep 2026 09:36:27 -0700

Author: erik.vonreis@ligo.org

Report ID: 91913

PicketFence was updated to the latest version and restarted.

CDS, SEI

H1 SUS - EX Temperature Setting Increased to 67 Deg F

richard.mccarthy@ligo.org — Tue, 15 Sep 2026 09:36:14 -0700

Author: richard.mccarthy@ligo.org

Report ID: 91912

Richard, Betsy, Eric.

Looking back many years we can not find a reason for the temperature setting of 65 Deg F at EX. Today I raised the temperature to 67 Deg F. Wtih the clean room on we have seen a diurnal swing of 3 Deg F with no effect on the suspension so this rise should not have a negative impact on the suspension.(sagging) It may actually help.

However, It will probably change the balance of the BRS. Jim W is aware

CDS, FMP, ISC, PEM, SEI, SUS, SYS

H1 ISC - BS slow let-go servo turned off

elenna.capote@ligo.org — Tue, 15 Sep 2026 09:35:50 -0700

Author: elenna.capote@ligo.org

Report ID: 91910

[Jenne, Elenna]

As a reminder, Jenne had engaged a "slow let go" servo for beamsplitter pitch during O4 because of some possible heating transient that affected relocking, see 85002.

Now we have the BBSS, so we don't expect to see this issue. I undid the steps that Jenne did in her alog above to revert the settings:

I re-engaged the BS M1 ASC lockloss trigger, see attached SDFs in SAFE and OBSERVE
I removed the separate BS loop on ISC_DRMI line 66 that kept the M1 LOCK pitch gain set to one and disengaged the integrator in FM1, and added BS back into the list on line 63
I returned the BS to the list on line 133 in ISC_DRMI that clears the history in BS M1 LOCK P and Y, we had separately only cleared history for BS Y so the BS pitch history would slowly bleed off over time

ISC_DRMI is loaded and I checked the code to the svn.

Images attached to this report

H1 CDS - Comment to h1seih16 IO Chassis issue with second 16bit-DAC

david.barker@ligo.org — Tue, 15 Sep 2026 09:21:12 -0700

Author: david.barker@ligo.org

Report ID: 91909

second 16bit-DAC:

old card (removed)	100922-16
new card (installed)	101118-18

At time of writing, h1seih16 has been running for 30mins.

H1 CDS - Comment to h1seih16 IO Chassis issue with second 16bit-DAC

david.barker@ligo.org — Tue, 15 Sep 2026 08:43:39 -0700

Author: david.barker@ligo.org

Report ID: 91907

Opened WP13616 to cover this work.

Fil is replacing the second 16bit-DAC.

H1 CDS - h1seih16 IO Chassis issue with second 16bit-DAC

david.barker@ligo.org — Tue, 15 Sep 2026 08:13:09 -0700

Author: david.barker@ligo.org

Report ID: 91906

Richard, Jonathan, EJ, Erik, Fil, Dave:

First thing this morning we did a round of h1seih16 power cycling, with Richard power cycling the IO Chassis. The models ran for about 5 minutes this time and then ADC1-timed-out like before.

Then we power cycled the CPU only, and this time the IOP would not run because of a card count issue. And indeed, both showcards and lscpi report that the A2-slot4 is empty, which contains the second 16bit-DAC card.

So we are operating under the theory that all the recent problems have been caused by a flakey DAC1, manifesting as ADC1 timing errors. We are preparing to replace DAC1.

Card 2
Extender 1
slot 1: (10ee d8c6) Xilinx Corporation,LIGO Timing Board
slot 2: empty
slot 3: (10b5 3101) PLX Technology, Inc.,General Standards 16AI64
slot 4: (10b5 3120) PLX Technology, Inc.,General Standards 16AO16
Card 3
Extender 2
slot 1: (10b5 3101) PLX Technology, Inc.,General Standards 16AI64
slot 2: (10b5 3101) PLX Technology, Inc.,General Standards 16AI64
slot 3: (10b5 3101) PLX Technology, Inc.,General Standards 16AI64
slot 4: empty <<< Should be 16AO16 DAC1 <<<<
Card 4
Extender 3
slot 1: (10b5 3101) PLX Technology, Inc.,General Standards 16AI64
slot 2: (10b5 3101) PLX Technology, Inc.,General Standards 16AI64
slot 3: empty
slot 4: empty
Card 5
Extender 4
slot 1: (1221 8682) Contec Co., Ltd,Digital I/O DIO-64
slot 2: (1221 8682) Contec Co., Ltd,Digital I/O DIO-64
slot 3: empty
slot 4: empty

LHO General - Ops Day Shift Start

thomas.shaffer@ligo.org — Tue, 15 Sep 2026 07:32:52 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91905

TITLE: 09/15 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Maintenance
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 4mph Gusts, 2mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.06 μm/s
QUICK SUMMARY: EX is still vented with the door off. Regular maintenance planned for the day. h1seih16 crashed last night and teh CDS team is currently working on it.

