aLIGO LHO Logbook

H1 PSL - PSL 10-Day (+7) Trends

ryan.short@ligo.org — Tue, 06 Jan 2026 11:26:13 -0800

Author: ryan.short@ligo.org

Report ID: 88697

Pulling these trends for an additional week back to capture the duration of the holiday break. Main changes over this time were the PMC and RefCav transmission dropping while PMC reflected power increased, but not sure exactly why at this point. The periodic temperature spiking we've been seeing in the diode and chiller rooms appears to have mostly stopped as of the start of the break. We think this was due to the mini-split turning on, so I'll check with facilities if a setting was changed that could have caused this.

There has been work in the enclosure starting as of yesterday, which explains the change in many trends starting then.

Images attached to this report

H1 CDS - Comment to h1ascimc model change and DAQ restart

david.barker@ligo.org — Tue, 06 Jan 2026 11:18:28 -0800

Author: david.barker@ligo.org

Report ID: 88696

Restart/Reboot Log --------------------------------------------------------

Mon05Jan2026
LOC TIME HOSTNAME MODEL/REBOOT
13:30:32 h1asc0 h1ascimc <<< Install Jennie's new model

13:32:11 h1daqdc1 [DAQ] <<< DAQ 1-LEG restart
13:32:19 h1daqfw1 [DAQ]
13:32:20 h1daqtw1 [DAQ]
13:32:21 h1daqnds1 [DAQ]
13:32:30 h1daqgds1 [DAQ]

13:37:38 h1daqgds0 [DAQ] <<< DAQ 0-LEG restart
13:37:43 h1daqfw0 [DAQ]
13:37:43 h1daqnds0 [DAQ]
13:37:43 h1daqtw0 [DAQ]

14:00:44 h1daqfw1 [DAQ] <<< Triple sponaneous FW1 restarts
14:09:39 h1daqfw1 [DAQ]
14:16:36 h1daqfw1 [DAQ]

16:41:00 h1daqgds0 [DAQ] <<< GDS0 DAQD restart on logout
16:45:12 h1daqgds0 [DAQ] <<< Test GDS0 crash reproducible
16:53:04 h1daqgds0 [DAQ] <<< Clean start of 0-leg
16:53:09 h1daqfw0 [DAQ]
16:53:09 h1daqtw0 [DAQ]
16:53:10 h1daqnds0 [DAQ]

H1 CDS - Comment to h1ascimc model change and DAQ restart

david.barker@ligo.org — Tue, 06 Jan 2026 10:15:30 -0800

Author: david.barker@ligo.org

Report ID: 88695

Good news: FW1 has now been running 20 hours. Its beginning to look like the usual frame-writer-restarts-soon-after-DAQ-restart but with 3 restarts this time. We are not sure if we had seen a triple before.

Bad news: later yesterday afternoon h1daqgds0 daqd restarted itself coincident with Erik logging off of this machine. We did two more login/logout tests, the first restarted daqd the second did not. At this time is appeared to be related to the method of logging out, CTRL-D crashing daqd and "exit" not. I did another "exit" test this morning and unfortunately this time it did crash GDS0 DAQD. I restarted the 0-leg soon after (at 08:54) to resync the uptimes. So it appears to be independent of the method of logging out and is intermittent.

FRS36466 opened for this issue.

H1 SEI - FYI - Picket Fence data server comment - all good

brian.lantz@ligo.org — Tue, 06 Jan 2026 10:12:25 -0800

Author: brian.lantz@ligo.org

Report ID: 88694

Brian, Edgard, TJ Shaffer,

I got a group email from the USGS letting people know about an update to their data services. We checked and this does not impact the picket fence. I'm putting some email here for documentation

-Brian

---

From: Edgard Luis Bonilla <edgard@stanford.edu>
Subject: Re: [Data Announcements] EarthScope fdsnws-dataselect service has moved to service.earthscope.org
Date: January 5, 2026 at 5:01:56 PM PST
To: Brian Thomas Lantz <blantz@stanford.edu>
Cc: TJ Shaffer <thomas.shaffer@LIGO.ORG>, "michael.thomas@ligo.org" <michael.thomas@ligo.org>

Confirmed. The picket fences work.

