aLIGO LHO Logbook

H1 General - OPS Wednesday Day shift start

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

Author: ryan.crouch@ligo.org

Report ID: 91038

TITLE: 07/15 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 9mph Gusts, 6mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.05 μm/s
QUICK SUMMARY:

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

Images attached to this report

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

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

Author: jonathan.hanks@ligo.org

Report ID: 91037

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

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

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

Author: jonathan.hanks@ligo.org

Report ID: 91036

Jonathan, Tony, Erik,

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

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

Notable changes:

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

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

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

H1 General - Laser Interlock System Down for Upgrade

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

Author: filiberto.clara@ligo.org

Report ID: 91035

WP 13417

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

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

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

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

LHO VE - Corner station and HAM1 pumpdown paused overnight

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

Author: travis.sadecki@ligo.org

Report ID: 91034

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

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

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

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

Author: jennifer.wright@ligo.org

Report ID: 91033

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

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

Committed the custom adls to the userapps svn.

Images attached to this report

LHO General - OPS Day Shift Summary

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

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91031

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

IFO is in IDLE for MAINTENANCE

Very productive day. Here's what happened:

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

LOG:

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

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

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

Author: patrick.thomas@ligo.org

Report ID: 91032

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

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

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

Author: sheila.dwyer@ligo.org

Report ID: 91013

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

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

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

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

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

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

Images attached to this report

LHO VE - Purge air compressor monitoring system installed

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

Author: travis.sadecki@ligo.org

Report ID: 91030

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

Images attached to this report

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

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

Author: rahul.kumar@ligo.org

Report ID: 91029

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

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

SQZ, SUS

H1 ISC - Comparing BBSS and BSFM models for DRMI locking

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

Author: elenna.capote@ligo.org

Report ID: 91028

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

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

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

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

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

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

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

SUS

Images attached to this report

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

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

Author: rahul.kumar@ligo.org

Report ID: 91027

R Crouch, R Kumar

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

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

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

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

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

SQZ, SUS

Images attached to this report

Non-image files attached to this report

allhxdss_2026-07-14_H1-ZM4_ZM5_ALL_TFs.pdf

allhxdss_2026-07-14_H1-ZM4_ZM5_ALL_ZOOMED_TFs.pdf

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

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

Author: david.barker@ligo.org

Report ID: 91026

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

mbuf_probe list # Check models are writing

systemctl start rts-local_dc

mbu_probe list # Check local_dc shows as last item

systemctl start rts-transport@cps_xmit

H1 PSL - PSL Cooling Water pH Test - Monthly

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

Author: ryan.short@ligo.org

Report ID: 91025

FAMIS 63880

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

H1 SEI - BSC 1-2-3 HEPI Unlocked

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

Author: jim.warner@ligo.org

Report ID: 91024

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

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

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

Author: jim.warner@ligo.org

Report ID: 91023

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

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

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

Author: jason.oberling@ligo.org

Report ID: 91022

J. Oberling, R. Short

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

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

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

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

Author: jim.warner@ligo.org

Report ID: 91021

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

Images attached to this report

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

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

Author: jim.warner@ligo.org

Report ID: 91020

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

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

Images attached to this report

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

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

Author: jonathan.hanks@ligo.org

Report ID: 91019

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

H1 CDS - workstations updated

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

Author: erik.vonreis@ligo.org

Report ID: 91018

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

LHO General - OPS Day Shift Start

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

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91017

TITLE: 07/14 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 7mph Gusts, 4mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.05 μm/s
QUICK SUMMARY:

IFO is in IDLE for MAINTENANCE

Plans today are:

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

We're also expecting some tours.

H1 OpsInfo - Comment to SPI laser unshuttered

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

Author: jim.warner@ligo.org

Report ID: 91016

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

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

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

Author: anthony.sanchez@ligo.org

Report ID: 91015

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

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

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

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

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

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

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

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

Images attached to this report

H1 SPI - Mean LP filter for heterodyne meas seems fine

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

Author: jennifer.wright@ligo.org

Report ID: 91014

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

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

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

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

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

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

SUS

Images attached to this report

LHO General - Comment to OPS Day Shift Summary

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

Author: oli.patane@ligo.org

Report ID: 91012

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

Extra reservation system entries:

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

LHO VE - Corner station pumpdown paused for the night

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

Author: travis.sadecki@ligo.org

Report ID: 91011

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

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

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

Author: camilla.compton@ligo.org

Report ID: 91009

Dr Todd, Camilla

Polarizers

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

Thermal PD

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

Final Checked on Fast PDs

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

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

Beam Dumps

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

Power control

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

Iris

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

For sdfs see attached and 90992

Images attached to this report

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

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

Author: jonathan.hanks@ligo.org

Report ID: 91010

Dave, Tony, and Jonathan

Supporting WP 13402 we did some prep work.

