This weird noise was first noticed in 82997 during OFFLOAD_DRMI_ASC. The first instance of this happening while relocking was three days ago 2025-02-23 03:59:19 UTC. It started showing up LSC-PR_GAIN and LSC-POPAIR_B_RF90_I_NORM and the lower stages of SR2 and SRM. Almost every relock since then has seen these glitches. They almost always start showing up in OFFLOAD_DRMI_ASC, but I've found a few instances(one, two, three) where the noise clearly starts during DRMI_LOCKED_CHECK_ASC, the state before OFFLOAD_DRMI_ASC. Next time we lose lock we will be sitting in DRMI_LOCKED_CHECK_ASC, so we will probably see this ringup then.

Based on Oli's range checks (alog83063) we decided to run the a2l script and a PRCLFF measurement after getting run coordinator approval. Below are the results of the a2l script, a few moving quite a bit. These have been added into lscparams.py and they are not in SDF. Jenne will post the PRCLFF results.

RESULTS

At the EY station the compressor is being replaced - after the one at EX is done. In this aLog, in the comments, the progress of this operation is tracked continuously, until the 1st startup by the supplier, Rogers Machinery.
Another important consideration here, is that the purge line at EY needs to be replaced (based on an FTIR test - see DCC LIGO-E2300222-v2. As it can be seen, the level of contamination reaches even the 10 ug/cm2 value). This operation will be done after the April-May vent, so the EY station will be ready to be vented after O4.

02-25 (maintenance Tuesday): the old compressor was pulled out (it is temporarily stored in the EY receiving area). The beginning of the purge and TMDS lines with the associated brackets and unistruts were taken off. The new compressor unit and dryer skid were anchored in the mechanical room. Here it is important to mention that the orientation of the inlet was brought closer to the purge line inlet into the VEA, so the overall length of the associated circulation lines will be much shorter.
Next is the electrical and pneumatic installation, which will be completed in the next 1-2 weeks.

Ran a low range check coherence check for a time during the early morning lock after we were thermalized (2025-02-26 10:05 UTC). Many of the channels came back clearly showing coupling between it and darm.

In almost all of them you can see that the coherence is higher in the last lock than the references, but the ones that stood out to me were:

CHARD Y

DHARD Y

WFS B P

WFS B Y

PRCL

Sheila, Matt, Camilla

We repeated the HD data set taken in 82202 as in 83022 we found we had pump depletion during these measurements so that the OPO trans powers were actually lower than reported. We had some issues at first which ended up being that with HAM7 ISI tripped the optics were moving around too much, plot of optics here. After we fixed that, we retook the data, so that our real data set is in 83039. Below documents the steps taken and initial data that we ended up not trusting. 

• Checked LO shot noise (LO on HD, Seed blocked) and HD dark noise (both beams blocked)
• Sheila increased Seed power form 0.5mW to 70mW.
• SQZ_MANAGER to LOCKED_SEED_DITHER. Went onto SQZT7, plugged oscilloscope into the outside of the table. Adjusted LO power to match.
• Then both Seed and LO beams on the HD Seed PZT scanning, starting visibility 89% (max-min/max+min), adjusted SQZ path optics to increase visibility to 98.6%
• Sheila decreased Seed power to 0.2mW.

Then started data taking:

• NLG measured at (Toggle SQZ/HD path and follow 76542)
• Took SQZ_MANAGER to SQZ_READY_HD (FC2 misaligned) and take data on HD DTT
• Change opo_grTrans_setpoint_uW in sqzparams.py, reload OPO guardian, take it to NO_ISS and then back to LOCKED_CLF_DUAL to check it can reach opo_grTrans_setpoint_uW
• Repeat

Sheila and Matt measured the LO OLG as 2.5kHz 80deg phase margin is LO loop with gain -12 LO on LOCKED_HD with opo_grTrans_setpoint_uW = 80uW before we started.

