aLIGO LHO Logbook

H1 CDS - Wed night 20:38 power glitch

david.barker@ligo.org — Thu, 16 Jul 2026 15:36:52 -0700

Author: david.barker@ligo.org

Report ID: 91082

Here is the Wednesday night power glitch which took down then vacuum pumps in the LVEA.

Images attached to this report

H1 SUS - Outage recovery: SUS restored to top mass OSEM pointing before power outage

oli.patane@ligo.org — Thu, 16 Jul 2026 15:32:23 -0700

Author: oli.patane@ligo.org

Report ID: 91081

After restoring SUS sliders (91065), I've now gone through and restored the pointing for the top mass OSEMs for every* suspension back to where they were yesterday before the outage (around 2026/07/16 04:11:58 UTC) (NOT back to where they were during last DRMI lock since we have since changed the alignment when doing our backwards alignment for the BS). Most didn't have to move much / at all but a few did have to move quite a bit on the sliders. Suspensions that have OPLEVs, I referenced those as well, and those all lined up with addressing the top level suspension alignment. All changed alignment offset values were accepted into SDF.

* A few suspensions where I did not restore pointing to where they were yesterday are ZM4 and ZM5 since I know those are actively being worked on and I didn't want to mess up any alignments from earlier today.

ISC, SQZ

H1 CDS - 15:23 power glitch

david.barker@ligo.org — Thu, 16 Jul 2026 15:29:15 -0700

Author: david.barker@ligo.org

Report ID: 91080

lights flickered 15:23:39

Images attached to this report

H1 AOS - Relocking JAC (Jennie, Keita)

keita.kawabe@ligo.org — Thu, 16 Jul 2026 15:14:56 -0700

Author: keita.kawabe@ligo.org

Report ID: 91079

Alignment into JAC was not great. Since JAC wasn't thermalized yet (heater was turned on merely 30minutes or so before we started aligning) and the fringes weren't staying put relative to the PZT voltage, I injected more than 250Vpp (with an appropriate offset) into JAC PZT to make sure that more than FSR is scanned and manually aligned JM1 and PSL PZT until 10/01 mode became less than 10% of 00 mode. Didn't bother to refine further. Attached shows the JM1 and PSL PZT alignment offsets.

I zero-ed the dark offset of JAC_REFL_A_RF43.

We had to turn on FM10 ("W_in_HAM2" which is not calibrated in reality) which was disabled at some point.

JAC guardian was able to lock JAC after the above.

We are able to see flashing in MC TRANS camera now, seems like it's mainly off in yaw but we can see 00 mode once in a while. Nothing in MC REFL camera, we'll work on IOT2L next.

IOO, ISC

Images attached to this report

H1 SEI - CRS Laser Turned on

shoshana.apple@ligo.org — Thu, 16 Jul 2026 15:00:25 -0700

Author: shoshana.apple@ligo.org

Report ID: 91077

I finished hooking up everything to the new CRS laser chassis (see alog 91067 and photo attached) and turned on the laser. There will be a couple of changes to be made to the chassis (swtiching which chassis the the plexi box covers, attaching stickers etc.) but for now the CRS is up and running (minus damping). I'll continue to keep an eye on it, but until the damping is hooked up it seems unlikely that it will damp down on it's own while there's still activity in the LVEA

SEI

Images attached to this report

H1 SQZ - Comment to SQZ beam profiles with different centering on ZM2, ZM4 strain guage wheatstone bridge adjusted, periscope adjusted

sheila.dwyer@ligo.org — Thu, 16 Jul 2026 14:53:18 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91076

Here is a plot of the data taken after the ZM4 preload adjustment. The line of 5 new points was taken with the ZM5 PZT at 100V, where the strain guage wasn't working, which doesn't correspond to any of the strain guage values from the previous data set. The 3 points taken at ZM5 strain guage at -4.5V should corresond to the previous ZM5 setting that thery are near. It would be very helpful to get this data for ZM5 values closer to good mode matching, but at first glance it seems like the ZM4 pre-load change moved us in the correct direction.

Images attached to this report

H1 SEI - Restoring BRSY

shoshana.apple@ligo.org — Thu, 16 Jul 2026 14:33:06 -0700

Author: shoshana.apple@ligo.org

Report ID: 91073

After the power outage last night the ETMY BRSs thresholds were changed and the BRS was stuck in a damping loop again.

I've changed the H1:ISI-GND_BRS_ETMY_HIGHTHRESHOLD from 8000-->4000 and did the usual 'disable the damping from 20 minutes and then re-enable it'

This might just be me not fully understanding the damping controls, but confusingly, when I re-enabled the damping, the BRS began to damp down despite the BRS remaining in the "BRS GOOD" state and the damping remaining off (shown in picture below, USER channel is whether damping is enabled or disabled, DAMPBIT is whether the damping is on or off.

This could be me not fully understanding the system, but it might explain why BRSY has had so many issues

Images attached to this report

H1 General - Illuminators Turned Off

ryan.short@ligo.org — Thu, 16 Jul 2026 14:21:35 -0700

Author: ryan.short@ligo.org

Report ID: 91075

At 20:40 UTC I turned off all the in-chamber illuminators that had been on for vent work (HAM3 and BSC1-3).

H1 CDS - Comment to CRS Laser Chassis D2600190 Installed

arnaud.pele@ligo.org — Thu, 16 Jul 2026 13:56:55 -0700

Author: arnaud.pele@ligo.org

Report ID: 91074

The plexi should be installed in front of the Laser Driver D1500207 rather than in front of the D2600190 chassis.

H1 SEI - Problem with ETMY ISI coilmon readback

jim.warner@ligo.org — Thu, 16 Jul 2026 13:21:29 -0700

Author: jim.warner@ligo.org

Report ID: 91071

I haven't found the alog, but there is a known issue with the ETMY ISI coilmon readbacks where they report the ISI coil drivers are tripped, but are in fact not. This seems to clear up after the coil drivers warm up over a few hours. This can be fixed by putting a test offset in the test input field on the BSCISI_COIL_THERMALSTATUS screen ( opened Overtemp link on the lower right of the BSC ISI overview screen). So far I have had to put 0xc, then 0x4 to clear up the coil driver status bitword, as show in the attached screen shot. Probably something wrong with something in one of the coildrivers.

The lights on the front of the coil driver don't seem affected by this, so if the overtemp protection is clear on the chassis in the rack, you need to do a bit of hexadecimal math to do clear the coilmon warning. To clear the current issue with the coilmon bit you need to find the difference between the good bitword (0xf50f0f0f) value and the current (0xf50f0f0b in the screenshot), so 0xf50f0f0f-0xf50f0f0b=0x4 is the value that goes into the test input field. This should go back to 0x0 after what ever component in the rack stops being grumpy.

Images attached to this report

H1 General - OPS Thursday DAY shift midshift summary

ryan.crouch@ligo.org — Thu, 16 Jul 2026 12:04:42 -0700

Author: ryan.crouch@ligo.org

Report ID: 91069

We have mostly recovered SEI and SUS, SUS pointing is still being verified and the BRSes are having issues. HV still needs to be enabled for further recovery. Team CDS is still working on some issues, IPC errors, long range dolphin, timing error at the CS...

H1 PSL - Comment to PSL Recovered After Power Outage

keita.kawabe@ligo.org — Thu, 16 Jul 2026 11:35:53 -0700

Author: keita.kawabe@ligo.org

Report ID: 91068

refcav temperature seems to be good as of now. I readjusted the fiber polarization controller and ALSX PLL relocked right away. ALSY PLL relocked after TJ restarted the laser.

H1 CDS - CRS Laser Chassis D2600190 Installed

filiberto.clara@ligo.org — Thu, 16 Jul 2026 11:12:23 -0700

Author: filiberto.clara@ligo.org

Report ID: 91067

WP 13426

The CRS laser Chassis D2600190 was installed in rack TCS-R2. Chassis houses the CRS laser, mount, and fiber spool. A plexi security cover was installed over the chassis.

SEI

H1 PSL - PSL Recovered After Power Outage

jason.oberling@ligo.org — Thu, 16 Jul 2026 10:54:10 -0700

Author: jason.oberling@ligo.org

Report ID: 91066

J. Oberling, R. Short, P. Thomas

We have recovered the PSL after this morning's power outage. Once again, the PSL software did not autostart so Patrick was called in to get things up and running. The system calibrations were all correct this time EXCEPT for the operating hours; we trended these to the time of the power outage and updated them manually (the OPHRS A, or the total system uptime, are still incorrect as this field is not updateable and we lost it over multiple failures of the system to retain the calibration settings). I've attached a picture of the current settings screen.

The PMC relocked without issue, although it is running a little cooler than usual ( ~304.5 K vs ~306.0 K). We'll monitor this as the system thermalizes and change the PMC temperature if necessary. The FSS RefCav also locked without issue. We have left the ISS off while the system thermalizes, please do not turn it on until things have settled down (hopefully by the end of the day).

Images attached to this report

LHO VE - Vent Recovery Pumpdown Interrupted

gerardo.moreno@ligo.org — Thu, 16 Jul 2026 10:31:29 -0700

Author: gerardo.moreno@ligo.org

Report ID: 91064

Power storm last night tripped all 3 turbos and a couple of aux carts. Pressure rose up to about 2.1x10^-04 Torr, noted on the attached plot.

As I was doing recovery work on the output mode cleaner tube turbo pump, I had just closed the main isolation valve and "reset" the box, I was taking a photo of the as found when we had the 6:01 am power glitch.

I returned to HAM1 SS-500 to check the system, it tripped, and I recovered pumping on the SS-500 system and HAM1 turbo. Moved back to the OMT turbo pumps system, by now the main isolation valve was closed, restarted the different components and spun up the turbo pump, while this one reached "normal" speed I moved to the other two turbo stations, and repeated the process, soon we had all three turbos back up.

The aux carts were restarted for BSC1 AIP, GV5 AIP, and HAM3 AIP.

The Kobelco compressor made it back on its own, but the dryer tower did not, I restarted it and visually checked the dew point, it was good, reported by the dryer at -63 ^oC.

Attached is a plot of the pumpdown for HAM1 and the corner via PT180 signal from BSC8.

Also I have attached a video capture of the power outage, on the video you can hear the solenoid valves closing for OMT turbo station and other items.

