TITLE: 10/15 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 0mph Gusts, 0mph 3min avg
    Primary useism: 0.08 μm/s
    Secondary useism: 0.13 μm/s 
QUICK SUMMARY:

• 14:00 UTC Observing
  • DCPD window shows something ringup then damp back down in the past 15 minutes, Transient PI? It was smaller than we saw yesterday (added plot at 18:39)
• 14:17 UTC GRD-Short E610359
• Secondary microseism continues to decrease, low winds
• Lockloss doesn't seem to be updating, the most recent one isn't showing up
  • The web site says: online last update: 1076.1 min ago (2025-10-14 13:42:18.164546)

Wed Oct 15 10:05:11 2025 INFO: Fill completed in 5min 8secs

Gerardo confirmed a good fill curbside.

The chilled water plants at the Mid stations have been shut down for the Winter. 

TITLE: 10/15 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Observing at 155 Mpc and have been Locked for about 8.5 hours. Nothing happened during my shift besides a couple of ITMX saturations.
LOG:

23:00UTC Observing and Locked for almost 3 hours
    23:34 Left Observing to close beam diverter
    23:34 Back into Observing

Still Observing and have been Locked for almost 7 hours. Secondary microseism has continued to drop. Our range has been a bit better than it has been the last couple of days, so that's cool. 

First attachment is a screenshot of D1300130 ISS array PD assembly (which is somehow called "PSL PDD MODULE").

Each PD (part #8) is entirely retained in an aluminum cylinder called the PDD main photodiode mount (part #9) and therefore the can of the PD is conductive to the cylinder. However, the cylinder is supposed to be isolated from the ISS array plate (and therefore the entire ISS array structure) by two pieces of kapton insulators (part #10). PCB assembly, which is connected to the PD, is sandwiched between two aluminum clamps (part #2 "PDD clamp" and part #11 "Clamping plate", which I refer to the bottom and the top clamp respectively), but the PCB ground is isolated from the clamps by an insulator ring (part "7?").

This way ground loop is broken even though the can of the PD is connected to the shield of two SMP coax cables on the PCB board (part #1).

Rahul and I checked the continuity between the cylinder and the ISS array cage. (Note that this check could not be done without disconnecting all SMP cables from the preamp first, because the preamp's ground is somehow connected to the optics table, which is connected to the ISS array cage.)

Issues found on the installation spare:

Unfortunately two of the PDs on the first floor (PD 5 and 6 in our notation in the lab, see the 2nd picture for the notation even though that is the picture of the 3IFO unit) didn't pass the check.

We also checked the grounding of the QPD and it was good.

Inspecting 3IFO, finding the same issue, and fixing it:

We quickly checked the 3IFO unit too and found that it also had a grounding issue for one of the PDs (PD 2). In the 2nd attachment, you can see that the space between the top and the bottom clamp of PD2 is smaller than the others.

We removed the top clamp and found no insulator (3rd attachment). We disconnected the PCB from the PD and learned that:

1. Disconnecting the PCB won't change the PD position. PD is somehow firmly attached to the main photodiode mount, and it won't shift unless we loosen the bottom clamp. 
2. The insulator was found on the other side of the PCB, between the PCB assy and the PEEK pin guide (part #4).
3. Installing the insulator on the correct side (4th attachment) and reinstalling the top clamp, the grounding was broken.

Fixing the issue on the installation spare:

With the new knowledge about the insulator, we looked at the gap between the top and the bottom clamps of the PDs for the installation spare unit and it looked like PD5, 6, 7 had the insulator on the wrong side of the PCB even though PD7 didn't have the grounding issue.

Sure enough, we removed the top clamp for these problematic PDs, found no insulator for any of these (5th attachment), removed the PCB and found the insulator on the wrong side (6th attachment shows you one example), installed them correctly and the grounding problem was gone.

