aLIGO LHO Logbook

H1 SPI - 2026-06-03 SPI Pathfinder Update: Packed up and ready for Launch

jeffrey.kissel@ligo.org — Fri, 05 Jun 2026 11:39:52 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90506

J. Kissel (Belated aLOG) After the great success on Tuesday 2026-06-02 solving the mystery with the MEAS IFO's efficiency drift (LHO:90455), we declared victory and spent the morning packing up all of the clean assembly to be ready for install. We - Weighed the mass of what components will be suspended on Stage 1 of the HAM3 ISI (see LHO:90504) - Packed up the optical fiber feedthrus (see Attached Pic #1) - Packed up the ISIK Transceiver and its in-vac cabling on a roll-able clean cart quadruple wrapped in foil (see Attached Pic #1) - Packed up the two D25 to D25 pico-motor and PD cables that span from Cable-Table-Bracket #3 to the HAM3-D6 feedthrough. - Powered down, disconnected, and packed up . the laser prep chassis (see bottom of Attached Pic #3) . the transimpedance amplifiers (no pic) . the commercial RF source Keysight 33600A (no pic). . all in-air cabling, including mock-feedthrough The fiber-coupled NPRO is still set up, but the laser is shuttered and key'ed off. Thank you optics lab, and good luck trail-blazing to you, SPI pathfinder!

Images attached to this report

H1 SPI - SPI Pathfinder Mass Budget

jeffrey.kissel@ligo.org — Fri, 05 Jun 2026 10:57:37 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90504

J. Kissel, S. Koehlenbeck Here's the mass of the SPI pathfinder's ISIK transceiver that will be suspended on HAM3. 10.958 [kg] :: Fully assembled ISIK Transceiver (D2400107) - no installation handles - no baffle bracketry - sensor/actuator cabling draped to the side 0.898 [kg] :: Fully assembled portion of in-vac cabling that will be suspended on Stage 1 of HAM3 ISI - includes cable table brackets - excludes QTY 2x D25 to D25 signal bus cables that span ST1 to ST0 to Feedthru. 0.703 [kg] :: Fully assembled portion of in-vac fiber optic cabling that will be suspended on Stage 1 of HAM3 ISI - 0.570 [kg] :: QTY 2x will be suspended so expect 2x0.285 = 0.570 [kg] . 0.285 [kg] :: QTY 1x Fiber spool (what was actually measured, rather than two) . Most of the optical fiber, plus wont-be-there fiber mating sleeve and cap - 0.133 [kg] :: QTY 2x Fiber spool assembly feet and installation hardware: 12.599 [kg] :: Total suspended mass. All this mass will be on the -X side wall of the ISI, below the optical table, as shown in D2400103. We have not measured the mass of any component of the ISIK shroud assembly D2400106.SEI

Images attached to this report

H1 AOS - Comment to HAM2 ISI Table Baffles and Bracket Serial Number Invetory

jeffrey.kissel@ligo.org — Fri, 05 Jun 2026 10:39:33 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90503

The middle, center baffle assembly was installed/updated on 2026-05-26; LHO:90335

H1 AOS - Comment to HAM2 Beard Baffle for SPI Placed and B&K'd on Friday

jeffrey.kissel@ligo.org — Fri, 05 Jun 2026 10:38:40 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90502

Serial numbers for these baffle assemblies can be found in LHO:90501.

H1 AOS - HAM2 ISI Table Baffles and Bracket Serial Number Inventory

jeffrey.kissel@ligo.org — Fri, 05 Jun 2026 10:37:20 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90501

J. Kissel, T. Shaffer, M. Robinson While in HAM2 doing BnK hammering (LHO:90493), Mitch asked us to note the serial numbers of all parts of HAM2 ISI Table Baffle Assembly (D1700335). Location Drawing Serial Number +Y Assembly Baffle D1700263-v1 004 +Y Bracket D1700264-v2 020 -Y Bracket D1700264-v2 014 Middle Assembly Baffle D2600042-v1 001 +Y Bracket D1700264-v2 013 -Y Bracket D1700264-v2 015 -Y Assembly Baffle D1700263-v1 006 +Y Bracket D1700264-v2 022 -Y Bracket D1700264-v2 017 Happy ICS'ing! (Will post picture proof in due time.)SEI, SPI

H1 AOS - SPI, RF Install Pt 4, Full Rack Install

joshua.freed@ligo.org — Fri, 05 Jun 2026 10:12:32 -0700

Author: joshua.freed@ligo.org

Report ID: 90500

J. Freed, S. Koehlenbeck, J. Kissel,

(Belated post)

Wednesday we continued from 90352, We installed the full rack for SPI in SUS R2 and wired everything up! (Pictures will be added as a comment). As well as, hooked up to all the required power supplies.

The RF power measurement going out from the 2W amp to the SPI prep was measured to be 31.6 dBm for both outputs of the 2W amp (after the amp warmed up).

This was measured by using the on site power mon w/ small power probe (Exact make and model will be added later). The site has a large power probe (the HP 8484A) but from 89523 it was found to have some strange nonlinearities. As such, the small probe was prefered for this test. Since the probe only has a 20dBm max power limit, 2x 10dBm attenuators (UNAT-10a) were used to lower the power to be able to be measured. Of course the UNATs have a 33dBm limit so special care was used to make sure that limit was not reached. This set up was calibrated by using a 0dBm signal which the probe measured as 0.1dBm. attaching the 2 attenuators the same signal read -20.0dBm (a 20.1dB difference). Then I measured the 2 ports which read 11.8dBm for the Meas output and 11.7dBm for the Ref output. Once the amp warmed up (~20 minutes of waiting with it on) these values both fell to 11.5dBm. Adding back that 20.1dB, this leaves both port with the expected output of 31.6dBm. With an error of +/-0.1dBm.

This value is 0.4dBm lower than the optics lab measurement with the larger probe but is a more precise measurement with less error.

H1 SPI - Comment to 2026-05-26 thru 2026-05-29 SPI Pathfinder Update

brian.lantz@ligo.org — Fri, 05 Jun 2026 08:52:14 -0700

Author: brian.lantz@ligo.org

Report ID: 90498

Fixed! see alog 90455

several things fixed, esp NPRO

LHO General - Fri Ops Day Transition

corey.gray@ligo.org — Fri, 05 Jun 2026 07:39:18 -0700

Author: corey.gray@ligo.org

Report ID: 90496

TITLE: 06/05 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 6mph Gusts, 3mph 3min avg
Primary useism: 0.05 μm/s
Secondary useism: 0.14 μm/s
QUICK SUMMARY:

ISS alignment final steps, BSC in-chamber of activities at BSC1+2, HAM3 SPI, viewport inspection are among activies on the docket today.

H1 SEI - CRS progress June 4 - 1 CRS balanced and x2 HOQIs tested

arnaud.pele@ligo.org — Fri, 05 Jun 2026 00:32:36 -0700

Author: arnaud.pele@ligo.org

Report ID: 90495

Alexandra, Shoshana, Arnaud, Fil, Dean (remote)

Today we completed the balancing of the CRS with a period of 61s (or 16.4mHz, which is our target frequency), aligned and tuned the HOQIs (with >75% fringe visibility) and connecterized the picomotor to the mighty mouse connector. Tomorrow, after verifying the balancing and alignments have not changed, we will mount the HOQIs to the CRS, which will complete this first assembly.

In detail :

Alexandra fixed the miswiring of the monitor signals on the HOQI board which allows us to connect those outputs directly to the oscilloscope
Fil wired a 18V power cable to the interlock so it can be used for the laser driver. This allowed the transition of the H2-PSL to laser hazard.
Shoshana rebalanced the CRS to achieved the target frequency of 61s. picture 1 shows the vertical mass arrangement : x2 8-32x3/8 on the back side, and x2 8-32x3/8 on the front siide +2 washers. picture 2 shows the measured resonant frequency.
After deciding to use the SPI spare pico channel, the picomotor was connecteriized to the might mouse connector via an extension cable (red (+) wire to pin 1, and white (-) wire to pin 2). Thanks to Jeff for offering the components and tooling. (picture 3)
x2 HOQIs (x1 Left and x1 Right versions) were setup on the optical table with a fixed target to align the various components. We tested with the laser driver knob at 6.3 and an output monitor voltage of 9.3V, which corresponds to ~20mW of laser power. We achieved the following fringe visibility:
- HOQI Left : PD1: 91%, PD2: 88%, PD3: 86% (Picture 4)
- HOQI Right: PD1: 86%, PD2: 78%, PD3: 83% (Picture 6)
The alignment was done as follow :
- Rotate the Fiber Coupler to maximize the power out of the first PBS (in the hoqi)
- Align the Fiber Coupler in Yaw to center the beam on the 3 PDs
- Align the HOQI baseplate to the target so the retro beam is centered on the 3 PDs - at this point we should see fringing when tapping on the table.
- Continue aligning to the target to maximize fringe amplitude
- Optimize the Lissajou figure with the 2 waveplates (see video for Lissajou figure)

Note1: We did break a set of flexures during balancing today (SN 18 and 11)
Note2: We could not get good fringe visibility on a 3rd HOQI (max 60%) we tested. We will have to get back to this one.
Note3: The Right HOQI has a PD wire that seem to have been pinched during assembly (see last photo). This doesn't seem to be an issue, we will just have to be careful when routing that it doesn't touch the baseplate.

Images attached to this report

Non-image files attached to this report

PXL_20260605_023036244LS.mp4

H1 ISC - Wednesday HAM1/2/3 alignment (Disha, Rahul, Keita)

keita.kawabe@ligo.org — Fri, 05 Jun 2026 00:32:22 -0700

Author: keita.kawabe@ligo.org

Report ID: 90464

Belated, as usual.

Things make more sense, no railing of RM2

We continued HAM2/3/1 alignment. Things are making more sense now after realizing that RM1 and RM2 slider polarity was wrong but we're still finding things.

1st attempt: We rotated IM1 to relieve RM2 YAW (IM1 y -987->-687 i.e. +300 from Tuesday value), aligned PRM so the beam retroreflects (but didn't touch up other IMs in the interest of time). After some confusion it worked and we were able to center REFL ASC sensors without railing RM2. Happy. (See ASCREFL_centered_RMs_dont_rail.png. If you do the math using flash peaks, REFL_A PIT=0.034, YAW=0.013, REFL_B PIT=-0.0097, YAW= -0.017, so it was very good.)

2nd attempt: Encouraged, we proceeded to center the beam on the IFI output baffle using IM2, steer the beam to the nominal beam position in front of PRM using IM3, steer the beam to the nominal position in front of PR2 using IM4 (which moves the beam position on PRM by a small amount but we didn't bother to iterate), and finally aligned the PRM so the retroreflection is restored. We were able to center REFL ASC sensors without railing RM2. Happy again. (eod.png, REFL_A P= 0.034, Y=-0.009, REFL_B P=-0.023, Y=-0.022.)

We looked at the beam position on IFO REFL baffle and it was off in YAW, so we changed the baffle position slightly in +Y direction.

Large difference in RM2 DAC output for two attempts, 80% or DAC range used in the 2nd attempt

We didn't change IM1-IM2 line, which means that the alignment into HAM1 should not have changed assuming that the PRM was retroreflecting, but the YAW offset necessary for RM2 to center the ASC sensors in the 1st and 2nd attempt were very much different.

all numbers are in urad

1st attempt

(PRM P, Y = -1165, 320)

2nd attempt

(PRM P, Y= -1165, -300)

2nd [P,Y] - 1st [P,Y]

RM1 [P, Y]

[-243, -45.3]

[-257, -114]

[-14, -68.7]

RM2 [P, Y]

[930, -989]

[950, -1489]

[20, -500]

In the 2nd attempt, RM2 Y offset changed by negative 500urad and the DAC output of two of the RM2 coils reached ~107 million, which is about 80% of the DAC range. That's closer than I'd be comfortable with before closing down the chamber.

That's consistent with the retroreflection error

It turns out that this is consistent with our retroreflection accuracy which I claimed to be "like +-50urad" in PRM rotation (not the beam rotation) in alog 90451.

Equivalent of positive PRM rotation of 50urad in YAW is replicated by the combination of physical negative 55urad for RM1 and physical negative 380urad for RM2 (note that the sliders for RMs as of now has the opposite sign as the physical rotation).

If retroreflection is off in terms of PRM YAW rotation by +-50urad, when the REFL ASC sensors are centered, RM2 YAW would be off by +-380urad from what would be required to center the beam that is truly retroreflecting. See attached script. 500urad difference between two attempts is consistent with that.

On top of that, it's possible that +-50urad error estimate is too optimistic. We set the PRM angle by centering an iris (placed between IFI input and IFI HWP) to the forward going beam and centering the back propagating beam on the back of the iris. The basis for the accuracy is that we could start seeing how the circumference of the back of the iris is unevenly illuminated by the back-propagating beam when we gave the PRM 50urad offset, but the beam is always moving in YAW and sometimes rather slowly, so we have to eyeball the average beam position.

We don't know if the 2nd attempt was closer to the true retroreflection or, for that matter, if the true retroreflection is "on the other side of" the 2nd attempt relative to the 1st.

As such, it's prudent to relieve RM2 YAW offset further.

Tomorrow

Relieve RM2 further by giving IM1 a positive 300urad YAW rotation. IM2, IM3, IM4 and PRM should be readjusted accordingly.

IM1 YAW offset hasn't changed much in the past 2 years except for this week, and we'll go back to that neighborhood. Even though this means that the beam on IFI input baffle will be off-centered (probably it's been like that for years), I'm absolutely sure that the forward-going beam won't be clipped, I'm also quite sure that the clipping-like thing of the IFO REFL beam on the IFI input baffle won't come back as far as PRM is retro-reflecting.

We might have to move the IFO refl baffle again.

We WILL move the IM4 baffle because whenever the beam is aligned to the nominal position in front of PRM the beam is too close to the +X edge of the baffle.

INS, IOO, ISC

Images attached to this report

Non-image files attached to this report

PRM_rotation.m

H1 SYS - BSC2 ISI SUS Cartridge Install Flight today

betsy.weaver@ligo.org — Thu, 04 Jun 2026 20:07:24 -0700

Author: betsy.weaver@ligo.org

Report ID: 90494

(Betsy, Randy, Jim, Tyler, Travis, Jordan, Gerardo, Mitchell, Corey, Ibrahim, Danny on watch)

Ibrahim and crew prepped the BBSS yesterday for flight.

This morning Jim and I finished cable routing and stowing and made some final pre-flight preps.

This afternoon, we successfully flew the BSC2 Cartridge from the West Bay Test Stand to the BSC2 chamber and installed in onto the support tubes via the dome.

We had a pre-flight meeting just before lunch, then met at 1pm to gear up and start.
Moved the West Bay cleanroom South to allow for cartridge lift off. Cartridge was covered via the multiple C3 cover layers (ISI cover+BBSS cover+Cartridge mega cover top to bottom over the whole thing which then was rolled up as the cartridge lowered into the chamber.
The cartridge was lifted off the test stand, checked for good level but no adjustment to rebalance the lifting fixture was needed - the setting used previously was good. Yay.
With the load cell, the cartridge weighed 9430lbs (pretty spot on for what it weighed at de-install flight as a BSFM). It was then set back down, load cell removed and flown the pre-planned path East over the X-Arm Beamtube manifold section and around diagonally onto BSC2. (Stays still not included, nor the HRTS for BHD, nor the HR/AR BBSS baffles, nor 1 of 4 vibration absorbers - basically the same ish payload as before with the BSFM weighing not much more than the BBSS plus or minus some bits at flight)
The hand rails with the notch worked well (switched in by Randy earlier this week) - no handrail sections needed removal as the cartridge passed right over this time. During the BSC chamber install the Platform tent was pulled back to allow for craning. Particle counts near the fans on the platform were 0-100 before the tent was pulled back.
By 2:45pm the cartridge was landed on the support tubes in the BSC2 chamber. The tent was restored and the ISI left covered at the dome.