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 15 Sep 2026 07:01:20 -0700

Author: erik.vonreis@ligo.org

Report ID: 91904

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

H1 SQZ - quick look at recovering squeezer

sheila.dwyer@ligo.org — Mon, 14 Sep 2026 21:51:23 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91903

Turned on the sqz laser, Marc Pirello turned on high voltage supplies.
with the OPO dither locked on the seed, I adjusted ZM3 to get full power onto SQZT7 IR PD, didn't see light on AS port PDs this way.
PMC transmission is normal at 660mW. SHG green power is 77mW, rather than 100mW normally, SHG launch power is 9mW max, compared to up to 30mW we normally have available.
I tried adjusting the SHG alignment picomotors, this didn't improve the SHG transmission much.
Filter cavity green flashes cavity modes.

H1 CDS - Comment to restarted h1seih16, it died again after running for a few minutes

david.barker@ligo.org — Mon, 14 Sep 2026 21:14:55 -0700

Author: david.barker@ligo.org

Report ID: 91902

Here is the CDS overview at this time. Note that DAQSTAT is in error because of the missing model DCUs.

Images attached to this report

H1 CDS - restarted h1seih16, it died again after running for a few minutes

david.barker@ligo.org — Mon, 14 Sep 2026 20:57:52 -0700

Author: david.barker@ligo.org

Report ID: 91901

I attempted to restart the models on h1seih16, but the iop would not run even though lspci could see all the cards. I tried to reboot the computer, but it hung up. Eventually I power cycled the computer using IPMI. The models restarted and all the cards were visible, it ran for a few minutes and then crashed again with the same ADC1 timeout error. At this point it looks like an IO Chassis issue, requiring power cycling, fiber cleaning or card replacment.

[Mon Sep 14 20:53:35 2026] h1iopseih16: ERROR - An ADC timeout error has been detected on ADC 1, waiting for an exit signal.

H1 CDS - h1seih16 all models stopped running 18:14 PDT

david.barker@ligo.org — Mon, 14 Sep 2026 20:40:26 -0700

Author: david.barker@ligo.org

Report ID: 91900

We had a model crash on h1seih16 due to an ADC timeout error on the second ADC.

logs show:

[4154453.936137] h1iopseih16: ERROR - An ADC timeout error has been detected on ADC 1, waiting for an exit signal.
[4154454.035791] h1isiham1: ERROR - Waiting for ADC cycle 39593, live read is 35497, mm: 4, ioMemCtr: 2729
[4154454.037584] h1isiham1: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
[4154454.037756] h1isiham6: ERROR - Waiting for ADC cycle 39593, live read is 35497, mm: 1, ioMemCtr: 2729
[4154454.037930] h1hpiham6: ERROR - Waiting for ADC cycle 39593, live read is 35497, mm: 1, ioMemCtr: 2729
[4154454.038103] h1hpiham1: ERROR - Waiting for ADC cycle 39593, live read is 35497, mm: 1, ioMemCtr: 2729
[4154454.038276] h1isiham6: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
[4154454.038448] h1hpiham6: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
[4154454.038620] h1hpiham1: ERROR - An ADC timeout error has been detected, waiting for an exit signal.

LHO VE - X-End Station Vacuum Volume Vented

gerardo.moreno@ligo.org — Mon, 14 Sep 2026 18:06:02 -0700

Author: gerardo.moreno@ligo.org

Report ID: 91899

(Travis, Jordan, Randy, Tony, Gerardo)

RGA scan taken of the X-End vacuum volume with GV20 hard closed. GV20 was hard closed and LOTOed. All metal valve was opened for GV20 gate annulus.
Purge air was measured, dp at -42.4 ^oC. Large ion pump and RGA were isolated. Then the vacuum envelope was vented, it appears as if the piranni gauge at BSC9 is out of calibration, it does have a larger than atmosphere number, 981 Torr at atmosphere, not right.
We proceeded to vent the BSC9 annulus with nitrogen gas. Soon after the +Y side door was convinced to let go of the flange, at first the outer O-ring was stuck at around 1 O'clock , maybe 3 inches long, but let go after a few minutes. We left the system with purge air going.