* Reviewed the work plan.

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

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

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

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

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

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

Author: rahul.kumar@ligo.org

Report ID: 91007

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

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

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

Author: rahul.kumar@ligo.org

Report ID: 91006

R Crouch, R Kumar

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

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

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

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

SQZ, SUS

Images attached to this report

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

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

Author: rahul.kumar@ligo.org

Report ID: 91005

R Crouch, R Kumar

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

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

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

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

Pin 12 & 24 = 708 Ohms (looks good)

Pin 11 & 24 = 355.9 Ohms (looks good)

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

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

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

SQZ, SUS

Images attached to this report

H1 SUS - Replacing/inventorying beamsplitter notches and bandstops

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

Author: elenna.capote@ligo.org

Report ID: 91000

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

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

M1: none as far as I can tell

M2:

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

M3:

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

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

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

Old foton design string for "NotBR_BS":

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

New foton design string for "NotBR_BBS":

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

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

ISC, SUS

LHO General - OPS Day Shift Summary

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

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 91002

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

IFO is in IDLE for MAINTENANCE

Productive day in which:

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

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

LOG:

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

Images attached to this report

H1 OpsInfo - Comment to SPI laser unshuttered

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

Author: arnaud.pele@ligo.org

Report ID: 91004

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

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

Images attached to this report

H1 SUS - BBSS QOSEM Sat Amp Whitening Modifications Installed

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

Author: marc.pirello@ligo.org

Report ID: 91003

WP13410

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

H1 OpsInfo - Comment to SPI laser unshuttered

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

Author: jennifer.wright@ligo.org

Report ID: 91001

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

Images attached to this report

H1 OpsInfo - Comment to SPI laser unshuttered

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

Author: jennifer.wright@ligo.org

Report ID: 90999

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

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

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

Images attached to this report

H1 OpsInfo - Comment to SPI laser unshuttered

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

Author: jennifer.wright@ligo.org

Report ID: 90998

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

SEI, SPI

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

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

Author: jennifer.wright@ligo.org

Report ID: 90996

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

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

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

Non-image files attached to this report

HAM1_isolation2025-09-08.pdf

H1 OpsInfo - SPI laser unshuttered

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

Author: jennifer.wright@ligo.org

Report ID: 90995

Jennie W

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

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

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

SPI

Images attached to this report

H1 TCS - CHETA PDs

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

Author: camilla.compton@ligo.org

Report ID: 90992

Matt, Camilla

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

Images attached to this report

H1 General - LVEA is Operations Phase Laser SAFE

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

Author: ryan.short@ligo.org

Report ID: 90994

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

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

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

Author: daniel.sigg@ligo.org

Report ID: 90993

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

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

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

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90991

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

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

SEI

Images attached to this report

LHO General - OPS Day Shift Start

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

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90990

TITLE: 07/13 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 5mph Gusts, 1mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.06 μm/s
QUICK SUMMARY:

IFO is in IDLE for MAINTENANCE

Plan today is to continue pumpdown. Other tasks:

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

LHO VE - Continued Corner Pumpdown

jordan.vanosky@ligo.org — Fri, 10 Jul 2026 17:47:55 -0700

Author: jordan.vanosky@ligo.org

Report ID: 90989

Restarted Corner pumpdown this morning ~8:08 am

Starting Pressure at PT180: 390 Torr

Stopping Pressure at PT180: 32.7 Torr

Today's pumping time: 9 hours and 25 minutes

Mobile ISP1000 pumps are isolated and powered off for the weekend. Turbopump station and backing scroll pump are powered on and isolated from the main volume.

Images attached to this report

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

sheila.dwyer@ligo.org — Fri, 10 Jul 2026 17:22:45 -0700

Author: sheila.dwyer@ligo.org

Report ID: 90986

Wed afternoon Nergis and I went to SQZT7 to get a couple of beam profiles after the ZM4 preload was adjusted, before the ZM5 swap.

We took two measurements with the same psams settings but different centering on ZM2, based on what Camilla and Madi did in 90946 . The data labeled as nominal position is for these sliders where Camila reports that the beam on ZM2 is 5.85" off the table, and the data labeled raised is for these sliders where the beam is actaully lowered to 5.75". The center of ZM2 should be 5.5" off the table. M^2 went from 1.35 to 1.28 horizontal and 1.25 vertical with the improved centering, and the relative astigmatism also improved from 0.13 to 0.02 Ryan found the definition of relative astigmatism on page 122 (pdf page 129) of the BC207 manual here.