Please let me know if anyone sees any issues and we will address them.

(... and ...)

I don't think this will be an issue. We don't use any restricted data for the Picket Fence.

I will go down to the lab before end of day to confirm we can still run it.

Best,
Edgard Bonilla

From: Brian Thomas Lantz <blantz@stanford.edu>
Sent: Monday, January 5, 2026 4:11 PM
To: Edgard Luis Bonilla <edgard@stanford.edu>
Cc: TJ Shaffer <thomas.shaffer@LIGO.ORG>; michael.thomas@ligo.org <michael.thomas@ligo.org>
Subject: Fwd: [Data Announcements] EarthScope fdsnws-dataselect service has moved to service.earthscope.org

Edgard -
I got this notice about the seismic network over the break. Do we need to do anything about this?
-Brian

Begin forwarded message:

From: Chad Trabant <chad.trabant@earthscope.org>
Subject: [Data Announcements] EarthScope fdsnws-dataselect service has moved to service.earthscope.org
Date: January 1, 2026 at 11:47:37 AM PST
To: data-announcements@earthscope.org
Reply-To: data-announcements+managers@earthscope.org

Happy new year!

EarthScope's fdsnws-dataselect web service, the primary source of miniSEED data from our seismological repository, has moved from service.iris.edu to service.earthscope.org as part of our cloud transition.

Details are below and documented on the service documentation page:
https://service.earthscope.org/fdsnws/dataselect/1

We've worked to make this transition seamless, but if you encounter issues please contact help@earthscope.org.

Action required for restricted data users: You will need new credentials. Visit https://www.earthscope.org/user, create an account (if you do not already have one), then:

navigate to the
Credentials tab

click "REVEAL MY
CREDENTIALS," and then "CREATE FDSNWS CREDENTIALS" if none exist. These credentials are specific to you and should be kept private.

Redirects from the old service to the new

The old service location (at service.iris.edu) continues to operate, but instead of providing data redirects to the new location. The vast majority of web software follow these redirects automatically or can be configured to do so.

New HTTPS (TLS v1.2+) requirement

The service now requires secure HTTPS, specifically TLS 1.2 or later. Requests to the un-secure HTTP endpoint will be redirected to the HTTPS endpoint according to current best practices.

Some older software may not follow redirects from unsecure HTTP to secure HTTPS. Configure the software, if possible, to use the direct URL to the service https://service.earthscope.org/fdsnws/dataselect/1

Some older software may not support TLS 1.2+. As this standard was defined in 2008 and became default on most client and server software by 2016, we do not anticipate this causing many problems.

More details for client developers and power users
Changes in the new service:

Some output formats are not yet supported: SAC and text. These will be added later.

The
following parameters are being permanently retired: quality,
minimumlength,
longestonly,
repository,
szsrecs.

With the removal
of the szsrecs
parameter the service will no longer remove zero-sample records (as was the previous default), which matches the behavior of all other data center implementations.

There are limits
on the volume of data that will be returned. We recommend limiting requests to one station for a 24-hour period at the most.

Some HTTP response codes for errors have changed to be more precise, but they remain
broadly recognized codes.

Please reach out to help@earthscope.org if you have any questions or run into trouble with this new service.

Thanks,
The EarthScope Data Services team

--
More info on EarthScope mailing lists: https://www.earthscope.org/news/mailing-lists/
---
You received this message because you are subscribed to the Google Groups "Data Announcements" group.
To unsubscribe from this group and stop receiving emails from it, send an email to data-announcements+unsubscribe@earthscope.org.
To view this discussion visit https://groups.google.com/a/earthscope.org/d/msgid/data-announcements/CAGJXgS5UnSPZOAt5fw8YUOTTSfHJbMJoS6SDC_LgW4ZVjv91PA%40mail.gmail.com.