One we got to the 110uW measurements, we felt the squeezing was unstable, moving independently of the SQZ angle, steps taken to help this:

• Sheila and Matt measured the LO OLG, it was the same as before, so it's changing significantly with OPO trans power
• OPO loop measured, 1.7kHz was UGF last week this week looks very different, changed gain from -8 to - 14 plots in 83039.
• CLF loop had 13.7kHz UGF with plenty of phase margin, was 12kHz last week.
• Realized that the ZM optics were noisy with HAM7 tripped and the increased (60mph!! wind), see plot.
• Then Sheila and Matt rechecked balancing and visibility after HAm7 was untripped, started at 98.3% but noisy, improved to 99.0%.

Data saved to camilla.compton/Documents/sqz/templates/dtt/20250225_HD.xml

FC2 is misaligned during this dataset.

Wed Feb 26 10:16:27 2025 INFO: Fill completed in 16min 24secs

This is the second run of new rate-of-change code. I have created a new set of MEDMs and a new Plot format to show the rate-of-change channels and the new trip level.

MEDM:

The main medm shows the six rate-of-change channels as bar charts (TC-A = blue, TC-B = purple). The trip level (60degc) is shown as a grey bar, the first ROC channel to exceed this stops the fill.

The related trend MEDM has been extended to show the six ROC channels, keeping with the same color scheme.

PLOT:

The plot has an additional panel showing the six ROC channels. The trip level is shown as a horizontal line. Both panels show start/stop times as vertical lines.

TITLE: 02/26 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Aligning
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 7mph Gusts, 3mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.31 μm/s
QUICK SUMMARY:

Currently in PREP_FOR_LOCKING, looks like H1 MANAGER went into error at 15:29 UTC. I reloaded it and we've just started an initial alignment.

Summary

Initial call was because the IFO was waiting to turn on the OMC whitening since the violins are elevated, though I thought this was something we fixed. The whitening was safe to turn on minutes after I started looking at it, but the SQZer couldn't lock the FC. Once I fixed the FC alignment, I had to futz with the SQZ ASC, then all was well. There were some SDF diffs. Violin modes 5&6 of ITMY aren't damping well, not a new issue. Back to Observing at 0905UTC.

SQZ

H1:SQZ-FC_TRANS_C_OUTPUT wasn't getting flashes above 17 (the wiki says it should be above 100). I followed the instructions in the wiki and adjusted FC2 to get good flashes in the cavity and eventually got it to lock. It was left with a "FC ASC not on??" notification. Sure enough, H1:SQZ-FC_ASC_TRIGGER_INMON was at 1.5, still lower than the recently lower 2.0 trigger threshold(alog82853). I tried to touch up FC2 a bit more and got the trans output up to 112, but the trigger input was still at 1.5. I cycled SQZ_FC guardian node and was back in the same place. I then lowered the threshold to 1.5 and it turned on the ASC, temporarily raising the trans output and bringing the trigger input to 4.5. Range was at 146Mpc but we were still thermalizing so I didn't want to tune much else.

SDFs

There were two SDFs - H1:LSC-LOCKIN_1_OSC_TRAMP and H1:SYS-MOTION_C_PICO_I_CURRENT_ENABLE, both reverted.

Violins

While I was here I checked to make sure the violins were damping well. All seemed good except maybe ITMY 5&6. We've recently gone through some gain and phase changes to this mode (alog82977 alog82963). At this point mode 5 looked to be slowly decreasing, but  mode 6 wasn't really moving. This was better than increasing though, so I left the settings as they were.

