18:45 UTC While Jim was running a measurement on ISI HAM5, SUS ITMY started to flash its' red Rocker Switch Death on L2 and report that its' L2 OSEMs were in fault, we also noticed there's a big new line at ~92Hz. Jeff turned off feedback from L2. It looks like it could be a sat amp issue, the L2 sat amp was upgraded this past Tuesday alog87469. Jeff is starting to work on characterizing a sat amp box in the EE shop to swap in. 

We would need a lockloss to swap this component.

We are going to try to go back into Observing for a bit until we can fix it or lose lock.

J. Kissel

This past Tuesday (Oct 14 2025), we upgraded the L2 (PUM) OSEM PD Sat Amps to improve their whitening filter, per ECR E2400330; see LHO:87469. These QUAD L2 PUM OSEMs (in which the flags are on the QUADs main chain PUM, and the LED & PD are on the reaction chain PUM [aka the "PenRe"]) are used in feedback. This "damping" of a "3.3" Hz reaction chain resonance is different ITMs and ETMs (ITM Install = LHO:65728; ETMs Install = LHO:68012 --- commissioning of both = LHO:68200); the ITM has resonances at 3.28 / 3.31 Hz and the ETM has modes at 3.18 Hz / 3.42 Hz.

Because the improved sat amps come with better compensation of the whitening filter frequency response, we know that the frequency dependent gain on each channel -- especially around 3.3 Hz may change by as much as ~10%. 

In the aLOG (and comments collection) I report 
    (a) That we *did* see a change in the open loop gain TFs of these loops, but (after ~2 days of observing since the upgrade) the IFO doesn't seem to mind the changes.
    (b) We were able to get better coherence on the open loop gain TFs in the 0.1 to 10 Hz region because of the sat amp whitening improvement
    (c) A comparison between all four QUAD's PITCH and YAW damping, so that we might understand them better and potentially improve them.

In this main aLOG I show the comparison between the PITCH and ROLL open loop gain TFs and loop suppression for all four QUADs.

Rushed commentary:
    - The surprising thing to me is that we're getting gain peaking and/or some suppression of other modes below 1 Hz, which I'm confident was not the design intent.
    - Even though the filters and EPICs gains are the same for EX and EY, ETMX has a lot more open loop gain below 1 Hz.
    - Also though the ETM loop suppression is about the same on these 3.18 / 3.42 Hz, the ITM loops have pretty different amount of gain peaking.
    - I'm guessing we *don't* want this much sharp gain peaking just *off* the "3.3" Hz mode.

Broadband:

Start: 2025-10-16 18:01:42 UTC

Stop: 2025-10-16 18:06:53 UTC

Files: /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20251016T180142Z.xml

Simulines:

Start: 2025-10-16 18:08:33 UTC // 1444673331.797786 GPS

Stop: 2025-10-16 18:31:47 UTC // 1444674725.604456 GPS

Files:

2025-10-16 18:31:47,448 | INFO | File written out to: /ligo/groups/cal/H1/measurements/DARMOLG_SS/DARMOLG_SS_20251016T180834Z.hdf5
2025-10-16 18:31:47,456 | INFO | File written out to: /ligo/groups/cal/H1/measurements/PCALY2DARM_SS/PCALY2DARM_SS_20251016T180834Z.hdf5
2025-10-16 18:31:47,461 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L1_SS/SUSETMX_L1_SS_20251016T180834Z.hdf5
2025-10-16 18:31:47,466 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L2_SS/SUSETMX_L2_SS_20251016T180834Z.hdf5
2025-10-16 18:31:47,471 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L3_SS/SUSETMX_L3_SS_20251016T180834Z.hdf5

Since we are still not happy with our buildups, I moved the ETMY beam spot again, following the assumption that this camera was bumped on Tuesday.

Instead of considering the A2L gains or ADS, I just chose to move the spot around by hand to make the buildups better. I did so slowly in pitch and then in yaw. Overall, the final camera offsets are P: -224 and Y: -346. This offsets brought the PRG up to 49.5 and the arm powers up to 380 "kW". I also noticed that this change brought the Y arm power up slightly about the X arm power, which is how it used to be before whatever happened on Tuesday.