Images attached to this report

H1 SUS - Comment to ETMX L1 stage (UIM) LL BOSEM recentered, hopefully not in a rubbing danger now

betsy.weaver@ligo.org — Mon, 14 Sep 2026 17:32:41 -0700

Author: betsy.weaver@ligo.org

Report ID: 91898

Oli and Tony in BSC9 with the ETMX stuff.

Images attached to this report

H1 SUS - Comment to ETMX L1 stage (UIM) LL BOSEM recentered, hopefully not in a rubbing danger now

betsy.weaver@ligo.org — Mon, 14 Sep 2026 17:31:11 -0700

Author: betsy.weaver@ligo.org

Report ID: 91897

And now after, with a much more centered flag between the 2 diode can lines to the left and right. Again, there is a video with much more compelling angle views, but no uploading allowed.

Images attached to this report

H1 SUS - Comment to ETMX L1 stage (UIM) LL BOSEM recentered, hopefully not in a rubbing danger now

betsy.weaver@ligo.org — Mon, 14 Sep 2026 17:29:36 -0700

Author: betsy.weaver@ligo.org

Report ID: 91896

Picture of before the move - the flag is the vertical dark line which is supposed to be centered between the LED and PD can vertical lines on either side. Instead, it is much much closer to one of them (only a tiny slit of light in the gap). I have a movie but can't upload it apparently.

Images attached to this report

H1 SUS - ETMX L1 stage (UIM) LL BOSEM recentered, hopefully not in a rubbing danger now

betsy.weaver@ligo.org — Mon, 14 Sep 2026 17:27:46 -0700

Author: betsy.weaver@ligo.org

Report ID: 91895

Oli, Tony and I went into BSC9 today after VAC got it vented and opened. We inspected earthquake stops and L1 and L2 stage magnet/flag-to-OSEM centering. True to what we suspected, the L1 LL flag was much more off-center in the side direction compared to others. So we embarked on holding the UIM stage and recentering the BOSEM on this floating mass. It looks alot more centered now. Although we did not touch the in-out direction of the flag (because it will pitch the ETM test mass) this one flag reads very well centered in that direction now too, much better than any others on L1. Oli will take more TFs in the morning and push it around in side shift and up-down to see if we are more free in motion now.

Note, the Top LF and RT OSEMs on the main and Reaction chain are still very mis-centered in the in-out direction (at ~6-8k counts vs the 15k nominal), now exacerbated by the bouyancy effect of air in the chamber. This is not how we left this suspension ~10 years ago, so I still suspect that migrating and or errand temp setpoints of the EX VEA over the last many years has been lifting this SUS up (VEA is too cold). More on this in alogs.

While inside, Tony took pictures of the inside of the GV20 gatevalve and PCAL inerds.

We also took pictures of the TMS optics and table top with the green beam on (thanks to Camilla). All to be posted tomorrow.

H1 PSL - Comment to Swapping JAC EOM in PSL

ryan.short@ligo.org — Mon, 14 Sep 2026 17:26:46 -0700

Author: ryan.short@ligo.org

Report ID: 91894

On the rotation stage calibration mentioned above, we started by closing the shutter to not allow any light into HAM1 (to be safest since we weren't sure exactly how well IOT1 would take ~100W of power in its current state) and paused the LASER_PWR Guardian while keeping the ISS enabled. I ran the typical calibration script (/userapps/psl/h1/scripts/RotationStage/CalibRotStage.py), updated the calibration factors, then used the Guardian to return to 2W; see SDF screenshot for the changes. It looks like it was October of last year when the last calibration was run, and now that we have high power through the EOM, it doesn't surprise me that the input maximum power is much higher (this time saw up to 92.1W).

Images attached to this report

H1 PSL - Swapping JAC EOM in PSL

jennifer.wright@ligo.org — Mon, 14 Sep 2026 16:57:11 -0700

Author: jennifer.wright@ligo.org

Report ID: 91891

Jennie W, Jason O, Ryan S,

Summary: PSL EOM swapped, alignment good enough to lock JAC but the mode-matching to JAC looks different as the JAC REFL camera spot has changed.

