aLIGO LHO Logbook

H1 ISC - OM2 Hot for Commissioning Period

camilla.compton@ligo.org — Thu, 04 Sep 2025 14:32:51 -0700

Author: camilla.compton@ligo.org

Report ID: 86738

This morning at 16:03UTC, Corey heated up OM2 by setting H1:AWC-OM2_TSAMS_POWER_SET to 4.6, plot attached.

Images attached to this report

H1 SQZ - sqz data set with om2 hot

sheila.dwyer@ligo.org — Thu, 04 Sep 2025 14:26:03 -0700

Author: sheila.dwyer@ligo.org

Report ID: 86736

Sheila, Camilla

no squeezing time: 20:06-20:11 UTC (ref 19)
20:15:17-20:19 UTC FIS demod angle 127.05 (ref 21)
FIS mid sqz + 20:21:52- 20:25:00 UTC demod angle 144.12 (ref 22)
FIAS 20:29- 20:32 demod phase 242.73 FIAS demod angle 242, clf servo sign flipped (ref 23)
20:36-20:39 FI mid sqz other side, CLF servo sign -, demod angle 110.39 (ref 24)
20:40:30 - 20:43:30 mean sqz, ADF off (ref 25)
20:48:30 - 20:51:30 FDS demod angle 121.63 tuned for High Freq (ref 26)
20:54:30 - 20:57:30 FDS demod angle 137.75 tuned for 200Hz at same time as Robert's sweep (ref 27)

Camilla then noticed that my angle tuning for FDS above wasn't very good, so she repeated that. 86737

Images attached to this report

H1 SQZ - SQZ FIS SRCL Offset for Brontosaurus Plot

camilla.compton@ligo.org — Thu, 04 Sep 2025 14:24:13 -0700

Author: camilla.compton@ligo.org

Report ID: 86737

Sheila, Camilla. While OM2 was hot 86735, we took the data for the SRCL offset SQZ brontosaurs plots as in 84794, 85362, 86422. Plot saved in camilla.compton/Documents/sqz/templates/dtt/20250904_SRCLSQZdata.xml and attached.

Type	Time (UTC)	SRCL Offset	Angle	DTT Ref
FIS SQZ	21:09:30 - 21:12:30	-382	(-)125.4	ref 1
FIS SQZ	21:14:45 - 21:17:45	-200	(-)151.0	ref 2
FIS SQZ	21:19:30 - 21:22:30	0	(-)211.7	ref 3

Took above data at NLG of 24.0, measaured a few hours ago 86729.

Images attached to this report

H1 SQZ - no sqz time, OM2 hot

sheila.dwyer@ligo.org — Thu, 04 Sep 2025 12:36:49 -0700

Author: sheila.dwyer@ligo.org

Report ID: 86735

at 19:25:38-19:56:30 UTC we went to no sqz with OM2 hot.

There was a 29Hz peak injected by Robert, and this was 1 hour 30 minutes after power up.

H1 ISC - DARM improvement from HAM1 ISI

elenna.capote@ligo.org — Thu, 04 Sep 2025 11:11:07 -0700

Author: elenna.capote@ligo.org

Report ID: 86734

In this alog, I showed a plot that compares the CHARD P and INP1 P noise before and after the HAM1 ISI install. Last night, I took the measured CHARD P coupling function and calculated the CHARD P contribution to DARM just before the vent to install the HAM1 ISI, and from a high range time this past weekend, with the HAM1 ISI installed. The attached plot compares DARM before and after the vent and the CHARD P contribution to DARM before and after the vent.

Turns out the change in CHARD noise may have actually directly reduced some noise in DARM. The DARM/CHARD coupling function remained the same before and after the vent, so the improvement is directly due to the reduction of noise in CHARD.

We were running HAM1 feedforward to the pitch ASC before the install, but it varied in performance. My plot in the linked alog shows the best performance achieved, but looking at the data closer to the vent, the noise in CHARD P may have been higher than the best performance I show in the linked alog above.

The low frequency noise in DARM has also changed for other reasons:

DHARD is now on two sensors, reducing the DHARD noise by rt2 (85774)
MICH ASC has better low pass filters engaged (85893)
CSOFT P has better low pass filters engaged (85823)
Improved LSC feedforward (86481, 86370, 86423)
PEM team sourced and reduced some large peaks (86257)

SEI

Images attached to this report

H1 PEM - DustMon Monthly Trends FAMIS

oli.patane@ligo.org — Thu, 04 Sep 2025 10:17:31 -0700

Author: oli.patane@ligo.org

Report ID: 86733

Closes FAMIS#37256, last checked 86348

ndscope

Things to note:
Possible issues:
CS_DUST_LAB1_{300,500}NM both stalled at a value 16 days ago
CS_DUST_DR1_300NM has been at zero for the past four days
CS_DUST_DR1_500NM has been at zero for the past six days

Not an issue:
CS_DUST_LVEA5_300NM has been at 0 for three months - since we turned it off after the vent
CS_DUST_LAB2_{300,500}NM both off as expected (comparing to last month when Ryan C didn't mention it as an issue)

Images attached to this report

LHO VE - Thu CP1 Fill

david.barker@ligo.org — Thu, 04 Sep 2025 10:14:41 -0700

Author: david.barker@ligo.org

Report ID: 86732

Thu Sep 04 10:05:52 2025 INFO: Fill completed in 5min 48secs

Gerardo confirmed a good fill curbside.

Images attached to this report

H1 SQZ - Comment to SQZ NLG Messurements at Different ISS AOM Setpoints

camilla.compton@ligo.org — Thu, 04 Sep 2025 10:07:44 -0700

Author: camilla.compton@ligo.org

Report ID: 86729

Repeated while Corey was relocking today. We had one strange measurement when the ISS setpoint at 3.3V where the un-amplified signal was much lower but when later repeating at 3.1V, we didn't see this.

OPO Setpoint	ISS Setpoint when locked on		Amplified		Unamplified		NLG
OPO Setpoint	CLF DUAL	SEED	Max	Min	UnAmp	Dark	NLG
80	5.0	5.0	0.042961	0.00051437	0.00176935	-2.1e-5	24.0
80	2.8	ISS Setpoint dropped to -5, so OPO TRANS not at 80uW
80	3.3	3.2	0.043273	0.0005247	0.00106713	-2.1e-5	39.7
80	6.2	6.2	0.041031	0.00051677	0.0017658	-2.1e-5	23.0
80	6.5	6.4	0.0409285	0.00051425	0.00175578	-2.1e-5	23.0
80	3.6	3.5	0.0429806	0.00051216	0.00175932	-2.7e-5	24.1
80	3.1	3.0	0.0431685	0.000516166	0.0017296	-2.7e-5	24.5
80	2.8	ISS Setpoint dropped to -5, so OPO TRANS not at 80uW
80	4.9	4.8	0.0429243	0.0005134	0.0017627	-2.7e-7	24.0

H1 TCS - Comment to TCS Monthly Trends

thomas.shaffer@ligo.org — Thu, 04 Sep 2025 10:00:38 -0700

Author: thomas.shaffer@ligo.org

Report ID: 86731

Two issues I'm seeing in these plots 1) The ITMX HWS SLED is degrading faster than previous SLEDs and 2) There is some weirdness going on with the ITMX CO2 flow meter a week and a half ago.

ITMX HWS SLED

The rate of degradation of these sleds is often on the order of roughly 2mW/yr. This is why we can generally get about a year's worth out of each SLED. Comparing the last ITMX SLED and the one that we just installed in May (alog84417), the old SLED decayed at a rate of 2.43mW/yr and the new one is 4.2mW/yr. This is just from making some lines in ndscope, so it's pretty rough, but we can definitey say that it is degrading about 2x as fast as the last SLED (attachment 1). The ITMY SLEDs are a bit more consistent at: previous = 2.7mW/yr and new = 2.2mW/yr.

We saw that on the ITMY SLED this last time around that we were still able to see spherical power changes from lock to lock even with the SLED power reporting 0.5mW, and ring heater changes were tough to see (alog84408). Let's consider 0.5mW to be our limit we can take these, but really it should be before we can't see anything, at our current rate this SLED would finish the run at ~0.3mW. Looks like we will need to swap this one before the end of the run.