Once the cameras converged on these new values, I ran the A2L script. This was a large beam shift for ETMY, so I had to run it a few times to get the script to cross zero for the ETMY lines. I would run it, guess where to go next, and rerun. Sheila pointed out to me that if you scroll up in the script output, it will tell you where it thinks the zero crossing is. I was able to use this to guess the final position. I reran one more time to see the script cross zero on all dofs, confirming that the A2L gains ended up in the right spot.

As a part of this, I was able to test TJ's new version of this script, /opt/rtcds/userapps/release/isc/h1/scripts/a2l/a2l_min_multi_sdf_cleanup.py

His script now does not leave SDF diffs, since it reverts all the tramps and matrices. However, when I cntrl-Ced, only half the lines turned off. It appears that cntrlC only turns off the matrix values for pitch, but not yaw, and it still leaves the clkgains and such in place. So the cntrlC capability needs more work. To get the scrpt to revert everything properly, you still need to let it fully run.

I updated the guardian lscparams to have these new ETMY A2Ls (P: 4.89, Y: 0.78) and camera offsets. I have loaded both the ISC_LOCK and the CAMERA_SERVO guardians.

While these A2Ls suggest that the ETMY spot has not ended up in the same place as before, I do believe this is a good place that gives us good buildups, so I think this is a fine spot to be in.

First run:

Second try I cntrl-Ced which sort of worked.

Third try:

I received our first units of a new brand of dust monitors (Temtop instead of MetOne) that we are going to test replacing the current MetOne GTs with. I got 2 different units, the PMD331 (handheld,  remote capable, pump less option available) and the PMS21 (fixed remote monitoring, no internal battery pack, pump less option available). Fil made me a custom 24v power cable for the PMD331 using its 5 pin terminal block, as it didn't come with one.

Both of the dust monitors passed their zero count and flow rate calibration checks right out of the box, the PMS21 requires a password to get to the settings menu (543210).

I have them running in the corner of the control room for right now.

Their serials are as follows;

PMD331: TD3350722828

PMS21: TM2150918004

Thu Oct 16 10:04:38 2025 INFO: Fill completed in 4min 35secs

Jordan confirmed a good fill curbside.

TITLE: 10/16 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 3mph Gusts, 2mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.14 μm/s 
QUICK SUMMARY:

• 15:30 -> 19:00 UTC Planned calibration measurement followed by comissioning, we are going to move the beam spot to it's previous position before running the calibration measurement.
• We're relocking and TR_CARM following a 13:01 UTC lockloss
  • We've had 1 short lock since the earthquake this morning, 6.5 from Indonesia
• Stand down query failure, I'll restart this

Got called at 3:30AM due to DRMI lock unable to lock. Flashes seem bad since the earthquake and there hasn't been an initial alignment for some reason. Set IFO to initially align then turned the manager back on.

BSC9 annulus ion pump (AIP) railed yesterday around 6:05 pm local time, railing is noted on the plot with the red trace.  The annulus system will be diagnosed on next opportunity.
After the pump railed there is no noted effect inside the main vacuum envelope, noted on the green trace on the attached plot.

The current ion pump body was replaced on September 2015, see aLOG entry here.

TITLE: 10/16 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 156 Mpc and have been Locked for just over 15 hours. The only thing that happened during my shift was the earthquake and needing to transition to ASC Hi Gain, but besides that we've just been Observing.
LOG:

23:00UTC Observing and Locked for 9 hours
02:38 Earthquake mode activated due to incoming 6.3 EQ
    02:39 Left Observing to go to ASC HI Gain
    03:08 Back to CALM
03:09 Reverted ASC Hi Gains and went back into Observing

Currrently Observing at 155 Mpc and have been Locked for almost 13.5 hours. We had a 6.3 earthquake from the Drake Passage roll through a bit ago - we had to go to earthquake mode and I dropped Observing to go to ASC Hi Gains, but we rode the earthquake out easily (it also didn't hit us as bad as expected - see three). We've been back in Observing for about 15 minutes now.