We entred the PSL enclosure and turned down power through EOM to less than 2W at the manual waveplate.

We then recentred the first iris in the MB path after the EOM in the vertical direction as the beam was slightly too low. The second iris was centred ok.

Then we closed shutter 2 and unplugged the 118 and 9 MHz cables.

We terminated the 45 MHz cable as this is the only one still plugged into an active voltage source.

We had to remove the EOM along with the white spacer it sits on to undo the screws on the bottom of this spacer that go into the EOM unit.

After swapping the new EOM onto the spacer we screwed it back down on the mount.

The beam was now off of the first iris in both pitch and yaw. It was too low and slightly in the +y direction.

To fix this in the y direction Jason adjusted IO_MB_M2 in yaw. The beam was not making it through the the EOM aperture. We loosened the side screws on white spacer and used slop in the large screws slots which hold the spacer on the bottom mount to yaw the eom and fix this . Then we used the pitch of the IO_MB_M2 mirror to centre the beam in the vertical dirtection on the first iris.

After tightening back the screws on the mount and spacer we took a calibration sweep of the rotation stage to re-calibrate the output power to the interferometer.

Then we took the power guardian to 2W and re-locked the JAC. The relfected beam from the locked JAC has changed shape on the camera so we assume the mode-matching is different.

Masayuki will measure the mode-matching and we will improve this with lens moves on the PSL table tomorrow.

H1 ISC - Updated MICH ASC plant compensators

elenna.capote@ligo.org — Mon, 14 Sep 2026 16:40:45 -0700

Author: elenna.capote@ligo.org

Report ID: 91893

I updated the MICH ASC plant compensators for the new BBSS. The filters for MICH P and MICH Y are now both in FM5, and they replace the BSFM compensators in FM10. I designed the compensators such that the pitch loop maintains a 2 Hz UGF with 58 deg phase, and the yaw loop a 3 Hz UGF with 42 deg phase.

Overall, the rest of the design stays the same, including overall loop gains, so I went through the ISC_DRMI and ISC_LOCK guardians and swapped out all instances of FM10 with FM5. I also updated MICH Y to only use the 12 Hz lowpass instead of the 9 Hz lowpass just to preserve phase (we can revisit the low pass if/when we see noise from MICH Y).

Guardians loaded, new filters SDFed.

The ISC_DRMI guardian still has useMICH set to false, so when we are ready to test MICH ASC we still need to set that to true.

Images attached to this report

LHO General - Mon Day Ops Summary (Afternoon)

corey.gray@ligo.org — Mon, 14 Sep 2026 16:30:52 -0700

Author: corey.gray@ligo.org

Report ID: 91889

TITLE: 09/14 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: None
SHIFT SUMMARY:

Helped cover the afternoon Ops Shift. Main order of the afternoon was ETMx "de-rubbing". Another big task was the replacing of a PSL EOM.
LOG:

1915 Covering afternoon shift
1900 VAC team heading back to EX (after lunch)
1936-2031 CDS checks at both end stations (dave)
1950-2007 JAC measurement (masayuki)
2002-2014 Looking for a hose + adapter (gerardo)
2006-2154 SEI ISI measurement for CPS whitening measurements for HAM2 at CER(jim)
- 2012 IMC offline & HAM2 ISI OFFLINE & HEPI ON
- 2154 Not coming back; Jim said leave tripped overnight
2006 SQZ measurements at HAM5/6/7 (sheila)
2011-2327 PSL EOM swap (jason.ryanS.jennie)
- PSL Phone is temporarily x223 (vs 226); Richard shuffled the phone around for us.
2031 Helping to break bolts at EX & continue w/ ETMx (tony)
2101 ETMx de-rubbing (betsy.oli)
2122-2145 CHETA viewports to Vacuum Prep (camilla)
2205 Gerardo & Jordan heading back from EX
2217 Travis heading to EX to check on SUS
2220-2258 Richard also heading to EX
2305-2319 grabbing pump cart from LVEAfor EX (gerardo.jordan)
2311 checking on EX group (tj)
2320 Taking Pump Cart down to EX (gerardo.jordan)
2328 heading to EX to check on status and her Hartman beam (camilla)

H1 SEI - HAM2 dead cps after whitening measurement

jim.warner@ligo.org — Mon, 14 Sep 2026 15:01:27 -0700

Author: jim.warner@ligo.org

Report ID: 91892

I unplugged some cables to an interface chassis in the CER this afternoon to do some CPS whitening measurements. Not sure what has happened, but when I plugged everything back in, the corner 2 cps didn't come back alive, and are sitting at ~0 cts. I have to leave early today, so I'm out of time to diagnose, but hopefully I can fix this tomorrow morning when I get back on site. This means HAM2 won't be able to isolate, until the corner 2 CPS are working again.