Tyler, Travis, Jordan, Corey, Jim in suits at the Test Stand for lift off

Randy on the Crane controls

Mitchell, Gerardo, Betsy in support

Jim and Ibrahim in the chamber for the lowering, alignment and support tube bolt attachments

Danny on Safety watch

More pictures to follow, but attaching a good one of the LVEA perspective actross the West bay and of Danny monitoring the flight.

Well done all, big job complete. Now tune-up, align and close! Easy button.

Images attached to this report

H1 General - Ops DAY Shift End

oli.patane@ligo.org — Thu, 04 Jun 2026 16:31:57 -0700

Author: oli.patane@ligo.org

Report ID: 90488

TITLE: 06/04 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

The LVEA is LASER HAZARD

BSC2 cartridge flown from test stand and into BSC2 DONE
SPI PSL pickoff shutter installed DONE
HAM2 B+K measurement DONE

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:28	FAC	Kim	LVEA	n	Tech clean + restocking garb	15:38
14:50		Betsy	LVEA	YES	Gathering headsets	15:04
15:05	SAF	Betsy	LVEA	YES	Transitioning LVEA to LASER SAFE	15:20
15:37		Betsy	LVEA	n	Looking for mic box	15:49
16:07	EE	Fil, Richard	LVEA	n	Looking at 24V (Richard out 16:36)	17:59
16:08	SEI	Jim, Shoshana	LVEA	n	Test stand ISI cabling (Shoshana out 17:09)	18:00
16:12	FAC	Kim	LVEA	n	Tech clean + restock	17:14
16:35	SEI	Mitchell, Arnaud	MY	n	Shopping for cables	17:06
16:45	SUS	Betsy	LVEA	n	Test stand work	18:04
16:49		Richard	LVEA	n	Knocking ladder out from under Fil	17:34
17:21		Tom, Radhika	LVEA	n	Tour	18:15
17:25		Mitchell	LVEA	n	Putting stuff away in mega cleanroom	17:32
17:26	FAC	Randy	LVEA	n	Prepping for craning	18:56
17:31	FAC	Kim	LVEA	n	Tech clean	17:59
17:47	SEI	Arnaud, Shoshana, Alex	H2 PSL	n	CRS work (Alex out 19:15)	20:37
18:00	EE	Fil	LVEA	n	Cabling	20:01
18:00	SEI	JIm	LVEA	n	Test stand SEI cabling	18:04
19:24	SPI	TJ, Jeff	LVEA	n	HAM2 B+K measurements (TJ out 21:53)	21:59
19:39	FAC	Randy	LVEA	n	Cartridge craning	21:39
19:42		Rahul	LVEA	n	Looking for socket wrench head	19:56
19:54		Corey	LVEA	n	Filming cartridge install	22:15
19:56	SUS/ISI	Betsy, Jim, Jordan, Ibrahim, Mitchell, Travis, Danny	LVEA	n	Cartridge flight (Mitchell out 21:56)(Danny,Travis out 22:03)(Jordan out 22:05)	22:07
20:07	FAC	Gerardo, Travis, Tyler	LVEA	n	Cartridge install	21:37
20:28	CRS	Alex	H2 PSL	n	CRS work	20:37
20:33	PSL	Jason, RyanS	LVEA	n	Installing SPI shutter in PSL enclosure	22:04
22:15	EE	Fil	LVEA	YES	CS HEPI pump controller work	23:08
22:20	CRS	Shoshana	H2 PSL	y(local)	CRS work	00:20
22:36	CRS	Arnaud, Alex	H2 PSL	y(local)	CRS work	00:06
22:36	SAF	Camilla	LVEA	YES	Transitioning LVEA to LASER HAZARD	22:48

H1 SPI - HAM2 SPI ISIJ and below table

thomas.shaffer@ligo.org — Thu, 04 Jun 2026 16:31:41 -0700

Author: thomas.shaffer@ligo.org

Report ID: 90493

When I hammered the below table "beard" baffle on May 26 (alog90335), something wasn't correct with the way I saved the data or my configuration or something else. Either way, Jeff and went in today and hit that as well as the SPI ISIJ assembly with and without the cylindrical shroud (D2500030). Preliminary results are looking much better, so I'll clean those up and post them soon with a whole writeup.

H1 SQZ - Options for HAM7 Alignment Reference, using O4 slider values for FC1.

camilla.compton@ligo.org — Thu, 04 Jun 2026 16:27:42 -0700

Author: camilla.compton@ligo.org

Report ID: 90467

In 89751 we found we could not trust the FC1 top mass osems for an accurate FC1 alignment, we then set an FC REFL iris on SQZT7 to help us capture correct FC1 alignment 89771, as we thought we couldn't trust any stage of the FC1 suspension. But this iris also depends on ZM1,2,3 which is confusing.

Since the FC1 issues this week, we checked that the sliders are working as expected 90466.

We have decided to not use the FC REFL iris to set FC1 as it puts FC1 in a very different position to O4. We will align FC1 using the slider positions from O4. This is as in the December vent, between the O4 under-vacuum and the vents, doors off time, the FC1 WIT channels were within ~10-20urad, see top two rows of table below. Additionally in February when we had our FC1 trouble, we though that we would have been fine if we had never touched the FC1 sliders.

From August to November, the FC1 M3 Pitch WIT drifted between 175 and 195urad so where we are currently at 170urad is not far outside of this range.

FC1	Temp (Zone 4 G)	Pitch		Yaw
FC1	Temp (Zone 4 G)	Slider	M3 WIT	Slider	M3 WIT
Under-VAC, O4, Nov 8th 2025	67.6degF	225	195	-153	-202
Vented, Dec 9th 08:30 UTC	71.2degF	231	181*	-153	-201
Vented, 04 June 2026 16:45UTC When tring to use 89694 (good FC flashes alignment) for ZMs and FC REFL iris for FC1	71.1degF	217	169	52	38
Vented, 04 June 2026 20:41UTC Back to O4 sliders.	71.3degF	225	170	-153	-202

* drifted down to 162 over next week

We have put ZM1,2 3 back to their O4 sliders as a starting place, you can see below that the top mass osems say this is not the same location as when under vacuum but we don't think this is trustworthy. We will change these alignments as needed to get the FC beam to retroreflect off FC1.

	To match 89694 (good FC flashes alignment). 04 June 2026, 16:45UTC		O4 time. Nov 8th 2025, 20:30UTC		Sliders back to O4 values 04 June 2026, 21:15UTC, plot
	Sliders	WIT*	Sliders	WIT*	Sliders	WIT*
FC1 P	217	169	225	195	225	171
FC1 Y	52	38	-153	-202	-153	-202
ZM1 P	530	420	0	-390	0	-253
ZM1 Y	0	417	0	432	0	429
ZM2 P	-429	-399	-196	-273	-196	-183
ZM2 Y	-132	184	-235	-43	-235	101
ZM3 P	-474	-422	-190	-68	-190	-57
ZM3 Y	-367	-282	-300	-463	-300	-261

*WIT is M3 WIT for FC1 but for ZMs there is no bottom mas WIT so we're using M1_DAMP_{P,Y}_INMON

Images attached to this report

H1 AOS - Comment to ITM Baffles Installed, Some Adjustment Still Needed

ryan.short@ligo.org — Thu, 04 Jun 2026 16:00:49 -0700

Author: ryan.short@ligo.org

Report ID: 90492

Adding some pictures of Anamaria and Robert installing baffles on ITMY.

EPO

Images attached to this report

H1 PSL - Comment to SPI PSL Shutter Installed

ryan.short@ligo.org — Thu, 04 Jun 2026 15:54:49 -0700

Author: ryan.short@ligo.org

Report ID: 90491

Adding pictures of the current location of the shutter controller outside the enclosure. Final picture is of the controller as it was left; unplugged with the shutter closed.

Images attached to this report

H1 SUS - Comment to General BBSS Pre-Flight Progress

madison.simmonds@ligo.org — Thu, 04 Jun 2026 15:54:00 -0700

Author: madison.simmonds@ligo.org

Report ID: 90489

EPO

Images attached to this report

H1 PSL - SPI PSL Shutter Installed

jason.oberling@ligo.org — Thu, 04 Jun 2026 15:49:51 -0700

Author: jason.oberling@ligo.org

Report ID: 90490

R. Short, J. Oberling, J. Kissel

This afternoon we installed the shutter in the SPI pickoff path on the PSL table. We installed it in between the 2 SPI lenses. The cable was tied down with some dog clamps and cable ties, and we checked to make sure it was well clear of all known beams (it doesn't really look like it in the picture, but the shutter cable is ~3 inches away from the ALS beam and cannot drift into its path). Once we ran the cable outside the enclosure, Jeff plugged it into the driver and we ran several on/off tests, with the shutter successfully actuating as expected, every time. I'll update the as-built PSL table layout to include the shutter.

PSL, SPI

Images attached to this report

H1 SQZ - Comment to HAM7 Vent Wednesday 3rd June

camilla.compton@ligo.org — Thu, 04 Jun 2026 14:39:33 -0700

Author: camilla.compton@ligo.org

Report ID: 90487

As the OPO has been locked in the same alignment is it's free hanging alignment, when the sliders are at ZM4 (P: -453.4, Y: -1275.0) and ZM5 (P: -258.0, Y: -761.0) as attached screenshot, when the beam is centered on the ZM4 iris the alignment can be recovered to the SQZT7 and the IR path irises.

Images attached to this report

H1 SUS - QOSEM Coil Sign Flip

thomas.roocke@ligo.org — Thu, 04 Jun 2026 13:17:35 -0700

Author: thomas.roocke@ligo.org

Report ID: 90486

[Tom, Oli]

Summary: There is a polarity flip between the BOSEM and QOSEM coils due to the wiring of the QOSEM flexi-circuit. To maintain consistency with existing BOSEM controls a sign flip should be implemented in CDS coil drives.

When commissioning the damping loops for the BBSS on the teststand, we noticed that there was a sign flip required in the QOSEM coil drive for the loops to be stable, when copying over the existing BOSEM damping. See LHO alog 90441. After some investigation, this sign flip is due to a polarity flip in the wiring from the coil drivers to the QOSEM coils. The QOSEM coils are wound in the same direction as the BOSEM coils, however on the QOSEM flexi-circuit I accidentally flip the coil connections with respect to that of the BOSEM. All QOSEM version to do date suffer from the coil sign flip.

In the attached screenshot, we see the BOSEM flexi-circuit has this weird flip between the coil pads (on the very left) and the uDB9 connection. I did not copy this flip over to the QOSEM flexi, which has caused this coil polarity flip.

SUS

Images attached to this report

H1 PSL - PSL Power Outage Recovery

ryan.short@ligo.org — Thu, 04 Jun 2026 13:12:25 -0700

Author: ryan.short@ligo.org

Report ID: 90436

J. Oberling, P. Thomas, R. Short

TLDR - Following the power outage(s) over the weekend, we've successfully restored the PSL.

Monday morning, Jason started by turning back on the benchtop power supply behind the PSL racks in the LVEA which powers CB2 and then restarted the Beckhoff computer in the diode room (we've seen in the past that the Beckhoff computer needs everything to be powered on before it boots so that it can "see" everything). However, even though the EPICS IOC auto-started when the computer came up, the PLC did not, so we were unable to bring the system up at first. I was able to find and launch the correct PLC (which, for our future reference is in the "Projekt_LIGO_240124" folder), but we noticed after the GUI came up that we were missing the amplifier PD WD, one of the newest additions to the software. Thinking we had an old version of the software somehow, we called in Patrick, who reminded me that instead of just starting TwinCAT in run mode, I should have also logged in and started the PLC to pull in all the updates to the code. This brought the Beckhoff computer back to full functionality, and we were able to bring the laser up without issue after clearing the site laser interlock (which wouldn't clear until the Beckhoff computer was functional). As usual, our calibration settings and operating hours for the NPRO, amps, and chiller were lost with the computer reboot, so we found the last saved screenshot of the settings table we took after the last outage (alog88368) and used it repopulate the table. The operating hours were all fixed also since we could trend back what they were before the outage. A new screenshot of the settings table is attached.

Relocking the PMC went without issue, and it's now been coming up to temperature since Monday with the transmitted and reflected powers slowly settling out. I can tell by the camera spots and the lower transmitted power that some alignment is needed into the PMC, which we can do eventually. The PMC relocked at a temperature a couple degrees cooler than before, which we've seen before, so this slightly different operating point isn't too surprising.

Trending the enclosure temperatures shows that the environmental controls seem to have come back no different than before the outage.

Images attached to this report

H1 SUS - ITM reference positions

anamaria.effler@ligo.org — Thu, 04 Jun 2026 13:03:39 -0700

Author: anamaria.effler@ligo.org

Report ID: 90485

Before starting the cage baffle install we took a reference of the optical levers (with ISI locked) such that later when we unlock the quad we can tell if there was a significant shift. NB there were small shifts at LLO when we installed these baffles and we are still baffled as to why. Since they attach to the cage, which is connected to the ISI and the ISI gets rebalanced, it's unclear why they'd shift more than some 20-30 urad.

I took one reference pre-vent, circa Nov 28, when we were still locking full ifo. The second reference is recent, at air, with the ISI locked.

ITMX	pre-vent	vent, pre-work
date	Nov 28 '25	Jun 3 '26
sliders P,Y	-113, 110	-35, 94
oplev P	8	0
oplev Y	6	0
oplev sum	3400	3200

ITMY	pre-vent	vent, pre-work
date	Nov 28 '25	Jun 2 '26
sliders P,Y	-14, -18	-90, -16
oplev P	-30	0
oplev Y	-15	0
oplev sum	9000	9000

AOS, SYS

H1 AOS - Comment to Measured ITM and CP Positions

anamaria.effler@ligo.org — Thu, 04 Jun 2026 12:46:35 -0700

Author: anamaria.effler@ligo.org

Report ID: 90484

For reference I got these numbers from the following e-drawing files:

HR cage baffles: DCC D2500081 FULL ASSEMBLY D2500081 A+, SLIC, QUAD SUS CAGE BAFFLE ASSY2.easm
CP cage baffles: DCC D2600035 D2600035 A+ SLIC CP SUS CAGE BAFFLE ASSY-15deg review2.EASM

For the keen eye you'll notice that the CP optic and the tests mass are not at the same height when in reality they should be. Because the CP optic isn't quite well aligned to the cage in this drawing in an IAS sense, it's ok because the baffle IS well aligned to the optic so the relative numbers we would use to align are, well, relative and hold true.

SUS, SYS

H1 SUS - General BBSS Pre-Flight Progress

ibrahim.abouelfettouh@ligo.org — Thu, 04 Jun 2026 10:46:36 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90483

Ibrahim, Oli, Thomas, Betsy, Jim, Mitchell

ISI rebalancing masses
BBSS stages locked
General torque checks done
BRD Measurements re-taken - these were too noisy so will re-re-take in-chamber
Some cabling done
Face sheilds secured for cartridge
Earthquake stop replaced (glass on fluorel tip was chipped)
Calibrate BOSEM vs QOSEM vs Slider Values
BBSS covered for cartridge flight

Images attached to this report

H1 SUS - BBSS Test Stand BOSEMs vs QOSEMs

oli.patane@ligo.org — Thu, 04 Jun 2026 10:40:33 -0700

Author: oli.patane@ligo.org

Report ID: 90481

Here's the analyzed data for the QOSEM transfer functions, as well as a comparison of transfer functions between the BOSEMs and the QOSEMs for the BBSS on the test stand. They're pretty similar.