ZM4 strain guage was saturated when the PZT was much above 100V, so this morning Daniel came to SQZ racks with Ryan and I and changed some resistors, Daniel will add the details. ZM4 strain guage is now working well, with values between -4.1V to 2.7V, and Ryan turned the servo back on.

Yesterday morning, I noticed that for some psams settings, the beam was clipping on the top periscope mirror and that then we measured quite high M^2 values. I wondered if clipping on that persicope could explain more of our M^2 measurements. Today Ryan Short and I carefully aligned the psams to get the beam centered on the two irises on SQZT7. We raised the top periscope mirrors, and Ryan adjusted both periscope mirrors to get the beam well centered on the irises again. When we did this, we noticed that only one of the bolts that holds the top periscope mount to the periscope structure was tight.

After this Ryan and I did another round of profile measurements with the new preload and working strain guage on ZM4. We took 5 points over the range of ZM4 with ZM5 PZT at 100V, with the ZM5 strain guage not working, then took 3 points with ZM5 at a strain guage of -4.5V which is 20V on the PZT, because the ZM5 strain guage is working there we can compare these to measurements taken before ZM5 stopped working.

Unfortunately, even after moving the periscope mirror the M^2 values are in the range of 1.4 to 1.23, so the clipping on the periscope mirror wasn't the explanation for the high M^2

Non-image files attached to this report

after_ZM4_torque_nominal_zm2_position.txt

after_ZM4_torque_raised_zm2_position.txt

Jul10_2026.zip

H1 SPI - Corrected DIFFDISP channel readback on SPI main screen

jennifer.wright@ligo.org — Fri, 10 Jul 2026 16:36:19 -0700

Author: jennifer.wright@ligo.org

Report ID: 90987

Jennie W

While trying to debug some other SPI readout problems I noticed that the main SPI overview screen had one of the readback channel names wrong.

The 'DISP OUT' block in red at the right of the screen should readout the channel 'H1:SPI-H23_DIFFDISP_DIAG_INMON' and 'H1:SPI-H23_DIFFDISP_DIAG_OUT16' in its bottom row.

These were reading out the channel above 'REFNULL' in boith cases. I corrected this in SPI_CUST_OVERVIEW.adl file and committed to the svn. In the picture the readouts are circled on the right with the channels they readout shown on the left in the filter banks.

Images attached to this report

LHO General - OPS Day Shift Summary

ibrahim.abouelfettouh@ligo.org — Fri, 10 Jul 2026 16:30:58 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90988

TITLE: 07/10 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

IFO is in IDLE for MAINTENANCE

Pumpdown continues - see attached screenshot

Ryan S, Sheila and Daniel also did some work at SQZT7

In other news,

HEPI pumps blip - alog 90984
GC Maintenance - WP 13395

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:57	VAC	Jordan	LVEA	N	Continuing Pumpdown	23:56
15:12	SEI	Shrey	LVEA	N	Seismometer Tests	18:06
15:19	FAC	Dawn, Kim	LVEA	N	Technical Cleaning	16:00
16:01	FAc	Kim	LVEA	N	Technical Cleaning	16:59
17:26	SQZ	Daniel, Sheila, Ryan S	LVEA	N	SQZT7	18:19
18:19	SUS	Mitchell	LVEA	N	\	18:29
20:19	SQZ	Ryan S	LVEA	Local	Transitioning to local laser hazard, then SQZT7 periscope mirror moving	22:37
20:33	SQZ	Daniel	LVEA	Local	SQZT7	20:39
20:39	SQZ	Sheila	LVEA	Local	SQZT7 Periscope mirror moving	22:37
20:46	FAC	Randy	LVEA	Local	Checking on fitted plates	21:00
23:09	PCAL	tony	PCAL Lab	Local	Sorting	00:09

Images attached to this report

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

ibrahim.abouelfettouh@ligo.org — Fri, 10 Jul 2026 12:27:52 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90985

Per Jim's request, here are HEPI Pump Controllers at the time of the pressure dip/kick.

Images attached to this report

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

ibrahim.abouelfettouh@ligo.org — Fri, 10 Jul 2026 08:53:13 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90984

Ibrahim

Got a message at 14:58 UTC to "Check HEPI pump station pressures".

At 14:58,

the pressure in HEPI Corner Station PS4_PRESS1 (brown) dipped by -5PSI and then spiked by +0.3PSI before recovering. Stable now.
the pressure in all other HEPI Corner Stations dropped by -0.3PSI from nominal and then spiked to +0.1PSI before recovering. It's stable now. Plots are below.

I checked the End Stations too but nothing was seen (also attached).

