The refcav transmission has been decaying quickly over the last day or so (down to about 0.7), and we've been getting a warning about the transmission being too low on DIAG_MAIN.  I took a few mins between locks to tourch it up briefly, now it's at about 0.76.  So, not a major improvement, but at least gets us away from the threshold we'd set for ourselves that we know is bad.  This should (hopefully) get us through the long weekend, and then later we can revisit whether or not we need to do any in-enclosure alignment during the break. 

As they've been skipped the last few weeks 75271, today while ISC_LOCK was in OMC_WHITENING waiting for violins, we took in-lock charge measurements. 21:19UTC to 21:35UTC.

There was a glitch at 21:33:10UTC at the end of the ETMX injections/ transition, should check if that's due to a mistake in the code.

Chiller 2 at EX had its Low Ambient Lockout enabled at 14 degrees. Early this morning, once the temperature dropped below 14 degrees, it went into inhibited mode. Because this chiller is running as the lead unit, Chiller 1 attempted to come on and cool the loop because its Low Ambient Lockout was disabled. There is an apparent issue with the second refrigerant circuit in Chiller 1 which caused it to fault. I disabled the Low Ambient Lockout on Chiller 2 which caused it to run again, since it is the lead unit, and this has cooled the loop back to where it had been running the last several days. 

I checked the chillers at EY as well and found that Chiller 2 also had its Low Ambient Lockout enabled at 14 degrees, and I disabled this as well. I will continue troubleshooting Chiller 1 at EX next week when the weather is less severe. Currently all chillers are set to run regardless of how cold it is outside. 

[Tony, Jenne, Sheila]

It's been a struggle to lock this morning.  We've made it up to some moderately-high locking states, but then the PRG looks totally fuzzy and a mess, and we lose lock before increasing power from 25W.  Since we've had some temperature excursions in the VEAs (due to the more than 25 F outside temp change in the last day!!), I ran the rubbing check script (instructions and copy of the script in alog 64760).  Everything looked fine, except MC1 (and maybe MC2).  RyanC notes that MC1 also looked a little like it had increased noise back in early December, in alog 74522.

In the specrtra in the first attachment, the thick dashed lines are how the MC1 RT and SD OSEMs looked when things weren't going well this morning.  They looked like that both when the IFO was locking and we were at 25W, as well as when the IMC was set to OFFLINE and was not locked.  The other 4 OSEMS (SD, T1, T2, T3) all looked fine, so I did not save references. The vertical didn't look like there was a significant DC shift, but I put in a vertical offset anyway into the TEST bank (10,000 counts), and saw that those 2 OSEMs looked more normal, and started looking like the other 4.  I also took away the vertical offset, expecting the RT and LF OSEM to look bad again, but they actually stayed looking fine (the 6 live traces in that first attachment). 

The ndscopes in the second attachment show the rough DC levels of the 6 MC1 OSEMs over the last week, to show that the signficant motion in the RT OSEM over the last 12 hours is a significant anomoly.  I'm not attaching it, but if you plot instead the L, P, Y degrees of freedom version of this, you see that the MC1 yaw has been very strange over the last 12 hours, in the exact same way that the RT OSEM has been strange. It seems that when I put in the 10,000 count offset, that got RT unstuck, and MC1's OSEM spectra have looked clean since then.

We're on our way to being locked, and we're now farther in the sequence than we've been in the last 4.5 hours, so I'm hopeful that this helped....

Julian, Camilla. WP 11614

With 4mW seed beam injected, we touched the quater and half waveplates in the SEED path on SQZT0 to minimize H1:SQZ-CLF_FIBR_REJECTED_DC_POWER. Plot attached. Reduced HAM7 rejected from 0.32mW to 0.12mW (we've not previously got this to 0 65063).

Throughput to SQZT7 is 1.2mW/4mW = 30%. We expect >40% and we have previously got only get 50%-75% though the fiber coupler switch only (not inc HAM7)  65392 65445.

If we need more power than this we can try to walk the alignment, we tried toughing only one mirror and didn't improve throughput, the second mirror was hard to reach from local laser hazard area.