I didn't modify the analysis script yet since we are currently only using the X of the QOSEMs, so I just exported the M1_OSEMINF_{F1,F2,F3,LF,RT,SD}_X_OUT_DQ channels in theplace of the M1_OSEMINF_{F1,F2,F3,LF,RT,SD}_OUT_DQ channels.

Data
/ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Data/2026-06-01_1700_tfs/2026-06-01_1700_H1SUSBS_M1_WhiteNoise_R_0p02to50Hz.xml r13024
Results
/ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Results/2026-06-01_1700_tfs/2026-06-01_1700_H1SUSBS_M1_ALL_TFs.pdf r13024 /ligo/svncommon/SusSVN/sus/trunk/BBSS/Common/Results/allbbss_BBSS_teststand_BOSEMsvsQOSEMs/allbbsss_BBSS_teststand_BOSEMsvsQOSEMs_ALL_TFs.pdf /ligo/svncommon/SusSVN/sus/trunk/BBSS/Common/Results/allbbss_BBSS_teststand_BOSEMsvsQOSEMs/allbbsss_BBSS_teststand_BOSEMsvsQOSEMs_ALL_ZOOMED_TFs.pdf r13025

Non-image files attached to this report

2026-06-01_1700_H1SUSBS_M1_ALL_TFs.pdf

allbbsss_BBSS_teststand_BOSEMsvsQOSEMs_ALL_TFs.pdf

allbbsss_BBSS_teststand_BOSEMsvsQOSEMs_ALL_ZOOMED_TFs.pdf

H1 SEI - Comment to CRS Report June 3 - 1st CRS suspended

alexandra.mitchell@ligo.org — Thu, 04 Jun 2026 10:24:28 -0700

Author: alexandra.mitchell@ligo.org

Report ID: 90482

The monitor channels in the CRS pre-amp D2500390 are connected up incorrectly. The following table details the current connections: HoQI/TEST POINT CONNECTION - MON CHANNEL CONNECTION HA PDS - HD PDS HA PDC - HA PDC HA PDMC - HD PDMC HB PDS - HC PDS HB PDC - HB PDC HB PDMC - HC PDMC HC PDS - HB PDS HC PDC - HC PDC HC PDMC - HB PDMC HD PDS - HA PDS HD PDC - HD PDC HD PDMC - HA PDMC

H1 SEI - corner station HEPI pump control migrated to Beckhoff PLC

patrick.thomas@ligo.org — Thu, 04 Jun 2026 09:56:59 -0700

Author: patrick.thomas@ligo.org

Report ID: 90480

Patrick T., Filiberto C., Richard M., Dave B., Jonathan H., Jim W. WP 13262. The summary of the work is detailed in the permit. There were some additional code changes needed to fix a scaling issue and some others made to clean things up. The only thing that should be left is to restart the DAQ to remove three channels. IOC code: https://git.ligo.org/cds/software/ads/ads-utils 9b98c481d6f9ab129fa4bc54475e05383d304aa2 https://git.ligo.org/cds/software/ads/epics7-ads c72c97eb4d1558d9de5c03234e90c8c651aab99b (in container), 9e5a10a014beeb0cb7b021649c459a0fa0488be7 (used to generated EPICS db) PLC code: https://git.ligo.org/cds/ifo/beckhoff/io 65f59557c1fefc90f4befc9338bd29a1fb27d8e0 https://git.ligo.org/cds/ifo/beckhoff/lho-hepi 3fd31d58fafc08e4d5a84dce1d0d57dfd8b6b74e CDS, SEI

H1 SQZ - Comment to HAM7 Vent Wednesday 3rd June

camilla.compton@ligo.org — Thu, 04 Jun 2026 09:04:13 -0700

Author: camilla.compton@ligo.org

Report ID: 90479

From 60068: If the beam coming out of VOPO is level with ISI surface, it's nominally 5.532" high, the beam travels up from ZM2 toward ZM3 to raise the beam height by 0.756".

So the beam would be 6.288" at ZM3 and FC1. This matches with our beam height measured yesterday at the ZM3 iris.

H1 SEI - CRS Report June 3 - 1st CRS suspended

arnaud.pele@ligo.org — Thu, 04 Jun 2026 08:43:26 -0700

Author: arnaud.pele@ligo.org

Report ID: 90476

Shoshana, Alexandra, Jim, Arnaud, Fil

Yesterday's activity log:

Shoshana and Jim suspended the first CRS with flexures and after a first round of balancing obtained a resonant frequency of 37mHz (using the Panasonic optical interferometer -HL-G105- to read the frequency, see picture). We had to add x8 8-32 screws (8) at the bottom of the CRS to compensate for a high COM. As per the SW model the balance mass type 2 in d230099 used in the mass adjuster, and the new coupler (-v4) move the COM up by 43um (compared to the MIT build). We will swap d230099 to type 1, which will help reduce the number of Ti screws we have to use. Table below shows the COM position wrt to the flexure center point with different mass adjuster configurations:

	Nominal	New Fork (D2300094-v4)	New Fork + D230099 type2 (4g vs 2g type 1)
Z	+186um	+189.8um	+229.2um
X	-2.4um	-3.75um	-3.75um

Alexandra confirmed the signal chain from each HOQI was working with the TIA we received from Caltech. The HOQI board D2300154 has some minor wiring issues on the monitor signals, but we can use the TP internal to the board instead for now.
Fil has started wiring the interlock system to the H2-PSL enclosure so we can turn on the laser.

Images attached to this report

H1 General - Ops DAY Shift Start

oli.patane@ligo.org — Thu, 04 Jun 2026 07:32:04 -0700

Author: oli.patane@ligo.org

Report ID: 90477

TITLE: 06/04 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 8mph Gusts, 4mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.13 μm/s
QUICK SUMMARY:

BSC2 cartridge will be flying back in after lunch today! The LVEA will be going to LASER SAFE soon but is currently still LASER HAZARD

LHO VE - Dew Point Measurement

gerardo.moreno@ligo.org — Wed, 03 Jun 2026 19:03:06 -0700

Author: gerardo.moreno@ligo.org

Report ID: 90475

(Jordan V., Gerardo M.)

We have noticed that the dew point at the dryer towers has been increasing since opening to HAM7 and or related to power glitch last Saturday, we are still looking into it.

We have had a constant dew point at the dryer towers of -72 ^oC, and now we are at -57 ^oC, because of those numbers we ran a short test, once work was finished for the day in-chamber, we stopped the purge air to the LVEA to see what the effect was on the drying tower's dew point, it changed but very slow, we started at -57 ^oC and after 20 minutes we ended up at -59 ^oC, and we noted that the right tower may be in trouble since the dew point did not improved while this tower "works", the dew point instead went up by the one degree, erasing the improvement of the left tower. We will look more into it.

To complete the test we took a dew point measurement at the point of use in the LVEA, and we got a -40.7^oC, getting close to a bad dew point, and remember this is while no in-chamber work is going on, so please mind those C3 soft covers on chamber doors, thank you.

Images attached to this report

H1 AOS - ITM Baffles Installed, Some Adjustment Still Needed

ryan.short@ligo.org — Wed, 03 Jun 2026 18:00:53 -0700

Author: ryan.short@ligo.org

Report ID: 90474

A. Effler, R. Schofield, R. Short

All of the new SLiC baffles have been installed on both ITMX and ITMY (both the test mass and compensation plate sides), but the CP side of ITMX still will need some alignment positioning touched up. Earthquake stop brackets on the test mass faces for both quads were also swapped out to accommodate for the new baffles.

One person always remained near the open door in BSC1 while others were around the corner working in BSC3, and oxygen monitors were worn out of an abundance of caution.

H1 PEM - Comment to DC to 30mHz PEM Seismic BLRMS could be added to the Monitor Screens

nathan.holland@ligo.org — Wed, 03 Jun 2026 17:45:40 -0700

Author: nathan.holland@ligo.org

Report ID: 90473

Added a comparison of all the BLRMS, minute trends for the last 24 hours, for comparison. See the attachment.

At least for the largest, earthquake (?), there is a significant transient in the DC to 30 mHz BLRMS.

SEI

Images attached to this report

H1 PEM - DC to 30mHz PEM Seismic BLRMS could be added to the Monitor Screens

nathan.holland@ligo.org — Wed, 03 Jun 2026 17:28:46 -0700

Author: nathan.holland@ligo.org

Report ID: 90471

[Nathan Holland, Jenne Driggers]

TL;DR

DC to 30 mHz BLRMS have been working as of 2022 - see LIGO-T2200025. These can be added to the BLRMS monitoring screen, and hopefully will be useful. They may need appropriate calibration. See attachment 1 for an example.

More Information

Historically the DC to 30mHz BLRMS did not work - they would diverge to +/- infinity after some time. This was corrected as of 2022, see LIGO-T2200025, by changing the C code in the RTCDS. This RTCDS change was approved in ECR LIGO-E2200027 and has been active for some time. One example of the relevant channels is H1:PEM-CS_SEIS_LVEA_VERTEX_X_BLRMS_0MHZ30, e.g. for the DC to 30 mHz seismic BLRMS at the LVEA along the x direction. Attachment 1 shows a 5 minute trace of the second trends for this channel.

Possibly this has been discussed in the past at the Friday SEI meetings, and no use yet, has been found for this BLRMS band. It may be interesting to properly calibrate these channels, place them on the monitoring screens, and then see if they are of use.

SEI

Images attached to this report

H1 SQZ - HAM7 Vent Wednesday 3rd June

camilla.compton@ligo.org — Wed, 03 Jun 2026 17:13:31 -0700

Author: camilla.compton@ligo.org

Report ID: 90472

Sheila, Begum, Ryosuke, Camilla

Sheila checked that FC1 is now working as expected but was not in May 90462.

Started the morning by setting FC1 to the FC REFL iris ZM1,2,3 sliders set to 90183 (when Sheila had the beam on SQZT7), we then set irises after ZM1 and ZM3. Doing this clipped the return beam on B:L1 aperture, this is expected as we could not get the return beam through the OPO when FC was aligned in Feb. Later we realized that this doesn't make scene, so set ZM1,2,3 sliders set to when we had good FC flashes in 89694 and then FC1 was moved to get the beam centered on the FC REFL iris, again this clipped the return beam on B:L1 aperture but the beam was considerably higher at the ZM3 iris than when we originally set it. Around or a little higher than 6.25". Tomorrow we will fully think this though and compare to O4 times.

We locked the OPO SUS iteratively looking at the beams off the OPO. It was finally lock with the FC REFL beam getting to the second iris but not centered and when we changed the alignment to the IR SQZT7 alignment, the beam made it through both irises when closed.

Sheila, Begum, Ryosuke then took beam profiles of the beam after ZM1 and ZM2 with the borrowed Phasics camera.

LHO VE - Quarterly Functionality Test Performed on EY/MY Turbo Pumps

jordan.vanosky@ligo.org — Wed, 03 Jun 2026 17:01:07 -0700

Author: jordan.vanosky@ligo.org

Report ID: 90470

Procedure checklist for both stations completed. No issues were identified at this time.

MY: Scroll pump hours: 243
Turbo pump hours: 105
Crash bearings: 100%

EY: Scroll pump hours: 1304
Turbo pump hours: 916
Crash bearings: 100%

Closing WP 13279 and FAMIS 79948 and 79949

H1 CDS - BSC2 - Feedthrough Cabling

filiberto.clara@ligo.org — Wed, 03 Jun 2026 16:49:02 -0700

Author: filiberto.clara@ligo.org

Report ID: 90469

WP 13292
BSC2 Flange Layout - D1003079

Part of the BBS upgrade required moving the SUS BS field electronics from the SUS-R6 rack to the SUS-R2 rack. A new set of field cables were pulled from SUS-R2 to BSC2 flange E3 per D1003079. The old cables at the flange were disconnected and labeled as spares to avoid confusion. Access to the flange is limited as we now have the platform and dial indicators that limit access to the flange. The dial indicators were bumped. SEI team was notified.

SUS

H1 General - OPS Wednesday DAY shift summary

ryan.crouch@ligo.org — Wed, 03 Jun 2026 16:37:57 -0700

Author: ryan.crouch@ligo.org

Report ID: 90461

TITLE: 06/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: HAM2 and HAM7 laser hazard work continued, the ITMY baffles installation progressed, and the SPI electronics are being staged into the LVEA. The cartridge is planned to be flown back into chamber tomorrow.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
22:09	SAF	LASER HAZARD	LVEA	Y	The LVEA is LASER HAZARD	02:09
13:40	FAC	Kim	LVEA	y	Tech clean	14:34
15:04	FAC	Kim	LVEA	Y	Tech Clean	16:37
15:43	PSL	Jennie	LVEA	Y	Open light pipe	15:49
16:07	ISC	Rahul, Keita, Ryosuke	LVEA	Y	HAM2 work, RM2 investigation // alignment	17:31
16:14	SQZ	Camilla, Begum	LVEA	Y	HAM7 work	19:05
16:19	ISC	Disha	LVEA	Y	Join HAM2 crew	17:31
16:23	SLiC	Robert, Anamaria	LVEA	Y	BSC in chamber cage baffle work	19:53
16:24	VAC	Gerardo, Jordan, Tyler	MidY	N	LN2 tank inspection	17:50
16:40	SLiC	RyanS	LVEA	Y	BSC cage baffle work	19:53
17:09	SPI	Jeff, Sina	Optics lab	LOCAL -> SAFE	SPI work, hand off analog electronics to EE	19:48
17:13	SUS	Ibrahim	LVEA	Y	BBS eliptical baffles	18:54
17:13	FAC	Kim	LVEA	Y	Tech clean	17:51
17:17	SUS	Betsy, Randy	LVEA	Y	Scope out HAM3 area, Randy out 17:35	17:43
17:28	EE	Josh, Marc	LVEA	Y	Install SPI electronics by HAM3, Marc out 18:03	18:14
17:28	SQZ	Sheila, Ryosuke	LVEA	Y	Join HAM7 work	19:05
17:35	FAC	Randy	EndY	N	Get some CR curtains	18:08
17:40	SUS	Thomas	LVEA	Y	Join BBS baffle work	18:26
17:50	SUS	Oli	LVEA	Y	Join BBS baffling	18:54
17:51	FAC	Kim	MidX	N	Tech clean	18:50
18:05	SUS	Betsy	LVEA	Y	Talk to BBS crew	18:26
18:11	EE	Fil, Marc	LVEA	Y	BBS cabling by HAM3	19:08
18:15	SEI	Shoshana	LVEA/H2 PSL	Y	CRS work	19:28
18:35	ISC	Rahul, Keita, Disha	LVEA	Y	HAM2 work	19:13
20:20	SEI	Jeff, Sina	LVEA	Y	R2 electronics rack work for SPI near HAM3	22:46
20:21	ISC	Rahul, Keita, Disha	LVEA	Y	HAM2 work	Ongoing
20:22	EE	Richard, FIl	LVEA, H2 enc	Y	H2 enclosure investigation	20:59
20:27	SUS	Betsy, Arnaud	LVEA	Y	Look at HAM3	20:59
20:32	SEI	Josh	LVEA	Y	Join SPI work	23:28
20:42	SQZ	Sheila, Begum, Ryosuke	LVEA	Y	HAM7 work, Sheila out 23:00	Ongoing
21:03	SEI	Shoshana, Jim, Arnaud, Alexandra	LVEA H2 enc	Y	CRS work	Ongoing
20:45	SEI	Jim	LVEA	Y	Talk to Betsy	21:05
21:20	SUS	Ibrahim, Oli, Thomas, Madi	LVEA	Y	Lock down BBS, Madi out 23:18	Ongoing
21:21	ISC	Jennie	LVEA	Y	Help HAM2 crew find tool	21:25
21:33	SLiC	Anamaria, RyanS, Robert	LVEA	Y	BSC in-chamber baffle work	Ongoing
21:49	ISC	Jennie	Optics lab	N	Grab tool	22:09
22:01	ISC	Camilla	Optics lab	N	Look for class B ruler then bring to HAM2 if found	22:16
22:22	SUS	RyanC	LVEA	Y	Bring small class B ruler to HAM2	22:25
22:42	SUS	Betsy	LVEA	Y	Join BBS crew	23:04
22:46	SQZ	Camilla	LVEA	Y	HAM7 SQZ work	Ongoing
23:19	EE	Fil, Jake	LVEA	Y	Check out door lock H2 enc	23:39
23:21	VAC	Jordan	LVEA	Y	Grab leak detector	23:29
23:27	SAR	Jennie	Optics lab, LVEA	N, Y	Cell phone search and rescue	23:34

15:05 UTC Light pipe open
18:24 UTC SUS OPO WD trip
23:09, 23:13 UTC ITMX SUS then SEI WD tripped

H1 IOO - Comment to Phased JAC WFS segments

jennifer.wright@ligo.org — Wed, 03 Jun 2026 16:05:35 -0700

Author: jennifer.wright@ligo.org

Report ID: 90468

Just realised WFS B wasn't very well aligned today. It's probably because the alignment has been changed into the JAC since the last time I aligned the JAC WFS on the IOT1 table (early May). Will redo the WFS B phasing Thursday with good alignment.