CDS

LHO VE - Tue CP1 Fill

david.barker@ligo.org — Tue, 06 Jan 2026 10:06:42 -0800

Author: david.barker@ligo.org

Report ID: 88693

Tue Jan 06 10:01:38 2026 INFO: Fill completed in 1min 37secs

Short fill because discharge line pressure had been bumping up since last fill.

Images attached to this report

H1 PSL - PSL mode match lens replacement

masayuki.nakano@ligo.org — Tue, 06 Jan 2026 09:23:33 -0800

Author: masayuki.nakano@ligo.org

Report ID: 88691

[Jason, Jennie, Masayuki]

We swapped and installed three new lenses—IO_MB_L1 (Rc = 250 mm), L2 (Rc = −150 mm), and L3 (Rc = 750 mm)—replacing the existing lenses with the same notation. The former two are 1″ diameter lenses, and the latter is a 2″ lens. All lenses were mounted in Newport lens mounts, with posts and post holders installed on Thorlabs BA2 bases.
Set the power stage to 2 W with 100 W of PMC output. The power along the path where the new lenses were installed was then reduced as much as possible using IO_MB_HWP1.
Before swapping the lenses, two irises were placed to provide alignment references. The final reference is the set of irises in HAM1; however, the in-PSL iris allowed alignment without external communication and made the process easier. These irises were placed downstream of the existing IO_MB_L2.
After removing the old lenses, the new IO_MB_L1 was installed such that the distance from IO_MB_M2 to L1 was 0.22 m. The beam was centered on the iris by adjusting the lens position. Subsequently, L2 was installed 6 cm downstream of L1 using the same procedure.
After alignment, we verified that the beam path around the beam adjustment stage was not clipped by any optics. All beam positions appeared nearly identical to those before the work began.
The third lens was then installed between IO_MB_M4 and M5 (the bottom mirror of the periscope) with a separation of 9 cm. To ensure the lens was centered on the beam, we centered the iris on the beam reflected from IO_AB_BS1 before and after installation. To observe the transmitted beam from M4, higher power was required; therefore, IO_MB_HWP1 was rotated to increase the EOM output power to 4–5 W.
The first and second pictures document the original lens positions, in case recovery of the mode matching directly to the IMC is required.
After completing the work, all power levels were restored. During this period, the new lenses were inspected with an IR viewer to confirm the absence of unusual stray light or unintended beam exposure.
Remaining work: alignment of the photodiodes monitoring the EOM output and PSL output. Since the overall beam profile has changed, it may be necessary to reposition the lenses to properly focus the beam onto the PDs.
During the work we found the beam is almost clipped on the beam dump capturing the mispolarized beam difracted by the EOM. So, we move the beam dump. The third picture shows this beam dump.

IOO, PSL

Images attached to this report

H1 General - OPS Tuesday Day shift start

ryan.crouch@ligo.org — Tue, 06 Jan 2026 07:27:43 -0800

Author: ryan.crouch@ligo.org

Report ID: 88690

TITLE: 01/06 Day Shift: 1530-0030 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: 0.03 μm/s
Secondary useism: 0.31 μm/s
QUICK SUMMARY:

JAC (HAM1, potentially more PSL enclosure), HAM7 work continues
NUC5 was dead and I restarted it

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 06 Jan 2026 06:01:24 -0800

Author: erik.vonreis@ligo.org

Report ID: 88689

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

H1 CDS - OMC HV Power Supply

filiberto.clara@ligo.org — Mon, 05 Jan 2026 16:53:38 -0800

Author: filiberto.clara@ligo.org

Report ID: 88688

WP 12953

I was notified of a buzzing/whistling sound coming from the CER mezzanine. The HV power supply for the OMC PZT was found with audible alarm on and LCD screen not displaying correctly. Power supply was power cycled. Unit tripped immediately. With unit off, the field cabling going to LVEA was disconnected. Unit tripped when powered on. Unit was replaced with spare.