ITMX CO2 Flow

In Ryan's alog I noticed that the usual change in flow, as reported by the paddle wheel flow meter on the floor, became much more stable on Sunday Aug. 24th. Looking back over two years (attachment 2), it actually looks like the flow has been unusually unstable since returning from the spring vent, and whatever happened on the 24th brought us back to normal. Being a Sunday, there wasn't much going on (alog86540), we were in the middle of a 40+ hour long lock. Zooming into the event doesn't show the laser doing anything during that time, as if it didn't actually see a change in flow. Not sure what's going on here.

Images attached to this report

H1 General - Comment to H1 Lockloss (after 42hr03min lock)

jennifer.wright@ligo.org — Thu, 04 Sep 2025 09:31:56 -0700

Author: jennifer.wright@ligo.org

Report ID: 86730

Not sure that the DARM offset step caused this as we were almost back at our nominal offset when we lost lock (step 6 out of 7 with H1:OMC-READOUT_X0_OFFSET = 9) which is ~27 mA, nominal is 40 mA.

We checked the lockloss ndscopes and couldn't see any smoking guns when the offset was changing from 8 to 9.

Images attached to this report

H1 CDS - Wed afternoon power glitch detected by MSR UPS.

david.barker@ligo.org — Thu, 04 Sep 2025 08:56:04 -0700

Author: david.barker@ligo.org

Report ID: 86728

15:59:33 Wed 03sep2025 PDT power glitch. H1 was in lock throughout and no impact on range.

Images attached to this report

H1 General - H1 Lockloss (after 42hr03min lock)

corey.gray@ligo.org — Thu, 04 Sep 2025 08:25:01 -0700

Author: corey.gray@ligo.org

Report ID: 86727

H1 lockloss a few after hitting the 42hr mark for a lock (42hrs03min). At this time we were in at the beginning of 6hr commissioning period and at the time of the lockloss we were about ~10min into running the DARM Offset script for OM2 heating set-up.

LHO General - Thurs DAY Ops Transition

corey.gray@ligo.org — Thu, 04 Sep 2025 07:33:12 -0700

Author: corey.gray@ligo.org

Report ID: 86724

TITLE: 09/04 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 2mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.08 μm/s
QUICK SUMMARY:

Day 2 of being locked since Maintenance (41.5hrs)! Commissioning starts in 12min. All is quiet seismically (microseism is below the 50th percentile even!) and winds are low.

H1 just had it's 3rd superevent in 10hrs 1hr ago (1350utc).

LHO General - Ops Eve Shift Summary

ryan.short@ligo.org — Wed, 03 Sep 2025 22:02:44 -0700

Author: ryan.short@ligo.org

Report ID: 86723

TITLE: 09/04 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Another very quiet shift with H1 locked and observing throughout, plus one candidate event. H1 has now been locked for 32 hours.
LOG:

03:33 - S250904ae

H1 SUS - In-Lock SUS Charge Measurement - Weekly

ryan.short@ligo.org — Wed, 03 Sep 2025 18:03:07 -0700

Author: ryan.short@ligo.org

Report ID: 86722

FAMIS 28421, last checked in alog86614

Once again, too low of coherence for ITMX, so no new data point there. The most recent point is from the August 19th measurement.

Images attached to this report

H1 TCS - TCS Monthly Trends

ryan.short@ligo.org — Wed, 03 Sep 2025 17:48:02 -0700

Author: ryan.short@ligo.org

Report ID: 86721

FAMIS 28464, last checked in alog86272

Nothing much out of the ordinary here that I can see aside from the fact that the ITMX SLED is getting awfully close to the 1mW lower power threshold and will likely hit it in the next month.

Images attached to this report

LHO General - Wed DAY Ops Summary

corey.gray@ligo.org — Wed, 03 Sep 2025 16:32:58 -0700

Author: corey.gray@ligo.org

Report ID: 86708

TITLE: 09/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

Today we had Commissioning time to make up for the time from Monday's holiday. Also had the opportunity to take H1 to the new ASC High Gain mode to ride out a Magnitude 6.0 earthquake! H1 is approaching 26.5hrs of lock.
LOG:

1435-1503 emergency light replacement @mx
1436 Check-in chat with RRT in teamspeak
1500-1530 Calibration
1503 opening receiving for grabbing cardboard & then garbage at woodshop via elec cart (kim)
1503-1550 MY cleaning (nellie)
1530 Commissioning Begins
- 1530-1615Robert measurements first
  - 1617-1630 Walking quietly in lvea (robert)
  - CR measurements
- 1616-1626 Jim HAM1 injection
- 1627 Sheila/camilla measurements
1557-1725 End Station trips (no VEA entry) for HEPI/Dust Monitor FAMIS (mitch)
1602-1626 EX to take a photo (no VEA entry) (chris)
1643-1702 SPI inventory in optics lab (jeffk)
1655-1740 TCS chiller FAMIS check (corey)
1723-1743 Optics lab clean & checks (kim)
1745-1849 MX cleaning (kim)
1755 Surveryors escorted to MY for CEBEX (tyler)
1813-1818 Checking ISC table enclosure vents in LVEA (corey---went out when Robert went out)
1838 Commissioning Ends
2023-2048 Dropping off stuff at MY (travis)
2102 EQ alert for M6.0 in Aleutians & SURVIVED via "ASC High Gain" Mode! (alog)
- 2112 - 2157 Out of Observing to "ride" the EQ
2115-2220 Benton PUD arrives to work at MY for CEBEX
2248 Taking a measurement in the Optics Lab area (travis)

LHO General - Ops Eve Shift Start

ryan.short@ligo.org — Wed, 03 Sep 2025 16:03:02 -0700

Author: ryan.short@ligo.org

Report ID: 86720

TITLE: 09/03 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 8mph Gusts, 3mph 3min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.11 μm/s
QUICK SUMMARY: H1 has been locked for 26 hours. Sounds like commissioning and riding through earthquakes today all went well.

Wind low, ground motion coming down after earlier EQ
All other systems nominal

H1 SEI - Riding Through A Magnitude 6.0 Aleutian Islands EQ !!

corey.gray@ligo.org — Wed, 03 Sep 2025 15:57:40 -0700

Author: corey.gray@ligo.org

Report ID: 86719

(Elenna C [in spirit], Ibrahim A, Corey G, Tony S, Jim W)

Summary: H1 survived a magnitude 6.0 EQ in Alaska via new ASC High Gain button/state. This preserved a 24+hr lock. This probably saved us (at minimum 2.5hrs of downtime!): (1) ~90 min for the earthquake seismic noise to die down & (2) for 1-2hrs of locking. L1 went DOWN due to this EQ about 20min after we saw it rolling through LHO!

Had my first experience getting to ENGAGE the new RED "ASC Hi Gn" button (see Elenna's alog) for an earthquake! This tool is still fairly new and "manual" (& cool!) for operators. Main items for engaging at this point (for me, as a newbie) was waiting for SEI_ENV to go to EARTHQUAKE mode and also watched for any colors on the Picket Fence. While we were dealing with this earthquake, Jim walked in to also observe and answer questions for us; Ibrahim also gave advice since he's engaged this EQ mode twice. All the details for what happened are logged below.

How Everything Went "Down"!

2102 VerbalAlarm: "EQ alert for M6.0 in Aleutians" (it said "Incoming earthquake from Canada")

2111 Seismic: EQ Mode Activated! (due to R-Wave arrival)
2112 Out of Observing & clicked Earthquake on Observatory Mode
2113 Hit the "ASC Hi Gn" (red) button (on this bright green pop-up terminal, I typed in "yes".....but had to open another one, because it only needs "y"). Within a minute or two, the script completed the transition to "ride" out the earthquake.
- Also around this time, started seeing yellow on picket fences, followed by some oranges. This EQ started to show up as a big spike on the earthquake band on the wall (see 1st attachment).
  - Also saw this EQ in secondary microseism.
- 2114 ASC oscillations appear
- 2116 ALL Picket Fences are yellow or orange!
- 2117 Peakmon reaches max just a hair under 2500 nm/s on Peakmon
- 2117, 2121: EX saturations on VerbalAlarms
- (2134 L1 goes DOWN due to EQ....2nd attachment for the earthquake when it took L1 down)
- 2154 Seismic back to CALM
  - SEI_ENV took about a minute or so to make the transition to CALM (all guardian nodes on ISI_CONFIG eventually go green). Once everything was GREEN....
  - On ISI_CONFIG, clicked the blue "ASC Low Noise" button & this pops up another bright green terminal, and I entered a "y" and this transitioned H1 back to NLN with our usual High Sensitivity.
- 2157 H1 Back to OBSERVING!
- (2254 L1 back to OBSERVING)