Images attached to this report

H1 SQZ - Comment to FC1 alignment

camilla.compton@ligo.org — Wed, 03 Jun 2026 14:43:23 -0700

Author: camilla.compton@ligo.org

Report ID: 90466

2nd April, FC1 was working. We moved FC1 sliders and FC1 moved the expected amount: in PIT: 217urad sliders, 235urad M3 WIT.; in YAW: 18urad sliders, 21urad M3 WIT.

On May 7th, FC1 did not move when the alignment sliders were changed, shown by bottom mass WIT channels not changing. DAC outputs did change. Plot attached. It was broken at this point.

30 minutes before this at 17:51UTC, the FC1 M3 witness channels show a change of ~7urad each, but the DAC outputs did not change. This may be the time the FC1 electronics broke. Plot attached.

Between 7th April and 7th May, and a period around the end of February, the DAC outputs were noisy, before and after this, they are not. I'm not sure what this is, plot attached.

Below is comparing today with Dec 9th 08:30 UTC (when CR was on temp ~71degF, HAM7 vented and doors removed). This shows the sliders are agreeing with what we have seen in the past.

	Temp	Pitch		Yaw
	Temp	Slider	M3 WIT	Slider	M3 WIT
Dec 9th 08:30 UTC	71degF	231	181*	-153	-201
Now, June 3rd 21:45 UTC	71.3degF	231	176	-153	-202

* drifted down to 162 over next week

CDS

Images attached to this report

H1 AOS - Measured ITM and CP Positions

ryan.short@ligo.org — Wed, 03 Jun 2026 14:26:39 -0700

Author: ryan.short@ligo.org

Report ID: 90465

Before locking down the ITM suspensions as part of the new baffle installations, we measured the positions of each test mass and compensation plate (CP) from the outer bevel to the inner cage:

EDIT: clarifying that "left" and "right" here refer to when looking at the face of either the test mass or CP, so left and right flip when going between TM and CP on the same suspension.

ITMY

Compensation Plate -

Left: 9mm
Bottom: 24mm
Right: 8mm

Test Mass -

Left: 14mm
Bottom: 22.5mm
Right: 16mm

ITMX

Compensation Plate -

Left: 8.5mm
Bottom: 20.5mm
Right: 8mm

Test Mass -

Left: 13mm
Bottom: 20mm
Right: 16mm

See attached photots for Anamaria's sketches of nominal positions and how they relate to the baffles.

Images attached to this report

H1 IOO - Phased JAC WFS segments

jennifer.wright@ligo.org — Wed, 03 Jun 2026 13:13:25 -0700

Author: jennifer.wright@ligo.org

Report ID: 90463

Jennie W

Summary: JAC WFS A and B readout has been phased.

I used Sheila's tremplate for the IMC WFS phasing (see Daniel's alog #89457 here when the IMC WFS was rephased in March) to make one for JAC WFS phasing. Since the length control is all done through CDS and does not use a common mode board the actuation channel to use is H1:JAC-L_SERVO_EXC.

The template is saved in userapps/h1/ioo/templates/dtt/JAC_wfs_phase.xml

New values were saved in the h1ascimc safe.snap.

Here is a photo of the WFS 'Settings' screens with the value to change highlighted in red and the Q and I error points highlighted in green. When running the template a line is injected into the JAC lenght control loop at 8 Hz. To phase the readout of the WFS segments, change the red-highlighted phases to minimise the line you inject in the Q error point channels, H1:JAC-WFS_{A,B}_{Q1,Q2,Q3,Q4)_ERR_DQ

Images attached to this report

H1 SQZ - FC1 alignment

sheila.dwyer@ligo.org — Wed, 03 Jun 2026 11:43:03 -0700

Author: sheila.dwyer@ligo.org

Report ID: 90462

Last Friday, HAM7 was vented and the mega cleanroom was on, but chamber doors were on, FC1 sliders were at 100 urad P, -162 urad Yaw, and the M3 witness sensors were -90 urad pitch, -15 urad. Since then, there was a power outage, the chamber doors are off and the purge air is on, and tha DAC has been changed as it was not working 90454. Now, with the same slider settings (100 urad P, -162 yaw), M3 withness sensors are at 24 urad pitch, -204 urad yaw.

In 89751, Oli noted that turning on the purge air caused a shift of -29urad in the bottom mass osems. If purge air were the only difference between now and Friday, we would expect M3 witness osems to say -120 urad, if the purge air is similar to what it was in December. So, it seems like the electronics change has changed the realtionship between the slider value and the witness sensor.

On May 7th, we moved the pitch alignment slider by 140 urad, and the M3 witness only saw a move of 10 urad. Today, when we move the slider by 262 urad, the M3 witness osems see a shift of 317urad, so the suspension is actuating now, but seems not to have been in May.

Images attached to this report

LHO VE - 8" gate valve removed from X-beam manifold

travis.sadecki@ligo.org — Wed, 03 Jun 2026 10:42:11 -0700

Author: travis.sadecki@ligo.org

Report ID: 90460

As part of WP 13284, the unused 8" gate valve on the X-beam manifold section was removed and the port was blanked off. We will need to remember to leak check this flange during pumpdown.

Images attached to this report

H1 CDS - TW0 raw minute trend offload complete

david.barker@ligo.org — Wed, 03 Jun 2026 10:34:09 -0700

Author: david.barker@ligo.org

Report ID: 90459

WP13772 TW0 Offload

Dave:

I have finally completed the TW0 offload which I started way back at 08:54 Saturday 30th May. It was interrupted soon after at 09:30 Saturday with the first of two power outages. It was restated 07:00 Monday 1st June and completed the file copy at 22:17 Monday night.

NDS0 was restarted Tuesday morning to serve from the archive area, but sush7 and other issues delayed the file deletion from TW0 till Wednesday.

This morning I deleted the old files from TW0 between 07:40 - 10:05. SSD-RAID usage on TW0 went from 94% to 3%, ready for the next 6 months of trends.

H1 CDS - Comment to h1sush7 first 20bit-DAC stopped driving, no error detected by h1iopsush7

david.barker@ligo.org — Wed, 03 Jun 2026 08:01:41 -0700

Author: david.barker@ligo.org

Report ID: 90458

FRS 38169

H1 TCS - TCS Chiller Water Level Top-Off (Bi-Weekly, FAMIS #64381)

corey.gray@ligo.org — Wed, 03 Jun 2026 07:36:10 -0700

Author: corey.gray@ligo.org

Report ID: 90457

Addressed TCS Chillers (Wed [Jun3] 713-726am local time) & CLOSED FAMIS #64381. It's been a while since this has been checked due to issues with FAMIS for LHO.

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

TCSx Chiller: Had level of 28.5 cm. Added 270mL for 30.6cm.
TCSy Chiller: Had level of 9.0 cm. Added 475mL for 10.5cm.
There was no water in the small cup under the slow leak.

TCS

H1 General - OPS Wednesday Day shift start

ryan.crouch@ligo.org — Wed, 03 Jun 2026 07:29:31 -0700

Author: ryan.crouch@ligo.org

Report ID: 90456

TITLE: 06/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 5mph Gusts, 2mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.12 μm/s
QUICK SUMMARY:

HAM2 work continues
HAM3, cabling, SPI install?
ITM cage baffling continues

H1 SPI - 2026-06-02 SPI Pathfinder Update: VICTORY -- It was the NPRO Crystal Temperature / Frequency Drift -- GO FOR INSTALL

jeffrey.kissel@ligo.org — Tue, 02 Jun 2026 22:37:50 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90455

J. Kissel, S. Koehlenbeck, J. Wright, P. Opperman After the most of the day Monday (2026-06-01) ruling out of the prime suspect (the picomotors causing alignment drift; see LHO:90438), I left discouraged that we had ruled our everything that could be spatially wrong with the MEAS beam going into the MEAS IFO (power, alignment, mode-shape, and polarization). However, Sina and special-guest consultant Patrick spent time reviewing everything that we ruled out and/or what it could be -- and Sina left the lab nudging the NPRO seed laser's crystal temperature from 24.6 [deg C] to 25.2 [deg C]. %%%%%%%%%%%%%%% Executive Summary: Nudging the NPRO seed laser by 0.6 [deg C] (we believe) changed the resonant mode in the laser, stabilizing its output frequency. (We believe) the laser was in-some-way frequency drifting and/or mode hoping (a thing that would also be driven by the clean room environment in the ways we suspected were impacting the transceiver), and the path length differences between the REF and MEAS IFOs were discrepant enough (per the design layout) that the efficiency impact was much larger on the MEAS IFO. Having adjusted the laser crystal temperature, both IFOs are stable for hours and if/when small drift is seen its common to both IFOs as the gods intended. We can't claim we 100% understand it, or believe our own story, but it worked! Finally happy with both the MEAS and REF IFOs, we mounted the transceiver vertically and confirmed its function in that orientation. We're a go for install, and have started to dissect the production equipment from the optics lab. %%%%%%%%%%%%%%% Some victory photos attached. Other things that happened: - Prior to laser temp adjustment -- with MEAS IFO path on fully manually driven mounts -- we foiled (as protection) then C3 covered (as isolation) the transceiver. We still saw drift. That put the nail in the coffin that it wasn't transceiver itself that was sensitive to the environment. - We re-installed all picomotor-driven IXM100 mounts to support M_M1, M_B4, and M_M2. - Prior to install, we were able to (rather barbarically) back off stopper nuts of the pitch picomotors for the M_B4 and M_M2, so there is no longer any question whether the stopper nut is driving moving plate. All pitch and yaw actuators push the moving plate kinematically via the intended ball-bearing-to-carbide-plate design. - Re-installed M_M4 M_M5 periscope mirror mounts, including their adapters and D1800200 Type 07 beam-dumps. The dumps were parked in a position that still allowed transmission of the MEAS beam (as confirmed with no change in the -- now stable! -- MEAS IFO efficiency). - Nudged IFO MEAS A and IFO REF A PDs because the beam spot on the diodes was a bit OFF. - Reviewed and confirmed all PD reflected beams were on their respective dump, except for the known issue with the FBR_PWRIN_REF PD that reflects 0.2 [mW] of power up above the breadboard. - Built up a temporary vertical mounting system with 1 [inch] posts and small cylindrical laser holding mounts with mini bread-board feet. - Re-installed the handles on ISIK. - Unbolted, and was easily able to single-person lift the entire assembly and mount it. - Both IFO efficiencies were actually not-that-bad after installing. Wow! - A quick alignment tune-up from Sina recovered all the IFO efficiency we had while mounted horizontally. - Both IFOs were stable and happy for the entire series of victory photos we took; about 1 hr.

Images attached to this report

H1 CDS - h1sush7 first 20bit-DAC stopped driving, no error detected by h1iopsush7

david.barker@ligo.org — Tue, 02 Jun 2026 21:56:46 -0700

Author: david.barker@ligo.org

Report ID: 90454

Camilla, Betsy, TJ, Fil, Ryan C, Richard, Erik, Dave

We had a very strange problem with the first 20bit-DAC in h1sush7, which h1susfc1 uses for its six M1 drives (T1, T2, T3, LF, RT, SD). Even though h1iopsush7 reported that DAC0 was driving correctly, there was no voltages being produced by the AI chassis.

We are in the early stages of figuring out what was wrong and how it got fixed. Due to HAM7 in-chamber urgency, once it started working we handed h1sush7 over the the HAM7 team.

Summary of what we did is:

tried various power cycles of IO Chassis and AI Chassis, no change. Put DVM onto DAC cable at rear of AI Chassis, looking at CH0 initially. No voltage. IOP correctly detected loss of AI.

With IO Chassis powered up, but computer down, Fil saw 3.5V on CH0, which went to 0V as soon as the computer was powered up. We are not sure this is normal behaviour, but we saw it on two different 20bit-DAC cards.

Next we replaced the 20bit-DAC, no change. Old (removed) 210303-09 New (installed) 210303-14.

Erik reminded us that since this is the first DAC in the IO Chassis, we can test CH7 with the DUOTONE loop back (IOP feeds ADC0-CH31 directly into DAC0-7, switches relays on Interface cards which routes DAC0-7 into ADC0-30). We turned this on, ADC0-30 saw the DT.

Next we replaced the DAC's ribbon cable and interface card. This make things worse, no CH0 signal and now no Duotone. Interface old (removed) S1101353, new (installed) S1000868.

Thinking that ribbon cables are more likely to fail than IF cards, we went back to the original IF card S1101353, installed another ribbon cable, and shuffled DAC0 over to the second Adnaco backplane. THIS FIXED IT.

Several changes were made here, so we are not sure if it was the slot move or the ribbon cable or both.

Here is the original card layout (not shown A4-1 = BIO0)

A3-4

A3-3

A3-2

A3-1

A2-4

A2-3

A2-2

A2-1

A1-4

A1-3

A1-2

A1-1

empty

16DAC1

16DAC0

20DAC1

empty

ADC3

ADC2

ADC1

20DAC0

ADC0

empty

Timing

and here is the one we ended up with (ADCs shuffled one left in A2, 20DAC0 moved to A2-1)

A3-4

A3-3

A3-2

A3-1

A2-4

A2-3

A2-2

A2-1

A1-4

A1-3

A1-2

A1-1

empty

16DAC1

16DAC0

20DAC1

ADC3

ADC2

ADC1

20DAC0

empty

ADC0

empty

Timing

We tested the first 6 channels (CH0-CH5) using h1susfc1 by untripping the watchdogs and driving the DAC with a FM offset of 10000, resulting in a 20bit-DAC drive of ~40000 counts, which gives 0.7V DAC output. CH7 was tested with the Duotone.

I was reminded that on the 1st December 2025 the h1iscex 18bit-DAC to 20bit-DAC upgrade failed with no drive on the new DAC. That was also the first DAC, and at the time we tested the DUOTONE signal (in fact DAC-DT is always on for CAL). In that DAC all the channels were not operational, and replacing the DAC fixed it immediately. So it looks like today's problem is different, and a much more insideous one because internally everything looks nominal but no voltage is actually sent by the DAC.