F. Clara, R. McCarthy, M. Pirello

ISC

H1 SQZ - Changes to IR dither lock setting

karmeng.kwan@ligo.org — Mon, 05 Jan 2026 16:33:36 -0800

Author: karmeng.kwan@ligo.org

Report ID: 88686

[Sheila, Karmeng]

To align OPO IR beam, we try to lock the IR dither lock at fundamental, but we were unable to see the error signal and dither. CLK_gain were changed from 0.1 to 1000, and the demodulation phase from 245 to 225. The resulting error signal as attached. A 200Hz wide bandpass filter added to the PD input dither around 3kHz, LSC_servo_gain changed from -10 to -300 to lock the OPO.

We also adjusted the beamsplitter (position before the IR camera) to center the IR beam on SQZT7 IR camera.

SQZ

Images attached to this report

H1 General - OPS Monday Day shift summary

ryan.crouch@ligo.org — Mon, 05 Jan 2026 15:54:52 -0800

Author: ryan.crouch@ligo.org

Report ID: 88685

TITLE: 01/05 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: HAM7 and JAC work continued today.

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:57	SAF	LASER SAFE	LVEA	NO	LVEA is Upgrade Phase Laser SAFE	17:16
16:46	FAC	Nellie, Kim	LVEA	N -> Y	Tech clean	17:29
17:00	OPS	Oli	LVEA	N -> Y	Transition to HAZARD	17:16
17:15	ISC	Jennie	Optics lab	LOCAL	Gather JAC parts	17:32
17:16	HAZ	LASER HAZARD	LVEA	Y	LVEA IS LASER HAZARD	01:35
17:26	SQZ	Sheila	LVEA	Y	Turn on SQZ laser, maybe take a look at the table	17:55
17:29	FAC	Nellie	MidY	N	Tech clean	18:26
17:32	FAC	Kim	EndX	N	Get garb	18:38
18:06	ISC	Jennie, Rick	PCAL lab	LOCAL	Get parts for JAC	18:20
19:01	ISC	Betsy	LVEA	Y	Check on headsets	19:14
19:20	EE	Marc, Fil	CER	Y	Investigate failing PS, HV HAM6 pzt	20:26
21:26	ISC	Jason, Jennie, Masayuki	PSL enc	Y	JAC work	Ongoing

19:32 UTC HAM1 ISI WD tripped

21:32 UTC DAQ restart

H1 CDS - h1ascimc model change and DAQ restart

david.barker@ligo.org — Mon, 05 Jan 2026 15:18:55 -0800

Author: david.barker@ligo.org

Report ID: 88687

Jennie, Erik, Dave:

Jennie's new h1ascimc model was installed at 13:30 Mon 05Jan2026. This required a DAQ restart to add 2 slow channels.

At 13:32 we restarted the 1-leg, followed by the 0-leg at 13:37. GDS1 did not need a restart.

Following this DAQ restart we had 3 sponaneous restarts of FW1 after it had ran for 27:48, 8:02 and 6:22 minutes respectively. At the time of writing it has been running with no further restarts for an hour.

H1 CDS - Comment to Need model restart in week of Jan 5th to correct JAC/IMC models

jennifer.wright@ligo.org — Mon, 05 Jan 2026 11:34:08 -0800

Author: jennifer.wright@ligo.org

Report ID: 88684

I also added two cdsepicsOutput blocks (ASC-PSL_PZT_P and ASC-PSL_PZT_Y) before the DAC outputs going to the PZT to check what the model is sending to the PZT which will help us double check the switch between IMC and JAC signals works correctly.
See screenshot attached. I rebuilt h1ascimc.mdl and committed it to the svn at userapps/asc/h1/models.

IOO

Images attached to this report

LHO VE - Mon CP1 Fill

david.barker@ligo.org — Mon, 05 Jan 2026 11:00:00 -0800

Author: david.barker@ligo.org

Report ID: 88683

Mon Jan 05 10:04:11 2026 INFO: Fill completed in 4min 8secs

I increased the setting for thermocouple nominal max from 20C to 30C to match current values and remove a VAC-SDF diff.