Images attached to this report

Non-image files attached to this report

20260716_PowerReset.mov

H1 SUS - Outage recovery: SUS sliders restored to before the outage + DAMP_IN pointing discrepancies

oli.patane@ligo.org — Thu, 16 Jul 2026 10:24:27 -0700

Author: oli.patane@ligo.org

Report ID: 91065

RyanC, Oli

We've gone through all the suspensions and restored the alignment sliders to what they were yesterday (around 2026/07/16 04:11:58 UTC) before the power outage. All slider values have been SDF'd and all is good slider/sdf-wise by 1468256527 (Jul 16 2026 17:01:49 UTC).

A quick look at pointing shows that even though the sliders are all restored, many suspensions have different pointing. Here's a quick look at the difference between most of the suspension pointing before vs after the power outage after restoring OPTICALIGN OFFSETs. Both of these sets have the same offset slider values. Note that at this time the ISIs and HEPIs are all still down.

Once the SEI system is back up I'll be starting to adjust suspension pointing for those that don't match where they were yesterday by adjusting the slider values to get DAMP_IN (driftmon) back.

ISC

Images attached to this report

H1 General - OPS Thursday Day shift start

ryan.crouch@ligo.org — Thu, 16 Jul 2026 07:42:47 -0700

Author: ryan.crouch@ligo.org

Report ID: 91063

TITLE: 07/16 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: MAINTENANCE
Wind: --
Primary useism: --
Secondary useism: --
QUICK SUMMARY:

There was a power glitch this morning, tons of disconnects
CS chamber pressures (BSC2, HAM1, HAM6...) are on the order of 10^-6 torr

H1 CDS - Comment to Site wide power glitch 06:01 PST

david.barker@ligo.org — Thu, 16 Jul 2026 07:02:22 -0700

Author: david.barker@ligo.org

Report ID: 91062

Gerardo reports that all three turbos on the main volume tripped last night. Attached trend of PT120B shows pumpdown starting 13:07 PDT yesterday afternoon, pressure starts increasing around 20:45 last night and recovery start 06:14 this morning

Images attached to this report

H1 CDS - Site wide power glitch 06:01 PST

david.barker@ligo.org — Thu, 16 Jul 2026 06:51:43 -0700

Author: david.barker@ligo.org

Report ID: 91061

We had a power glitch at 06:01, most probably due to an electrical storm.

Richard and Gerardo are on-site recovering FAC and VAC.

CDS status: both main DAQ legs are down. All front ends are down. NDS3 (vacuum trends) is up.

Images attached to this report

H1 CDS - WP 13402 & 13401 DAQD ethernet transition

jonathan.hanks@ligo.org — Wed, 15 Jul 2026 18:14:34 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91060

Jonathan, Erik,

Per WP 13402 the h1daq 0 systems where update to remove the dolphin interconnect and use ethernet.

The work plan is in T2600271. The basic work flow:

* Redirect nds queries to h1daqnds1

* Move the nds2 and ngdd data feeds to the 1 leg.

* I was unable to get the ngdd services properly running on h1daqkc1. I will look into this later.

* power down the systems.

* remove the dolphin cards, add in the ethernet nics as needed (some systems already had enough nics)

* reconfigure the networking.

* update the dns to drop gds0.

* start and test services.

We moved the h1daqscript0 to a temporary location so that we could mount sw-msr-daqd1. After we convert the daqstat ioc to a container we will be able to retire that machine. Pending daqstat updates I have re-enabled the dc0_epics_mirror and added a dc1_epics_mirror so that we can see the gds broadcast crc. Note even though the system shows a h1daqgds0 and h1daqgds1 those systems are gone, and the broadcast is being done from dc0 and dc1.

I finished off WP 13401 by configuring the frame writers to use the run number server on in the container cluster. This will be tested at the next daqd restart.

We still need to pull the dolphin switches out of the racks.

Then there is OS upgrades for the daqd systems.

H1 TCS - first stab at using FLIR Boson+ to image thermal profile of ITM

matthewrichard.todd@ligo.org — Wed, 15 Jul 2026 18:10:21 -0700

Author: matthewrichard.todd@ligo.org

Report ID: 91059

M. Todd, C. Compton, T. Shaffer

We had a go today at pointing the FLIR Boson+ camera at ITMY with the ring heaters on at 2W per segment. In short, we were not able to see anything with the FLIR Boson+ yet. My feeling is that the camera should definitely be able to see it, as we pointed another hand-held FLIR and were able to see a bright spot where we though the test mass was (though it was pretty out of focus because the hand-held is not as great as the Boson+). The issue with the current setup is the camera pointing is not easily adjusted, and did sit centered in the camera can that we were able to fit on the viewport.

The setup with the guillotine was to take the back off of a camera can and mount the camera in there as best we could without anylenses to maximize our field of view. Then we attached the camera can and removed the guillotine to look at the ITM. We tried removing the background because the image seemed completely saturated as if it was catching a reflection from something. We tried adjusting the aperture to reduce this but had no luck. We tried removing the camera can and pointing the handheld FLIR at the ITM and saw a bright spot that looked like it could be the ITM, so we tried again with the camera can slightly rotated to see if the seating in the camera can was an issue --- again without any luck.

Overall, I think it deserves another test using a pitch-yaw mount or something and a little bit smaller footprint so that it fits in the camera can more easily. Additionally, we should see what the lenses are for the other cameras used pointing at the ITMs, as they will probably be useful.

I also found a Windows GUI that interfaces with the camera a little more customizably, which may be useful for future tests as well.

Images attached to this report

H1 TCS - Comment to Ring Heaters Chassis Turned back on. ITMX at nominal 0.44W/segment. ITMY at 2W/segment for test.

camilla.compton@ligo.org — Wed, 15 Jul 2026 17:13:56 -0700

Author: camilla.compton@ligo.org

Report ID: 91058

ITMY has been turned back off to 0W /segment, this is nominal.

H1 SUS - Comment to BBSS M1 QOSEM satamp compensation filters updated

oli.patane@ligo.org — Wed, 15 Jul 2026 17:08:50 -0700

Author: oli.patane@ligo.org

Report ID: 91057

I had forgotten to update the satamp compensation filters for the M1 sus watchdogs, so I have now done that. Those are loaded into H1:SUS-BS_M1_WD_OSEMAC_BANDLIM_{F1,F2,F3,LF,RT,SD}_{SUM,X_RAW,Y_RAW} and have been committed to the H1SUSBS.txt filter file as r35497

H1 SUS - BBSS M1 QOSEM SatAmp LED current changed to Sum Feedback mode

oli.patane@ligo.org — Wed, 15 Jul 2026 17:00:50 -0700

Author: oli.patane@ligo.org

Report ID: 91056

Now that we're in vacuum I have switched the QOSEM M1 satamp current from Constant Current mode to Sum Feedback mode. This adjusts the current to maintain 9V on the QPD (T2600172). This means that the SUM channels for F3 and RT have stopped saturating since the current has been slightly lowered to those LEDs.

There was some movement in the QOSEM positions, but nothing moved very much (ndscope). The most movement was on F3 Y, which moved 0.5 µm

Images attached to this report

H1 General - OPS Wednesday DAY shift summary

ryan.crouch@ligo.org — Wed, 15 Jul 2026 16:33:41 -0700

Author: ryan.crouch@ligo.org

Report ID: 91051

TITLE: 07/15 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR:
SHIFT SUMMARY: The CS pumpdown continues, the interlock work was finished up and lasers were recovered, DC0 was worked on by CDS.

BSC2 pressure is currently at7.01e-06 Torr, BSC8 is at 6.97e-06 Torr, HAM1 is at 9.33e-06 Torr, and HAM6 is at 9.41e-05 Torr.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:49	FAC	Kim	LVEA	N	Tech clean	17:44
16:30	VAC	Gerardo	LVEA	N	Restarting the VAC pumps.	18:30
16:33	IFO	Betsy	LVEA	N	DRopping off parts & coordinating.	17:09
16:38	SQZ	Rahul, Sheila	LVEA	N	HAM7 work	17:42
15:50	EE	Fil	LVEA	N	Cable terminations	16:39
16:45	FAC	Mitchell	LVEA	N	Cleaning up & other House Keeping activities.	17:38
16:46	VAC	Travis	LVEA	N	Join Gerardo, check on pumps	17:09
16:47	Safety	Richard	LVEA	N	coordinating Interlock and VAC plans.	17:03
16:56	PSC	Christina	LVEA/ FTCE	N	looking for fork lifts.	17:08
17:09	PSC	Christina	FCES	N	Search for a forkflift	17:40
17:38	IAS	Jason	LVEA	N	Cleanup and store IAS equipment	18:54
17:42	TCS	Camilla, TJ, Matt	Prep lab/ CHEETA ab	LOCAL	CHEETA work, TJ out 1800	18:59
18:50	TCS	Camilla, Matt	LVEA	N	Look for a camera	18:59
18:56	EE	Fil	LVEA	N	Interlock work	19:34
19:21	FAC	Randy	LVEA	N	High bay to west bay craning	19:43
19:55	GRD	TJ	CR	N	SEI manager testing, HAM6 BSC10	20:35
20:04	FAC	Betsy, Randy	LVEA	N	Checks	21:02
20:15	EE	Marc, Tony	EndX, EndY	N	Interlock test	20:58
20:28	IAS	Jason	LVEA	N	IAS cleanup	21:13
20:58	SAF	Marc	FCES	N	Interlock test	21:24
21:17	SUS	Jason	LVEA	N	Check out BSC2 oplev	21:32
21:54	ALS	Tony	EndY, then EndX	N	Check on ALS lasers	22:31
22:31	TCS	Camilla, Matt	CER	N	Turn on ring heater chassis	22:34
22:32	SEI	Shoshana, Jim	LVEA	N	CRS laser enclosure install	22:47
22:43	TCS	TJ, Matt	LVEA	N -> Y	3IFO rack parts search, into JAC lab as well	Ongoing
22:50	OPS	Camilla	LVEA	N -> Y	Laser hazard transition	22:59
22:59	TCS	Camilla	LVEA	Y	Join TJ and Matt	Ongoing
23:06	SUS	Oli	LVEA	Y	Flip switches on BBSS sat amp	23:09
23:10	SEI	Shoshana	LVEA	Y	Quick CRS check	23:15

H1 SUS - BBSS alignment scare aka remember to sdf

oli.patane@ligo.org — Wed, 15 Jul 2026 16:33:26 -0700

Author: oli.patane@ligo.org

Report ID: 91049

Elenna, RyanS, Oli

Summary: BBSS alignment in vacuum is looking good. It was looking bad earlier but we figured out the issue and now it's looking good.