H1 SEI - CRS progress June 2 - x4 HOQIs built

arnaud.pele@ligo.org — Tue, 02 Jun 2026 21:37:03 -0700

Author: arnaud.pele@ligo.org

Report ID: 90452

Shoshana, Alexandra, Jim, Arnaud

Today we completed the build of x4 HOQIs (D2500104), wired the capacitive plates of two CRS (following pinout from D2500389, with cap A = Left plate and cap B = Right plate), and hung one CRS with a dummy flexure.

Tomorrow we will align and tune the HOQIs, and hung the CRS with its final flexure.

A few things to note:
*We used undersize (0.0625" for 0.063" hole) dowel pins on the baseplate to set the alignment of the 4 BS cubes, then removed the pins from underneath the plate. While this was our plan B, it worked quite well (initial design was to use 1/16" spring pins, but they are hard to insert without bending them).
*Some baseplates holes for the dog clamps were not threaded all the way through, we had to use washers to reduce the screw travel range. We will have to order a 4-40 tap and retap those holes.
*Some photodiodes cracked from screwing the setscrew in the holder (but we have enough spares). Details in the HOQI PD Testing tab of the spreadsheet attached to E2400153.
*For next time, we should make sure the photodiode vent hole is not aligned with the setscrew holding the photodiode in place (maybe update drawings D2600047)
*The waveplate holders were scribed with 4 lines for the 1/4 waveplate and 2 lines for the 1/2 waveplate so we can recognize them

Images attached to this report

H1 CDS - DAQ and EDC restart, new CS HepiPumpCtrl channels, removed h1susbs FEC, removed end station DUST VEA2

david.barker@ligo.org — Tue, 02 Jun 2026 21:33:31 -0700

Author: david.barker@ligo.org

Report ID: 90453

Jonathan, Patrick, Erik, Dave:

We restarted the DAQ + EDC around 16:00 this afternoon primarily to install Patrick's new H1EPICS_HEPIPUMPL0.ini to match his new IOC.

At the same time we removed the end station VEA2 Dust monitor channels, there hasn't been a second dust monitor at the ends for some time and the Sat power outage required an EY Dust restart which removed its VEA2 channels from the ioc. We also made the EX INI change for when its IOC is restarted.

To green up the EDC, we temporarily removed h1susbs' FEC-31 channels. Erik has put H1EPICS_[FEC,SDF].ini under puppet control, so these will be added back when h1susbs is reinstalled.

We also fixed an issue whereby yesterday puppet added some incorrect KC0 channels to the EDC. This was fixed today and there are now no KC0 channel in H1EPICS_DAQ.ini, they all reside in the hand-built H1EPICS_DAQKC0.ini. Around today's restart time KC0 coincidently went unstable, restarting itself every 5 seconds. The problem was downstream of KC0. Jonathan contacted LDAS and the problem was fixed within the hour.

The EDC is green again, first time since the power outage.

H1 ISC - HAM1/HAM2 alignment: RM sliders sign seems to be consistently wrong, confusing us (Disha, Rahul, Keita)

keita.kawabe@ligo.org — Tue, 02 Jun 2026 19:49:04 -0700

Author: keita.kawabe@ligo.org

Report ID: 90451

Good thing:

In the morning, we placed an iris placed between the IFI input baffle and the IFI HWP baffle (irisposition.png). We used an IR sensitive DSLR as a viewer to center the iris for the forward-going beam, and observed the back side of the iris using the same camera to see the PRM reflection.

This allowed us to set the PRM angle in much better accuracy than using a card with a bigger-than-needed hole handheld at an inconvenient location and observe with naked eyes through the laser glasses. We had to close down HAM3 cover as well as one side of HAM2 so PRM quiets down, but the retro-reflection accuracy was like +-50 urad (rather than +-500urad of yesterday).

With this new PRM alignment ([P, Y]=[-1165, +750]), I was able to center REFL sensors despite that RM2 was so close to railing, RM2 YAW offset was -1800urad. (ASC_REFL_balanced_20260602_morning.png and ASC_REFL_balanced_but_RM2_close_to_railing_20260602_morning.png.)

Nice thing was, at this point the beam was much closer to the center of IFI input baffle, IFO REFL beam clipping-like thing observed on the IFI input baffle was completely gone as well as the clipping on IM4 baffle. So things looked better in general than they were yesterday.

Bad thing:

RM2 was so uncomfortably close to railing nobody should leave it like that before pumping down, so I decided to relieve RM2 by tilting IM1. (Calculation is in alog 90404.)

I thought RM2 should be rotated counter-clockwise seen from the top because that would mean the positive YAW offset, we added negative 100urad to IM1 YAW offset (i.e. from -887.1 to -987.1 urad) based on my calculation, expecting to shave off 300 or 400 urad from the RM2 YAW. We reset the iris position for the forward-going beam, then reset the PRM angle, fully opened the iris and started centering the REFL sensors. Disappointingly, we couldn't center them, RM2 railed.

What was wrong:

We wasted some time trying to somehow find a magic slider values for RMs and going through how the angle of IM1 propagates to RMs, but it turns out that RM alignment sliders seem to have the opposite sign than all other suspensions. As far as we believe that the OSEM sensor (not actuator) produces positive DAC output that is proportional to the number of photons, the conclusion is that the sign of the sliders is wrong for both RM1 and RM2.

This is clearly shown in wrongsign.png where slider offsets of RMs were zero-ed one by one (top row) while the OSEM sensors in Euler bassis (bottom) were observed. Ignore the cross coupling from P actuation to Y sensing. In a suspension that follows the LIGO sign convention, the slider and the sensors move in the same direction roughly by the same amount. RM is the opposite of that, sensors move in the opposite direction of the sliders. We have done the same test for RMs, PM1 (see PM_is_good.png), OM1 (because they're all tip-tilts) and IM1 (because we touched it today) and confirmed that RMs are an exception.

If you're not sure about the rotation convention of LIGO optics, positive YAW rotation means counter-clockwise seen from the top. This will increase the light power on RIGHT OSEM sensors and decrease it on the LEFT. Given that the ADC reports positive voltage (i.e. positive counts), and given that usually OSEM YAW signal is proportional to voltage(RIGHT)-voltage(LEFT), positive physical YAW rotation will produce positive OSEM YAW change. See my cartoon (LIGO_YAW_sign_convention.jpg).

Now, RM1, RM2 and PM1 sensing look identical to me (osemsensors_look_good.png).

All OSEMs produce positive numbers for all three suspensions, there's no sign flip in the filters, filter output sign is only determined by whether or not the input is bigger or smaller than the mid-point offset, they all use identical OSEM2EULER matrix as well as SENSALIGN matrix, and the sign of DAMP_P as well as DAMP_Y are all according to the filter outputs and these matrices. So the sensors for RM1 and RM2 are working in the same way as PM1, they're fine.

The conclusion to me is that somehow the actuation sign is wrong for RM1 and RM2.

Rahul told me that the magnet polarity was wrong for RM1 or RM2 and people spent some time to address that issue. But that sounds like the actuation side issue which should NOT affect the validity of the sensors. Unless people tell me that somehow the physical UL/UR/LL/LR sensors are wired to the LR/LL/UR/Ul channel or something, we just believe the OSEM sensors and assume that the sign of sliders is flipped.

Tomorrow:

Regardless of the reason of the sign flip, we'll proceed to move IM1 in the opposite direction, i.e. somewhere between this morning and Friday.

FYI below is the history of IM1 YAW offset in the past week. The change made on Monday was motivated by the "need" to relieve RM2, but now that we know that the PRM retroreflection accuracy matters, I'm not sure if it would have been impossible to center REFL ASC sensors on Friday if we used the iris technique to align PRM.

	Friday last week	Monday	Monday	This morning	This afternoon
IM1 YAW slider	-387urad	-887urad	-887urad	-887	-987
PRM retroreflection	questionable	questionable (YAW offset = 1000urad)	questionable (YAW offset = 700 urad)	better (YAW offset = 750)	better (YAW offset = 1000)
REFL ASC centered	No (RM2 rails)	No (RM2 rails)	yes	yes (RM2 close to railing)	no (RM2 rails)

INS, IOO, ISC

Images attached to this report

H1 SQZ - Comment to HAM7 IR ZM4 Iris Set

sheila.dwyer@ligo.org — Tue, 02 Jun 2026 17:21:43 -0700

Author: sheila.dwyer@ligo.org

Report ID: 90450

Adding some other details:

We became concerned that we could not reproduce the alignment that we had yesterday that got IR beam onto SQZT7 IR PD. We were able to get the beam back without cliping by setting the ZM sliders back to the screenshot from yesterday (90426), and restoring FC1 M3 WIT to where they were yesterday (-85 P, -34 Y). This is not the same alignment of FC1 as O4, or as it was in our reference time 90183, but it convinced us that the ZMs hadn't moved since yesterday.

Camilla then reverted the changes she made to ZM4 + ZM5 sliders, so that they now match our in vacuum reference time for IR reaching SQZT7, 90183. She also set the FC1 sliders to reproduce the FC1 M3 wit from that reference time (P -49, Y -13) . The beam was then not centered on the SQZT7 irises, and was clipping somewhere on the VIP. Camilla then adjusted FC1 pitch to reduce the clipping and center the beam on the SQZT7 irises. This brought FC1 pitch back toward's yesterday's value (now it is at -144 urad P, -31 yaw).

We centered the iris in front of ZM4, and we think this iris will be good enough for us to recover alignment onto SQZT7 once we have recovered FC1 alignment to O4, fixed the clipping on the VIP.

H1 SQZ - Comment to HAM7 IR ZM4 Iris Set

camilla.compton@ligo.org — Tue, 02 Jun 2026 16:49:30 -0700

Author: camilla.compton@ligo.org

Report ID: 90449

Attached is current sliders.

Images attached to this report

H1 SQZ - HAM7 IR ZM4 Iris Set

camilla.compton@ligo.org — Tue, 02 Jun 2026 16:48:27 -0700

Author: camilla.compton@ligo.org

Report ID: 90448

Sheila, Begum, Camilla, Fil, Dave, Erik

Day 2 of the HAM7 work, follow on from 90426. The CDS/EE team fixed the FC1 top mass, unsure how. We found we then could not trust the sliders at all. We reverted all optics (apart from FC1) to the 90183 time. We tired putting the FC1 M3 WIT back to this time but the beam clipped on the OPOS.

Then we moved FC1 to center the IR on the SQZT7 irises. Got perfectly centered on far iris, a little high on iris at the bottom of the periscope.

Begum and Sheila then moved the ZM4 iris to mark this alignment.

H1 General - OPS Tuesday Day shift summary

ryan.crouch@ligo.org — Tue, 02 Jun 2026 16:34:00 -0700

Author: ryan.crouch@ligo.org

Report ID: 90442

TITLE: 06/02 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: HAM3 FAROing finished, HAM2, BBS, and SPI work continue. The LVEA is in LASER HAZARD.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
19:26	SAF	Laser HAZARD	LVEA	YES	LVEA is Laser HAZARD	21:23
14:54	FAC	Kim	LVEA	Y	Tech clean	17:34
15:08	FAC	Randy	EndX	N	Engine hoist inspection	15:54
15:51	FAC	Chris	LVEA	Y	PEst contractor walkthrough	16:03
15:55	FAC	Randy	LVEA	Y	remove lights @bsc platform	17:36
15:57	FAC	Keita, Rahul, Disha	LVEA	Y	HAM2 work	19:14
16:04	FAC	Chris	Out Bldgs	-	Pest control	17:17
16:05	IAS	Jason, RyanC	LVEA	Y	MC2 FAROing	18:39
16:15	vac	travis.gerardo.jordan.jake.owen	lvea	-	XBeamMani VENT	18:32
16:15	vac	travis.gerardo.jordan.jake.owen	lvea	-	GV2 OPENING (Gerardo out @1833)	18:42
16:26	SLiC	betsy.ryanS.anamaria.robert	lvea	Y	baffle prep at bsc1 (Betsy out @1900)	20:17
16:43	CRS	shoshana.jim.alexandra	h2psl	-	CRS	19:22
16:43	SPI	jeff.jennie.sina	OpticsLab	yes	SPI (Jennie, Sina out @1939) Jennie back in 20:45	21:32
16:45	bbss	ibrahim.tom.ollie	West Bay	-	Test stand work	19:17
16:46	sqz	sheila.begum.camilla	lvea	yes	HAM7 SQZ (Sheila, Begum out @1913)	19:28
18:39	CC	Ryan C	LVEA	Y	Checking on HAM7 dust monitor	19:24
18:49	CDS	Fil	LVEA	yes	Troubleshooting FC1, swap DAC card	20:45
20:13	SUS	Betsy, Tom, Oli	LVEA	Y	BBSS test stand cabling, Oli in @ 20:42, Tom out 20:58, Oli out 21:02	22:12
20:20	VAC	Travis	LVEA	Y	Gatevalve BTmanifold swap	21:35
20:28	SUS	Mitch	LVEA	Y	Test stand work	22:45
20:35	VAC	Gerardo	Yend	n	Grab tools	21:13
20:36	SUS	Ibrahim	LVEA	Y	Join Mitch, test stand bbs	22:45
20:37	SEI	Jim, Shoshana, Alexandra, Arnaud	LVEA, H2 PSL	Y	CRS work, Arnaud in @ 21:20	Ongoing
20:59	OPS	TJ	LVEA	Y -> N	LASER hazard transition	21:27
21:12	SQZ	Camilla, Arnaud	LVEA	Y	Grab power meter	21:20
21:28	FAC	Richard	LVEA	N	Safety checks	21:43
21:31	SEI	Jim	LVEA	no	Lock BSC3 ISI	21:51
21:33	SPI	Jennie	LVEA	N	Check test stand for allen key	21:42
21:41	SUS	Jeff, Sina	LVEA	n	Looking at BBS	22:00
21:43	SLiC	Robert, Anamaria, Ryan S	LVEA	Y	BSC SLiC baffling	Ongoing
21:48	OPS	TJ	LVEA	N	Check with Jim, laser transition	22:03
22:00	SUS	Disha, Rahul, Keita	LVEA	Y	HAM2 work, Disha Keita out at 23:17	23:19
22:01	SQZ	Sheila	LVEA	Y	HAM7 work	Ongoing
22:06	SQZ	Camilla	LVEA	Y	HAM7 work	Ongoing
22:09	SAF	LASER HAZARD	LVEA	Y	The LVEA is LASER HAZARD	02:09
22:15	VAC	Travis, Gerardo	LVEA	Y	Survey viewports, travis out 22:50	23:15
22:26	PEM	TJ	Ends	N	Check on dust monitor pumps	23:04
22:27	SPI	Sina	Optics lab	LOCAL	SPI work	23:27
22:46	H2PSL	Fil	H2PSL	Y	h2psl work	23:30
22:47	SLIC	Jennie W	BSC2	Yes	batteries	22:48

FC1 issues were investigated (FRS38162) and fixed.
19:53 UTC sush7 restart
21:15 UTC Transition to LASER SAFE for Jim to lock ITMX ISI then back to HAZARD
22:50-23:05 UTC Periodically I saw seeing red blocks flashing around the COIL OUTPUT FILTER boxes on M0 and M1 for ITMY, I'm guess this was from the crew installing baffles making the osems angry.

H1 IOO - Comment to Found mistake in WFS Q matrix for both JAC WFS

jennifer.wright@ligo.org — Tue, 02 Jun 2026 16:33:24 -0700

Author: jennifer.wright@ligo.org

Report ID: 90447

I also had a check through the wiring in the simulink h1ascimc/jac model for both WFS_A and WFS_B and this looks to be the correct wiring for each segment.