Electrical test:

Since we have disconnected the PCB and reconnected to the PDs, we reconnected all of the PDs to the preamp again and confirmed that all PDs still respond to the light as they used to.

We haven't measured if any one of these are much noisier than the others, which we'll check later.

Closes FAMIS#28427, last checked 87380

ITMX had too low of coherence again this week so it didn't run. Everyone else is looking normal.

ETMX

ETMY

ITMX

ITMY

Jenne, Elenna, Oli, Ryan S, Ryan C, Matt

Today the engagement of the camera servos significantly reduced the buildups. The first attachment shows how the PRG, REFL LF and circ power signals dropped as the camera servo guardian engaged the cameras. After reengaging the ADS, we saw that the buildups increased again, although not to the exact same level that they were before the camera engaged. This suggested to us that the camera servos were not going to the same camera set point as before. Oli spoke to the vacuum team that had been doing work at EY and found out that the EY camera cable had been very taut and they tried to loosen it. It's possible they bumped the camera during their work.

While we were considering what to do, we noticed that OMC DCPD sum was increasing rapidly. We realized this was due to a PI ringing up at 10.2 kHz. It's not a PI we usually damp, so there were no PI guardian warnings, and we didn't know how to damp it. Matt thinks this is a PI that we usually see ring up early in the lock, but with a relatively small amplitude, as the Y arm mode passes by. It usually does not need damping. We started getting DCPD saturations warnings, and we were certain we were going to lose lock. We thought perhaps that if we were in a slightly different beam position, that could cause this PI to ring up more than usual. Matt also pointed out that the CO2s had stayed on much longer for commissioning today. I had also held the IFO at 25 W before and after moving spots to perform some ASC measurements. So this was definitely not a normal locking process. However, the PI started to turn around on its own (we think), and we held the lock.

Jenne and I tried engaging the camera servos again, and saw that indeed doing so does reduce the buildups. Our thinking is that if the EY camera got bumped, the digital offset we normally use has probably changed. We also noticed that the low frequency sensitivity was slightly worse than usual, suggesting that wherever the beam was, the A2L decoupling was bad. So, we decided to move the EY camera offsets to see if we could regain the buildups, following the assumption that something had changed at EY. We looked at the camera offset value that was present when the ADS lines were on. We changed the ETMY pitch and yaw offset values. This resulted in a 2 count change for ETMY pitch, from -230 to -228 and a 0.5 ct change in yaw from -349.5 to -349. Changing to these new offsets increased the buildups again. We also saw that the ADS had taken the ETMX camera error signal to a slightly different offset, so we tried changing the ETMX pitch value, but this had no change on the buildups so we reverted.

Even though this whole process was designed to bring us back to the nominal ETMY spot position, it appeared that the low frequency sensitivity was still bad, I ran the A2L script. I watched TJ's A2L script scope and noticed that the A2L starting value for ETMY pitch was very far from zero, so the script never took the A2L value to the minimum. Jenne and I ended up guesstimating what a good A2L value was so that the starting point would be close enough to the minimum that the script steps would go there. This results in a significantly different A2L gain than before for ETMY pitch. I copied the tables below for each A2L script attempt. The nominal ETMY pitch value before was 5.62 and now it is 6.43. According to the a2l lookup script, this is a 3.8 mm change in spot position. The ETMX A2L gains also updated slightly, as you can see below. I did not make any changes to the gains where the diff between final and inital was 0.01 in magnitude.

Now that we have been in NLN for 3.5 hours, the buildups still seem lower than usual. Circulating powers usually read about 382 "kW", but they are currently reading about 374 "kW". Kappa C is also 0.975, and it is usually 0.98. I'm not convinced that the beam is in the correct spot.

Jenne suggested that we could try going back to the old A2L gains, and then adjusting the camera offset until the ADS lines are minimized, which I think is a good idea. However, I do want to point out that our range is currently reading 160 Mpc on sensmon clean.