Whole explanation: I noticed that the BBSS was super Yawed in M1. LF was very large in +Y, RT was very large in -Y, F2 was reasonably large in +X, and F3 was reasonably large in -X (medm). Referencing E2600243, this correlates with a rotation in -Yaw. This was strange, and we noticed that this shift in alignment had happened over a few seconds yesterday 2026/07/14 20:57 UTC (ndscope). At the same time this happened, we had fallen off the OPLEV. After some concern, we were reminded that the models in b2h34 had been restarted yesterday, and so we realized that the OPTICALIGN alignment sliders hadn't been saved in a while and were from back when we had initially been checking BBSS alilgnment into HAM3 (which had a lot of Yaw). We reverted the slider values to what they had been last set to (from Keita's alog 90920, ndscope), and we are looking good on all three stages(medm) and are back on the OPLEV (ndscope). Slider values have been SDF'd (sdf). I will be checking the sliders on the rest of the b2h34 suspensions to make sure we didn't lose any pointing on them due to the model restart either.

Images attached to this report

H1 CDS - Comment to laser safety interlock code updated

patrick.thomas@ligo.org — Wed, 15 Jul 2026 16:20:51 -0700

Author: patrick.thomas@ligo.org

Report ID: 91055

The channels still need to be updated in the DAQ.

H1 CDS - laser safety interlock code updated

patrick.thomas@ligo.org — Wed, 15 Jul 2026 16:19:06 -0700

Author: patrick.thomas@ligo.org

Report ID: 91054

July 14 - 15, 2026 Filiberto C., Richard M., Ryan C., Marc P., Tony S., Patrick T. The TwinSAFE laser safety interlock code has been updated to https://git.ligo.org/cds/ifo/beckhoff/lho-laser-safety/-/commit/88c39ba2a1ff25ce7f710fd496c78f42fb911d38. This is a rewrite using scripts to generate a large part of the code and configuration. It also does the following: * Adds support for the addition of CHETA. * Adds a bypass mode that is enabled using a key switch on the wall of the control room. When in this state the lasers will remain on even if an estop is pressed or an enclosure is opened. * Adds a single channel/medm button to reset all of the function blocks. * Removes the code and channels for the diode room. Issues run into: * The existing version of TwinCAT on h0safety would not open the new safety code that was created with a newer version of TwinCAT. I installed the TwinCAT Package Manager on h0safety and used it to migrate the version of TwinCAT there to 3.1.4026.24. * There were multiple TwinSAFE boxes that had their hardware address set to 0. Filiberto set the following through their rotary dials/dip switch: IOT1 -> 205 ISCT1 -> 210 IOT2L -> 215 TCSY -> 220 TCSX -> 225 CHETA -> 230 HWS -> 235 SQZT7 -> 240 SQZT0 -> 245 TCS_INTLK -> 250 * The diagnostic test pulses had to be turned off for the inputs to the CHETA box. That is, 8040:04 Diag TestPulse active, 8050:04 Diag TestPulse active, 8060:04 Diag TestPulse active, and 8070:04 Diag TestPulse active, were all set to FALSE (0) on the alias device (see attached picture). * The light in the control room used to indicate that the bypass mode is active is not being turned on. Will need to be fixed in hardware. Each of the doors and emergency stops have been tested.CDS, Laser Safety

Images attached to this report

H1 ISC - SURF Earthquake Mode Linear Noise Subtraction

matilda.damon@ligo.org — Wed, 15 Jul 2026 15:55:52 -0700

Author: matilda.damon@ligo.org

Report ID: 91050

We have an earthquake mode that allows us to move into higher bandwidth interferometer controls during an Earthquake. Those controls also cause extra noise, as noted in this alog, so we are trying to subtract the injected linnear noise during this mode. Here is a trend of the seismic environment state and the sensmon range channel detector sensitivity. The plot shows that once we transitioned into earthquake mode, we were in earthquake mode for about 15 minutes before a lock loss. It is also visible that the gains are changing on the channels.

Elenna and I decided to try subtracting the noise from the interferometer controls during those 15 minutes starting at GPS 1443544132 and ending at 1443544932, see this alog for reference. I am comparing this GPS time for this earthquake to one hour before so we can know what the sensitivity should look like if we subtract all of the noise. We decided to subtract the channels whose gains changed. The channels subtracted were

H1:ASC-DHARD_P_OUT_DQ,

H1:ASC-CHARD_Y_OUT_DQ,

H1:ASC-DHARD_Y_OUT_DQ,

H1:ASC-CHARD_P_OUT_DQ,

H1:ASC-DSOFT_Y_OUT_DQ,

H1:ASC-DSOFT_P_OUT_DQ,

H1:LSC-MICH_OUT_DQ,

H1:LSC-PRCL_OUT_DQ,

H1:LSC-SRCL_OUT_DQ.

The channel with the greatest noise contribution was H1:LSC-MICH_OUT_DQ, which I determined through taking the coherence of all the LSC and ASC channels and the witness channel. The final subtraction and BNS change are visble in this GWSubtract file. Therefore, if we run a noise subtraction during earthquake mode we know we can get back at least 11 Mpc of sensitivity. This would be useful if we made a detection during earthquake mode, however we could still do better by around 70 Mpc. I plan to make this into a more usable tool and look into what is causing the rest of the noise next. I also plan to look into more channels to see if others might be causing noise as well. Since this is an earthquake mode time, it is possible the earthquake is modulating some of these channels, so a nonlinear noise subtraction may make more sense.

SEI

Images attached to this report

H1 PSL - PSL Recovered Following Interlock Work and Chiller Swap

ryan.short@ligo.org — Wed, 15 Jul 2026 15:45:02 -0700

Author: ryan.short@ligo.org

Report ID: 91053

This afternoon I recovered the PSL successfully after it had been down since yesterday morning when work on the site laser safety interlock began.

The recovery went as expected and without issue. I've relocked the PMC and FSS, but am leaving the ISS disabled until the amplifiers and PMC have had time to warm up and the output power levels out. Looks like we'll need some alignment touchup into the PMC and RefCav, but that will also wait until things are warmed up, likely sometime tomorrow. Power watchdogs have been enabled for the night.

H1 TCS - Ring Heaters Chassis Turned back on. ITMX at nominal 0.44W/segment. ITMY at 2W/segment for test.

camilla.compton@ligo.org — Wed, 15 Jul 2026 15:38:53 -0700

Author: camilla.compton@ligo.org

Report ID: 91052

WP 13421 Matt, Camilla

We turned on the two RH chassis that were off as per M1300464.

ITMX came back on to nominal 0.44W/segment.

ITMY we turned on to 2W/segment for a test, just for an afternoon.

H1 SEI - Small change to SEI GRD chamber manager to handle HEPI offline times

thomas.shaffer@ligo.org — Wed, 15 Jul 2026 13:33:02 -0700

Author: thomas.shaffer@ligo.org

Report ID: 91048

The chamber managers now better handle the recovery for the case of HEPI's master switch OFF but the ISI's master ON (ie. if HEPI tripped but not the ISI for some reason).

Years ago we added the ISI_DAMPED_HEPI_OFFLINE state to the chamber managers, but one small fallout from that is that if HEPI's master switch was off, but the ISI's master switch was on, when someone would untrip the HEPI, the manager would run through INIT which would immediately jump to turn HEPI back on. This would then potentially retrip the HEPI, frustrating users. I've changed the INIT state to just go to ISI_DAMPED_HEPI_OFFLINE for this case, as it should.

I tested this with SEI_ETMY and SEI_HAM6 by setting the nodes to ISI_DAMPED_HEPI_OFFLINE first, then tripping HEPI by changing the trip level, turning OFF the HEPI master switch, then untripping the HEPI. All tests successful and I loaded this into all other chamber managers.

GRD

H1 TCS - Measuring CHETA Beamsize with FLIR camera

camilla.compton@ligo.org — Wed, 15 Jul 2026 12:13:28 -0700

Author: camilla.compton@ligo.org

Report ID: 91047

Matt, TJ, Camilla

Today we did proof of principle measurements of the CHETA beam size using the FLIR camera.

In 13940 the CO2 beam was projected onto black construction paper in the LVEA. Today we projected the CHETA beam (at low power, <100mW) onto the laser curtains in the CHETA lab. We measured it using a ruler with paper markings taped on at 2" increments, it was easier to see the ruler once it was warmed up by our hands.

We also moved the QPD 2" lens 200mm FL into the path 230mm after M4 and 500mm from M4, for both of these, the beam appeared to be ~1" in diameter. The laser curtain was 67" from M4. Photo attached.

Images attached to this report

H1 SQZ - lens distances in HAM7

sheila.dwyer@ligo.org — Wed, 15 Jul 2026 10:37:57 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91043

Rahul, Sheila

We measured distances in HAM7 on the VIP. For optic names see D2000021 (A:L2 and A:L3 are actually one lens, we will call it A:L2)

A:M3 to A:DC2: = 61mm
D:DC2 to A:L2 = 35+-2mm
A:DC2 to SFI1 wedge= 215mm
A:L2 to SFI1 wedge:
SFI1 wedge to A:P1 = 257mm
SFI1 wedge to B:M1= 389mm
B:M1 to B:M2= 221mm
BM1 to B:L1= 87+-3 mm
B:L1 to B:M2: skip
B:M2 to B:P1 = 57mm (+-1mm)
B:P1 to SFI2 wedge: 277+-2mm
SF2 wedge to B:M3: 57mm
B:M3 to B:L2= 96 +-2mm
B:M3 to B:BS1 = 207mm
B:BS1 to B:M4:97+-2mm
A:P1 to A:L1: 66+-2mm
A:P1 to A:M2= 87mm
A:M2 to A:M1: 41mm
A:M1 to A:DC1 = 67mm
A:DC1 to edge of OPO box:63mm

SQZ

H1 SEI - Comment to ETMY BRS not damping down

shoshana.apple@ligo.org — Wed, 15 Jul 2026 10:34:59 -0700

Author: shoshana.apple@ligo.org

Report ID: 91045

Turning off the damping for 20 minutes seemed to reduce the velocity slightly, but it still seems stuck in a loop with the velocity under 2000 counts, which happens to be the lower damping threshold. I then turned back on the damping and have let it run for another ~30 minutes and it looks like the BRS has damped back down. If this continues to be a recurring issue it might be good to look into a more permanent fix, but just switching the damping off and on again seems to work for now.