H1 IOO - Found mistake in WFS Q matrix for both JAC WFS

jennifer.wright@ligo.org — Tue, 02 Jun 2026 16:31:35 -0700

Author: jennifer.wright@ligo.org

Report ID: 90446

Jennie Wright

Summary: Started debugging JAC WFS, two corrections made in WFS segment -> euler basis matrix.

Not sure if this change was made by the power outage or it has been set up wrong the whole time but the channels for segment 3 and 4 in the Q phase matrix for both JAC WFS QPDs were wrong.

This meant yaw = + segment 1 - segment 2 + segment 3 - segment 4 which would be some kind of weird pringle mode.

I corrected the sign, and also updated the note at the bottom right of the JAC_WFS_SETTINGS screen to reflect the sign that the WFS should have (the previous note here described the IMC WFS euler basis as I had copied the medm screen from the IMC custom screens).

now yaw = +1 -2 -3 + 4.

NB: JAC WFS euler basis matches other ASC QPDs but the IMC has P & Y swapped due to the persicopes in HAM2 and so has yaw = +1 + 2 -3 -4 and pitch = +1 -2 -3 +4.

New values for Q matrices are accepted in sdf, as is the PSL PZT mirror offset values that align the beam to the JAC as this has changed since it was last set before the power outage.

IOO

Images attached to this report

H1 SUS - BBSS Vacuum Buoyancy OSEM Offset

thomas.roocke@ligo.org — Tue, 02 Jun 2026 15:20:25 -0700

Author: thomas.roocke@ligo.org

Report ID: 90445

Summary: The QOSEMs on the BBSS will see a vertical sag of ~50um. The LF and RT QOSEMs should be offset 50um low of center in there x axis, and the F1, F2, F3, SD QOSEMs should be offset 50um low of center in there y axis; such that they will be well centered when under vacuum.

In T2600176 (write up to come) we calculate the expected vertical sag of the BBSS suspension chain to be 58um at M1. This is slightly larger than the 50um predicted for the BSFM (T1100616), which is consistent with the fact the payload is lighter. To verify these calculations, we pulled OSEM data from the last pump down of the BSFM (April 26 2025 = 1428872333)), and see that there was a vertical sag on the LF and RT BOSEMs of ~35um. See the figure attached.

This is about 10um less than predicted by the calculations for the BSFM, a trend which is also seen on the Quads (LHO alog 15887). As such we suggest that the BBSS should have its M1 QOSEMs offset by ~50um low of center, also about 10um less than the theoretical value. The M2 and M3 OSEMs do not need to be offset, as they don't measure in the vertical direction.

SUS

Images attached to this report

H1 SQZ - Comment to HAM7 started placing irises

sheila.dwyer@ligo.org — Tue, 02 Jun 2026 14:47:57 -0700

Author: sheila.dwyer@ligo.org

Report ID: 90444

This morning we reverted the -710 counts on H1:SYS-MOTION_C_PICO_J_MOTOR_3_X_POSITION (H:M2 yaw), undoing the change that we made in 89596. This seems to have improved the co-alignment, I will attach a photo here to compare to the co-alingment photos from yesterday (90426)

We also lowered the PZT scan range to get the OPO seed dither locking to work well, as it was trying to lock at the top of the PZT range and not staying locked. (line 654 of the OPO guardian).

We attempted to go to the alignment in 89694 to check the alignment of FC1, but we saw that FC1 was not actuating. This is probably why Camilla had to adjust the alignments of ZM4 + ZM5 yesterday. 90426. The CDS team is working on the issue with FC1 alignment.

H1 AOS - ITMY Baffle Install Progress

ryan.short@ligo.org — Tue, 02 Jun 2026 14:31:07 -0700

Author: ryan.short@ligo.org

Report ID: 90443

A. Effler, R. Schofield, R. Short

This morning, we started working in BSC1 to prep for the new cage baffle installation on ITMY. Before going into any chambers, Anamaria and Robert moved ITMY to center the OpLev signals. Once at BSC1, Anamaria and I were in the chamber while Robert handled tools in and out as well as kept an eye on particle counts. We started by attaching the long locker bracket on the arm cavity baffle (ACB), then pushed the ACB up and away from the quad after undoing the hinge assembly. While holding the ACB up, we inserted and screwed in the wedge that keeps the ACB away from the quad. With this out of the way, we locked down the bottom two stages of both the main and reaction chains of ITMY by pushing in the earthquake stops until they just came into contact. We then went about replacing the stops on the HR surface of the ITM. After this, we realized that we meant to get measurements of the test mass and reaction mass before they were locked down, so we unlocked the bottom stages of each chain so they were free hanging and took measurements, then re-locked the stages. At this point, we stopped for lunch.

H1 SUS - BBSS QOSEM First Transfer Functions

oli.patane@ligo.org — Tue, 02 Jun 2026 12:21:19 -0700

Author: oli.patane@ligo.org

Report ID: 90440

Ibrahim, Tom, Oli

Yesterday we were able to take our first set of transfer functions with the QOSEMs! They are looking good. The measurement files can be found in /ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Data/2026-06-01_1700/2026-06-01_1700_H1SUSBS_M1_WhiteNoise_{L,T,V,R,P,Y}_0p02to50Hz.xml. I have committed the data files to svn as r13024, but I have not yet exported them or analyzed them in matlab because I want to make sure I do it the same way that LLO has decided to do it.

Images attached to this report

H1 SUS - BBSS Test Stand Work 2026/06/01

oli.patane@ligo.org — Tue, 02 Jun 2026 12:20:10 -0700

Author: oli.patane@ligo.org

Report ID: 90441

Tom, Ibrahim, Oli

Yesterday we made a lot of progress on the BBSS, specifically on the QOSEMs.

First, we went around between all the QOSEMs and worked on centering in the X and Y directions. Once we got everything within +/-1000 counts, we made sure the cam adjusters were all tightened. We did this with the constant current switched ON for all the QOSEMs at the satamp, and with the whitening OFF on the satamp but had the compensation ON in medm.

Then we left and were ready to try damping and transfer functions.

We switched the constant current OFF for the QOSEMs now, since we wanted the satamp to be able to adjust the currrent to keep it the same. We also ended up needing to turn the whitening compensation OFF in the model to be able to see the actual amount of movement since it had also been OFF at the satamp.

While trying to damp, we found that we needed to swap the sign of the damping gains to get damping to work. We believe this is because these QOSEM coils, which were made out of older BOSEMs, had the opposite wires from normal connected up, leading to the current flowing the opposite way than expected.

We also needed to lower some of the damping gains.

I've attached a screenshot of how our damping filter bank looks now, but it seems to be working well!

Images attached to this report

H1 General - Comment to OPS Tuesday Day shift start

corey.gray@ligo.org — Tue, 02 Jun 2026 10:57:50 -0700

Author: corey.gray@ligo.org

Report ID: 90437

1610-1756 Covering Ops while RyanC does morning FARO work, and then handing off to TJ.

Have had a few connection drops for the EY Dust Monitor

LOG:

1611 Ryan joining Jason for MC2 FAROing
1615 VAC team: XBM venting + GV2 opening (travis,gerardo,jordan)
1617 Randy out
1623 Kim out of lvea for quick break.
- 1653 heading back to LVEA for cleaning around mega cleanroom
1623 baffle prep @BSC1 (betsy.ryanS)
1631 ham7 sqz (sheila, begum)
- 1640 camilla joining
1632 HEPI Pump station @lvea pressing RESET button, and then moving on to CRS (jim)
1640 SPI work (sina, jennie, jeff)
1640 CRS team (shoshonna, jim, alexandra, arnaud)
1644 BBSS test stand (ibrahim)
- 1654 tom joining, 1724 ollie joining
1703-1732 Removing lighting on BSC platform (randy)
1716 BSC1 baffling team (anamaria.robert)
1716 Chris & Pest Control done (found lots of snakes...3 live ones released to desert).
1724 Have had EY disconnects which alarm the Dust Monitors.
1734 Joining VAC team (jordan.jake (new intern).owen(new intern)

H1 SUS - h1suslo12 model update - COIL2M1DAC and BIO IPC receivers/senders back in

oli.patane@ligo.org — Tue, 02 Jun 2026 10:00:46 -0700

Author: oli.patane@ligo.org

Report ID: 90358

Yesterday I made some changes to the h1suslo12 model(before, after). We were now done with the BOSEMs on the BBSS, so we needed the BBSS model to be able to drive to the DAC for M1 so we could test the QOSEMs. We also needed to be able to switch the BIO on the BBSS, so we also needed to connect the BIO senders and receivers back up to be able to communicate with MC2, which controls the BIO switching for the b2h34 models.

To be able to run this updated model, we would also need to stop the h1susbs model so there wouldn't be mulitple sets of channels trying to write to the same DAC.

Erik and Jonathan (90422) helped with stopping h1susbs, and with building and restarting h1suslo12.

CDS

Images attached to this report

H1 SPI - 2026-06-01 SPI Pathfinder Update: More Things Ruled Out -- it's NOT the picomotor mounts

jeffrey.kissel@ligo.org — Tue, 02 Jun 2026 09:20:44 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90438

J. Kissel, S. Koehlenbeck (in person!) D2400107 for the annotated layout of SPI Pathfinder ISIK's Transceiver Assembly. After an easy recovery from other-the-weekend, site-wide power outages (LHO:90413), we resumed last week's investigations of what might be causing the MEAS IFO to drift (LHO:90382). %%%%%%%%%%%% Executive Summary: No magic bullet found. Today we ruled out the collective idea we all had that the picomotor-actuated mounts were the problem (LHO:90384) by replacing every pico-actuated mount with manually driven mounts. We also replaced the last optic we hadn't swapped in the MEAS path to the MEAS IFO -- M_B1. No impact -- we still see the MEAS IFO alone drift. %%%%%%%%%%%% It was only a half-day of forward investigative progress given the power outage, but having Sina on-site really helped confirm my (in)sanity and accelerate investigatory iterations. Upon arrival in the lab Sina re-confirmed my construction and alignment of the D2400107-v5 board and the quality of things: - Centering on optics with IR card :: good. - Centering on photodiodes with IR camera :: good. - No stray beams (even from what would be AR coatings of beam splitters) :: good. - The as-we-left-off Friday assessment that with M_M2 and M_B4 down-graded to manually driven mounts, we still see drift. - Having one or the other REF or MEAS beam into the MEAS IFO blocked, that the power on each beam is stable without drift. - After an alignment drift, quickly touching the alignment of all three M_M2, M_B4, and M_M1 cannot recover the MEAS IFO efficiency. As we continue to grasp at straws, we replaced the last optic in the MEAS path into the MEAS IFO -- M_B1. This optic splits the MEAS beam on the board feeding it to the MEAS and REF IFOs, so we were hesitant to swap it. But now that we're getting so good at re-aligning the board after changing out optics (once optic is placed, re-alignment can be done within 2-5 minutes), we figured we must. So, all at the same time, we - unlocked all manual drive set-screws on all optics (recall the REF path had been "locked down" the day I'd gotten ~95% efficiency), - loosened and re-tightened R_B1's 1/4-20 bolt that secured the mount to the breadboard. It wasn't "loose" but it wasn't "cranked on" either. - Replaced M_B1 optic - Replaced the M_B1 manual-drive pitch actuator's 1/4-100 alignment screw and bushing because it was "crunchy" and "stiff" to use. This had been this way, but when I was driving solo I'd suffered thru it and locked it down the day I got 85% efficiency on the MEAS IFO and didn't look back. Now what we're touching the mount anyways, we figured we might replace it in case the issue was some sort of stick-slip thing happening. Upon doing all these things ... things looked solid for ~10 minutes... and then the efficiency started to drift again. Especially after turning on the Clean Room fans. This again resurrects the theory we thought debunked: "it must be the environmental conditions..." Why did we rule this out before? (1) The REF IFO does not see any drift. Ever. The board is so small and so local, and both IFOs are sampling the same beams. *Very* hard to believe that the few differences in paths and path lengths would cause only ONE of the IFOs to drift. The environment should impact both IFOs equally. (2) We *do* see phase noise when we make environmental changes -- as expected. Path length differences caused by - physically manipulating the board, its mounts, or optical fibers, - waving hands over the board - talking, even at a medium volume (3) Any environmental change in the efficiency we can cause -- be it: - clean-room fans ON/OFF, - clean-room or room lights ON/OFF, - people coming in-and-out of the clean room, - standing in different positions around the optical table -- they all only some-times seem correlated, and never is it reproducible. But we've run out of things to change, so today we're going to try to adjust the environment and/or other things that *should* be common to the IFOs: (a) We're gunna being in an incandescent lamp to try to create thermal gradients (b) We'll put on our tin-foil hats and enclose the breadboard in a temporary foil enclosure (c) We'll try adjusting the NPRO seed laser controller's parameters (like diode temperature) ...and keep trying all the other wild theories we can concoct.

H1 General - Comment to OPS Tuesday Day shift start

ryan.crouch@ligo.org — Tue, 02 Jun 2026 08:15:59 -0700

Author: ryan.crouch@ligo.org

Report ID: 90435

A ~2 week trend of the LVEA temperatures.

Images attached to this report

H1 General - OPS Tuesday Day shift start

ryan.crouch@ligo.org — Tue, 02 Jun 2026 07:30:34 -0700

Author: ryan.crouch@ligo.org

Report ID: 90434

TITLE: 06/02 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: 8mph Gusts, 4mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.14 μm/s
QUICK SUMMARY:

FAROing on HAM3, HAM2 work, and HAM7 continues
DAQ_KCO channels are disconnected

H1 CDS - Comtrol power supply replaced at EY

erik.vonreis@ligo.org — Tue, 02 Jun 2026 07:07:07 -0700

Author: erik.vonreis@ligo.org

Report ID: 90433

Yesterday (June 1) I replaced a failed power supply on the Comtrol communication device at EY that bridges a dust monitor and a weather station to the network.

CDS

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 02 Jun 2026 07:05:17 -0700

Author: erik.vonreis@ligo.org

Report ID: 90432

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

CDS

LHO VE - Corner station vent update

travis.sadecki@ligo.org — Mon, 01 Jun 2026 19:55:46 -0700

Author: travis.sadecki@ligo.org

Report ID: 90431

Today started with removal of the HAM7 +X and -Y doors, WP 13283. These were already on 4 bolts/piece, so removal was relatively quick. Nothing to note other than the usual O-ring sticking business. The 2x 12" CF blanks on the +Y door were also removed for ISI locker access. Since the final cleaning happened ~1 hour from door removal, particle counts were very minimally elevated, 40 @ 0.3um and 20 @ 0.5um (see pic).

We then moved on to the X-beamtube manifold vent work, WP 13284. The X-manifold turbo pump was valved out. We then cycled GV7 open, then hard closed again. The GV opened at 10 psi, and hard closed at 20 psi, so we believe the piston O-ring replacement is working well. Then, the X-manifold vent was started. After burping the system a few times and confirming there was no communication past GV7, we started venting the manifold section. We noted that the Kobelco's duty cycle seemed to increase audibly as the pressure in-vacuum rose, which isn't surprising given that we have 7 doors and 2x 12" ports open on the corner volume, so we elected to keep the vent slow, maybe 5 torr/minute. We stopped the vent for the night at around 400 torr. Tomorrow, we'll finish venting and open GV2.

Images attached to this report

H1 IOO - HAM1/2/3 alignment Monday (Disha, Rahul, Jenne, Keita)

keita.kawabe@ligo.org — Mon, 01 Jun 2026 19:29:04 -0700

Author: keita.kawabe@ligo.org

Report ID: 90430

After JAC was recovered (alog 90421) we moved IM4 by negative 500urad YAW (from -387.1urad to -887.1urad) and adjusted PRM so that it retroreflects (without bothering to adjust IM2, 3 and 4 in the interest of time) and Jenne started centering the REFL A and B using RMs.