OpsInfo, PEM, SEI

Images attached to this report

LHO FMCS - Famis Using Vibration Sensors To Gauge Health Of HVAC Fans Site Wide

anthony.sanchez@ligo.org — Wed, 03 Sep 2025 15:39:57 -0700

Author: anthony.sanchez@ligo.org

Report ID: 86718

Using Vibration Sensors To Gauge Health Of HVAC Fans Site Wide FAMIS 26592

H0:VAC-EX_FAN2_570_1 & 2 both seem to have gotten significantly more noisy for about 27 hours from 1800 UTC on Sep 1st to 2100 UTC on Sep 2nd

PEM

Images attached to this report

H1 SQZ - FC Injection, Shape is Changing day to day...

camilla.compton@ligo.org — Wed, 03 Sep 2025 11:54:27 -0700

Author: camilla.compton@ligo.org

Report ID: 86717

Sheila and I repeated her 86683 yesterday's FC injections

10,000 Gain: refs 0-3 (compare to yesterday's refs 23-25)
3,000 Gain: refs 4-7 (compare to yesterday's refs 20-22
Quiet time: refs 8-11 (compare to yesterday's refs 14-16)

Interestingly the shape of the injection has changed, meaning the FC loop shape is changing, see quite time today vs yesterday on FC2_M3 plot. The coupling into DARM is also significantly less today. This isn't;t a surprise as we see the FC causing noise into DARM only intermittently 86608, but we don't know the reason why yet. Sheila checked the FC OLG and it looked fine.

Images attached to this report

H1 SQZ - Comment to OWL Shift SQZ Issues

camilla.compton@ligo.org — Wed, 03 Sep 2025 11:16:13 -0700

Author: camilla.compton@ligo.org

Report ID: 86715

Sheila, Camilla

This morning the SHG PZT was still around 5V so we changed the Offset, Min and Max scan rangers to force it to lock at the peak closer to 50V, see attached for old vs new values and sdfs accepted. Checked it scanned over the correct range by setting the SQZ_SHG guardian to DOWN and under manually scanning the SHG PZT.

Then I copied what Tony did last night and further optimized the SHG temperature to bring the power up from 96mW to 106mW, see attached. Thanks Tony!

Images attached to this report

H1 OpsInfo - Comment to Instructions for running DARM OFFSET STEP to do output loss meas with hot OM2.

jennifer.wright@ligo.org — Wed, 03 Sep 2025 11:12:35 -0700

Author: jennifer.wright@ligo.org

Report ID: 86716

Test for Thursday morning at 7.45 am, assuming we are thermalised, rewrote instructions above and took out last part.

In NLN.
Turn off OMC ASC:
- sitemap -> OMC -> OMC Control -> turn MASTER GAIN slider to 0 (its blue and on the bottom centre of screen).
Run DARM offset step:
- Go to /ligo/gitcommon/labtutils/darm_offset_step
- run:

conda activate labutils

python auto_darm_offset_step.py

Wait until program has finished ~15 mins.
Turn OMC ASC back on by putting master gain slider back to 0.020.
Heat up OM2 heater (~ 3 hours):
- IFO out -> OM2 -> change H1:AWC-OM2_TSAMS_POWER_SET value to 4.6.
Open beam diverter.
- Go to sitemap -> LSC -> Beam Diverter -> Corner -> Press top right button labelled 'OPEN' under Corner_POP section.

Commissioners will turn off OMC ASC and close beam diverter once heating has finished then do DARM offset step and other tests before turning on ASC and opening beam diverter before cooling down OM2 again.

H1 TCS - TCS Chiller Water Level Top-Off (Bi-Weekly, FAMIS #27823)

corey.gray@ligo.org — Wed, 03 Sep 2025 11:04:00 -0700

Author: corey.gray@ligo.org

Report ID: 86714

Addressed TCS Chillers (Wed [Sept3] 957-1040am local) & CLOSED FAMIS #27823:

Had a little bit of a rigmarole since I hadn't done this for a while. In my quick procedure scan, I didn't see how to read the "floating red ball" in the chillers. I had remembered using the bottom of the ball, but wasn't sure, so I consulted Camilla & TJ. I ended up using the bottom for my initial measurements, but later learned we measure the top of the ball! Either way, they were a little low, but I overfilled them since I used the bottom of the ball for readings. Also not clear what exactly is the "Max level" (reason for overfill). Either way, chillers had received water since June, so adding water an ok thing! :) Attached is a photo of what I'm talking about, and the red ball is about 4mm in diameter so I updated readings I initially entered when filling by adding 4mm to all water level readings.

TCSx Chiller: Had level of 29.5 cm. Added 550mL for 30.9cm.
TCSy Chiller: Had level of 9.8 cm. Added 425mL for 10.7cm.
There was no water in the small cup under the slow leak.

TCS

Images attached to this report

H1 ISC - Comment to Recent measurements of ASC calibrations

elenna.capote@ligo.org — Wed, 03 Sep 2025 10:51:02 -0700

Author: elenna.capote@ligo.org

Report ID: 86713

Here is data for MICH yaw and SRC2:

DoF	Input Matrix	Calibration	Notes
MICH Y	1 * AS A 36 Q	0.00248 urad [BS M2] / ct	measured as BS M2 WIT/AS A 36 Q, must transform into M3 urad
SRC2 P (SRM + SR2)	1 * AS_C	33.4 urad [SR2 M3] / ct 44.7 urad [SRM M3] / ct	SRC2 drive matrix is a combination of SRM and SR2: -7.6 * SRM + 1 * SR2
SRC2 Y (SRM + SR2)	1 * AS_C	20.9 [SR2 M3] / ct 48.8 [SRM M3] /ct	SRC2 drive matrix is a combination of SRM and SR2: 7.1 * SRM + 1 * SR2

LHO VE - Wed CP1 Fill

david.barker@ligo.org — Wed, 03 Sep 2025 10:44:13 -0700

Author: david.barker@ligo.org

Report ID: 86712

Wed Sep 03 10:15:46 2025 INFO: Fill completed in 15min 42secs

Gerardo confirmed a good fill curbside.

Images attached to this report

H1 SQZ - Comment to OWL Shift SQZ Issues

camilla.compton@ligo.org — Wed, 03 Sep 2025 10:09:54 -0700

Author: camilla.compton@ligo.org

Report ID: 86711

I edited SQZ_ANG_ADJUST which had a conditional, reading from sqzparams.use_sqz_angle_adjust, to set the nominal state (which stopped the script running correctly) to just stating the nominal state. Now there is a note in sqzparams.py to change the nominal state in SQZ_ANG_ADJUST and sqz/h1/scripts/switch_nom_sqz_states.py if the flag is changed.

H1 CAL - Comment to Wed Morning H1 Calibration Measurement (broadband headless + simulines)

elenna.capote@ligo.org — Wed, 03 Sep 2025 09:07:38 -0700

Author: elenna.capote@ligo.org

Report ID: 86710

For some reason this error is still happening where the report generation pulls a very old report from March 2024 as the reference. I think this is some environment error. I regenerated the report now and it pulled the last valid report, which makes the comparisons much more sensible.

Non-image files attached to this report

H1_calibration_report_20250903T150641Z.pdf

H1 CAL - Wed Morning H1 Calibration Measurement (broadband headless + simulines)

corey.gray@ligo.org — Wed, 03 Sep 2025 08:47:17 -0700

Author: corey.gray@ligo.org

Report ID: 86709

With the Monday holiday and no calibration run last Sat, ran a calibration this morning to start of a Wed Commissioning session.