H1 SQZ - Squeezer HV Power Turned On

marc.pirello@ligo.org — Mon, 14 Sep 2026 13:14:25 -0700

Author: marc.pirello@ligo.org

Report ID: 91890

HAM7 HV restored per WP13613

At the power rack, I found the disconnect switched on, while the supplies were switched off at the supplies. Anyone changing the state of the HV should know there is a labeled disconnect directly above the supplies. Please use the disconnect.

LHO FMCS - Temperature changes correlated to ETMX top mass over last 12 years

oli.patane@ligo.org — Mon, 14 Sep 2026 11:15:34 -0700

Author: oli.patane@ligo.org

Report ID: 91886

Betsy, Oli

We looked back many years to see how temperature has correlated with the Vertical (LF and RT) position on ETMX M0 and R0. Over the last 12 years there have been a few instances of VEA temperature changes that have led to permanent shifts in position for the LF and RT (Vertical) osems on ETMX M0 and R0. Each shift to a lower VEA temperature has moved the top masses and osem flags closer to the osems, raising the suspension over many years. It does also look like even without those temperature changes, the whole suspension has been drifting up on its own in between temperature changes

Here are three dates where we see a larger shift in either temperature or position.

Date	M0 ΔVertical [µm]	R0 ΔVertical [µm]	Temp change [°F]	Comments
2014-12-17	113	109	+3 °F	Temperature raised and looked like it brought top mass OSEMs almost all the way back to their nominal (half light) positions
2017-05-18	none	none	-3 °F	Even though the temperature changed by 3 °F here we didn't see any change in V on M0 or R0
2018-02-22	120	165	all <=-0.5 °F	Small shift in temperature but led to largest single change in Vertical offset
2022-01-26	93	61	A,D sections shifted by ~-1 °F

SUS

Images attached to this report

H1 PSL - PSL 10-Day Trends

ryan.short@ligo.org — Mon, 14 Sep 2026 11:02:24 -0700

Author: ryan.short@ligo.org

Report ID: 91887

FAMIS 63916

No major events of note, things continue to run smoothly.

Images attached to this report

H1 General - Ops DAY Shift Start

oli.patane@ligo.org — Mon, 14 Sep 2026 07:44:32 -0700

Author: oli.patane@ligo.org

Report ID: 91885

TITLE: 09/14 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 7mph Gusts, 6mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.07 μm/s
QUICK SUMMARY: Should be opening EX today. We're still in full vac at EX, but as a recheck, ETMX L1 LL is showing to not be rubbing when in ALIGNED (with that R0 Y offset still in), but it is getting stuck or at least rubbing when I turn alignment sliders off. It also still isn't showing that it's moving as much as it should be moving, which we saw before and is another sign of rubbing.

H1 SUS - Comment to QOSEM Noise Hunting - Seismic Driven Motion

thomas.roocke@ligo.org — Mon, 14 Sep 2026 04:11:13 -0700

Author: thomas.roocke@ligo.org

Report ID: 91884

Thanks Brian!

I should have been clearer in my original post, but I am indeed ploting the GAP motion, as seen by the QOSEMs, rather than the M1 inertial motion. I am ignoring the phase shift introduced by the SUSP -> M1 transfer function, so perhaps this is causing things to look not quite right...

H1 SEI - Picket fence updated

edgard.bonilla@ligo.org — Sun, 13 Sep 2026 12:51:12 -0700

Author: edgard.bonilla@ligo.org

Report ID: 91883

Original post: https://alog.ligo-la.caltech.edu/SEI/index.php?callRep=2603

I updated the picket fence code to source the stations from an active server, hopefully they will be working correctly now.

Additionally, I added some real-time monitoring for the data latencies, so we can use it to diagnose things in the future.

To get this update, please git pull at the picket fence folder.