However, RM2 still railed.

Turns out that the accuracy of retroreflection matters because 100urad rotation of PRM causes the equivalent of 280urad rotation of IM1 as far as the beam angle leaving RH9 (IFO REFL pickoff) is concerned.

The retroreflection technique was nothing sophisticated, we used an IR card with a hole, put the card between the IFI output baffle and DKDP baffle, put the forward going beam in the hole in the card so it goes through. Rahul would make a huge (like 1.5mrad) YAW rotation for PRM, first positive YAW to find the reflected beam on one side of the hole in the card, and then negative YAW to find it in the other side of the hole, and find a good PRM YAW offset where the reflected beam for +1.5mrad positive and negative offsets are balanced on the card. The retroreflection accuracy is no better than +-500urad.

Anyway, using this technique we moved the PRM slider offset to [P, Y]=[-1165, +1000] (from [-1165, 20.5]).

Out of curiousity I changed the YAW offset of PRM from +1000 to +700 so [P,Y]=[-1165, +700], used RM1 to center REFL_B and RM2 to center REFL_A and it was easy without railing RM2 nor RM1. See attached.

I'll see if there's a space for an iris on IFI where both faces are clearly visible. If so we can probably use an IR sensitive camera as a better resolution viewer, center the iris for the forward going beam well, and observe the centering of the return beam on the iris.

(However, it's still a good idea to reduce the output impedance of the RM OSEM coil drivers. Small actuation range is fine if things are working well, but they're not.)

IOO

Images attached to this report

H1 SEI - CRS progress log

arnaud.pele@ligo.org — Mon, 01 Jun 2026 18:17:58 -0700

Author: arnaud.pele@ligo.org

Report ID: 90429

Jim, Shoshana, Alexandra, Arnaud

Today we continued setting up the H2-PSL lab to start the testing the HOQIs.

* Received and moved the laser system (RIO+Laser Driver+TEC), and readout (HOQI TIA) in the H2-PSL (see picture 1)
* Gathered needed electronics from the EE shop (See list below) and plugged them in the lab
* Bagged and tagged the peek HOQI components from VPW (waveplate holders, photodiode holders, in-vac cables)
* Visually inspected the new batch of 10 flexures after c&b (see picture 2), and brought them to the H2-PSL (no issues found so far)
* Started setting up the Panasonic optical readout for CRS balancing. We will need some basic components from the optics lab to hold this readout.

Items borrowed from the EE shop :

x2 GWINSTEK power supply
x1 Hewlett P power supply
x1 multimeter with probes
x1 Techtonik oscilloscope
x1 Bnc banana plug
x4 bnc to clips
x4 bnc cables
x1 db9 cable
x3 power cables
x3 breakout boards (x2 db9 and x1 db25)
x3 db9 gender changers

Images attached to this report

H1 CDS - WP 13286 Migrating the fmcs IOC off of the mac mini failed

jonathan.hanks@ligo.org — Mon, 01 Jun 2026 17:06:47 -0700

Author: jonathan.hanks@ligo.org

Report ID: 90428

As per WP 13286 I tested the copy of the fmcs epics ioc that I had extracted from fmcs-epics-cds. Unfortunately the IOC would crash each time I ran it. There was not time to debug and see if it could be fixed today. So the mac mini is still running the ioc.

H1 AOS - HAM7 started placing irises

sheila.dwyer@ligo.org — Mon, 01 Jun 2026 17:03:03 -0700

Author: sheila.dwyer@ligo.org

Report ID: 90426

Sheila, Camilla, Disha

After Jim locked the ISI, Marc bypassed the high voltage interlock, and Camilla restored the psams, we reset the alignment sliders following 90483 which was in air. The dither locking worked without any issue, and we saw that the beam was low on both the irises in the homodyne path on SQZT7. Camilla adjusted the alignments of ZM4+ZM5 to center the beam on the irses, screenshot attached shows the alignment that she found.

We placed an iris in front of ZM4 for this alignment, we were able to look from the +X side of the chamber to check the centering. We also took photos of the IR/green co-alignment, it looks good coming right off the VIP, but looking right after ZM3 you can see that there is a small misalignment in yaw. We will continue with placing irses tomorow.

Images attached to this report

H1 CDS - Comment to Model restart and DAQ restart

jonathan.hanks@ligo.org — Mon, 01 Jun 2026 17:00:24 -0700

Author: jonathan.hanks@ligo.org

Report ID: 90427

The following channels where removed from the broadcast list:

H1:SUS-BS_M1_DAMP_L_IN1_DQ
H1:SUS-BS_M1_DAMP_P_IN1_DQ
H1:SUS-BS_M1_DAMP_R_IN1_DQ
H1:SUS-BS_M1_DAMP_T_IN1_DQ
H1:SUS-BS_M1_DAMP_V_IN1_DQ
H1:SUS-BS_M1_DAMP_Y_IN1_DQ
H1:SUS-BS_M2_WIT_L_DQ
H1:SUS-BS_M2_WIT_P_DQ
H1:SUS-BS_M2_WIT_Y_DQ
H1:SUS-BS_M3_OPLEV_PIT_OUT_DQ
H1:SUS-BS_M3_OPLEV_SUM_OUT_DQ
H1:SUS-BS_M3_OPLEV_YAW_OUT_DQ

They were replaced by BBSS variants:

H1:SUS-BBSS_M1_DAMP_L_IN1_DQ
H1:SUS-BBSS_M1_DAMP_P_IN1_DQ
H1:SUS-BBSS_M1_DAMP_R_IN1_DQ
H1:SUS-BBSS_M1_DAMP_T_IN1_DQ
H1:SUS-BBSS_M1_DAMP_V_IN1_DQ
H1:SUS-BBSS_M1_DAMP_Y_IN1_DQ
H1:SUS-BBSS_M2_WIT_L_DQ
H1:SUS-BBSS_M2_WIT_P_DQ
H1:SUS-BBSS_M2_WIT_Y_DQ
H1:SUS-BBSS_M3_OPLEV_PIT_OUT_DQ
H1:SUS-BBSS_M3_OPLEV_SUM_OUT_DQ
H1:SUS-BBSS_M3_OPLEV_YAW_OUT_DQ

We are told in a future update the original names will be restored.

H1 AOS - Quad cage baffles staged for ITMY

anamaria.effler@ligo.org — Mon, 01 Jun 2026 16:38:58 -0700

Author: anamaria.effler@ligo.org

Report ID: 90425

Betsy, Anamaria

With the helpful kits Mitchell had prepared, we assembled the cage baffle brackets and panels on a table by BSC1; this includes CP and HR cage baffles. We chose SN 3's for ITMY and SN 4's for ITMX for both panels and brackets. We also checked that we have the various tools we need chamber side. Still need to make one more set of brackets for ITMX CP baffle, but that can wait. We found and staged two ACB long lockers but only one wedge.

LHO General - Ops Day Shift Summary

ryan.short@ligo.org — Mon, 01 Jun 2026 16:35:58 -0700

Author: ryan.short@ligo.org

Report ID: 90424

TITLE: 06/01 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: Very busy day with lots of visitors on site! Essentially everything was recovered following the weekend power outage, doors on HAM7 were removed and SQZ work in the chamber started after the ISI was locked, QOSEM work continued on the BBSS, the ISI was balanced on the test stand, prep began for the ITM cage baffle installation, GV7 was cycled and left closed for venting of the X-manifold, more beam alignment went on in HAMs 2 and 3, turbopumps at EY and MY were tested, FARO surveying began in HAM3, CRS building continued, and SPI work in the optics lab is ongoing. The EDC is still showing several disconnected channels, some of which relate to EY dust monitors.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
19:29	SAF	Laser HAZARD	LVEA	YES	LVEA is Laser HAZARD	17:21
14:36	FAC	Kim	LVEA	-	Technical cleaning	17:01
14:43	FAC	Randy	LVEA	-	Prep for HAM7 doors	15:12
15:01	VAC	Jordan	LVEA	-	Checking pumps	15:10
15:37	SPI	Jeff	Opt Lab	Local	Turning on laser	17:00
15:38	IAS	Ryan C	LVEA	-	Checking on FARO	15:47
15:46	ISC	Keita	LVEA	-	Opening light pipe	15:48
15:46	VAC	Jordan	MY, EY	-	Turbopump checks	16:40
16:04	PSL	Jason	LVEA	-	Powering on PSL CB2	16:22
16:19	VAC	Travis	Lvea	-	HAM7 door prep	16:25
16:28	SAF	Ibrahim	LVEA	-	Transition to SAFE	17:21
16:54	SUS	Oli, Tom	LVEA	-	BBSS QOSEM	18:19
17:21	SUS	Ibrahim	LVEA	-	BBSS work	18:19
17:22	FAC	Randy	LVEA	-	HAM7 door removal	19:22
17:22	VAC	Travis, Jordan	LVEA	-	HAM7 door removal	18:40
17:22	FAC	Kim	EX, EY	-	Technical cleaning	18:19
17:24	CDS	Erik	EY, EX	-	Power outage recovery	18:27
17:29	VAC	Gerardo	LVEA	-	HAM7 door removal	18:41
17:33	SLiC	Mitch, Anamaria	LVEA	-	Baffle install planning	17:46
17:38	SPI	Corey	Opt Lab	-	Optic cleaning	19:46
18:15	IAS	Jason, Ryan C	LVEA	-	FARO surveying HAM3	20:33
19:04	SAF	Sheila	LVEA	YES	Transition to Laser HAZARD	19:26
19:09	TCS	Camilla	MER	-	Turning on TCS chillers	19:25
19:26	SAF	Laser HAZARD	LVEA	YES	LVEA is Laser HAZARD	Ongoing
19:27	SEI	Shoshana, Arnaud	H2 PSL	-	CRS builds	19:53
19:34	SEI	Jim	LVEA	-	Locking HAM7 ISI	19:54
19:55	SEI	Jim	EX, EY	-	Bringing up HEPI	20:33
20:13	SPI	Jeff, Sina	Opt Lab	Local	SPI alignment	22:04
20:24	VAC	Jordan, Jake, Owen	EY, MY	-	Shutting down turbopumps	21:20
20:33	ISC	Marc, Keita	CER	-	PZT power supply	20:37
20:50	SLiC	Betsy, Anamaria	LVEA	-	Staging for baffle install (Anamaria out @ 23:04)	Ongoing
20:59	SEI	Jim, Ibrahim	LVEA	-	BBSS ISI balancing	Ongoing
21:08	VAC	Travis, Gerardo	LVEA	-	X-man vent and open GV2 (Gerardo out @ 23:03)	Ongoing
21:24	VAC	Jordan, Jake, Owen	LVEA	-	X-man vent and open GV2	22:18
21:28	SEI	Marc, Patrick	MER	-	HEPI electronics	21:58
21:30	SQZ	Sheila, Camilla	LVEA	Y	HAM7 SQZ beam hunting (Camilla out @ 22:58)	Ongoing
21:38	IAS	Jason, Ryan C	LVEA	-	FARO surveying HAM3	Ongoing
21:58	ISC	Keita, Rahul, Disha	LVEA	Y	HAM2/3 beam alignment	Ongoing
22:04	SEI	Arnaud, Shoshana, Alex	H2 PSL	-	CRS builds (Alex out @ 23:11)	Ongoing
22:32	VAC	Jordan, Jake, Owen	LVEA	-	Venting X-manifold	Ongoing
22:35	SPI	Jeff, Sina	Opt Lab	Local	SPI alignment (Jeff out @ 23:05)	Ongoing
23:18	AOS	Mitchell	LVEA	-	Delivering garb	Ongoing

H1 CDS - Model restart and DAQ restart

erik.vonreis@ligo.org — Mon, 01 Jun 2026 14:55:03 -0700

Author: erik.vonreis@ligo.org

Report ID: 90422

[Jonathon, Ollie, Erik v., Tom]

h1susbs front end model was shut down and h1suslo12 was rebuilt and restarted, moving control of mc2 form h1susbs to h1suslo12.

This required DAQ and EDCU restarts. The DAQ restart ran into problems because some channes were renamed (temporarily, hopefully) from BS to BBSS that were part of the GDS broadcast. These channels have been renamed in the broadcaster lists for h1daqgds0 and g1daqgds1.

H1 IOO - JAC recovery from power outage (Ryan, Patrick, Marc, Rahul, Jenne, Keita)

keita.kawabe@ligo.org — Mon, 01 Jun 2026 14:54:40 -0700

Author: keita.kawabe@ligo.org

Report ID: 90421

JAC PZT HV was off -> Mark reset the interlock.

JAC heater chassis was off -> I switched it on at the rack.

JAC error signal was not crossing zero -> I updated the dark offset H1:JAC-REFL_A_RF43_I_OFFSET to a new number 2.4.

Beckhoff was reporting "invalid value" error for JAC PZT whitening -> Patrick did something to clear that.

Rahul restored slider numbers for JM1/3, IMC1/2/3, IM1/2/3/4 and PRM to Friday evening numbers as he reported in alog 90419.

JAC guardian didn't want to lock because H1:JAC-TRANS_A_DC_NORMALIZED kept getting below the threshold of 0.5. -> I temporarily changed it to 0.1.

JAC PZT voltage was drifting quickly for 30 minutes or so and JAC kept unlocking (probably because JAC was heating up) -> waited for a while.

JAC still didn't want to keep lock for a long time. -> I put it to DOWN state, followed the resonance manually using the PZT voltage for a minute or so, changed the state to LOCKED and the guardian liked that.

Jenne refined the JAC alignment using PZT and JM1. H1:JAC-TRANS_A_LF_OUT_DQ momentarily went up to 620 and the best number in the past month before today was like 580. It's trending down in the past two hours, now it's ~580 and that's still a very good number.

Temperature drift is still going on, the symptom is that the PZT voltage drifts down to -10 Volts and at that point JAC unlocks, but the guardian relocks to higher voltage fringe position right away, and the drift is slow enough it's bearable. Last lock lasted for an hour.

Now we can set H1:JAC-TRANS_A_DC_NORMALIZED back to 0.5 if we want to.

IOO, ISC

H1 ISC - Quick notebook script to calculate pit/yaw values when beam is flashing

jenne.driggers@ligo.org — Mon, 01 Jun 2026 14:24:05 -0700

Author: jenne.driggers@ligo.org

Report ID: 90420

Aligning beams onto QPDs while the IMC is flashing (eg, during a vent) is very challenging. We want to know what the pit and yaw values are, but can only trust the values at a moment when there is a flash.

The jupyter notebook that has just been placed into git can (with lots of patient help from Jamie Rollins) read data that has been exported from an ndscope (so, can be data that is not DQ'd), and then will calculate the pitch and yaw values at the time of the largest flash in that time window.

This is a direct link to the notebook right now for a snapshot of this first iteration, and you can see the plots at the very end and a printout of the pit/yaw values of all of the QPDs that I have collected data for.

Hopefully this will help make things a bit quicker as we work to center on our various ASC PDs and close out this vent.

H1 SUS - SUS alignment sliders for HAM1_2_3 restored to Friday evening (6.30pm) values

rahul.kumar@ligo.org — Mon, 01 Jun 2026 14:20:18 -0700

Author: rahul.kumar@ligo.org

Report ID: 90419

I have restored the SUS alignment slider values (P/Y) for all the suspensions in HAM1, 2 and 3 chambers (i.e JM1, JM3, MC1, MC2,, IM1, IM2, IM3, IM4) which had changed after the Saturday site power outage. I trended the pitch and yaw slider values for all of the suspensions in these three chambers and restored the ones which I found have changed. I selected Friday evening (29 May 2026, 6.30 PM when Keita et al were done with moving the suspensions).