Images attached to this report

H1 SQZ - Comment to Determining the ROC for ZM4 and ZM5

eric.oelker@ligo.org — Wed, 15 Jul 2026 10:01:11 -0700

Author: eric.oelker@ligo.org

Report ID: 91046

I was curious to see what Sheila's improved fits imply for our hunt for the source of astigmatism in HAM 7. Below I've tabluated some calculations for the astigmatism, which I define as the difference in focusing power between the horizontal (X) and vertical (Y) directions for ZM4/5

For ZM4

ZM4 SG	2	4	6	8
Rx (m)	-7.621	-6.886	-6.313	-5.798
Ry (m)	-8.687	-7.699	-6.923	-6.280
Dx - Dy (mD)	-32.2	-30.7	-27.9	-26.5
Dx/CosT - Dy*CosT (mD)	-50.5	-51.1	-50.4	-51.1

Here T is the angle of incidence (15.5 degrees for ZM4). The total astigmatism (line 5 in the table) includes both the physical astigmatism (line 4 in the table) due to non-uniformity in the ROC of the PSAM optic as well as the astigmatism resulting from non-normal incidence. By comparing lines 4 and 5, we see that, for ZM4, the impact of the relatively large angle of incidence is also a significant source of astigmatism.

For ZM5

ZM5 SG	-4.5	-2	0	2
Rx (m)	3.544	3.852	4.190	4.273
Ry (m)	3.600	3.889	4.266	4.315
Dx - Dy (mD)	8.8	4.9	8.5	8.4
Dx/CosT - Dy*CosT (mD)	13.0	8.9	12.1	11.9

Here T is the angle of incidence (5 degrees for ZM5)

The physical astigmatism (Dx - Dy) of the PSAM optics appear to be typical of the characterization data at Caltech in 2021.

See this presentation from Lee McCuller: https://docs.google.com/presentation/d/12UynUfIfyXmggvRKFq-OTcJKO3U0TrhD8XnKnrJE1CA/edit?usp=sharing

And his corresponding calcuations from the raw data: https://git.ligo.org/wieldphysics/wield-ligo-mcculler/-/tree/main/src/wield/LIGO/mcculler/mirror_maps?ref_type=heads

Implications for X/Y overlap in HAM 7:

Note: I do my best here to calculate the expected impact of the various ZM mirrors on our X/Y mismatch. I'm fairly new to analyzing AWC optics, so take these calculations with a grain of salt.

From this we can calculate the astigmatism-induced mode mismatch between the x and y directions due to reflection off of ZM4 and ZM5. This can be done using Equation 23 in the following technical document: https://dcc.ligo.org/LIGO-T1900144

I believe that one wants to take the square root of eqn 23, since we are interested in calculating a 1D overlap integral between X and Y of a single beam rather than a 2D overlap between two separate beams.

We use the following paramters in Eqn 23:

w = beam spot size on ZM4 or ZM5 (roughly 1 mm and 2 mm respectively)

D = difference in defocus between X and Y for either ZM4 or ZM5 (Just the last line of the two tables above)

I find roughly that |k₀₀|² = 0.997 for both ZM4 and ZM5. The impact is small and, because the astigmatism appears to have the opposite sign for each optic, the effect of ZM4 and ZM5 will probably cancel one another to some degree (this should be straightforward to calculate, I just haven't done it here). This suggests that the impact on our X/Y overlap due to the astigmatism on ZM4 and ZM5 is likely not a significant limit to our squeezing level at present. I'll take a look at the raw q values later to see if they tell a consistant story, will hopefully confirm that these back-of the envelope calcs using this T-doc are reliable.

However, our measurements on SQZT7 suggest that we do have noticible astigmatism. ZM2 seems like a more likely culprit due to the larger beam spot size on that optic (w = 2.5 mm).

Rough estimate of the impact of ZM2:

Based on Lee's analysis of the Zygo data for the ZM2, ZM4, and ZM5 PSAMS, it appears that 10-20 mD of astigmatism is typical near the center of a PSAM optic.

For 10-20 mD of astigmatism from ZM2 with w =2.5 mm, the mode overlap between X and Y would lie between:

|k₀₀|⁴ = 0.9916 to 0.9671

I dont think that this naive calculation where I square the result for a double-passed optic is correct in general for a retroreflected path, but my intuition is that this should be roughly right in our case because ZM2 actuates mostly on the beam defocus at FC1. I'm not that confident in my intuition, so I plan to confirm this with some finesse modeling.

This might account for the astigmatism measured on SQZT7. Further measurements before/after ZM2 would allow us to confirm this theory.

H1 SUS - BBSS M1 QOSEM satamp compensation filters updated

oli.patane@ligo.org — Wed, 15 Jul 2026 09:59:03 -0700

Author: oli.patane@ligo.org

Report ID: 91044

On Monday Marc updated the BBSS M1 QOSEM satamp (91003). Today I updated the satamp compensation filters. These compensation filters were updated in the FM01 spot in the H1:SUS-BS_M1_OSEMINF_{F1,F2,F3,LF,RT,SD}_{SUM,X_RAW,Y_RAW} filter banks.

Previous filter: zpk([145e-3],[720e-6],1,"n"), named 0.15:7e-4

New filter: zpk([2.89],[14.4e-3],1,"n"), named 2.9:14e-3

Filters were loaded in and H1SUSBS.txt has been committed as r35492.

**These filters are still currently off because we have not turned the whitening on yet

H1 SEI - Comment to ETMY BRS not damping down

shoshana.apple@ligo.org — Wed, 15 Jul 2026 09:32:01 -0700

Author: shoshana.apple@ligo.org

Report ID: 91042

Looks like this issue has popped back up. When Michael Ross was here he increased the damping thresholds (see 90693) which seemed to fix it temporarily but starting last night ETMY got stuck again in a damping loop. I'm going to shut off the damping for maybe 20 minutes to see if that fixes things and if not I'll mess with the damping thresholds again.

Images attached to this report

H1 TCS - Beam Profiles of CHETA Y-arm Table Laser 0918 with L2 in different locations

camilla.compton@ligo.org — Wed, 15 Jul 2026 09:30:17 -0700

Author: camilla.compton@ligo.org

Report ID: 91041

Matt, Camilla

On July 9th, we used the Ophir Nanoscan to take data on the CHETA Y-arm Table Laser 0918 with L2 at different locations on the translation stage. Data is attached to D2500319.

We then used Fintrace to project this to the ITM. Data must be saved with correct file name for this analyzer to work, using logger function of Nanoscan V2 to save. Used command: python beam_profile_analyzer_nonlinear.py /DATA/20260709_0918_after_L2_m10/ --z-offset 245

L2 Translation Stage Offset	Fitted q propagated to ITM		% Astigmatism (Beam size)
L2 Translation Stage Offset	Horizontal	Vertical	% Astigmatism (Beam size)
-35mm	46.65 mm	48.73 mm	4.4%
-10mm (Nominal)	53.06 mm	51.03 mm	3.9%
+15mm	62.17 mm	57.87 mm	7.4%

At the nominal beam size of ~53mm on the ITMY, the beam size astigmatism is 3.9% which we think is acceptable.

We also took some data with the analyzer at a fixed position while moving L2 along the translation stage, this is also attached to D2500319.

LHO VE - Comment to Purge air compressor monitoring system installed

david.barker@ligo.org — Wed, 15 Jul 2026 09:23:50 -0700

Author: david.barker@ligo.org

Report ID: 91040

I repositioned wincam (fish eye camera) to get a good view of this screen.

Images attached to this report

H1 General - OPS Wednesday Day shift start

ryan.crouch@ligo.org — Wed, 15 Jul 2026 07:47:35 -0700

Author: ryan.crouch@ligo.org

Report ID: 91038

TITLE: 07/15 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: MAINTENANCE
Wind: 9mph Gusts, 6mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.05 μm/s
QUICK SUMMARY:

HAM1's pressure has been rising slowly over the past 18 hours, 0.035 torr/18hours
17:32 interlock alarms went off
The pumpdown is to continue today, along with leak checking and LVEA cleanup
CDS EDC show GDS1 channel disconnnects

Images attached to this report

H1 CDS - Comment to WP 13402 Update, h1daqd1 leg converted to use ethernet instead of dolphin

jonathan.hanks@ligo.org — Tue, 14 Jul 2026 18:36:21 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91037

To help with load testing, h1daqfw2 was moved to reading data from dc1, and kc1 is pulling data from dc1 even though it is not publishing data yet (only kc0 does at this point).

H1 CDS - WP 13402 Update, h1daqd1 leg converted to use ethernet instead of dolphin

jonathan.hanks@ligo.org — Tue, 14 Jul 2026 18:34:01 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91036

Jonathan, Tony, Erik,

As per WP 13402 the h1daq*1 systems where updated today. We removed the Dolphin PX cards from the systems, installed the new ethernet cards.

In the prep stages the GDS broadcast was moved to the 0 leg and h1daqfw2 was changed to pull data from the 0 leg.

Notable changes:

* h1daqgds1 -> is now the the data concentrator + broadcaster. It is named h1daqdc1. This is the machine that receives the front end data.

* h1daqdc1 -> is now h1daqkc1 (h1daq kafka connector) for use with the ngdd project.

We found one issue where the daqd could not write jobs into the nds servers job queue folder. This was a permissions issue. Not sure why this popped up as a problem now. I updated the puppet config specifically avoid this happening again.

H1 General - Laser Interlock System Down for Upgrade

filiberto.clara@ligo.org — Tue, 14 Jul 2026 17:27:47 -0700

Author: filiberto.clara@ligo.org

Report ID: 91035

WP 13417

The MSR Safety System Chassis D1600176 was modified. The EL6900 terminal was replaced with an EL6910. Internal connections were made for the Bypass input and Bypass LED in the control room.

The EtherCAT safety modules EP1908 for IOT1R, ISCT1, and IOT2L were mounted over HAM2. The same was done for the safety modules (EP1908 and EP1957) for TCSX, CHETA_Y&X, and HWS. They are mounted on top of TCS-R1.

Two E-Stop buttons were mounted down the X&Y arms for CHETA.

Software upgrades are ongoing. The system will be left offline. System will need to be fully tested before bringing lasers back online.

LHO VE - Corner station and HAM1 pumpdown paused overnight

travis.sadecki@ligo.org — Tue, 14 Jul 2026 16:59:36 -0700

Author: travis.sadecki@ligo.org

Report ID: 91034

We are still on scroll pumps for the corner station, so the pumpdown was paused for the night and the pumps valved out. Pressure in the corner is ~0.5 Torr. We should be able to get on turbo tomorrow.