TITLE: 02/26 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: TJ
SHIFT SUMMARY: The winds calmed down to the 20s and lower around 6 but locking issues persisted, the 2ndary microseism is still at or above the 90th percentile, so that wasn't helping us. There was a dolphin glitch but Dave helped me to get everything up and running. I just finished an IA as of the end of the shift.
LOG:

• 01:10 UTC Initial alignement
• I saw a repeat (noisy PR_GAIN and LSC_POPAIR) of what Corey saw yesterday each time we went through OFFLOAD_DRMI_ASC, SRM and SR2 saturations (alog82997). I held in that state for a few minutes but we then lost it at CHECK_AS_SHUTTERs a few times. Each acquisition the shaking got a little lessened, and there were less suspension saturations. Then on acquisition 6 I forgot to pause at the state and we continued on and it was all good, there were also zero suspension saturations this time but there the shaking/fuzziness was still present.
  • I was looking at the ASC_OVERVIEW medm while this was happening and noticed that the TMS's output was higher than typical? Especially TMSY in P & Y. Maybe this is related to the fact that ALS_Y wouldn't/couldn't converge earlier?
  • 03:48 UTC OMC_WHITENING, the violins are kinda high so we're gonna be damping for a little bit, I also restarted the DARM diaggui as it timed out.
• 04:14 UTC lockloss from a dolphin glitch, HAM1 HEPI tripped, iopsush34 and ioplsc0 have DACKILLs alog83057
  • 04:45 UTC I started recovering SEI and SUS, oddly after I untripped HAM1 HEPI it retripped pretty quickly, then it was fine the 2nd time.
  • 05:05 UTC I tried normal locking couldn't find IR so I decided to do another IA
    • Got stuck at INPUT_ALIGN XARM_IR
    • PR2 was soooooo far off after the restart. I had to move PIT by 140 and YAW by 3080!

Ryan C, Dave:

At 20:14:41 Tue 25 Feb 2025 PST we had a corner station issue which put the IOP models for h1sush34 and h1lsc0 into a DACKILL state. First attachment shows the status before any resets had been issued, second shows overview and the iop models after DIAG_RESET and DAQ_CRC_RESET had been issued.

There were no dmesg messages on either h1sush34 and h1lsc0 from today. I checked that both of these front ends had their full complement of cards in their IO Chassis.

In prep for restarting the IOP models, which requires restarting all the models on these front ends, Ryan put HAM3,4 into a safe state. I engaged the SWWD bypass on the SEI system for HAM 3,4.

After restarting the models on h1sush34 and h1lsc0 they came back with no issues.

The initial cause of the crash is not clear. Timing of the IOP STATE_WORDs going offline suggests sush34 crashed first glitching lsc0 at that time, but lsc0 didn't go fully offline until 6 seconds later.

04:14 UTC HAM1 HEPI tripped and killed the lock, lots of red on CDS_OVERVIEW, something crashed. I called Dave who's gonna log on and help. Theres a DACKILL trip on iopsush34 and ioplsc0

I have recently reported that the “mystery” beam on the spool piece wall near HAM3 was coming from the direction of ITMX (82252). To further this investigation, I started photographing the area around the ITMs and BS as best I coluld through our viewports (there is not a good view towards HAM3).  I found several unexpected distributions of light in the vertex:

1. 20 degree conical annular beams from ITMs

Both ITMX/CPX (Figure 1) and ITMY/CPY (Figure 3) cast an expanding annular “beam” towards the BS with a cone half angle of roughly 20 degrees from the main beam. My best guess is that it is produced by arm cavity light hitting the bevel of the ITMs (see cartoon in Figure 1). A good test of this would be to install the new test mass cage baffles at one or more of the ITMs at LLO (presuming Anamaria finds this beam at LLO) this upcoming break. The baffle should hide the bevel and eliminate the ring of light.

2. 45 degree conical annular beams from BS

The BS appears to cast an expanding annular “beam” with a cone half angle of 45 degrees, centered around the -X, -Y direction (Figure 2), and likely another annular beam, also with a half angle of 45 degrees, centered around  the  -X, +Y direction (evidence in Figure 3). I tried to find a geometry where the bevels were also the source of these beams but didn’t. My best guess is that the annular cone is produced by reflections of light from PR3 and the ITMs off of the inner surface of the circular cage around the BS, or the inside surface of the circular barrel of the BS itself (see drawings on third page of Figure 2). 