SUS

Images attached to this report

H1 SQZ - HAM7 HiVoltage Bypass On

camilla.compton@ligo.org — Mon, 01 Jun 2026 14:05:14 -0700

Author: camilla.compton@ligo.org

Report ID: 90418

Marc and I turned on the HAM7 Hi Voltage Bypass in the Mech Rm Mezzanine. We first turned the PSAMS down to zero, they hadn't been zero'ed before Hi-voltage was turned off. WP13282

H1 IOO - IMC, IM2/3/4 and PRM are aligned, cannot center ASC REFL sensors (JennieW, Rahul, Keita)

keita.kawabe@ligo.org — Mon, 01 Jun 2026 12:34:10 -0700

Author: keita.kawabe@ligo.org

Report ID: 90404

Belated alog from Friday.

Summary:

After realigning IMC and IM2 on Thursday, we continued aligning IM3 to put the beam in front of the PRM to the nominal position, IM4 to set the beam position in front of PR2, and PRM so the beam retroreflects. IM1 was left untouched, so the only change in IM1-IM2 line is from the change in the IMC alignment.

Clipping on IM4 baffle (HA12) disappeared completely. Beam position on IFI output baffle looked OK. Beam position on IFI input baffle didn't change (as expected) and still looked OK. There are some mystery

We saw flashes on ASC REFL sensors but they were weak. We tried to center them using RMs but RM2 seems to rail in YAW.

	Before P, Y [urad]	After P, Y	difference P,Y
RM1	-196, 281.8	-242, -19.3	-46, -301.1
RM2	910, 490	912.1, -2125.15 (railing)	+2.1, -2615.15

What to do:

Scan PRM to make sure that we're NOT looking at some kind of ghost beam on ASC REFL sensors.

Assuming that we're looking at the real beam on REFL sensors, we can do either (or some of) these:

Relieve RM2 by rotating RH9 (the fixed IFO refl pick off mirror in HAM2) by positive 500urad or so in YAW. This is the equivalent of the combination of negative 0.53 mrad for RM1 and negative 2mrad for RM2 in YAW. After doing this we can add 530urad to RM1 and 2000urad and continue centering from there. See attached cartoon (doesn't scale but the sign of things is correct) and the script.
IM1 is almost degenerate as RH9 as far as relieving RM1 and RM2 is concerned, so we can rotate IM1 by negative 500urad or so in YAW. This requires that we tweak IM3, IM4 and PRM again but has an added benefit of moving the beam spot on the IFI input baffle closer to the center. See IM1rotation.png.
- If you aren't sure how IM1 rotation is translated to the IFO refl beam, IM1rotation_straightened.png is a simplified and unfolded version. The beam going out of IM1 goes through CWP at the IFI input (deflected but it's not written in the cartoon for simplicity), is retroreflected and comes back to CWP and defflected, the deflection for the REFL beam is depicted here. Without IM1 rotation the beam goes along the black path. With IM1 rotation (red path), the red refl beam converges with the black refl beam where the distance from the conversion point to the CWP is equal to that from the IM1 to CWP. The angle change of REFL is the same with the input and the lateral displacement of red refl relative to black is ~(distance(IM1_CWP)-distance(RH9_CWP))*angle_change.
Make the OSEM coil driver output impedance smaller for RMs to gain more range. 1.2k to 500 Ohm should be safe.

INS, IOO, ISC

Images attached to this report

Non-image files attached to this report

REFL_VS_IMs.m

H1 TCS - TCS CO2 Chillers turned back on after power outage

camilla.compton@ligo.org — Mon, 01 Jun 2026 12:22:50 -0700

Author: camilla.compton@ligo.org

Report ID: 90416

Both CO2X and CO2Y Chillers turned back on with no issue. Interestingly as the laser is off they are currently heating the water.

H1 CDS - CDS Recovery Status

david.barker@ligo.org — Mon, 01 Jun 2026 11:41:44 -0700

Author: david.barker@ligo.org

Report ID: 90414

All CDS systems have been recovered with the exception of EY dust monitor. The EY Comtrol serial-to-ethernet is not working, Erik is replacing its power supply.

Erik started the HWS code. At EX he powered up the h1cdsrfm expansion chassis and power cycled the BRS_EX. At EY he powered the expansion chassis.

We started h1cdsrfm which has cleared all the long-range-dolphin IPC errors. EY WAP just needed powering up via the Pulizzi.

Patrick started the code on the Beckhoff systems for CHILLER_CS, CHILLER_EX, BRS_EX, BRS_EY, NCALX and MAINS_EX.

EDC is currently down to 16 disconnected channels, all EY_DUST.

H1 IOO - Comment to IMC, IM2/3/4 and PRM are aligned, cannot center ASC REFL sensors (JennieW, Rahul, Keita)

keita.kawabe@ligo.org — Mon, 01 Jun 2026 11:36:55 -0700

Author: keita.kawabe@ligo.org

Report ID: 90412

Baffle pictures. Whenever appropriate, there are two pictures (one to access PIT and the other to access YAW) to avoid the parallax problem as the thickness of the baffles cannot be ignored.

IFO REFL looks good on the IFO REFL baffle (HA13) in front of the HAM2-HAM1 septum window (IFO_REFL_HA13.jpg).

IM4 baffle (HA12) is good in PIT (IM4_HA12_PIT_good.jpg), not great in YAW but is OK (IM4_HA12_YAW_OFF.jpg). Next time I'll take a picture through IM4 to show you it's quite acceptable than it looks from these pictures.

IR picture of the IM4 baffle (HA12) shot from IM3 side shows a ghost beam it catches when there's a flash (IM4_HA12_ghostbeam.jpg). Circled in red is the ghost beam (in this case it was 10 mode flash). Circled in green are things that are always visible (IM4_HA12_noflash.jpg) and aren't the ghost beam.

IFI input beam position is great in PIT, not great in YAW (IFI_INPUT_PIT_GREAT_YAW_OFF.jpg, IFI_INPUT_PIT_GREAT.jpg).

However, I still see some kind of clipping of bacdkward-going beam once in a while. See the IR photo shot from IM3 direction IFI_INPUT_clipping.jpg. You're looking at the baffle aperture through calcite wedge from the direction of IM1. Compare with IFI_INPUT_noflash.jpg where there was no flashing.

Not every flash shows this clipping-like thing, it seems to happen less frequently than the flashing.

To make things more confusing, there's a reflection of something shiny in IFI and the edge of that shiny thing is almost on top of the edge of the IFI input baffle aperture so it's hard to say what's going on. Nothing like this was visible on the input side facing IM2.

We temporarily moved IM1 to move the beam spot on IM2 more centered (IFI_INPUT_IM1movedtocenter.jpg) and I can see something closer to the center (probably scattering from the CWP?) but no clipping. So probably it's a good thing to move IM1 counter-clockwise as I indicated in the alog above. We cannot do it too much as we rail RM2 in the opposite direction, but we can probably move the beam by a mm or so on IM2.

Images attached to this report

H1 SPI - 2026-06-01 SPI Pathfinder Power Outage Recovery: No issues

jeffrey.kissel@ligo.org — Mon, 01 Jun 2026 11:30:04 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90413

J. Kissel" As is all over the aLOG this morning, LHO had back-to-back site-wide power-outages this past Saturday 2025-05-30 -- LHO:90395. Here's the quick, pain-free record of recovering the SPI pathfinder's function to the levels we left it on Friday 2026-05-29 (LHO:90382). LASER State of laser as I found it (entering the lab with laser safety googles ON): - Yellow chain and signage across the entry warning of "laser running unattended" still blocking entry. - Magnetic lock of "outer" curtain released, manually hook-locked "inner" curtain still closed. - Laser hazard sign OFF - Laser STOP Button still "OUT" (in the ON position) - Laser Hazard sign still keyed "ON" - NPRO shuttered, still keyed ON, but not powered. In short -- everything worked as expected in the event of a power outage if it happened while a laser system was running unattended. RECOVERY (all with laser safety glasses ON; obviously but just saying it "out loud"): - Unchained and stored "unattended laser" sign. - Pushed in ("OFF") laser stop button. - Keyed OFF laser hazard sign. - Pulled out ("ON") laser stop button to allow for re-energizing of interlock. - Keyed ON laser hazard sign. - Closed magnetic "outer" curtain and swiped in, laser hazard sign lit up as expected. - Confirmed NPRO laser output is shuttered. - Looked at NPRO controller, red light ON under the OFF button (as expected because it was already/still keyed ON). - Plugged in and turned on PD100D interface for on-board S304C power monitor PD (installed within the laser conditioning/fiber collimating bread-board), confirming 1064 [nm] wavelength readout settings. - Waited ~2 minutes for the diodes' controllers to settle, then hit the green ON button - No issues with diode temp transients, laser worked just fine. - Unshuttered laser, and on-board S304C power monitor PD happily confirmed the expect ~198 [mW]. ELECTRONICS State of electronics as I found it: - Electronics +/-18 V and +/-24.0 V power supplies were ON, with their outputs producing voltage at their nominal settings. - Laser prep chassis and PD TIA chassis all showed happy green lights. - Keysight 33600A RF source had reset, with outputs off and all the wrong settings. RECOVERY (all with laser safety glasses ON; obviously but just saying it "out loud"): - Ran through T2600039 to restore all frequency settings - Exported March 2026 notes to LHO:90409 and restored CH1 (REF) and CH2 (MEAS) amplitude settings to -1.7 and -1.4 [dBm], respectively - Turned CH1 and CH2 output ON. Laser Prep Chassis SM05PD01A monitor PD ADC voltage: 7.83 [V]. Laser Prep Chassis RF monitors M2 (REF) and M3 (MEAS) ADC voltage: ~750 and ~750 [mV] FBR_PWRIN_REF On-board power monitor PD ADC voltage: 4.68 [V]. In short :: All these monitor ADC voltages are at normal values. SPI IFOs No actions required after turning on LASER and ELECTRONICS. REF IFO Efficiency -- 4.96 V / (2 * 2.69V) = 0.922 MEAS IFO Efficiency -- 3.00 V / (2*3.95 V) = 0.38 Recovered! Hopping back into The Mystery Machine...CDS, Laser Safety

H1 TCS - Started to assemble D1700340-type02 for CHETA VPs

camilla.compton@ligo.org — Mon, 01 Jun 2026 10:31:57 -0700

Author: camilla.compton@ligo.org

Report ID: 90411

Gerardo, Jordan, Camilla.

On Thursday we assembled VAC sealing part of the CHETA VPs, D1700340-type02. The thinnest part of the optics are at 12o'clock if the VP is oriented with the P/N of D1700338 writing also ~12o'clock.

D1700338-v2-001 with D1700339-v2-001 and D1700338-v2-003 with D1700339-v2-003. Both have optics D1100439-type02, which are DAR coated for 1064nm and 10.6um.

Next steps is VAC testing, then first contact the window surfaces and add secondary window.

Images attached to this report

H1 CDS - Comment to State of CDS following recovery from second power outage

erik.vonreis@ligo.org — Mon, 01 Jun 2026 10:03:56 -0700

Author: erik.vonreis@ligo.org

Report ID: 90410

h1hwsex and h1hwsey are running in a tmux session. To get to the process, ssh as controls to the server and run "tmux a".

H1 SPI - Comment to SPI, Prep Chassis RF Input Chain to Monitor output Chassis

jeffrey.kissel@ligo.org — Mon, 01 Jun 2026 09:12:21 -0700

Author: jeffrey.kissel@ligo.org

Report ID: 90409

J. Kissel Easy look up table after setting up Keysight 33600A per T2600039, and setting the amplitudes as we have had for most of the build :: CH1 = AMP 1 = REF = M2 MON f = 79.995904 MHz (79,995,904 Hz) amp = -1.7 dBm M2 MON = 740 mV CH2 = AMP 2 = MEAS = M3 MON f = 80.000000 MHz (80,000,000 Hz) amp = -1.4 dBm M3 MON = 755 mV Remember to turn the output ON for each channel.SPI

LHO General - Comment to Ops Day Shift Start

ryan.short@ligo.org — Mon, 01 Jun 2026 08:24:04 -0700

Author: ryan.short@ligo.org

Report ID: 90408

Current status:

Cannot remote login to PSL computer to restart the laser
- I expect I won't be able to power it on anyway as the benchtop power supply in the PSL racks powering CB2 probably needs to be turned back on manually
- Site laser interlock is tripped too; can't reset since PSL Beckoff is down
HEPI_ETM{X,Y} and CDS_CA_COPY Guardian nodes were in error, reloading fixed
- Guardian machine does not seem to have gone down as nodes all look okay
All suspesnions recovered (except BS and ITMs, did not touch these)
All HEPI pump stations are down, cannot untrip HEPI
- Not untripping ISIs while HEPIs are down
ISI HAM8 recovered, ISI HAM7 recovered but then quickly tripped again (chamber is vented, makes some sense)
~~Cannot seem to trend any data via ndscope before the outage on Saturday~~
End BRSs are down (if Beckhoff is still down, this makes sense)

LHO General - Ops Day Shift Start

ryan.short@ligo.org — Mon, 01 Jun 2026 07:39:00 -0700

Author: ryan.short@ligo.org

Report ID: 90407

TITLE: 06/01 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, 5mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.16 μm/s
QUICK SUMMARY: Will continue recovery of various sytems following power outages over the weekend and will work on discovering what still needs attention.

H1 CDS - Comment to State of CDS following recovery from second power outage

david.barker@ligo.org — Mon, 01 Jun 2026 07:36:27 -0700

Author: david.barker@ligo.org

Report ID: 90406

Here are all the MSR UPS Emails we received on Saturday. The UPS clock appears to be incorrect and about 14mins fast. No GC UPS emails were received on Saturday.

Sat Morning Outage 09:39

Date: 05/30/2026
Time: 10:12:59
Code: 0x0002
Critical - System: Warmstart. (2 copies received)

Date: 05/30/2026
Time: 10:13:06
Code: 0x0101
Informational - UPS: Restored the local network management interface-to-UPS communication.

Sat Afternoon Outage 14:27

Date: 05/30/2026
Time: 14:45:38
Code: 0x020F
Critical - UPS: An input voltage or frequency problem prevents switching to bypass mode. (4 copies received)

Date: 05/30/2026
Time: 14:45:40
Code: 0x0109
Warning - UPS: On battery power in response to an input power problem. (2 copies received)

Date: 05/30/2026
Time: 14:45:45
Code: 0x010A
Informational - UPS: No longer on battery power. (2 copies received)

Date: 05/30/2026
Time: 14:45:57
Code: 0x0210
Informational - UPS: An input voltage or frequency problem no longer prevents switching to bypass mode. (2 copies received)

H1 IOO - Comment to IMC, IM2/3/4 and PRM are aligned, cannot center ASC REFL sensors (JennieW, Rahul, Keita)

keita.kawabe@ligo.org — Mon, 01 Jun 2026 01:09:50 -0700

Author: keita.kawabe@ligo.org

Report ID: 90405

See screenshot for before/after slider values for RM, IM and other optics.

Images attached to this report

H1 CDS - State of CDS following recovery from second power outage

david.barker@ligo.org — Sun, 31 May 2026 09:36:53 -0700

Author: david.barker@ligo.org

Report ID: 90403

Thankfully no more power outages following the second (14:27) outage Sat 30may2026. Here are the systems we left offline which will be restarted tomorrow, Mon 01jun2026.

PSL Diode Room Beckhoff Controls

Long range dolphin end station Adnaco expansion chassis (h1cdsrfm)

NCAL EX

BRS EX, EY

HWS EX, EY

MAINSMON EX

CHILLERMON EX, EY