Measurement NOTES:

Following instructions (link)
H1 at NLN for for ~18hrs (had recent SQZ issue however)
Calibration_Monitor medm screenshot is attached
1500 utc Out of Observing for CALIBRATION
Broadband measurement started at 1500 utc ended 1505utc
Measurement at: /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250903T150035Z.xml
Simullines measurement
- gps START time: 1440947220 (1506utc)
- gps STOP time: 1440948616 (1529utc)
- File written out to: /ligo/groups/cal/H1/measurements/DARMOLG_SS/DARMOLG_SS_20250903T150641Z.hdf5
- File written out to: /ligo/groups/cal/H1/measurements/PCALY2DARM_SS/PCALY2DARM_SS_20250903T150641Z.hdf5
- File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L1_SS/SUSETMX_L1_SS_20250903T150641Z.hdf5
- File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L2_SS/SUSETMX_L2_SS_20250903T150641Z.hdf5
- File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L3_SS/SUSETMX_L3_SS_20250903T150641Z.hdf5
1530utc ISC_LOCK taken back to NLN & started commissioning

CAL

Images attached to this report

Non-image files attached to this report

H1_calibration_report_20250903T150641Z.pdf

LHO General - Wed DAY Ops Transition

corey.gray@ligo.org — Wed, 03 Sep 2025 07:44:03 -0700

Author: corey.gray@ligo.org

Report ID: 86707

TITLE: 09/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 3mph Gusts, 1mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.11 μm/s
QUICK SUMMARY:

H1 had issues last night with the SQZ (as noted by Tony in his OWL alogs), but h1 has been locked/thermalized for just over 17hrs37min. Bring up thermalization, because the plan is for a calibration suite of measurements to be run at 8am. Also looks like there will be commissioning right after this measurement TODAY (830-1130amPDT).

On nuc23, the DARM .5-2kHz bands have been recovering from the SQZ issue starting 2hrs ago and look like they are at normal levels for the last hr or so (see attached).

Images attached to this report

H1 SQZ - OWL Shift SQZ Issues

anthony.sanchez@ligo.org — Wed, 03 Sep 2025 05:56:07 -0700

Author: anthony.sanchez@ligo.org

Report ID: 86706

@ 2:43 am (Local time) H1 called for assistance.
I noticed that it was a SQZ issue, specifically the SHG "PZT was out of range" error on the SQZ_SHG Guardian.
It was bouncing from Locking to Locked then scanning. etc.
I tried Init-ing SQZ_SHG manager..... SQZ_Manager.
Then I took all SQZ GRD Nodes to down except SQZ_PMC & SQZ_SHG and tried to troubleshoot the SQZ_SHG directly.
Looking at the SQZ troubleshooting guide: There wasn't a section for SQZ _SHG troubleshooting. So I searched the ALOG with no hits for "PZT Out of Range".
I tried to adjust the OPO temp to maximize H1:SQZ-CLF_REFL_RF6_ABS_OUTPUT. But changing the OPO temp had no impact.
This is when I started to realize it may take me awhile to find out what is going on, since it's too late to call a SQZ expert, I should just take us to NO-SQZ.

So I ran the noconda python switch_nom_sqz_states.py without script.

Sadly I did accept the SDFs and these too, because I thought they were causing an SDF issue. But it may have been SQZ_ANG_ADJUST needed to be at ADJUST_SQZ_AND_ADF instead of DOWN for the SQZr to be considered ready for OBSERVING.
Made it back to OBSERVING at 11:30:44 UTC
Now that we have made it back to OBSERVING albeit without SQZing I'm using a finer toofed comb on my troubleshooting.

I went looking for Sitemap>SQZ>SQZT0>SHG That last SHG Button was a bit difficult to find when your eyes are still crossed..

I then took a screenshot of the SHG screen before any changes.
I then locked the SQZ_PMC and the SQZ_SHG. The SQZ_SHG was cycling between locked and Unlocked. Dropped from Observing at 11:57:53 UTC.
Then while trying to maximize H1:SQZ-SHG_GR_DC_POWERMON I changed H1:SQZ-SHG_TEC_SETTEMP from 35.89 to 35.61.
After this I ran the noconda python switch_nom_sqz_states.py with script to try and get us the SQZ SQuoZe.
SQZ_MAN was having an issue with the SQZ_FC losing lock at Transition_IR_LOCKIN, I then re-touched up the OPO temp.

Success! The SQZr Is SQUOZE!!
Now I need to accept all the SDF's again (and these too ) cause I didn't follow the directions when i ran the initial no sqzing script.
Observing reached again at 12:51:32 UTC.

Images attached to this report

LHO General - Ops Eve Shift Summary

ryan.short@ligo.org — Tue, 02 Sep 2025 22:03:52 -0700

Author: ryan.short@ligo.org

Report ID: 86705

TITLE: 09/03 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY: Very quiet shift with H1 locked and observing throughout; lock stretch is currently up to 8 hours. A M5.3 EQ out of Japan rolled through about an hour ago but didn't even put us into EQ mode.

H1 ISC - Bi-Weekly Locking Histograms

anthony.sanchez@ligo.org — Tue, 02 Sep 2025 17:47:55 -0700

Author: anthony.sanchez@ligo.org

Report ID: 86703

Bi-weekly Histograms of Locking statew times.

Histogram of time spent at NLN or higher:
Length of data 22
max Duration 2613 Min
Average 770.5 Min
% below 5 minutes : 0.0
Between 2025-08-20 00:27:34 and 2025-09-03 00:27:34

PowerUp Histogram
Length of data 30
max Duration 39 Min
Average 24.966666666666665 Min
% above 30 minutes 73.33333333333333
Between 2025-08-20 00:45:04 and 2025-09-03 00:45:04

DRMI-Histogram
Length of data 51
max Duration 49 Min
Average 11.647058823529411 Min
% above 5 minutes 54.90196078431373
Between 2025-08-20 00:46:03 and 2025-09-03 00:46:03

ALS Histogram
Length of data 53
max Duration 30 Min
Average 5.471698113207547 Min
% above 5 minutes 32.075471698113205
Between 2025-08-20 00:46:40 and 2025-09-03 00:46:40

Images attached to this report

LHO General - Ops Day Shift End

thomas.shaffer@ligo.org — Tue, 02 Sep 2025 16:30:50 -0700

Author: thomas.shaffer@ligo.org

Report ID: 86691

TITLE: 09/02 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 149Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: A fair amount of work done even though it was looking to be a slower maintenance day. We managed to stay locked for a few hours into it, while staying in light maintenance mode. We relocked automatically with an initial alignment, then lost lock 39 seconds later from an ETMX glitch. On the way up the second time, Elenna opportunistically tuned up PRMI ASC since it has shown some signs of non-convergence (alog86694). We have now been locked for 2.5 hours while a small dropout when the SQZr unlocked.
LOG:

1627 Lock loss from maintenance activities
1734 ISI BS WD tripped
1846 GRB short - Fermi E596650
1941 Back to NLN
1942 Lock loss
2109 Observing
2204-2207 Briefly out of observing while the squeezer unlocked and relocked

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:30	CDS	Fil, Erik	EX	n	HWWD cable	16:10
15:31	FAC	Erik	Ends	n	Chiller alarms	16:03
15:34	FAC	Kim, Nelly	mids, ends	n	Mats	15:35
15:34	FAC	Randy	CS	n	Forklift from VPW to LSB	16:28
15:35	FAC	Tyler	vertex	n	Fire hydrant	15:36
15:35	VAC	Norco	CP7 (EY)	n	LN2 delivery	16:54
15:36	VAC	Travis	MX	n	Pump work	20:03
15:37	FAC	Tyler	LVEA	n	Yellow tape	15:38
15:37	FAC	Someone	Staging	n	Rock moving	19:35
15:38	FAC	-	site	n	Fire pumps running	19:33
15:43	SQZ	Sheila	CR	n	SQZ meas.	16:34
15:55	VAC	Janos	MX	n	Joining Travis for pump work	20:03
15:56	SEI	Jim	EX, EY	n	Wind fence inspection	17:53
15:58	FAC	Kim, Nelly	LVEA	n	Tech clean	17:04
16:12	CDS	Fil	LVEA	n	SUS56 racks and near HAM3 racks, cable and chassis prep	17:16
16:15	FAC	Randy, Tyler	OSB rec., LVEA	n	Forklift into OSB receiving and then moving into LVEA (craning?)	16:33
16:27	VAC	Gerardo, Jordan, Anna	LVEA	n	Taking measurements near HAM6 (Jordan, Anna out 1659)	17:17
16:34	FAC	Chris	LVEA, Y arm, X arm	n	Pest control escort	17:52
16:37	PCAL	Rick, Tony	PCAL lab	local	PCAL lab meas.	20:23
16:42	ISC	Daniel	LVEA	n	AS_C whitening cable	18:32
16:53	PSL	Jason	CR	n	Ref cav remote alignment	17:11
17:01	-	Richard	LVEA	n	LVEA check	17:26
17:05	FAC	Kim, Nelly	EY, EX	n	Tech clean	18:24
17:21	PEM	Robert	LVEA	n	Shaker setup	19:35
17:32	CDS	Marc	MY, EY	n	Checking on power supplies	18:05
17:51	SYS	Betsy	LVEA	n	Grabbing dog clamps	18:08
17:53	FAC	Chris	LVEA	n	FAMIS checks	18:26
18:08	SYS	Betsy	Opt Lab	-	Parts	18:38
18:24	FAC	Kim, Nelly	FCES	n	Tech clean	18:50
18:27	FAC	Chris	Ends, Mids	n	FAMIS checks	18:54
18:35	SQZ	Camilla, Fil	LVEA - SQZT7	LOCAL	Noise hunt	19:05
18:42	SYS	Mitchell	LVEA - W	n	Parts hunt	18:53
18:47	-	Matt	LVEA	n	Sweep	19:05
18:56	VAC	Gerardo, Jordan	MY	n	Parts hunt	19:35
19:46	PEM	Robert	LVEA	n	Wrapping up	20:03
21:38	PCAL	Francisco	PCAL lab	-	Packing up to ship out	22:33
22:12	SYS	Betsy	Opt Lab	n	Parts	22:40
22:51	ISC	Camilla	Opt Lab	n	Parts hunt	23:17