HAM1 pumpdown was started today after sorting some gauge issues. Pressure is 6e-2 Torr at COB. This will also go onto turbo tomorrow.

H1 SPI - Comment to Parts added to seiproc for HAM2-3 and HAM4-5 differential supersensor comparison,

jennifer.wright@ligo.org — Tue, 14 Jul 2026 16:43:20 -0700

Author: jennifer.wright@ligo.org

Report ID: 91033

I made a medm screen for these super sensor comparisons. Its under the SPI menu on sitemap as 'ISI DIFF'.

I haven't got the layout pretty or the displays working for the resultant differential supersensor filter banks. WIP...

Committed the custom adls to the userapps svn.

Images attached to this report

LHO General - OPS Day Shift Summary

ibrahim.abouelfettouh@ligo.org — Tue, 14 Jul 2026 16:29:04 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91031

TITLE: 07/14 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

IFO is in IDLE for MAINTENANCE

Very productive day. Here's what happened:

EPO IPA + Other Tours
PSL Chiller Swap - Done - alog 91022
HAM7 ZM5 Work - Done - alog 91027
Various CDS Work:
- h1susb2h34 20bit-DAC fix - alog 91026
- work station swap - alog 91018
- NUC22 maintenance - the two screens are down and Erik and Tony are fixing them
- DAQD Dolphin with Ethernet Upgrade - alog 91022
Interlock Work (to add JAC, SPI, CHETA) and upgrade. This work is going longer than expected because of some backwards compatibility and version issues. Should be done later today or tomorrow.
Seismometer work at BSC2
Craning scissor lift at LVEA
HEPI BSC1,2,3 HEPI unlocked and HAM3 Z Loop Instability investigation - alog 91020, alog 91024

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:34	VAC	Travis	LVEA	N	Resume pumpdown	16:20
15:44	FAC	Christina	Recieving	N	Forklifting some palettes	18:43
15:46	EE	Fil	LVEA	N	Working on adding JAC , SPI, and Cheta to LASER interlock	00:31
15:50	CDS	Jonathan	Remote	N	NDS & FrameWriter restarts	20:12
15:53	PEM	Ryan C	LVEA	N	Restarting Dust monitors	16:07
16:00	PSL	Ryan S, Jason	LVEA	Local	PSL Chiller Swap	17:00
16:18	FAC	Christina	Ends, Mids	N	Supply photos	17:41
16:19	FAC	Tyler	LVEA, Ends	N	Getting parts	16:19
16:20	SUS	Ryan C, Rahul	LVEA	N	HAM7 work	18:19
16:29	PEM	Shrey, Miranda, Carlos	LVEA	N	Seismometer work\\	17:28
17:22	EPO	Mike (+ tour)	LVEA	~	Tours	17:53
17:52	SEI	Jim	LVEA	N	Unlocking HEPI	18:05
18:14	SEI	Jim	LVEA	N	Unlocking BSCs HEPI	20:04
18:27	PEM	Shrey, Carlos, Miranda	LVEA	N		18:27
18:33	SUS	RyanC	CR	N	ZM5 intial health check TF	18:59
19:13	FAC	Randy, Erik	LVEA	N	West Bay scissor lift craning to High Bay	19:55
20:05	PEM	Carlos, Shrey, Miranda	LVEA	N	Seismometer checks	21:49
20:05	VAC	Travis	LVEA	N	Checking on pumps	23:12
20:10	CDS	Dave	CER	N	Turning off AI chassis	20:22
20:16	SUS	Ryan C	LVEA	N	HAM7 Work PSAMs Cable	20:17
20:26	SUS	Rahul	LVEA	N	HAM7 Work	21:17
21:51	TCS	Madi	Optics lab	N	Measuring Focal length of optics with eye safe laser.	23:51
21:51	Safety	Richard	LVEA	N	Helping Fil	22:10
23:26	FAC	Richard	LVEA	N	Checking on Fil	00:26

H1 SEI - Comment to End station HEPI Pump Station Trip from Power Glitch

patrick.thomas@ligo.org — Tue, 14 Jul 2026 16:28:18 -0700

Author: patrick.thomas@ligo.org

Report ID: 91032

I find it best to ramp it by slowly increasing the setpoint from 0 to 70 in auto mode: Set it to manual. Tweak the output slowly to 0. Set the setpoint to 0. Clear the integral term if there is one. Set it to auto. Slowly ramp the setpoint up to 70.

H1 SQZ - Comment to Determining the ROC for ZM4 and ZM5

sheila.dwyer@ligo.org — Tue, 14 Jul 2026 15:46:14 -0700

Author: sheila.dwyer@ligo.org

Report ID: 91013

Above, Eric found ROCs for each strain guage value that can predict our measured q's after ZM5 (90783) starting with the measured q before ZM4, where the predicted qs overlapped with the measured qs by more than 98%. We are aiming for sqz to OMC mode matching of better than 99%, so I wondered if we can get better agreement than this with our measurement technique. If we want to be able to set ROCs or distances based on these measurements, we want to know if they are repeatable and consistent with a model at a level better than the mode matching that we are trying to acheive. In O4 we had squeezer to OMC mode mismatch of 2.2%, we would like that to be less than 1%.

I take the q's measured after ZM5, propagate them back to before zm4 using the guesses for ROCs and the AOIs from the finesse .yml file, and calculates the overlap with the measured q before ZM4 for each. The sum off the mode mismatches is the cost function used to fit either vertical or horizontal ROCs. In this version of the script, it is fitting either the vertical or horizontal data, I would like in the future to have it include both in the cost function.

These plots (horizontal and vertical) show that this fitting results in overlap between the measured beam and the forward propagated beam using the fit ROCs is better that 99.5% for all the data. This is true when I use only the horizontal (vertical) data in the fit, and use those ROCs to propagate the vertical (horiztonal) mode. The worst overlaps are all for points measured where ZM5 strain guage was at -4.5V, which also had the worst values of M^2 (see top left panel).

Using these fit ROCs and the measured q before ZM4, we can propagate to the usual Sw plot on the AR side of SRM, using either vertical or horizontal data gives us an sw plot that looks a lot closer to the measured data than the guesses above. I think this means that we can use this kind of fit data to determine what ROC we need to move us to a particular place in Sw space in the future, at least at the level of 0.5% mode matching.

ZM4 (strain guage voltage)	2	4	6	8
ROC fit with vertical data[m]	-8.687	-7.699	-6.923	-6.280
ROC fit with horiztonal data [m]	-7.621	-6.886	-6.313	-5.798
ZM5 (strain guage voltage)	-4.5	-2	0	2
ROC fit with vertical data [m]	3.600	3.889	4.266	4.351
ROC fit with horizontal data [m]	3.544	3.852	4.190	4.273

The script to make these fots and plots can be found here

Images attached to this report

LHO VE - Purge air compressor monitoring system installed

travis.sadecki@ligo.org — Tue, 14 Jul 2026 15:28:00 -0700

Author: travis.sadecki@ligo.org

Report ID: 91030

Roger's Machinery installed the Enmet Matrix Air monitoring system on the purge air skid today. The air is sampled after the drying towers. The system is intended to monitor the air and alarm if breathable air conditions are not met.

Images attached to this report

H1 SUS - Comment to HAM7 status update - ZM5 (PSAMS) replaced, re-installed in chamber and is fully functional now.

rahul.kumar@ligo.org — Tue, 14 Jul 2026 15:00:48 -0700

Author: rahul.kumar@ligo.org

Report ID: 91029

We re-tested (see picture01 and picture02) the strain gauge readout for the PSAMS units after installing it in ZM5 and then placing it in HAM7 chamber, connected to the electronics chain of ZM5. Given below are the test results,

Voltage Calibrator Setting (Voltage)	PZT (Voltage)	Strain Gauge (Voltage)
+10	0.384	2.780
+9	103.5	2.966
+8	20.33	3.179
+7	30.30	3.408
+6	40.28	3.658
+5	50.25	3.910
+4	60.23	4.177
+3	70.2	4.453
+2	80.1	4.744
+1	90.1	5.090
0	100.1	5.350
-1	110.1	5.660
-2	120.0	5.965
-3	130.0	6.275
-4	140.0	6.591
-5	150	6.900
-6	159.9	7.210
-7	169.8	7.530
-8	179.8	7.850
-9	189.8	8.170
-10	194.0	8.320

SQZ, SUS

H1 ISC - Comparing BBSS and BSFM models for DRMI locking

elenna.capote@ligo.org — Tue, 14 Jul 2026 14:55:44 -0700

Author: elenna.capote@ligo.org

Report ID: 91028

Inventory of DRMI locking data in 87768. By eye (someone overwrote the data in the MICH xml since it was taken), the MICH UGF is roughly 15 Hz when we achieve DRMI 1f lock.

I used the BSFM model in /ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/TripleModel_Production (bsfmopt_metal) to generate a model of the MICH loop using the MICH control filters and BSFM locking filters. I applied a fudge factor to generate a loop with a 15 Hz UGF, which I then used to estimate the m/ct calibration required to generate a BBSS model, assuming we have the same optical gain when locking with the new beamsplitter. (suspension calibration table is G1100968). This model indicates that the MICH L M1/M2 crossover is 30 mHz, which agrees with the data in the table in Evan Hall's thesis, Table 2.4 page 33. See first attachment for BSFM model

Then, I generated a BBSS model in the same triple model directory using bbssopt. I applied the same beamsplitter locking filters and MICH control.

Overall, it shows us that if we use the same feedback design with M1/M2 control, we should end up with a MICH loop that is almost the same as the one we have now in DRMI 1f lock- 15 Hz UGF, 30 mHz crossover between M1 and M2. See second attachment for BBSS model

It also seems to me that it should be fairly straightforward to move the MICH length control from M2 to M3, although we will likely need to adjust the locking filters to achieve the same crossover frequency. See third attachment of the comparison of each stage sus transfer function to M3.

I have not been able to generate a model of the oplev damping that looks reasonable, so I will poke around the alog to see if I can figure out what the design is supposed to be.

Executive summary: we should have no problem locking DRMI with the current MICH and BS control scheme, and it shouldn't take that much effort to move BS feedback from M2 to M3 if we so choose.

SUS

Images attached to this report

H1 SUS - HAM7 status update - ZM5 (PSAMS) replaced, re-installed in chamber and is fully functional now.

rahul.kumar@ligo.org — Tue, 14 Jul 2026 14:51:49 -0700

Author: rahul.kumar@ligo.org

Report ID: 91027

R Crouch, R Kumar

SUS ZM5 has been re-installed in HAM7 chamber after replacing the faulty bottom mass PSAMS unit with a spare one sent by CIT.