Images attached to this report

H1 SEI - Ground Seismometer Mass Position Check - Monthly

ryan.crouch@ligo.org — Mon, 05 Jan 2026 09:03:02 -0800

Author: ryan.crouch@ligo.org

Report ID: 88682

Closes FAMIS38887 , last checked in alog88362

HAMs 1-4, 7 and BSC2 are in non nominal SEI states due to the vent work.

2026-01-05 08:58:15.266231
There are 14 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 2 DOF X/U = -1.625 [V]
ETMX T240 2 DOF Y/V = -1.709 [V]
ETMX T240 2 DOF Z/W = -0.94 [V]
ITMX T240 1 DOF X/U = -2.28 [V]
ITMX T240 1 DOF Y/V = 0.313 [V]
ITMX T240 1 DOF Z/W = 0.485 [V]
ITMX T240 3 DOF X/U = -2.433 [V]
ITMY T240 3 DOF X/U = -1.065 [V]
ITMY T240 3 DOF Z/W = -2.971 [V]
BS T240 1 DOF Y/V = -0.372 [V]
BS T240 3 DOF Z/W = -0.449 [V]
HAM8 1 DOF X/U = -0.316 [V]
HAM8 1 DOF Y/V = -0.444 [V]
HAM8 1 DOF Z/W = -0.755 [V]

All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 1 DOF X/U = -0.007 [V]
ETMX T240 1 DOF Y/V = -0.041 [V]
ETMX T240 1 DOF Z/W = -0.024 [V]
ETMX T240 3 DOF X/U = -0.016 [V]
ETMX T240 3 DOF Y/V = -0.069 [V]
ETMX T240 3 DOF Z/W = -0.045 [V]
ETMY T240 1 DOF X/U = 0.066 [V]
ETMY T240 1 DOF Y/V = 0.208 [V]
ETMY T240 1 DOF Z/W = 0.266 [V]
ETMY T240 2 DOF X/U = -0.075 [V]
ETMY T240 2 DOF Y/V = 0.226 [V]
ETMY T240 2 DOF Z/W = 0.049 [V]
ETMY T240 3 DOF X/U = 0.282 [V]
ETMY T240 3 DOF Y/V = 0.096 [V]
ETMY T240 3 DOF Z/W = 0.149 [V]
ITMX T240 2 DOF X/U = 0.158 [V]
ITMX T240 2 DOF Y/V = 0.283 [V]
ITMX T240 2 DOF Z/W = 0.263 [V]
ITMX T240 3 DOF Y/V = 0.139 [V]
ITMX T240 3 DOF Z/W = 0.086 [V]
ITMY T240 1 DOF X/U = 0.07 [V]
ITMY T240 1 DOF Y/V = 0.147 [V]
ITMY T240 1 DOF Z/W = 0.021 [V]
ITMY T240 2 DOF X/U = 0.021 [V]
ITMY T240 2 DOF Y/V = 0.239 [V]
ITMY T240 2 DOF Z/W = 0.152 [V]
ITMY T240 3 DOF Y/V = 0.085 [V]
BS T240 1 DOF X/U = -0.107 [V]
BS T240 1 DOF Z/W = 0.123 [V]
BS T240 2 DOF X/U = -0.031 [V]
BS T240 2 DOF Y/V = 0.038 [V]
BS T240 2 DOF Z/W = -0.052 [V]
BS T240 3 DOF X/U = -0.222 [V]
BS T240 3 DOF Y/V = -0.289 [V]

Assessment complete.
Averaging Mass Centering channels for 10 [sec] ...