SQZ

LHO General - Ops Eve Shift Start

ryan.short@ligo.org — Tue, 02 Sep 2025 16:11:13 -0700

Author: ryan.short@ligo.org

Report ID: 86702

TITLE: 09/02 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 10mph Gusts, 5mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.11 μm/s
QUICK SUMMARY: H1 has been locked for 2 hours.

Dust monitors for the Optics Lab and Diode Room both report counts have not changed
Wind and ground motion low
All other systems nominal

H1 PSL - PSL 10-Day Trends

ryan.short@ligo.org — Tue, 02 Sep 2025 16:00:36 -0700

Author: ryan.short@ligo.org

Report ID: 86701

FAMIS 31101

The fire alarm yesterday briefly shut off air handlers, so we see some temperature changes in several places that appear to have all settled back to nominal. Also, Jason's PMC, RefCav, and ISS adjustments this morning are seen clearly. No other major events of note in the past week.

Images attached to this report

H1 PSL - PSL Cooling Water pH Test - Monthly

ryan.short@ligo.org — Tue, 02 Sep 2025 15:47:33 -0700

Author: ryan.short@ligo.org

Report ID: 86700

FAMIS 26684

pH of PSL chiller water was measured to be between 10.0 and 10.5 according to the color of the test strip.

X1 SEI - Measurement of SPI HR mirror transmissivity and SPI BS AR surface reflectivity

richard.savage@ligo.org — Tue, 02 Sep 2025 15:34:50 -0700

Author: richard.savage@ligo.org

Report ID: 86699

TonyS and RickS

Today, we measured the transmissivity of one of the SPI HR mirrors and the AR surface reflectivity of one of the SPI beamsplitters, as requested by Jeff Kissel. The reflectivities of the beamsplitters were measured earlier, see this aLog entry.

HR mirror reflectivity: We used a set of Gentec power meters procured for the Pcal effort. An SPI HR mirror (see attached photo for details). Aligned at 45 deg. AOI with p-polarized light, the power transmissivity (P_trans/P_inc) was measured to be 23 e-6 W/ 567 e-3 W or 4.1e-5 (0.004%).

BS AR surface reflectivity: The reflectivity of the AR surface of a 50/50 beamsplitter was measured in two ways, both after mounting the BS with the AR surface closest to the input beam.

1. Using the PS5 Pcal power sensor and blocking the beam reflected from the 50 % reflectivity surface near the beamsplitter, the output voltage (after zeroing the no-laser-light level) was - 0.387 mV. With both the main reflected beam (~ 50 % of the incident light) and the beam reflected from the AR surface, the voltage was - 1.3699 V. Doubling the voltage for what would have been expected with the full incident power, the estimated AR reflectivity is 0.387 e-3 / (2 x 1.3699) = 1.4 e-4 or 0.014 %.

2. Using power meters to measure the power in the beam reflected from the AR surface and the power incident on the BS, we measure 52.6 e-6 W / 564 mW = 9 e-5 or about 0.01 %.

SEI

Images attached to this report

H1 SQZ - SQZ NLG Messurements at Different ISS AOM Setpoints

camilla.compton@ligo.org — Tue, 02 Sep 2025 15:21:44 -0700

Author: camilla.compton@ligo.org

Report ID: 86692

Tried to measure NLG (following 76542) at different ISS setpoints (by changing the SHG waveplate to adjust how much power is incident on the AOM), with the same OPO TRANS power. Because in 86363 we were confused that the NLG increased significantly when we realigned Pump fiber, with the same OPO Trans setpoint.

This was confusing and I'd like to repeat next week. I initially thought we were getting pump depletion so decreased the seed power, but later noticed the ISS was just unable to keep up and the control voltage was dropping to -5 for the low values of ISS setpoint, see attached, it could hold in LOCKED_CLF_DUAL with 80uW OPO_TRANS fine but not with the SEED beam.

OPO Setpoint	ISS Setpoint when locked on		Amplified		Unamplified		NLG	Notes
OPO Setpoint	CLF DUAL	SEED	Max	Min	UnAmp	Dark	NLG	Notes
80	4.9	3.2	0.192924	0.002389	0.0079612	-2.1e-5	24.2
80	2.9	2.9	0.045037			-2.2e-5	39 ?(using below unamp)	Pump deplation? Reduced SEED power from 0.7 to 0.3 to keep it locked on SEED (still didn't work first time).
80	6.3	6.3	0.0430464	0.000546	0.0011063	-2.2e-5	38 ?	Unamp signal decreased from SEED power change.
80	4.8	4.7	0.0454944	0.0005378	0.0018533	-2.7e-5	24.2
80	2.9	-5 ?						Noticed ISS Controlmon at -5.
80	3.5	3.5	0.0452317	0.00054049	0.0018636	-2.4e-5	24.0
80	4.95		0.04523				24.0	Leaving here.

Images attached to this report

H1 SQZ - Comment to SQZT7 Pico causing buzzing now disabled and monitored in sdf

camilla.compton@ligo.org — Tue, 02 Sep 2025 14:52:07 -0700

Author: camilla.compton@ligo.org

Report ID: 86698

TJ and I then checked that all other picos are monitored in sdf.

H1 SQZ - SQZT7 Pico causing buzzing now disabled and monitored in sdf

camilla.compton@ligo.org — Tue, 02 Sep 2025 14:43:20 -0700

Author: camilla.compton@ligo.org

Report ID: 86696

Fil, Camilla, Sheila. WP#12784

In 86323 we noticed a high pitched noise in SQZT7. Today we found the SQZT7 picos were enabled. When Sheila disabled them, the noise disappeared. It did not come back when they were re-enabled.

All picos should be off in Obserivng so I monitored the sdf. However, even when enabled, the picos should not make this noise. Fil suggests we watch this pico controller closely as when used it it might intermittently get stuck trying to drive and start to make this noise again.

Tagging DetChar: this pico has been on in Observing from 24th June until 2nd September.

DetChar

Images attached to this report

H1 General - Back to Observing at 2109UTC

thomas.shaffer@ligo.org — Tue, 02 Sep 2025 14:16:09 -0700

Author: thomas.shaffer@ligo.org

Report ID: 86697

We made it up to NLN at 1941UTC but this only lasted 39 seconds before an ETMX glitch took us out. On the way back up we noticed that it would need to go through PRMI, so Elenna took the time to fix it since we ran into some issues with it last week (alog86618). We wrapped up a few SDFs that were left over from maintenance day activities, and then to observing at 2109 UTC.

H1 SEI - Comment to St0 to St1 feedforward on HAM1 ISI today

elenna.capote@ligo.org — Tue, 02 Sep 2025 14:10:53 -0700

Author: elenna.capote@ligo.org

Report ID: 86695

Using the calibration factors I report in this alog, here is the CHARD plot roughly calibrated into radians.