SEI

H1 IOO - JAC mode-matching correction from the LDWFS-measured injection beam

masayuki.nakano@ligo.org — Fri, 11 Sep 2026 17:59:08 -0700

Author: masayuki.nakano@ligo.org

Report ID: 91882

Using the injection beam measured with LDWFS, I computed an IO_MB lens layout that improves the JAC mode-match at 62 W from 1.8 % to ~0.1 %.
LDWFS method and measurement results: LIGO-P2600491

Move the two injection mode-matching lenses upstream:

IO_MB_L1: 21.3 mm (0.84")
IO_MB_L2: 48.3 mm (1.90")

(common shift −34.8 mm sets the waist position; differential +13.5 mm sets the waist size.)

Figure: beam radius w(z) along the injection path — cavity eigenmode, injected beam, and the beam after the L1/L2 correction.

IOO

Images attached to this report

LHO VE - Comment to BSC9 Leak Check Done

gerardo.moreno@ligo.org — Fri, 11 Sep 2026 17:37:33 -0700

Author: gerardo.moreno@ligo.org

Report ID: 91870

(Travis S., Jordan V., Gerardo M.)

Late entry.
Just to add a comment regarding GV20, when opening this gate valve it complained all the way up, there was lots of clanking noises all the way to the top, compared to the other gate valves this one is very noisy, as far as I remember it is getting louder. We did not recorded the noise made by the gate valve.

LHO VE - X-End Prep Work for Vent

gerardo.moreno@ligo.org — Fri, 11 Sep 2026 17:35:43 -0700

Author: gerardo.moreno@ligo.org

Report ID: 91881

(Travis S., Gerardo M.)

The cleanroom above BSC9 is on, 2:45 pm today.
The purge air system is on, compressor and dryer towers are on, but only in the vacuum support equipment room, the valve to deliver air to the VEA is closed.
We delivered two ISP-1000 scroll pumps and an electrical bang box, we left them inside the receiving area.

PEM, VE

LHO VE - HAM7 Vent Recovery Update

gerardo.moreno@ligo.org — Fri, 11 Sep 2026 17:28:13 -0700

Author: gerardo.moreno@ligo.org

Report ID: 91880

(Jordan V., Travis S., Gerardo M.)
The turbo pump and SS-500 cart are off now, since HAM7 ion pump is able to maintain the chamber's vacuum pressure, and the ion pump continues to pump down the chamber, see atached plot. So, we decided to introduce the HAM7 volume to the main vacuum envelope at the corner station. The filter cavity tube also is part of the main vacuum envelope.
We only need to move the vacuum equipment near HAM7; SS-500 cart, two CUBE aux carts and flex hoses. The SS-500 still cabled to the turbo pump since it needs to spun down.

Images attached to this report

H1 ISC - A quick summary of ALS diff attempts

elenna.capote@ligo.org — Fri, 11 Sep 2026 17:26:14 -0700

Author: elenna.capote@ligo.org

Report ID: 91879

Oli, Louis, Caroline, Sheila, Elenna, Gabriele

At the start of the day I did a check by measuring the ETMX M0 L2L transfer function and saw that with the alignment offsets ON and the R0 yaw offset of -25000 ct, we still see no evidence of rubbing in the transfer function.

Then, I locked ALS on both arms, and was able to drive tidal feedback and WFS feedback to ETMX.

Louis and I proceeded to lock ALS diff on ETMX and started troubleshooting the issues with ALS diff on ETMY.

In short, we still have no idea what the issue is. I measured a transfer function of ETMX L1 to DARM err and compared it to the same transfer function from ETMY L1. They are the same except for an overall minus sign, which is expected.

We then tried to do the sam measurement of the ETMY L3 feedback, but held in down due to an earthquake. After the earthquake, I found we could not lock ALSX and send tidal feedback to ETMX L1. This indicated rubbing again, but the transfer function showed no rubbing.

I was able to turn on the WFS control to ETMX, which drives L2 and M0, and this works fine. The problem seems to be confined to ETMX L1.

I have attached some screenshots and also SDFs that came up during the day- I had to SDF the ETMY L2 length feedback switch OFF and I SDFed the ETMX R0 yaw offset.

Images attached to this report

LHO General - Fri Ops DAY Shift Summary

corey.gray@ligo.org — Fri, 11 Sep 2026 16:32:17 -0700

Author: corey.gray@ligo.org

Report ID: 91874

TITLE: 09/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: Tony
SHIFT SUMMARY:

Some prep work started for a vent of EX for in-chamber work on Monday (to address ETMx rubbing which returned yesterday).