The bottom wires were replaced and the entire was chain was re-balanced after suspending all stages. The PSAMS cable (with mighty mouse connector) was carefully laced around the cage and clamped at strategic position (so that it doesn't short with the cage). We then took a health check and the suspension looks healthy - see transfer function results in attachment01 and attachement02 (we see some slight shift in frequencies, especially P dof - however they can be easily damped with the current filters we have in place).

Attached below are many pictures showing ZM5 in chamber after the repair work was complete and suspension re-installed.

We also took pictures for reference after installing the wires and balancing it after suspending all stages - outside the chamber on the table.

Details of our repair work are listed in this checklist attached below.

SQZ, SUS

Images attached to this report

Non-image files attached to this report

allhxdss_2026-07-14_H1-ZM4_ZM5_ALL_TFs.pdf

allhxdss_2026-07-14_H1-ZM4_ZM5_ALL_ZOOMED_TFs.pdf

H1 CDS - Fixed h1susb2h34 20bit-DACs with kernel boot parameter pcie_bus_safe

david.barker@ligo.org — Tue, 14 Jul 2026 14:15:24 -0700

Author: david.barker@ligo.org

Report ID: 91026

Ibrahim, Ryan S, EJ, Erik, Jonathan, Dave:

We chose to fix h1susb2h34's 20bit-DAC issue with the boot parameter pci=pci_bus_safe rather than a BIOS MPS=128 change. We did however make the BIOS change to Enable PERR/SERR support.

1. Control room put BS, MC2, SR2, PR2 into safe. I bypassed the seismic SWWD for BSC2, HAM3,4

2. I powered down the AI chassis which is driven by the two 20bit-DACs. It is in rack SUS-C1 U24. From front, left side is DAC0, right side is DAC1.

3. I verified the IOP shows both 20bit-DACs in AI-WD mode. I turned on DAC-DUOTONE and verified no readback on ADC0-30 (safe to do so now the AI is powered down)

4. EJ configured h1vmboot5-5 to boot h1susb2h34 with pci=pcie_bus_safe and disabled the auto-start of the models.

5. We stopped the models, fenced from Dolphin and rebooted.

6. EJ caught the reboot, went into BIOS, Enabled PERR/SERR Support and reset.

7. After the reboot, we verified the Adnaco cards had MPS=128B and the Dolphin IX had MPS=256B.

8. We started the models. I enabled DAC-DUOTONE (AI still off) and now DAC0-7 is driving correctly.

9. EJ ran his DAC-FIFO-Check, both 20bit-DACs checked out.

10. We started the local_dc and cps_xmit to get DAQ data moving again.

11. I powered the AI chassis on. Unbypassed SWWD and handed system over to the control room.

We will leave this system in no-auto-start state from now until the upgrade at the end of this month.

Instructions to start the DAQ data after models have been started (as root):

mbuf_probe list # Check models are writing

systemctl start rts-local_dc

mbu_probe list # Check local_dc shows as last item

systemctl start rts-transport@cps_xmit

H1 PSL - PSL Cooling Water pH Test - Monthly

ryan.short@ligo.org — Tue, 14 Jul 2026 13:19:50 -0700

Author: ryan.short@ligo.org

Report ID: 91025

FAMIS 63880

I've been neglecting to check this for a while, but with today's chiller swap (alog91022), it seemed like a good time to check the pH. As expected, the pH of the PSL cooling water is right around 10 according to the color on the test strip.

H1 SEI - BSC 1-2-3 HEPI Unlocked

jim.warner@ligo.org — Tue, 14 Jul 2026 12:43:34 -0700

Author: jim.warner@ligo.org

Report ID: 91024

I've unlocked HEPI on BSCs 1-2-3. I haven't had a chance to look at the loop design for BSC2 yet, but B1&3 are both able to fully isolate. HEPI runs on all three chambers. Almost back to normal running.

H1 SEI - Comment to HAM3 Z loop instability from notch in loop gain cause by locked HEPI

jim.warner@ligo.org — Tue, 14 Jul 2026 12:41:20 -0700

Author: jim.warner@ligo.org

Report ID: 91023

Things were still kind of ringing even with the modified loop gain, so I asked Travis if he was done climbing around HAM3. He said the only thing was an annulus pump that could be accessed from the cover on the pier, so I've unlocked HEPI on HAM3. The ISI is much happier now. I haven't tried reverting the filter change yet, I will wait for a bit before changing anything, in case HAM3 HEPI needs locked and we need to try to run the ISI.

H1 PSL - Annual PSL Chiller Swap Complete (WP 13413)

jason.oberling@ligo.org — Tue, 14 Jul 2026 10:40:15 -0700

Author: jason.oberling@ligo.org

Report ID: 91022

J. Oberling, R. Short

With the PSL down for safety interlock work, Ryan and I have completed the annual PSL chiller swap. There were no issues with the swap, the backup chiller started right up and has been running for over 1 hour now. We let it run at a higher flow rate (~4.7 lpm) to push any accumulated air out of the line, and then returned it to our operating flow rate of ~2.8 lpm. While the system was down we also changed the system filter; there was some slight yellowing to the filter, but other than that it looked pretty good for being installed for ~15 months. We updated the chiller operating hours in the PSL control software to match the new chiller, 17004.0 hours at time of update. We will continue to monitor the chiller over the course of the day.

The SN of the now in-service PSL chiller is 119247. This closes LHO WP 13413.

H1 SEI - Comment to HAM3 Z loop instability from notch in loop gain cause by locked HEPI

jim.warner@ligo.org — Tue, 14 Jul 2026 09:46:15 -0700

Author: jim.warner@ligo.org

Report ID: 91021

The boost filter is a pair of poles at .2hz and normally a pair of zeros at 9 hz. I've moved the zeros down to 7hz, which has substantially increased the phase margin shown in the attach plot. Red is the current, modified loop. I will test if this is stable. The other vertical loops don't seem to be affected by this.

Images attached to this report

H1 SEI - HAM3 Z loop instability from notch in loop gain cause by locked HEPI

jim.warner@ligo.org — Tue, 14 Jul 2026 09:33:45 -0700

Author: jim.warner@ligo.org

Report ID: 91020

Jennie found that HAM3 ISI loops wouldn't turn on. This morning I have been looking at why the loops are unstable. I'm pretty sure that the locked HEPI on that chamber is creating a notch in the ISI plant at 15 hz, where the loop gains and phase margin are both pretty low. The easiest way to fix this would be to unlock HEPI, but I don't think vac is ready for that. I could also tweak the boost filter to get some phase margin back, but that will reduce the loop gain below 10hz. I think that's probably the best choice at this point.

Attached plot shows some open loop gain measurements I've done for this chamber. Red trace is the unboosted loop, the cursor is at 15 hz, which is where HAM3 was ringing up when Jennie tried to turn the ISI on. This notch is not visible in the green trace, which is the unboosted loop gain with HEPI unlocked.

Images attached to this report

H1 DAQ - WP 13402 work started h1daq*1 systems are down

jonathan.hanks@ligo.org — Tue, 14 Jul 2026 09:27:23 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91019

Started on WP13402. The 1 leg of the daqd system is down for upgrade. The control room workstations and FOM displays were pushed to using the h1daq0 nds last night.

H1 CDS - workstations updated

erik.vonreis@ligo.org — Tue, 14 Jul 2026 08:07:50 -0700

Author: erik.vonreis@ligo.org

Report ID: 91018

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

LHO General - OPS Day Shift Start

ibrahim.abouelfettouh@ligo.org — Tue, 14 Jul 2026 07:46:16 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91017

TITLE: 07/14 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: MAINTENANCE
Wind: 7mph Gusts, 4mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.05 μm/s
QUICK SUMMARY:

IFO is in IDLE for MAINTENANCE

Plans today are:

Continue pumpdown
PSL Access button work for CHETA and CRS
PSL Chiller swap for maintenance
CDS DAQ Work
Roger's machinery on-site for Kobelco work

We're also expecting some tours.

H1 OpsInfo - Comment to SPI laser unshuttered

jim.warner@ligo.org — Mon, 13 Jul 2026 20:32:28 -0700

Author: jim.warner@ligo.org

Report ID: 91016

I think this ring up could be due to HEPI being locked on that chamber. I think this happened after the last vent as well. Could be that just adding a notch to the cps low pass will let us isolate the ISI. I will need a little bit of time to do some measurements.

H1 SEI - End station HEPI Pump Station Trip from Power Glitch

anthony.sanchez@ligo.org — Mon, 13 Jul 2026 18:00:27 -0700

Author: anthony.sanchez@ligo.org

Report ID: 91015

Ryan And I drove to EX and TJ drove to EY.
Ryan and I turned off the HEPI VFD power supply then turned it Back on.
Then hit the reset button.
The Pump then Whirled back to life !!!
Then H1:HPI-PUMP_EX_PRESS_HIGH Flashed Bright red for less than a second and the Interlock turned red and and the Whirling sound died.
Welp that didn't work.

We then ensured the setpoint: H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_INPUT was set to 70.
Tried it again with H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_MODE set to manual. But we ramped H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_OUTPUT_TWEAK_REQ too fast(?) and H1:HPI-PUMP_EX_DIFF_PRESS_PSI went too high and the interlock tripped again.
...
Then we tried a bunch of attempts to manually increase H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_OUTPUT to the value [2.29 V] that holds H1:HPI-PUMP_EX_DIFF_PRESS_PSI at 70 and Every time it would shoot well past 70 and trip the interlock again.

We then opened up the control loop screen and noticed this integral term was set to 6. Which perhaps was too high.
So we hit the reset button.... H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_ITERM_RESET_REQ....
Thankfully that reset the Integral Term down to 0.....

We then tried again to turn it all back on manually, and keep the H1:HPI-PUMP_EX_DIFF_PRESS_PSI at 70 PSI. Once H1:HPI-PUMP_EX_DIFF_PRESS_PSI was stable at 70 PSI we then switched over to auto. Now this Tanks the Output voltage that we just set to 2.29 ..... all the way down to 0.0...... ok...... then back up..... ok..... then over shoots to the moon, Again Tripping the interlock and shutting it down..... again.
We tried using different H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_OUTPUT_TWEAK_SIZEs and otherwise tried to baby poor lil HEPI back into it's setpoints.... and it just wanted to FULL Send to the MOON!.