Images attached to this report

H1 ISC - Updated PRC1 error signal in PRMI

elenna.capote@ligo.org — Tue, 02 Sep 2025 13:35:37 -0700

Author: elenna.capote@ligo.org

Report ID: 86694

After problems with PRC1 ASC, reported here, I checked the PRC1 P error signal and saw that the REFL signal seems to have a small offset. However, it appears that the POP X I signal has no offset, so I updated the error signal and tested the sign. The ISC DRMI code is updated with this new matrix.

H1 SQZ - filter cavity injection during maintence day

sheila.dwyer@ligo.org — Tue, 02 Sep 2025 12:09:41 -0700

Author: sheila.dwyer@ligo.org

Report ID: 86683

Sheila, Matt, Camilla

As the interferometer stayed locked during the early part of maintence day, we did some injections into the filter cavity length to try to measure the noise caused by backscatter. (Previous measurements 78579 and 78262, recent range drops that we think are filter cavity related: 86596)

The attached screenshot from Camilla shows the excitations and their appearance in DARM. (Compare to Naoki's measurement here, and to the time with no injection but elevated noise here). I made a simple script to make the projection based on this injection, which is available here. It does show about a factor of 3 a higher level of noise in DARM than Naoki's projection 78579, this is large enough that we should add it to our noise budget but far too small to explain our low range times last week.

Dtt file is userapps/sqz/h1/Templates/dtt/filter_cavity/backscatter_20250825.xml
reference 14-16 no excitation
17-18 amplitude 1000
ref 20-22 amplitude 3000
ref 23-25 amplitude 10000 start to see
ref 26-28 amplitude 20000 pretty linear, maybe I unlocked FC

Images attached to this report

Non-image files attached to this report

FC_backscatter.py

H1 General - H1 Sweep 2025-09-01 before transistion back to observing

matthewrichard.todd@ligo.org — Tue, 02 Sep 2025 12:01:42 -0700

Author: matthewrichard.todd@ligo.org

Report ID: 86693

M. Todd

I did a sweep of the LVEA, everything looked fine.

I unplugged an extension cord from outside the PSL racks, and noted that a forklift by the 3IFO racks was left plugged it. I left it plugged in as it was.

Robert was still in there while I was doing my sweep, and he was notified that he was the last one.

LHO General - Ops Day Shift Start

thomas.shaffer@ligo.org — Tue, 02 Sep 2025 10:39:46 -0700

Author: thomas.shaffer@ligo.org

Report ID: 86690

TITLE: 09/02 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 5mph Gusts, 2mph 3min avg
    Primary useism: 0.30 μm/s
    Secondary useism: 0.13 μm/s
QUICK SUMMARY: A bit delayed of a entry, but we are in maintenance mode. We stayed locked until 1627 UTC (927PT) before we were knocked out by some maintenance activities.

H1 PSL - PSL PMC and RefCav Remote Beam Alignment Tweaks

jason.oberling@ligo.org — Tue, 02 Sep 2025 10:26:48 -0700

Author: jason.oberling@ligo.org

Report ID: 86689

The FSS TPD has been slowly trending down again, so I did a quick remote adjustment of beam alignment into both the PMC and FSS RefCav today.

Starting with the PMC, I turned the ISS OFF, then adjusted the beam alignment from the Control Room using our picomotor mirrors. Unfortunately, I did not get any improvement in either PMC Trans or PMC Refl. PMC Refl has been very slowly increasing over the last couple of months, it may be time to take a look at adjusting the amplifier pump currents; we'll monitor this over the next week or two and move forward from there as necessary. To end the PMC adjustments, I turned the ISS back ON. It was diffracting ~4.2% (jumping between 4% and 4.5%), so I decreased the ISS RefSignal -1.99 V (from -1.98 V) to lower this a small bit. The ISS diffracted power is now hanging around 3.8% (jumping between 3.6% and 4%); at this new diffracted power, PMC Trans is ~105.7 W.

Moving on to the FSS RefCav, with the IMC unlocked the TPD began at ~0.78 V. I was able to get the TPD up to ~0.809 V, an OK improvement but not back where it was at the end of the last on-table alignment. With the IMC locked the TPD is ~0.813 V.

LHO VE - Tue CP1 Fill

david.barker@ligo.org — Tue, 02 Sep 2025 10:11:37 -0700

Author: david.barker@ligo.org

Report ID: 86688

Tue Sep 02 10:08:32 2025 INFO: Fill completed in 8min 29secs

Gerardo confirmed a good fill curbside.

Images attached to this report

H1 SEI - Sept 2025 wind fence inspections

jim.warner@ligo.org — Tue, 02 Sep 2025 10:06:32 -0700

Author: jim.warner@ligo.org

Report ID: 86687

No new issues found.

Images attached to this report

H1 ISC - Whitening chassis for ASC-AS_C and OMC-REFL_A changed

daniel.sigg@ligo.org — Tue, 02 Sep 2025 10:01:44 -0700

Author: daniel.sigg@ligo.org

Report ID: 86686

Rinse and repeat.

H1 General - Lock loss 1627 UTC

thomas.shaffer@ligo.org — Tue, 02 Sep 2025 09:30:21 -0700

Author: thomas.shaffer@ligo.org

Report ID: 86685

We tried staying locked through some of the maintenance activities and we made it pretty far. I had the SEI_ENV in Light Maintenance. There were people in the LVEA at the time, as well fork lifting into OSB receiving and maybe even some craning, so I'm unsure what actually knocked us out.

H1 OpsInfo - Instructions for running DARM OFFSET STEP to do output loss meas with hot OM2.

jennifer.wright@ligo.org — Tue, 02 Sep 2025 09:28:45 -0700

Author: jennifer.wright@ligo.org

Report ID: 86623

Test for Thursday morning at 7.45 am, assuming we are thermalised.

In NLN.
Turn off OMC ASC:
- sitemap -> OMC -> OMC Control -> turn MASTER GAIN slider to 0 (its blue and on the bottom centre of screen).
Run DARM offset step:
- Go to /ligo/gitcommon/labtutils/darm_offset_step
- run:

conda activate labutils

python auto_darm_offset_step.py

Wait until program has finished ~20 mins.
Turn OMC ASC back on by putting master gain slider back to 0.020.
Heat up OM2 heater (~ 3 hours):
- IFO out -> OM2 -> change H1:AWC-OM2_TSAMS_POWER_SET value to 4.6.
After power has leveled out on H1:AWC-OM2_TSAMS_THERMISTOR_1_TEMPERATURE and H1:AWC-OM2_TSAMS_THERMISTOR_2_TEMPERATURE, turn off OMC ASC again by putting MASTER GAIN slider back to 0 on OMC Control screen.
Run auto_darm_offset_step.py again.
Put OM2 heater H1:AWC-OM2_TSAMS_POWER_SET back to 0.
Test done, wait for thermistors to level out again.

H1 CDS - EX Hardware watch test

erik.vonreis@ligo.org — Tue, 02 Sep 2025 09:12:14 -0700

Author: erik.vonreis@ligo.org

Report ID: 86684

[Fil, Erik]

Hardware watchdog at EX started count down when disconnected from either satellite amp.

CDS, SEI, SUS

H1 General - OPS Monday EVE shift summary

ryan.crouch@ligo.org — Mon, 01 Sep 2025 22:00:27 -0700

Author: ryan.crouch@ligo.org

Report ID: 86682

TITLE: 09/02 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY: One lockloss from the fire alarm, easy relock. We've been locked for just over 2 hours.
LOG: No log.

There was a small LVEA temperature excursion from AHU2 not restarting after the fire alarm. It looks mostly leveled out now.

01:28 UTC lockloss
03:03 UTC Observing

H1 General - Comment to 01:30 UTC lockloss from the fire alarm

ryan.crouch@ligo.org — Mon, 01 Sep 2025 20:03:49 -0700

Author: ryan.crouch@ligo.org

Report ID: 86681

03:03 UTC Observing

H1 General - 01:30 UTC lockloss from the fire alarm

ryan.crouch@ligo.org — Mon, 01 Sep 2025 18:42:00 -0700

Author: ryan.crouch@ligo.org

Report ID: 86680

01:30 UTC lockloss, the fire alarm went off. It was reported as a "trouble alarm, I called Richard and I then reset the alarm on the panel in the CUR.