Commissioners worked on mostly ALS work to possibly allow for DRMI work next week.

HAM7 + Filter Cavity added to the main volume!

LOG:

(all-day) beam tube enclosure patch work with manlift (randy)
1500-1526 JAC remote measurements (masayuki)
1638 Aligned Green Y-arm (ALS_YARM to INITIAL ALIGNMENT OFFLOADED)
- Elenna will be working on X-arm (I had touched up green X-arm flashes, but I backed this out because Elenna will be working on X-arm)
1734-1752 dustmonitor huddle test in optics lab (ryanC)
1909-1947 JAC measurements (masayuki)
2025-2114 Opening HAM7 + Filter Cavity into the main volume & turning off HAM7 turbo (gerardo)
- 2056 looking for gerardo
2052-2213 Taking pelican case to H2PSL room and loading it with CRS parts for LLO (jim)
2055-2116 measurements around BSC3 (jenne)
2119-2158 Moving equipment from LVEA to EX in prep for vent (gerardo.travis)
2142 M6.6 Christmas Island EQ notification
- 2144 EQ mode activated
- 2215 EQ mode activated
2151-2227 Scoping out plumbing for tcs (tj)
2145 EX cleanroom turned ON -and- purge air compressor + dryer tower turned ON for EX vent (gerardo)

H1 SEI - SEI ground seismometer mass position check - Monthly

thomas.shaffer@ligo.org — Fri, 11 Sep 2026 16:09:47 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91878

FAMIS64118

2026-09-11 16:05:55.288609

There are 21 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 2 DOF X/U = -2.315 [V]
ETMX T240 2 DOF Y/V = -2.182 [V]
ETMX T240 2 DOF Z/W = -1.542 [V]
ITMX T240 1 DOF X/U = -2.689 [V]
ITMX T240 1 DOF Z/W = 0.374 [V]
ITMX T240 3 DOF X/U = -2.979 [V]
ITMY T240 1 DOF X/U = -0.499 [V]
ITMY T240 1 DOF Y/V = 0.328 [V]
ITMY T240 2 DOF Y/V = 0.347 [V]
ITMY T240 2 DOF Z/W = -0.417 [V]
ITMY T240 3 DOF X/U = -1.206 [V]
ITMY T240 3 DOF Y/V = -0.47 [V]
ITMY T240 3 DOF Z/W = -3.195 [V]
BS T240 1 DOF X/U = -1.427 [V]
BS T240 1 DOF Z/W = 0.638 [V]
BS T240 2 DOF X/U = 0.764 [V]
BS T240 2 DOF Y/V = 0.335 [V]
BS T240 2 DOF Z/W = -1.276 [V]
BS T240 3 DOF Y/V = -1.523 [V]
HAM8 1 DOF Y/V = -0.535 [V]
HAM8 1 DOF Z/W = -0.873 [V]

All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 1 DOF X/U = -0.149 [V]
ETMX T240 1 DOF Y/V = -0.205 [V]
ETMX T240 1 DOF Z/W = -0.224 [V]
ETMX T240 3 DOF X/U = -0.192 [V]
ETMX T240 3 DOF Y/V = -0.251 [V]
ETMX T240 3 DOF Z/W = -0.228 [V]
ETMY T240 1 DOF X/U = -0.1 [V]
ETMY T240 1 DOF Y/V = 0.123 [V]
ETMY T240 1 DOF Z/W = 0.164 [V]
ETMY T240 2 DOF X/U = -0.147 [V]
ETMY T240 2 DOF Y/V = 0.161 [V]
ETMY T240 2 DOF Z/W = -0.051 [V]
ETMY T240 3 DOF X/U = 0.167 [V]
ETMY T240 3 DOF Y/V = -0.084 [V]
ETMY T240 3 DOF Z/W = 0.052 [V]
ITMX T240 1 DOF Y/V = 0.064 [V]
ITMX T240 2 DOF X/U = -0.04 [V]
ITMX T240 2 DOF Y/V = 0.183 [V]
ITMX T240 2 DOF Z/W = 0.216 [V]
ITMX T240 3 DOF Y/V = 0.1 [V]
ITMX T240 3 DOF Z/W = -0.099 [V]
ITMY T240 1 DOF Z/W = 0.095 [V]
ITMY T240 2 DOF X/U = 0.227 [V]
BS T240 1 DOF Y/V = 0.284 [V]
BS T240 3 DOF X/U = 0.106 [V]
BS T240 3 DOF Z/W = 0.3 [V]
HAM8 1 DOF X/U = -0.189 [V]