Then I had a weird thought... what if we set it too high? Will it go to 0? Will it go to negative Moon?! IDK but I wanted to find out.

Really what I truly wanted was for H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_ITERM to simply go to the 2.28 value that allows H1:HPI-PUMP_EX_RMT_PRESS_PUMP_CTRL_OUTPUT to be 2.28 Volts which keeps the Diff pressure H1:HPI-PUMP_EX_DIFF_PRESS_PSI @ 70 PSI. But for some reason I cannot change that value Integral Value at all. Or atleast I couldn't directly....

So this is what I did:
I set the output voltage a bit High.... such that the Differential pressure was just a lil too high. This is to convice the control loop to go down instead of Up.
I then reset the Integral Term so it starts at zero when we switch it from manual mode to auto mode.
Then I hit auto.... the Output voltage drops to 0 and comes back up.... but.... this time I'm ready! ..... I'm waiting to switch it back to Manual mode Right AFTER the output votage PASSES the output voltage that I want . This has now set both the Differential pressure, Output voltage, AND the Integral Value ABOVE my desired destination. I let it settle a little high. THEN I clicked Auto again, which finally allowed the control loop to stablize at 70 PSI.
We were on the phone with TJ at EY and that worked for EY as well.
Then we watched it for a bit and drove back to the corner station.
Shoutout to Ryan S. and TJ for showing me the ropes and pointing things out that that helped me jump to my conclusions.

TLDR: The Control loop overshoots when approaching from below. Approach it from above. It works for both End stations. ¯\_(ツ)_/¯

Images attached to this report

H1 SPI - Mean LP filter for heterodyne meas seems fine

jennifer.wright@ligo.org — Mon, 13 Jul 2026 17:28:38 -0700

Author: jennifer.wright@ligo.org

Report ID: 91014

Item 1 on our commissioning for SPI is to figure out why we are not getting the same results for heterodyne efficiency in CDS as we did with an oscilloscope chamber side.

To evaluate the heterodyne measurement made by the measurement and reference interferometers we use the efficiency measurement of Vpp/(2*V_mean).

Ths is calculated by low passing the demodulated signal from each ifo in CDS and then multiplying by 2, befre dividing the demodulated signal by this mean. Shown in this photo here in the spi medm screens.

Jeff's firwst suspect was the low pass filter we use to get the mean demod signal.

The attached picture shows the raw demod signal on the left and the mean signal on the right. The mean for both looks roughly correct.

Jeff has put in a 4th order butterworth at 10Hz, see LHO alog #90638.

SUS

Images attached to this report

LHO General - Comment to OPS Day Shift Summary

oli.patane@ligo.org — Mon, 13 Jul 2026 17:14:21 -0700

Author: oli.patane@ligo.org

Report ID: 91012

Power glitch at 22:31 UTC, tripping the HEPI pump controller and both ISI stages of ETMX and ETMY. Tony, RyanS, and TJ went down to the end stations and turned the pump controllers back on. Then I was able to bring HEPI and the ISIs back up.

Extra reservation system entries:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
22:44	SEI	RyanS, Tony	EX	n	Restarting HEPI controllers	23:48
22:49	SEI	TJ	EY	n	Restarting HEPI controllers	23:48
23:16	PEM	Carlos, Miranda, Shrey	LVEA	n	Seismometer work (Miranda back 23:37)	00:00

LHO VE - Corner station pumpdown paused for the night

travis.sadecki@ligo.org — Mon, 13 Jul 2026 17:10:53 -0700

Author: travis.sadecki@ligo.org

Report ID: 91011

The roughing scroll pumps were valved out and shut down for overnight. Pressure in the corner was ~2 Torr at the break.

H1 TCS - Final Checks for CHETA laser Y-arm 0918

camilla.compton@ligo.org — Mon, 13 Jul 2026 17:05:45 -0700

Author: camilla.compton@ligo.org

Report ID: 91009

Dr Todd, Camilla

Polarizers

We put the S405C power meter after Polarizer1 and Matt adjusted the polarizer to maximize the power through. We then put the power meter after PowerMeterPickOff and adjusted Polarizer2 to maximize the power at the Waveplate setting for max power. Max power measured was 1.45W. Minimum power using waveplate ~30mW.

Thermal PD

Matt zero'ed this diode and we used the S405C power meter to calibrate is to the power being injected after PowerMeterPickoff.

Final Checked on Fast PDs

We changed this to -2000ohm so the fast PDs report positive power.

Checked beam was centered on both PDS by using PDPickoff and PDBeamsplitter. There isn't much flat plateau on these, meaning the beam is still larger than ideal on these diodes. Matt then adjusted Waveplate2 to get PDA and PDB powers equal. Using the S405C power meter, we measured 4.3mW before PD Lens. Adjusted Responsivity from 1.42 to 1.53 and splitter to 50% to show this.

Beam Dumps

Double checked the beam was dumped after Polarizer 2 and the flipper.

Power control

Matt filled in the calibration screen for power control. We still plan to edit and run Ryan Short's calibration script.

Iris

Checked the beam was centered on the iris between M4 and M5.

For sdfs see attached and 90992

Images attached to this report

H1 DAQ - WP 13402 prep work, switches, fibers, and nds redirection

jonathan.hanks@ligo.org — Mon, 13 Jul 2026 17:00:41 -0700

Author: jonathan.hanks@ligo.org

Report ID: 91010

Dave, Tony, and Jonathan

Supporting WP 13402 we did some prep work.

* Reviewed the work plan.

* Added the new daqd switches to the DNS as sw-msr-daqd[0,1,2].

* Configured sw-msr-daqd0 and moved it to its final position.

* Reviewed the inventory of fiber, nics, and optics.

* Put a hostname override into puppet the workstations and display machines to point them towards h1daqnds0 so that tomorrow we can take h1daqnds1 down.

H1 SUS - Comment to HAM7 ZM5 (PSAMS) repair work status update - Inspection and in-chamber testing of replacement PSAMS (s/n 03) received from CIT.

rahul.kumar@ligo.org — Mon, 13 Jul 2026 16:38:38 -0700

Author: rahul.kumar@ligo.org

Report ID: 91007

reference - E2100371-v1 (Testing Procedure for PSAMS Strain Gauge Readout)

H1 SUS - HAM7 ZM5 (PSAMS) repair update - suspension taken out of chamber for PSAMS replacement work.

rahul.kumar@ligo.org — Mon, 13 Jul 2026 16:36:57 -0700

Author: rahul.kumar@ligo.org

Report ID: 91006

R Crouch, R Kumar

This morning we took out ZM5 suspension from HAM7 chamber for replacing the broken PSAMS unit. Before removing ZM5 we marked the current position of it on the ISI table using a machinist square - see picture attached for reference.

We then placed ZM5 on the table near the chamber and carefully removed the bottom PSAMS units (after removing the mighty mouse cable) - see reference picture.

The replacement PSAMS shipped to us from CIT and tested at LHO (see alog 91005) was then prepared for installation into ZM5 cage - see two pictures for reference.

Tomorrow (Tuesday), our plan is to insert the wires and suspend the entire chain, balance it before moving it back into HAM7.

SQZ, SUS

Images attached to this report

H1 SUS - HAM7 ZM5 (PSAMS) repair work status update - Inspection and in-chamber testing of replacement PSAMS (s/n 03) received from CIT.

rahul.kumar@ligo.org — Mon, 13 Jul 2026 16:18:44 -0700

Author: rahul.kumar@ligo.org

Report ID: 91005

R Crouch, R Kumar

CIT (Camille Makarem) shipped us a spare ZM5 PSAMS (s/n 03 with 72 in-lbs pre-load on the mirror for ROC 4.35m) for replacing the broken (strain gauge) PSAMS unit currently installed on ZM5 suspension in HAM7 chamber. We took the new unit out of the shipping container - see attachment01 , attachment02 and attachment03 for reference.

We inspected the optic housing and optic and found no issues with it, posting two pictures for reference - attachment04 and attachment05.

This new unit was then plugged into the electronics chain of ZM5 PSAMS in HAM7 chamber (the suspension was pulled out of chamber and kept on a bench outside HAM7) - see attachment07 and attachment08 for reference.

At first we checked the strain gauge resistance and the results are as follows,

Pin 12 & 24 = 708 Ohms (looks good)

Pin 11 & 24 = 355.9 Ohms (looks good)

Next we varied the PZT voltage from 0 - 200V and measured the Strain Gauge (SG) voltage and the results are posted in the table below,

Voltage Calibrator Setting (Voltage)	PZT (Voltage)	Strain Gauge (Voltage)
+10	0.5	2.642
+9	10.35	2.905
+8	20.32	3.095
+7	30.29	3.32
+6	40.27	3.60
+5	50.24	3.90
+4	60.72	4.08
+3	70.2	4.38
+2	80.1	4.65
+1	90.1	4.94
0	100.1	5.32
-1	110	6.32
-2	120	6.50
-3	130	6.69
-4	140	6.90
-5	149.8	7.11
-6	159.8	7.35
-7	169.7	7.58
-8	179.7	8.02
-9	189.6	8.17
-10	194.9	8.35

The above test tells us the this replacement unit is healthy and can be installed in ZM5 suspension for HAM7 work.

SQZ, SUS

Images attached to this report

H1 SUS - Replacing/inventorying beamsplitter notches and bandstops

elenna.capote@ligo.org — Mon, 13 Jul 2026 15:58:54 -0700

Author: elenna.capote@ligo.org

Report ID: 91000

In preparation for locking with the new BBSS, I have taken an inventory of the beamsplitter filters to note where various notches and bandstops are located by suspension stage.

As a reminder, Oli copied over much of the BSFM filters into the BBSS model, 90154.

M1: none as far as I can tell

M2:

M2 LOCK L: Violin modes, butterfly mode
- need to be measured and replaced, can wait until IFO lock
M2 LOCK P and Y: FM5 BS bounce/roll, FM7 QUAD bounce/roll
M2 OLDAMP P: FM5 BS bounce/roll, FM6 20 Hz bandstop
- what is this 20 Hz bandstop for? can we turn it off?
M2 OLDAMP Y: FM5 BS bounce/roll

M3:

M3 LOCK P and Y: FM6 28.45 Hz notch
- tracked down to alog 43968
- can we turn this off?

Ibrahim and Oli have measured the BBSS bounce and roll modes to be at 19.80 Hz and 32.09 Hz respectively, 90319.