H1 General - Ops Day Shift End

oli.patane@ligo.org — Mon, 01 Sep 2025 16:33:01 -0700

Author: oli.patane@ligo.org

Report ID: 86679

TITLE: 09/01 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY: Observing at 153 Mpc and have been Locked for over 1.5 hours. Relocking after the lockloss today went fine besides needing to touch ALSX and ALSY a bit. Weirdly, the first two times ALSX locked and turned on WFS, after a bit the WFS pulled the alignment away and caused ALSX to unlock. I set everything up to be able to turn the WFS off for the next time, but then there was no problem.
LOG:

14:30 UTC Relocking and in DRMI_LOCKED_CHECK_ASC
15:09 NOMINAL_LOW_NOISE
    15:11 Observing
    18:59 Superevent S250901cb
    19:38 Earthquake mode activated - I moved us into earthquake mode because of some ground motion that USGS hadn't seen yet
    19:46 Back to CALM
20:07 Lockloss
    - ALSX and Y needed my help for locking
    - Twice ALSX WFS pulled ALSX away and unlocked it
21:54 NOMINAL_LOW_NOISE
    21:55 Observing

H1 ISC - Increasing ETMX bias has increased length of IFO locks

oli.patane@ligo.org — Mon, 01 Sep 2025 16:29:31 -0700

Author: oli.patane@ligo.org

Report ID: 86678

Back on July 28th, we doubled the bias on ETMX in an effort to try and survive more DARM Glitch locklosses (previously referred to as ETMX Glitch locklosses) (86027). Now that we've been at this new bias for a month, I have made some visuals to compare the number of locklosses from low noise before and after the change. We wanted to stay at this bias for at least a few weeks because sometimes throughout O4, we've had periods of a couple weeks or so where we barely have any locklosses caused by DARM Glitch, and we wanted to make sure we weren't just entering one of those periods.

TLDR;
In August, we spent more time locked with longer locks and less locklosses. The difference between August and the other months of O4 has been very drastic, and the plots make it look like to me that this is due to the bias change in ETMX.

Not TLDR:
A birds-eye view:
O4 All Locklosses vs DARM Glitch Locklosses
I've posted similar versions of this figure before, it just gives a visual representation of the amount of locklosses we've had during O4 that have been attributed to DARM Glitch versus every other lockloss. From this plot, you can see that since we doubled the ETMX bias, we have seen less ETMX glitch locklosses, and less locklosses in general!

A more in-depth examination:
I've decided to compare the month of August to the other full months of Observing we've had in O4c: February, March, June, and July. April was only a couple days of Observing, and May we were fully venting. The important thing to note here though is that for June, we started Observing 5 days into the month, and there was a lot of commissioning going on the rest of the month, so the June data points aren't the best comparison.

O4 Lock Length Distribution by Month
The xaxis shows the number of hours we had been locked for each NLN lockloss during the month, and the yaxis shows how many locklosses occurred after that lock lengh. Each months' plot has the same x and y axes limits, and on the right side of each plot is the total number of locklosses from low noise for the month as well as the average lock length.
You can see the distributions for February, March, June, and July all look pretty similar, with the majority of locklosses happening after 10 hours or less of being locked, and the average lock length for those four months is around 5.5 hours. February, March, and July also all have a similar number of locklosses, while June has a quarter less, partially due to commissioing at the beginning of the month and partially for unknown reasons.
August, however, is completely different. The distribution of lock lengths is a lot wider, and not just by one or two longer locks, in August there were 9 locks that were longer than during the other four months. There is also a lot flatter distribution for the shorter locks. This results in an average lock length of 13.3 hours, more than double the other months. There were also approximately half the number of locklosses during August, which is a very drastic drop. Even compared to June we had a lot less locklosses.

Lockloss Stats per Month for O4c
Here's a table I made with some more lock and lockloss stats. There's the number of days that that month consists of, the number of locklosses during that period of time, the number of locklosses attributed to DARM Glitches during that time, the average length of lock, and the total time spent locked during that period of time. The new info here is the total time locked - in August we spent about 25 days locked, which is 6 days more than the next highest month, July, and is a big jump up compared to the total locked time between February, March, and July.

Lockloss

Images attached to this report

H1 General - OPS Monday EVE shift start

ryan.crouch@ligo.org — Mon, 01 Sep 2025 16:13:22 -0700

Author: ryan.crouch@ligo.org

Report ID: 86677

TITLE: 09/01 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 14mph Gusts, 6mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.08 μm/s
QUICK SUMMARY:

We've been locked for a little over an hour
Wind and secondary microseism is low

H1 DetChar - Data Quality Shift Report: LHO 2025-08-25 to 2025-08-31

vicente.sierra@ligo.org — Mon, 01 Sep 2025 15:11:00 -0700

Author: vicente.sierra@ligo.org

Report ID: 86676

Link to report here.

Summary:

H1 had an average duty cycle of 83.41% for the week, which is an increase from last week (78.1%).
A somewhat quiet (glitch and noise-wise) week for the detector.
Nine relevant seismic events throughout the week; five of these caused lock-losses (Monday, Tuesday, Saturday, and Sunday), while the rest caused some noise in the spectrograms in the 15-50Hz frequency band (Wednesday to Saturday).
The BNS range fluctuated from around 150 to 160Mpc throughout the week. On Wednesday, we had a significant 10MPc drop around 11:00-11:45 UTC; the corresponding aLog pointed “FC backscatter into the IFO” as the responsible.
On Tuesday we had eight very short lock-losses due to the OPO losing lock.
ETM glitches caused two lock-losses throughout the week (Tuesday and Thursday).
We observed persistent violin modes (specifically fundamental at ~500Hz, and some 2nd harmonics at ~1000Hz) following large lock-losses all week but on Wednesday. The most persistent one appeared later on Thursday and did not fade away until Friday morning. Last week the fundamental modes were also reported due to their persistency.
FScan Plots appeared everyday but on Monday. Lowest line count on Tuesday with ~2300 lines and highest on Friday with ~2900 lines.
Relevant Round Winners:
- H1:ASC-Y_TR_B_NSUM_OUT_DQ: Winnertwice (Monday and Saturday) and second place twice (Wednesday and Friday).
- H1:ASC-Y_TR_B_PIT_OUT_DQ: Third place twice (Monday and Thursday) and once on second place (Saturday).
- H1:ASC-Y_TR_A_NSUM_OUT_DQ: Third place twice (Tuesday and Sunday) and once on second place (Thursday).
- H1:ASC-Y_TR_A_YAW_OUT_DQ: Winner once (Wednesday) and second place once (Tuesday).
- H1:SQZ-FC_WFS_A_I_PIT_OUT_DQ: Winner once (Tuesday).
- H1:SQZ-FC_LSC_DOF2_OUT_DQ: Winner once (Thursday).
- H1:SQZ-FC_LSC_DOF2_IN1_DQ: Winner once (Friday).
- H1:LSC-POP_A_RF9_I_ERR_DQ: Winner once (Sunday).

DetChar

H1 General - Comment to Lockloss

oli.patane@ligo.org — Mon, 01 Sep 2025 14:56:00 -0700

Author: oli.patane@ligo.org

Report ID: 86674

21: 55 UTC Observing

H1 General - Lockloss

oli.patane@ligo.org — Mon, 01 Sep 2025 13:09:33 -0700

Author: oli.patane@ligo.org

Report ID: 86673

Lockloss at 2025-09-01 20:07 UTC after almost 5 hours locked

Lockloss

LHO VE - Mon CP1 Fill

david.barker@ligo.org — Mon, 01 Sep 2025 10:21:22 -0700

Author: david.barker@ligo.org

Report ID: 86672

Mon Sep 01 10:08:48 2025 INFO: Fill completed in 8min 44secs

Images attached to this report

H1 General - Comment to Ops Day Shift Start

oli.patane@ligo.org — Mon, 01 Sep 2025 08:12:10 -0700

Author: oli.patane@ligo.org

Report ID: 86671

15:11 UTC Observing

H1 General - Comment to Ops Day Shift Start

oli.patane@ligo.org — Mon, 01 Sep 2025 08:03:44 -0700

Author: oli.patane@ligo.org

Report ID: 86670

Two locklosses last night:

2025-09-01 06:55 UTC - There is a possible MICH ringup of 1.6 Hz starting two seconds before the lockloss? Tagging ISC

2025-09-01 11:11 UTC - Earthquake. Seems like it was pretty large and local, so unsure if we would have survived it even if someone had used the ASC Hi Gains state