2026-01-05 08:58:27.267417
There are 2 STS proof masses out of range ( > 2.0 [V] )!
STS EY DOF X/U = -4.63 [V]
STS EY DOF Z/W = 2.377 [V]

All other proof masses are within range ( < 2.0 [V] ):
STS A DOF X/U = -0.492 [V]
STS A DOF Y/V = -0.851 [V]
STS A DOF Z/W = -0.499 [V]
STS B DOF X/U = 0.153 [V]
STS B DOF Y/V = 0.944 [V]
STS B DOF Z/W = -0.303 [V]
STS C DOF X/U = -0.867 [V]
STS C DOF Y/V = 0.801 [V]
STS C DOF Z/W = 0.594 [V]
STS EX DOF X/U = -0.218 [V]
STS EX DOF Y/V = -0.16 [V]
STS EX DOF Z/W = 0.036 [V]
STS EY DOF Y/V = 1.254 [V]
STS FC DOF X/U = 0.161 [V]
STS FC DOF Y/V = -1.157 [V]
STS FC DOF Z/W = 0.625 [V]

H1 SEI - ISI CPS Noise Spectra Check - Weekly

ryan.crouch@ligo.org — Mon, 05 Jan 2026 08:53:08 -0800

Author: ryan.crouch@ligo.org

Report ID: 88680

FAMIS 27701, last checked in alog88650

The script reports high frequency noise is elevated for HAM1_V3, HAM7_V{1,2,3} which makes sense as they're vented. ITMX_ST1_V1 also reports elevated noise, ETMX_ST1_{H1,V3} are slightly elevated at high frequency.

HAMs 1-4 are still locked and the SEI configuration for the BS is in ISOLATED_DAMPED.

Non-image files attached to this report

CPS_spectra_08:20-01_05_2026.pdf

H1 General - Comment to OPS Monday Day shift start

david.barker@ligo.org — Mon, 05 Jan 2026 08:39:28 -0800

Author: david.barker@ligo.org

Report ID: 88681

Erik, Dave:

All workstations and NUCs which had been powered down during the break have been powered back up.

1. picket fence is working again.

2. I have stopped running nuc_dummy_ioc.py which was temporarily serving dummy NUC EPICS channels to the EDC

3. cds_report has been reverted to the pre-break version (it had been expecting WS to be down and NUC reported had been removed)

H1 General - OPS Monday Day shift start

ryan.crouch@ligo.org — Mon, 05 Jan 2026 07:29:39 -0800

Author: ryan.crouch@ligo.org

Report ID: 88679

TITLE: 01/05 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 12mph Gusts, 6mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.31 μm/s
QUICK SUMMARY:

HAM1 and HAM7 work today
Picket fence IOC seems to not be running (CDS)

CDS

LHO VE - Sun CP1 Fill

david.barker@ligo.org — Sun, 04 Jan 2026 10:21:32 -0800

Author: david.barker@ligo.org

Report ID: 88678

Sun Jan 04 10:09:35 2026 INFO: Fill completed in 9min 31secs

Images attached to this report

LHO FMCS - EX Chilled Water Supply

tyler.guidry@ligo.org — Sat, 03 Jan 2026 21:57:09 -0800

Author: tyler.guidry@ligo.org

Report ID: 88677

At 9:42p local I received a cell alert declaring a loss of chilled water supply at End X. After remotely logging into FMCS I observed that the lead chiller (1) was in alarm and the CH-1 supply temp was hovering around 54F. I've since toggled the lead lag, and manually forced chiller 2 and chilled water pump 2 on. Given the low outside air temps and the lack of temp demands that vent require, this should suffice until all return from the break where we can investigate further. T. Guidry

LHO VE - Sat CP1 Fill

david.barker@ligo.org — Sat, 03 Jan 2026 10:40:14 -0800

Author: david.barker@ligo.org

Report ID: 88676

Sat Jan 03 10:09:51 2026 INFO: Fill completed in 9min 48secs

Images attached to this report

H1 SEI - Reset ISI and HPI WDs after EQ trips earlier today

oli.patane@ligo.org — Fri, 02 Jan 2026 17:09:40 -0800

Author: oli.patane@ligo.org

Report ID: 88675

There were some SEI trips earlier today due to an earthquake. Dave went in and reset the software WDs earlier (88671), so to get the system back up to where it was before the earthquake, I went through and reset ISI and HPI to nominal for the chambers that needed them reset (aka not resetting them for the systems where we already have them down due to venting). Tony's overview and WD screenshots from Wednesday are a good reference for what state everything was in before the earthquake. This is what the OPS Overview looked like before I started resetting everything. Everything now that needed to be reset is back how it was before the earthquake (overview now).