I'm replacing the bounce and roll bandstops on M2 LOCK and OLDAMP to be centered around these frequencies.

Old foton design string for "NotBR_BS":

ellip("BandStop",4,1.5,40,17.7,17.9)ellip("BandStop",4,3,40,25.7,26.4)gain(1.6788)

New foton design string for "NotBR_BBS":

ellip("BandStop",4,1.5,40,19.7,19.9)ellip("BandStop",4,3,40,32,32.2)gain(1.6788)

As a final note, I'm not sure how necessary the BR bandstops are if we have dampers, so we could consider not having any on at all.

ISC, SUS

LHO General - OPS Day Shift Summary

ibrahim.abouelfettouh@ligo.org — Mon, 13 Jul 2026 15:03:07 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91002

TITLE: 07/13 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

IFO is in IDLE for MAINTENANCE

Productive day in which:

Corner pumpdown continued
- HAM6 vacuum sensor PT110 - detected an increase/bounce of pressure. I informed Travis and VAC is looking into it. Screenshot is attached.
HAM1 pumpdown started
The LVEA is now in OPERATIONS SAFE, meaning all viewports and "holes" were confirmed affixed and closed. The lightpipe and lasers have not been turned on. Alog 90994
Marc finished modification to the QOSEM whitening chassis and BBSS controls look healthy.
DM10 Dust has been sitting at ~6800 counts for 1 hr (threshold is 300). Richard went out to investigate. A screenshot is attached in which the actual counts are on the left and the thresholds are on the right.
HAM7 ZM5 work is ongoing.
Biergarten PEM work on seismometers is ongoing.

Oli is taking over the remainder of this shift and will add comments if relevant.

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:57	VAC	Jordan	LVEA	N	Continuing Pumpdown	14:52
14:52	FAC	Kim	LVEA	N	Technical Cleaning	15:55
15:52	TCS	Matt	CHETA Lab	Local	Aligning	16:27
16:14	FAC	Kim	LVEA	N	Technical Cleaning	17:04
16:25	TCS	Camilla	CHETA Lab	Local	Aligning	16:27
16:29	SEI	Shrey, Carlos, Miranda	LVEA	N	Seismometer Checks	17:54
16:36	SUS	Rahul	LVEA	N	ZM5 Work HAM7	18:29
16:39	SUS	Ryan C	LVEA	N	ZM5 Work HAM7	18:24
16:57	EE	Fil	LVEA	N	HAM4 TCS Rack	18:29
17:12	OPS	Ryan S	LVEA	N	Laser Transition to Operations Safe	17:58
17:16	VAC	Travis	Ey	N	Parts	17:58
17:37	SUS	Mitchell	EX/EY	N	FAMIS Task	18:19
17:40	FAC	Kim	LVEA	n	Grabbing garb	17:52
17:53	FAC	Kim	EX	n	Tech clean	18:21
17:53	EE	Marc	LVEA	N	Whitening chassis change	18:45
18:01	VAC	Travis	LVEA	n	Troubleshooting pumps	18:29
18:06	TCS	Matt	Prep Lab	y(local)	CHETA work	19:23
18:07	SPI	Jennie	LVEA	n	Unshuttering SPI laser	18:10
18:16		Madi	OpticsLab	n	Grabbing laptop	18:22
18:23	VAC	Gerardo	LVEA	n	Troubleshooting pump	18:29
18:24		RyanC	LVEA	n	Grabbing phone	18:27
19:10	FAC	Camilla, Tyler	LVEA	N	Scaffolding tagging + camera cans -tyler out 19:16utc	19:21
19:50	EE	Fil	MSR	N	Cabling	21:47
20:15	VAC	Gerardo	LVEA	N	HAM1 Pump	22:15
20:16	SUS	Ryan C	LVEA	N	ZM5 Work HAM7	22:16
20:20	VAC	Travis	LVEA	N	HAM1 Pump	22:10
20:21	FAC	Christina	Optics, LVEA, MSR	N	Label Photos	21:32
20:30	PEM	Shrey, Carlos, Miranda	LVEA	n	Seismometers	22:30
20:36	SUS	Rahul	LVEA	N	ZM5 Work	22:36
20:58	FAC	Richard	LVEA	N	Checking on DM10	21:10
21:14	EE	Marc	LVEA	n	Reinstalling BBSS M1 satamp	21:31
21:47	SUS	Betsy	LVEA	N	HAM1 Pump	22:47

Images attached to this report

H1 OpsInfo - Comment to SPI laser unshuttered

arnaud.pele@ligo.org — Mon, 13 Jul 2026 14:59:51 -0700

Author: arnaud.pele@ligo.org

Report ID: 91004

The RY blend filter was still set to the CRS damping path BLND7, so I changed it back to the nominal BLND4 path. Even after this change, the ISI was still ringing up.

Looks like the it's the Z loop that is unstable at 14.74Hz (see pictures). Having a good plant measurement will help retune the loop to avoid this ring up. If HAM3 needs to be isolated before then, the Z loop can be ran without the boost filter, which seem to be triggering the instability.

Images attached to this report

H1 SUS - BBSS QOSEM Sat Amp Whitening Modifications Installed

marc.pirello@ligo.org — Mon, 13 Jul 2026 14:53:55 -0700

Author: marc.pirello@ligo.org

Report ID: 91003

WP13410

Replaced multiple signal path resistors to reduce gain and adjust the filter to match work done at Caltech linked here.

H1 OpsInfo - Comment to SPI laser unshuttered

jennifer.wright@ligo.org — Mon, 13 Jul 2026 14:15:58 -0700

Author: jennifer.wright@ligo.org

Report ID: 91001

Here is the plot for the GS13s on HAM3 as it tripped.

Images attached to this report

H1 OpsInfo - Comment to SPI laser unshuttered

jennifer.wright@ligo.org — Mon, 13 Jul 2026 12:47:58 -0700

Author: jennifer.wright@ligo.org

Report ID: 90999

This caused HAM 3 tp trip so both ISIs have been taken to DAMPED.

Right ndscope is the QPD on HAM3, you can see the alignment changed massively when it tripped and then went back after both ISIs were taken to DAMPED.

Left ndscope shows the HAM2 QPD which doesn't have a big change between damped -> isolated -> damped.

Images attached to this report

H1 OpsInfo - Comment to SPI laser unshuttered

jennifer.wright@ligo.org — Mon, 13 Jul 2026 12:26:03 -0700

Author: jennifer.wright@ligo.org

Report ID: 90998

After consulting with Jim I set the guardian to take HAM2 and 3 to isolated at 19:23 UTC. They had been damped so this will change the HAM2-3 relative alignment a bit.

SEI, SPI

H1 SEI - Comment to Comparing HAM1 ISI motion to HAM1 Passive stack TT L4Cs

jennifer.wright@ligo.org — Mon, 13 Jul 2026 11:39:23 -0700

Author: jennifer.wright@ligo.org

Report ID: 90996

Jim redid this measurement with data from 28/08/25 in order to get a good comparison for the Sep 2025 LVK. Posting here for continuity.

The old data was taken on 2025-03-30 at 22:57:46 UTC with 10 averages and a BW of 0.0468748 Hz.

The data post installing the ISI on HAM1 was taken on 2025-08-28 at 08:22:38 UTC with 10 averages and a BW of 0.0468748 Hz.

Non-image files attached to this report

HAM1_isolation2025-09-08.pdf

H1 OpsInfo - SPI laser unshuttered

jennifer.wright@ligo.org — Mon, 13 Jul 2026 11:20:34 -0700

Author: jennifer.wright@ligo.org

Report ID: 90995

Jennie W

As per work permit #13412 the SPI laser has been unshuttered using the shutter controller on the floor behind the R4 electronics racks.

This is to monitor SPI alignment as the pumpdown continues and uses powers below 100 mW.

See photo showing the demodulated signals for the Rreference and Measurement SPI interferometers after the laser was unshuttered at 18:08:11 UTC.

SPI

Images attached to this report

H1 TCS - CHETA PDs

camilla.compton@ligo.org — Mon, 13 Jul 2026 11:18:30 -0700

Author: camilla.compton@ligo.org

Report ID: 90992

Matt, Camilla

We updated H1:AWC-ITMX_PD_{A,B}_TRANSIMPEDANCE and H1:AWC-ITMX_PD_{A,B}_RESPONSIVITY as per D2500105, as attached.

Images attached to this report

H1 General - LVEA is Operations Phase Laser SAFE

ryan.short@ligo.org — Mon, 13 Jul 2026 10:51:12 -0700

Author: ryan.short@ligo.org

Report ID: 90994

Per WP13409, I've transitioned the LVEA to Operations Phase Laser SAFE according to M1100115, meaning all viewports, tables, and bellows have been checked that they're closed and beams are allowed back into the vacuum envelope. However, as the corner volume is pumping down and HAM1 is still at-air, I did not unlock/open light pipes or turn back on auxiliary lasers (CO2, HWS, etc.).

H1 SQZ - Comment to SQZ beam profiles with different centering on ZM2, ZM4 strain guage wheatstone bridge adjusted, periscope adjusted

daniel.sigg@ligo.org — Mon, 13 Jul 2026 10:50:52 -0700

Author: daniel.sigg@ligo.org

Report ID: 90993

The little box attached to the PSAMS driver for ZM4 had a 88.6K and a 751 Ohm resistor in series between pins 11 and 24 (sstrain gauge readout and ground). This was replaced by a 227K resistor to better balance the bridge circuit.

H1 SEI - HEPI Corner Station Pressure Dipped, Spiked and Recovered Again

ibrahim.abouelfettouh@ligo.org — Mon, 13 Jul 2026 07:45:48 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90991

Over the weekend, there was another HEPI corner station dip/spike which prompted the verbal alarm notification. This last happend on Friday (alog 90984)

This time, the PS2_PRESS1 (red in attached plot) dipped by 10PSI before recovering. The bottom row of the plot are the controllers. Tagging SEI.

SEI

Images attached to this report

LHO General - OPS Day Shift Start

ibrahim.abouelfettouh@ligo.org — Mon, 13 Jul 2026 07:38:14 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90990

TITLE: 07/13 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: MAINTENANCE
Wind: 5mph Gusts, 1mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.06 μm/s
QUICK SUMMARY:

IFO is in IDLE for MAINTENANCE

Plan today is to continue pumpdown. Other tasks:

BBSS QOSEM whitening chassis work
BBSS P to Y decoupling matrix work
EE recabing around ICST1/IOT2L/TCSX/TSCY