TITLE: 10/15 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: We stayed locked the whole shift, over 9.5 hours now.
LOG:                                                                                                                                                                                                                                                                                                                            

18:48 - 18:57 UTC We dropped Observing to input some values and load some GRDs in relation to the beam spot, so the next lock aquisition should bring us back to our old spot. alog87495

TITLE: 10/15 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: 9mph Gusts, 5mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.13 μm/s 
QUICK SUMMARY:

Observing at 155 Mpc and have been Locked for over 9 hours. Everything looking good.

Following our influx of bees, M. Landry ordered an interior inspection of each beam tube enclosure (BTE) interior to document potential areas of ingress. R. Thompson with Apollo Mech is presently tasked with this inspection. During inspection of the X1 enclosure, roughly 5 sections -X of the X arm overpass, Randy observed cracking at the base of the interior of the enclosure. After further investigation he found 4-5 cracks running parallel of one another across the entire section at roughly the 10 & 2 o'clock positions. I was called to come give this section a second look. The cracks were also immediately concerning to me. The first thing I wanted to better understand was the interior width to assess if the section was shifting.

With Randy's help, I measured the interior spans of each end of the neighboring tube sections (4 measurements) as well as an additional 4 of the same spans of the tube sections on display outside of the LExC. On average, these spans measure 151" +/- .25". The section in question measures 154" at each end. Moreover, during installation Fred Raab has informed us that grouting was done on the BTE interiors to mitigate a "walking" effect that was causing misalignment between sections. This grouting has clearly separated from the BTE interior which confirms that there is in fact splaying of this section.

The current short term "fix" implemented by FAC and VAC has been the erection of scaffolding topped with planking across the 10' area of beam tube at risk of falling debris. This should act as makeshift roof. For the long term, R. McCarthy is currently consulting with structural engineers whom we hope can help us work up a solution to prevent further splaying.

Contained in the photos attached are measurements with appropriate labeling of each section (number counted from second door on X1 traveling -X), as well as a "+X" or "-X" which simply denotes if the measurement is on the +X or -X end of the tube section, photos illustrating the separation of the BTE interior from the as-installed BTE grouting, the scaffolding presently in place, the cracking at the footing/mid sections, and a LIGO Yelp review written in welders soapstone (circa ~96') near the splayed tube section.

C. Soike, E. Otterman, T. Guidry, G. Moreno, T. Sadecki, J. Vanosky, R. McCarthy

J. Kissel, M. Pirello

There are four pico-motor actuated mirrors in the HAM2-3 ISI SPI Pathfinder (or, generically HAM2 = ISI"J" and HAM3= ISI"K"), M_M1, M_C1, M_B4, and M_M2 (see page 3 of D2400108). Those optics have the following mounts:
    - M_M1 = IXM100.C2L-VC LIGO = 1" optic mount, left-handed.
    - M_C1 = IXM200.C2-VC LIGO = 2" optic mount, right-handed.
    - M_B4 = IXM100.C2-VC LIGO = 1" optic mount, right-handed.
    - M_M2 = IXM100.C2-VC LIGO = 1" optic mount, right-handed.

To-date the assembly procedure has been scattered into incomplete pieces, including separated mechanical assembly (D1100362 and E2500163-v1) and electrical assembly (D1400279). 

As such, I've created an all-inclusive assembly procedure in E2500163-v2, and the DCC file-card now perma-links to a google photo album containing many more photos than even what's in the procedure.

So, now I can write this aLOG, which "just" says -- we've completed the assembly for SPI's four pico-actuated mirrors, per E2500163-v2 assembly instructions.

It's always challenging to get a photo highlight, so I'll attach the best one I got mid assembly (i.e. the picomotors weren't yet connectorized, nor were the ECR E1400327 range-limiting shafter collars installed). 

The 2nd, 3rd, and 4th attachment show three photos I got of the completed M_M1 (IXM100.C2L, 1" left-handed) mount.

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).