Dave called and informed us that he is getting an FMCS alarm about the H0:FMC-EX_CY_H2O_SUP_DEGF channel.
This information was passed down to Eric, and he went out to EX to check it out and clear the fault.
When he returned, he mentioned that there was a change that he made that he may need to make at EY.
We will be watching these channels throughout the day to make sure that solves the problem.

Fri Jan 12 10:10:30 2024 INFO: Fill completed in 10min 26secs

Gerardo confirmed a good fill curbside. Starting TCs were high, trip temp was increased to -60C for this fill. TCmins = -77C,-72C.

NLN Lockloss :
https://ldas-jobs.ligo-wa.caltech.edu/~lockloss/index.cgi?event=1389100118

The Lockloss tags said Windy, and the wind is gusting up to about 30MPH so this makes sense.
Lockloss plots and Log attached.

TITLE: 01/12 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 23mph Gusts, 14mph 5min avg
    Primary useism: 0.07 μm/s
    Secondary useism: 0.34 μm/s
QUICK SUMMARY:
When I came in H1's ISC_LOCK was in LOCKING_ALS after a Lockloss from NOMINAL_LOW_NOISE .
I noticed the Earthquake, check to see if Mr.Short had been called, and saw his alog .
The Chiller in the CER seems to have been fixed and the temperature is coming back down.
Ryan call and gave me the Short story of the last few hours of the OPS OWL Shift, and did a wonderful handoff after calling Dave and Camilla in for help.
Camilla just arrived and will be helping resolve the SQZ issues.
My plan is to try to lock while she is resolving issues and hopfully SQZer will be ready before INJECT_SQZING.
Taking H1 Initial_alignment since it's having a hard time locking beyond Find IR.

I am seeing a rise in LVEA ZONE 1A temperature that has not turned around yet.

H1 called for help this morning at 6:15 PST when it could not go to observing because of the SQZ system not functioning properly. Eventually I saw that the Slow Controls section of the CDS overview was red, so I called in Dave for assistance. So far we have not found evidence of an actualm hardware failure, but Richard noted that a chiller in the CER had failed this morning, causing temperatures to rapidly rise there, potentially creating this issue with the SQZ Beckhoff terminals. Richard has turned on a fan and both chillers in the CER to bring the temperatures back down.

I discovered this morning that my new HWS camera control code, which only talks to the camera when it needs to turn the camera on or off, was locking up in its caget of the IFO lock status. The last change was for the lock status function to return both the caget call status and the ifo_lock_state.

I reverted the code back to the previous version, and it is now running correctly on h1hwsex, h1hwsey and h1hwsmsr1 but for an unknown reason is still locking up on caget on h1hwsmsr. When I run the caget command on h1hwsmsr's command line it works. Investigation is continuing.

Note due to this bug HWS ITMX camera was mistakingly left ON overnight until I manually turned it OFF at 08:33 PST this morning.

Louis, Jenne, TJ, Sheila

Today we continued to try to transition to the new Darm configuration, which we had suceeded in doing in December but weren't able to repeat last week (75204). 

In our first attempt today we tried a faster ramp time, 0.1 seconds.  This caused immediate saturation of ETMX ESD.  We struggled to relock because of the environment. 

Because Elenna pointed out that the problem at roughly 3 Hz with the earlier transition attempts might have been the soft loops, we thought of trying to do the transition before the soft loops are engaged, after the other ASC is on.  We tried this first before transitioning to DC readout which wouldn't work because of the DARM filter changes.  Then we made a second attempt at DC readout.  We also lost lock due to a 2 Hz oscialltion, even without the soft loops on. 

Some gps times of transitions and attempt:

• 1387034100  succsesful transition from December
• 1388520329 attempt from last week with 5 second ramp
• 1388520329 attempt from last week to transition to the NEW DARM in TRANSITION_FROM_ETMX and LOWNOISE_ESD_ETMX with a 5 second ramp
• 1388952732 attempt from today to transition with a 0.1 second ramp, imediate saturation of ESD
• 1388961745 attempt at 2W with soft loops off (5 second ramp)