ISC, Lockloss

Images attached to this report

H1 General - Ops Day Shift Start

oli.patane@ligo.org — Mon, 01 Sep 2025 07:38:53 -0700

Author: oli.patane@ligo.org

Report ID: 86669

TITLE: 09/01 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 2mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.09 μm/s
QUICK SUMMARY:

Currently Relocking and in DRMI_LOCKED_CHECK_ASC

H1 General - OPS Sunday EVE shift summary

ryan.crouch@ligo.org — Sun, 31 Aug 2025 22:00:39 -0700

Author: ryan.crouch@ligo.org

Report ID: 86667

TITLE: 09/01 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY: One lockloss with an easy recovery, YARM just took a little while. We've been locked for 45 minutes.
LOG: No log

02:54 UTC Lockloss
- 03:10 UTC We started getting lightning around site, as seen on the cameras
- 04: 19 UTC Observing

H1 General - Comment to Lockloss 02:54 UTC

ryan.crouch@ligo.org — Sun, 31 Aug 2025 21:19:37 -0700

Author: ryan.crouch@ligo.org

Report ID: 86668

04: 19 UTC Observing

H1 General - Lockloss 02:54 UTC

ryan.crouch@ligo.org — Sun, 31 Aug 2025 19:55:41 -0700

Author: ryan.crouch@ligo.org

Report ID: 86666

Lockloss 02:54 UTC

Lockloss

H1 General - Ops Day Shift End

oli.patane@ligo.org — Sun, 31 Aug 2025 16:37:00 -0700

Author: oli.patane@ligo.org

Report ID: 86665

TITLE: 08/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY: Currently Observing at 158 Mpc and have been Locked for 5 hours. Lockloss was fast and easy to recover from - the IFO just needed my help grabbing ALSY for the same reason we've been seeing for a while: SCAN_ALIGNMENT had taken it to a good-looking spot (above 1), but it wasn't high enough to catch. A few taps was all that was needed.
We had another test of using the ASC Hi Gains button again! During the earthquake, peakmon started creeping up above 500, and picket fence was showing multiple stations were yellow or orange. I tried to hold off on leaving Observing as long as possible since the ground motion wasn't that bad yet, but I eventually started the transition to ASC Hi Gain when I saw peakmon hit 900, but it quickly went above 900 and by the time we started transitioning over, we were above 1200 and quickly increasing. Luckily, we didn't lose lock, but we were close, so I definitely should've transitioned over sooner! This earthquake went up to 2200 on peakmon. Afterwards, the transition back went smoothly.
LOG:

14:30 UTC Observing and Locked for almost 3 hours
17:17 Lockloss
   - Had to adjust ALSY a bit for it to be able to catch
18:30 NOMINAL_LOW_NOISE
   18:33 Observing
   20:06 Earthquake mode activated
   20:17 I took us out of Observing and selected ASC Hi Gain to try and ride out the earthquake
   20:34 Back to regular NLN gains and back into Observing

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
18:25	PEM	Robert	LVEA	n	Carefully taking photos for Virgo	18:30

ISC, SEI

Images attached to this report

H1 General - OPS Sunday EVE shift start

ryan.crouch@ligo.org — Sun, 31 Aug 2025 15:58:20 -0700

Author: ryan.crouch@ligo.org

Report ID: 86664

TITLE: 08/31 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 13mph Gusts, 7mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.08 μm/s
QUICK SUMMARY:

We've been locked for 4.5 hours
Secondary microseism is decreasing, wind is low

H1 General - Comment to Lockloss

oli.patane@ligo.org — Sun, 31 Aug 2025 11:33:37 -0700

Author: oli.patane@ligo.org

Report ID: 86663

18:33 UTC Back to Observing

H1 General - Lockloss

oli.patane@ligo.org — Sun, 31 Aug 2025 10:18:40 -0700

Author: oli.patane@ligo.org

Report ID: 86662

Lockloss at 2025-08-31 17:17 UTC after 5.5 hours locked

Lockloss

LHO VE - Sun CP1 Fill

david.barker@ligo.org — Sun, 31 Aug 2025 10:10:33 -0700

Author: david.barker@ligo.org

Report ID: 86661

Sun Aug 31 10:07:39 2025 INFO: Fill completed in 7min 35secs

Images attached to this report

H1 General - Ops Day Shift Start

oli.patane@ligo.org — Sun, 31 Aug 2025 07:39:39 -0700

Author: oli.patane@ligo.org

Report ID: 86660

TITLE: 08/31 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 157Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 4mph Gusts, 2mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.11 μm/s
QUICK SUMMARY:

Currently Observing at 156 Mpc and have been Locked for almost 3 hours.

LHO General - Sat EVE Ops Summary

corey.gray@ligo.org — Sat, 30 Aug 2025 21:56:48 -0700

Author: corey.gray@ligo.org

Report ID: 86659

TITLE: 08/30 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY:

H1 has been locked entire shift and NO drops from Observing (H1 locked for 7.75hrs). Did not get to run Simulines due to L1 also being UP the whole time.
LOG: n/a

H1 General - Ops Day Shift End

oli.patane@ligo.org — Sat, 30 Aug 2025 16:41:32 -0700

Author: oli.patane@ligo.org

Report ID: 86658

TITLE: 08/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY: Observing at 158 Mpc and have been Locked for 2.5 hours. Relocking after the earthquake knocked us out was pretty easy - I just had to run an initial alignment after we lost lock in START_TR_CARM from a bad alignment.
LOG:

14:30 UTC Observing and Locked for over 13.5 hours
16:23-16:27 Small plane flying overhead Tagging DetChar
18:31 Out of Observing for Calibration suite
19:01 Lockloss during calibration sweep due to sudden local earthquake
- Initial alignment run
21:10 NOMINAL_LOW_NOISE
21:13 Observing

DetChar

LHO General - Sat EVE Ops Transition

corey.gray@ligo.org — Sat, 30 Aug 2025 16:40:41 -0700

Author: corey.gray@ligo.org

Report ID: 86657

TITLE: 08/30 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 11mph Gusts, 5mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.13 μm/s
QUICK SUMMARY:

Handoff from Oli was straightforward. I'll monitor L1 for downtime, in case H1 can have an opportunity for a Simulines Calibration opportunity (simulines failed earlier due to the Nevada EQ). H1's currently been locked for 2.5hrs (almost thermalized).

H1 General - Comment to Lockloss

oli.patane@ligo.org — Sat, 30 Aug 2025 14:13:49 -0700

Author: oli.patane@ligo.org

Report ID: 86656

21:13 UTC Back to Observing

H1 CAL - Calibration Measurement August 30, 2025 (broadband only)

oli.patane@ligo.org — Sat, 30 Aug 2025 12:13:10 -0700

Author: oli.patane@ligo.org

Report ID: 86655

At the time of this measurement, we had been Locked for over 17.5 hours and so we were well thermalized. Close to the very end of simulines (4 excitations still running), we had a lockloss due to a local earthquake, so we only have the broadband measurements.

Calibration monitor screen

Broadband
2025-08-30 18:32:35 - 18:37:53 UTC
/ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20250830T183242Z.xml

Images attached to this report

H1 General - Lockloss

oli.patane@ligo.org — Sat, 30 Aug 2025 12:09:00 -0700

Author: oli.patane@ligo.org

Report ID: 86654

Lockloss at 2025-08-30 19:01 UTC due to sudden local earthquake (picket fence, ndscope) right near the end of running simulines. We had been Locked for just over 18 hours.

Lockloss

Images attached to this report

LHO VE - Sat CP1 Fill

david.barker@ligo.org — Sat, 30 Aug 2025 10:22:08 -0700

Author: david.barker@ligo.org

Report ID: 86653

Sat Aug 30 10:08:29 2025 INFO: Fill completed in 8min 25secs

Images attached to this report

H1 General - Comment to Ops Day Shift Start

oli.patane@ligo.org — Sat, 30 Aug 2025 08:07:26 -0700

Author: oli.patane@ligo.org

Report ID: 86652

Early this morning at 10:24 UTC we had Superevent S250830bp come in on Tony's OWL

H1 General - Ops Day Shift Start

oli.patane@ligo.org — Sat, 30 Aug 2025 07:39:16 -0700

Author: oli.patane@ligo.org

Report ID: 86651

TITLE: 08/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 1mph Gusts, 0mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.13 μm/s
QUICK SUMMARY:

Observing at 156 Mpc and have been Locked for over 13.5 hours.