3. Reflection of BS in ITM elliptical baffles likely visible at ITMY and HAM3

The BS beam spot is reflected towards ITMY by the slanted piece of the ITMX elliptical baffle (Figure 3). While the actual beam is not reflected towards ITMY (it isn’t clipped), the baffle reflects light towards ITMY that is scattered out of the main beam by only a few degrees.

FLlamas - Tuesday, 2025-02-25

Start of report

Moved the Pcal upper beam at END-X to test for repeatability of the results seen on LHO:78373.

Recap:
As seen on first figure (chi_klm), the red squares highlight the inconsistency when moving the upper and the lower beam to the same direction (left aperture on target - fourth and fifth figures show the target) on the ETM. The other moves are consistent between upper and lower beam. Additionally, the second (2024_06_11_transition_upper_center2left_rawpcals_out) and third (2024_06_18_transition_upper_left2center_rawpcals_out) figure show the Pcal channels during the upper beam moving from the target center aperture to the left aperture and back. The blue color is for the PD values before making an actuation, the orange is for the values after the actuation, the title tells the actuation direction on the target and the x-axis is the time needed to average 10 hours within lock for each state (10 hrs before and 10 hrs after). From these plots we see that, during the upper-beam actuation to the left and back, the END-X Tx sensor - middle-left plot - decreased by 8 HOPs and 6 HOPs, affecting chi_XY. The END-X Rx value - top-left plot - dropping by 20 HOPs suggests additional losses of the beam downstream from the Tx sensor, potentially from clipping, but it is hard to see with the Tx changing simultaneously. There was an initial concern at the time of moving the upper beam that the actuations to the right aperture were the inconsistent ones, but after moving the lower beam we can have more confidence on the values corresponding to an actuation to the right aperture and raise concern on the actuations done to the left aperture.

Today:
Went to END-X to move the upper Pcal beam by actuating on yaw of the last folding mirror before the vacuum window (aka: the "inner beam" folding mirror.) The objective is to maximize the signal measured by the Rx PD when the target is in place. This is done by blocking the beam that will not be used and monitor the actuated beam with a voltmeter reading from "RX PD Mon" from the Pcal interface chassis (D1400153). The table below documents each relevant step from the procedure and the voltage used to assess such step.

The increase in signal after the actuation could be from clipping on the center aperture. An extra step between 3 and 4 where the beam is "optimized" on the center aperture would reveal if there is such clipping. The previous alog from a Pcal upper-beam actuation to the left agrees that this location increases the Voltage signal from RX PD Mon but the data shows 20 Hops of clipping... odd.

Nominal plan is to get a few hours of lock to assess the results from this actuation, and return the beam to it's nominal "center" state on the following maintenance Tuesday.

End of report

TITLE: 02/26 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Wind
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 29mph Gusts, 17mph 3min avg
    Primary useism: 0.12 μm/s
    Secondary useism: 0.57 μm/s
QUICK SUMMARY:

• We're holding down as the wind is too high for locking
  • Windy.com forecasts the winds dying down this evening, around 7/8pm
• We're also shaking from an EQ from Indonesia
• 2ndary microseism is high but is going down

Sheila, Matt, Camilla

We aligned and took some SQZ HD data this morning but realized that the ZM optics were noisy with HAM7 tripped and the increased (60mph!! wind). After un-tripping HAM7, Matt and Sheila rechecked balancing and visibility, started at 98.3% but noisy, improved to 99.0%. Since then HAM7 tripped and was un-tripped again but assumed nothing would have changed.

NLG Measurements:

Data saved to camilla.compton/Documents/sqz/templates/dtt/20250225_GOOD_HD.xml

FC2 is misaligned during this dataset.