Images attached to this report

LHO General - After hours site work 1/2/26

tyler.guidry@ligo.org — Fri, 02 Jan 2026 13:51:30 -0800

Author: tyler.guidry@ligo.org

Report ID: 88674

Upcoming LN2 deliveries at x mid and x end required some tumbleweed attention this afternoon. X1 is still largely clear and x mid should be easily accessible. The earlier half of X2 is the worst area. I was able to cut a single lane to X2 before the harvester jammed up beyond what I could free by myself. What remains in the harvester chute needs a few days to dry out. As do I. As a follow up to my previous log I checked the magmeter in the water room which meters domestic supply to the site and found a reading of 1011247. T. GuidryVE

LHO General - First site inspection of the new year.

richard.mccarthy@ligo.org — Fri, 02 Jan 2026 12:02:28 -0800

Author: richard.mccarthy@ligo.org

Report ID: 88673

Site Walk Through 2 Jan 2026

LExC is in great shape no indication of problems.

Staging building is in good shape.

VPW two ovens running and in the parameters that Chris told us. Weld shop temperature was fine so no pipe issues.

LSB looks fine. Tyler was in his office

OSB/LVEA everything was in order. Kobelco running door covers billowing slightly. No signs of problems.

Mid and Ends were fine.

Carpenter shop/ water room fire pump room and electrical room were all fine.

FCES in great shape.

I leave the site with, Tyler clearing a path to EX for LN2 delivery. I am his phone buddy.

LHO VE - Fri CP1 Fill

david.barker@ligo.org — Fri, 02 Jan 2026 10:40:38 -0800

Author: david.barker@ligo.org

Report ID: 88672

Fri Jan 02 10:03:34 2026 INFO: Fill completed in 3min 32secs

Images attached to this report

H1 CDS - Earthquake tripped both end station SWWDs Fri 02Jan2026 06:22 PST

david.barker@ligo.org — Fri, 02 Jan 2026 10:32:44 -0800

Author: david.barker@ligo.org

Report ID: 88671

Both end station test mass Software Watchdogs tripped around 06:22 during an earthquake. The Seismic systems also tripped for ETMX and ETMY. The TMS suspensions did not trip.

At 10:30 I reset these SWWDs, end station SUS and SEI are driving again.

LHO VE - Thu CP1 Fill

david.barker@ligo.org — Thu, 01 Jan 2026 10:21:48 -0800

Author: david.barker@ligo.org

Report ID: 88670

Thu Jan 01 10:04:27 2026 INFO: Fill completed in 4min 24secs

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H1 CDS - VACSTAT detected EX vacuum glitch 03:39:34 Thu 01Jan2026 PST

david.barker@ligo.org — Thu, 01 Jan 2026 08:53:00 -0800

Author: david.barker@ligo.org

Report ID: 88669

VACSTAT detected a small beamtube vacuum gas release originating at the EX BT-IonPump which is located at approx -300m from EX.

Pressure trend shows the pressure at PT527 increased from its baseline of 1.9e-09 to a max of 1.4e-08 Torr. Several seconds later the EX gauges showed a minimal increase when the dispersed molecules reached them.

PT527 had pumped back down to its baseline by 04:30, +50 minutes after the glitch.

VACSTAT raised a single-gauge alarm for PT527, its rate-of-rise did not trip (reached 40% of trip level) but its Delta-P did trip (reached130% of trip level).

At 08:39 I restarted the vacstat_ioc.service on cdsioc0 to clear this alarm. As before, HAM1's gauge is currently set to disabled.

Images attached to this report