2026-09-11 16:06:07.290491
There are 5 STS proof masses out of range ( > 2.0 [V] )!
STS C DOF X/U = 10.0 [V]
STS C DOF Y/V = -10.0 [V]
STS C DOF Z/W = -2.641 [V]
STS EY DOF X/U = -5.513 [V]
STS EY DOF Z/W = 4.467 [V]

All other proof masses are within range ( < 2.0 [V] ):
STS A DOF X/U = -0.465 [V]
STS A DOF Y/V = -0.803 [V]
STS A DOF Z/W = -0.603 [V]
STS B DOF X/U = 0.033 [V]
STS B DOF Y/V = 0.979 [V]
STS B DOF Z/W = -0.355 [V]
STS EX DOF X/U = 0.457 [V]
STS EX DOF Y/V = -0.708 [V]
STS EX DOF Z/W = -0.483 [V]
STS EY DOF Y/V = -0.036 [V]
STS FC DOF X/U = 0.165 [V]
STS FC DOF Y/V = -1.218 [V]
STS FC DOF Z/W = 0.589 [V]

H1 SEI - ISI CPS

thomas.shaffer@ligo.org — Fri, 11 Sep 2026 15:59:56 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91877

FAMIS62990

Last time this was run seems to be in May (90233). ETMY ST1 H2 seems more elevated compared to last time this was run. Everythign else looks okay to me.

Non-image files attached to this report

CPS_spectra_15:53-09_11_2026.pdf

H1 SUS - Comment to QOSEM Noise Hunting - Coil Driver & DAC Noise

marc.pirello@ligo.org — Fri, 11 Sep 2026 13:01:59 -0700

Author: marc.pirello@ligo.org

Report ID: 91876

I added a comment to the FRS analyzing the Transimpedance OpAmp circuit, go have a look. Good news there is hope!

TLDR The OpAmp used for the TIA cirucit is not optimal for that application. The rest of the use of that OpAmp should be fine, but for current sensiitve measurements, the TIA should be low input bias current, i.e. JFET.

In this application, the chopper is better on paper due to the elimination of 1/f noise at low frequencies, and choppers arent as bad as they used to be, so I stand corrected. If only they were synchronized!

H1 SUS - Comment to ETMX is rubbing (again)

elenna.capote@ligo.org — Fri, 11 Sep 2026 09:42:50 -0700

Author: elenna.capote@ligo.org

Report ID: 91875

I am the one who put excitations in the M0 opticalign filter bank. I remember doing this *after* we were found to be not rubbing with the transfer functions. I did it as a check to see if we could lock ALSX since we were no longer rubbing. We didn't have any flashes down the arm, so I did an ETMX raster to move the suspension around. I did notice that after doing this raster, ETMX did not have to be moved at all in the slider and we got flashes, so that does seem in line with the idea that I "fixed" the rubbing with this excitation. ~~But just to reiterate, I did this raster after we measured *no rubbing* in a transfer function (otherwise I would not have done it).~~ I'm now doubting my memory about the order of operations here, I may have just been proving we could still send feedback to ETMX despite the rubbing.

H1 SEI - HEPI Pump Trends (FAMIS #63076 )

corey.gray@ligo.org — Fri, 11 Sep 2026 09:16:55 -0700

Author: corey.gray@ligo.org

Report ID: 91864

Attached are trends for 45 days of HEPI pressure signals and they are pretty flat. (This is for FAMIS 63076.)

(NOTE: Recently restarted Operator FAMIS checks and this one's ndscope template originally did not run due to "old" channels--this is because of the because Beckhoff switch for the HEPI pumps earlier this year--new template updated and mentioned this to Jim.)

SEI

Images attached to this report

LHO General - Fri Ops Day Transition

corey.gray@ligo.org — Fri, 11 Sep 2026 07:49:41 -0700

Author: corey.gray@ligo.org

Report ID: 91873

TITLE: 09/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 4mph Gusts, 1mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.13 μm/s
QUICK SUMMARY:

Focus will be for prep & venting EX for ETMx (~~with 2nd round of TMDS (Test Mass Discharge System [aka "Rai Gun"] or~~ in-chamber incursion).