The new ETMY camera offsets and the updated A2L gains are saved in lscparams and loaded in ISC_LOCK. First try:

Second try:

TITLE: 10/14 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: We ran into some issues after relocking following maintenance, but everything is stable currently. Is it in the best setup/orientation? Maybe not.
LOG:                                        

• 15:32 UTC SUS PR3 and SR3 model restarts
• 15:47 UTC GRD reboot alog87463
• 16:00 UTC SAT amp swaps, QUADs L2 (ITMY, ITMX, ETMX, ETMY) alog87469
• 16:43 UTC Norco arrived at the gate, CP2
• 18:00 UTC TCS CO2Y trips off IR alarm
• 18:08 UTC Back to regular locking
  • 18:19 UTC IA
• 18:54 UTC CO2 X & Y OUTPUT OFF "Power too low"
  • 2 seconds before there was a HAM7 cps glitch that tripped the ISI
• 19:18 UTC I followed the wiki and minimized the SHG_FIBER_REJECTED_DC as we relocked
• 20:24 UTC we finished up the ASC loop measurements
• 20:46 UTC GRB-Short E610126
• 20:50 UTC While we were investigating the buildups dropping once the camera servo turned on a PI started to ring up around ~10.2k
• 22:08 UTC Observing

TITLE: 10/14 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 12mph Gusts, 7mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.18 μm/s 
QUICK SUMMARY:

Observing at 155Mpc and have been locked for almost three hours. Everything looking good.

WP12827 SUS HLTS Estimator

Jeff, Oli, Brian L, Edgard, Dave, Ryan C:

New h1suspr3 and h1sussr3 models were installed. Slow channels had been renamed and therefore a DAQ restart was required.

WP12835 h1guardian1 reboot

TJ:

h1guardian1 was rebooted, all nodes now have the latest userapps files and changes will be tracked by GRD-CFC.

DAQ Restart

Dave, Jonathan:

The DAQ was restarted for the model changes. GDS0 needed a second restart. FW1 spontaneously restarted itself soon after the 1-leg restart.

Jennie W, Keita, Rahul

On Friday, Keita and Rahul and I tried moving PDs 2 and 6 to align them better with the others. As can be seen from the scans we did of the DC voltage of the diodes as we moved the input alignemnt in horizontal translation and yaw from alog #87290, 2 and 6 have a range of alignment that is shifted relative to the other 6.

We also checked this with a IR sensitive camera with a zoom lens.

One person used the camera with a zoom lens to check the spot on the PDs as another person loosened the screws from behind the array and the third person held the barrel of the PD assembly to stop it moving or rotating in an undesired direction.

There is not a lot of space as 2 and 6 are in a column and are very close to diodes 1 and 5 on the right.

The horizontal scan we took after these moves showed we had made things worse, see this image.

Later that afternoon, Keita moved the PD 2 back and checked the alignment and it looks better.

The alignment as of yesterday (Monday) was 143mm in pitch (as read out by the allen key in the PZT mirror pitch actuator wheel) and 0.4145 inches in horizontal translation as read out by the translation stage the PZT mirror sits on.

Keita measured the coupling (after finding an error in my code from the previous coupling measurement I plotted last Thursday (alog #87400)).

The coupling in both vertical and horizontal is below 10, so this should be good enough for install if all else checks out.

Yesterday afternoon, Rahul and I did the vertical scan (slightly off from the horizontal reference position of 0.4145 inches that Keita had aligned to). The data in this graph was collected at a horizontal translation stage reading of 0.4162 inches.

We had to redo the horizontal scan today as I missed out some scan values yesterday. The data was collected with the pitch indicator at 143mm (the allen key on the pitch wheel actuator).

WP 12836
ECR E2400330
Modified List T2500232

The following SUS SAT Amps were upgraded per ECR E2400330. Modification improves the whitening stage to reduce ADC noise from 0.05 to 10 Hz.

F. Clara, J. Kissel, O. Patane