SEI

Images attached to this report

LHO VE - Comment to HAM7 A1F1 and A2F1 viewports removed and blanked off

jordan.vanosky@ligo.org — Fri, 10 Jul 2026 08:45:41 -0700

Author: jordan.vanosky@ligo.org

Report ID: 90983

The HAM3 A1F3 viewport was a coated ZV-800 which had many small scratches on the vacuum side of the window, we replaced this with the HAM7 Uncoated ZV-800 SN R136. The A1F4 viewport was a D1100999 High Quality viewport (O-ring sealed), it was determined that this port no longer needs the high quality viewport and was then swapped with the other removed viewport from HAM7 (ZV-800 Uncoated R134).

Per Betsy, both of these ports are only used for views inside the chamber, so Uncoated viewports could be used to replace the two coated viewports which were removed.

The viewports removed from HAM3 will be inspected on the bench and if they pass inspection criteria they will be put into spares inventory.

Images attached to this report

LHO General - OPS Day Shift Start

ibrahim.abouelfettouh@ligo.org — Fri, 10 Jul 2026 07:35:24 -0700

Author: ibrahim.abouelfettouh@ligo.org

Report ID: 90982

TITLE: 07/10 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, 3mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.08 μm/s
QUICK SUMMARY:

IFO is in IDLE for MAINTENANCE

No specific tasks today since it's RDO Friday for most

Corner pumpdown yesterday afternoon (alog 90979)

LHO VE - Comment to CP1 Cooldown Update

gerardo.moreno@ligo.org — Fri, 10 Jul 2026 05:22:08 -0700

Author: gerardo.moreno@ligo.org

Report ID: 90981

Update for CP1.

Last Tuesday 7/7/26, Jordan removed the turbo pump and introduced the small ion pump to the CP1 vacuum volume, this closed the warm up of CP1. Attached plot of small ion pump controller and pressure reported by the cold cathode at CP1.

Images attached to this report

H1 AOS - Comment to HAM3 DOORS PUT ON YESTERDAY JUL 8th, 2026

gerardo.moreno@ligo.org — Fri, 10 Jul 2026 04:44:32 -0700

Author: gerardo.moreno@ligo.org

Report ID: 90980

(Travis, Jordan, Tyler, Randy, Richard, Gerardo)

We did not touch the blue cross members.

Doors went on as smooth as they could. The first door -Y side, where the bulky optical lever next to HAM3 adds a degree of difficulty to install the door (maybe more than one degree). Nothing to report, flanges look good on both sides, door and chamber, O-rings have lots of tiny metal shavings incrusted on them, however they did not cross the sealing surface, we opted not to poke at them. We found a small hex key inside the chamber, finders keepers. The second door for +Y side went on good, after we figured the angle of attack for the forklift, we running out of turning room next to this chambers. On this side of the chamber as we were removing the aluminum O-ring protectors a small section of O-ring decided to pop out of its groove around 6 O'clock, when Jordan was working to place the O-ring back in he found a tiny, very tiny metal washer, he grabbed it and we handed it to Richard, we also found a peek wire clamp at the bottom of the chamber (example shown at the bottom of the second photo), that one we just tossed out of the chamber. No issues noted with the flanges on door and chamber. O-rings have similar particulate on them as the O-rings on the -Y door, did not poke at them either.

For both doors we inspected their respective viewports from the inside, we found a viewport with a high density of scratches on the coating, and we decided to remove it and replace it, see entry Travis' entry.

A nice feature that we noticed and made world of difference from previous installations is the enhancement to the cleanroom, it sits a bit taller allowing for good clearance of forklift's mast during the installation of both doors, and we did not have to move the cleanroom.

Images attached to this report

LHO VE - Corner Pumpdown Started

gerardo.moreno@ligo.org — Fri, 10 Jul 2026 02:58:54 -0700

Author: gerardo.moreno@ligo.org

Report ID: 90979

(Jordan, Travis, Richard, Filiberto, Randy, Gerardo)

Corner pumpdown started Thursday afternoon, around 4:40 pm local time.
We setup the twin mobile ISP-1000 scroll pump stations at the YBM turbo station, we chose this area due to the real estate available, the other 2 stations are a bit crowded. After setting up all of the required equipment the pumpdown was started with procedure E2300169, to setup the turbo pump unit for the pumpdown, then Jordan and Filiberto covered procedure M1300464 to make sure all high voltage DC power supplies were off, then continued following E2300443 to start the pumpdown with the ISP-1000 scroll pumps through the YBM turbo pump. Pumpdown was done for about 2 hours taking us down to 340 Torr. The pumpdown was stopped at 7:02 pm local time for the night.

No issues to report during the startup of the pumpdown, however something to note is that during the blow down of the vacuum envelope the system was not pressurized, last minute work on the different chambers did not allowed to pressurize the envelope.

Images attached to this report