TITLE: 07/17 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: None
SHIFT SUMMARY: Detector in IDLE for the night.
After the discovery while locked that 20% of our power was unaccounted for(79180), Keita wanted to check that the ASC_AS sensors were still reading similar values as they had been before the lock. This ended up taking the entire evening though since the AS_AIR beam spot had dissappeared(attachment1)! We did a lot of trending and eventually were able to figure out what happened and how to get the beam back. With the beamspot back, we went into MANUAL_INITIAL_ALIGNMENT and to SR2_ALIGN in ALIGN_IFO. We got decently good values (attachment2 - cursors are min/max of values in 10W single bounce before this last lock) so our ASC_AS photodiodes are good!

Looking for the beamspot:
TLDR; It looks like a combination of alignment work and HAM5 being taken to DAMPED and ISI_DAMPED_HEPI_OFFLINE changed the AS_AIR beamspot alignment, but we were able to get it back by adjusting the slider values until the SR3 oplev values were back to what they had been previously.
    Part of what happened probably: 
    - Images of the AS_AIR camera are saved every hour in /ligo/data/camera/archive/2024/07/16/. In this attachment3 showing AS_AIR for the last several hours of 07/16, we were Locked and had the beamspot present up to the screenshot at 19:56 UTC, but it was absent* starting the next hour at 20:56 UTC (*Important note: sometimes the beam will be swinging out of view when the image is taken, so maybe it was still there, but a beamspot missing three times in a row is a little unusual). We had a lockloss in between these two times at 20:34 UTC, but that shouldn't have affected the spot on AS_AIR. Attachment4 is looking at LSC_DARM_IN1 vs the ASC-AS_{A,B,C} channels, with the left cursor being the time of the lockloss. 22 minutes after the lockloss, there is a spike seen in all three ASC_AS channels followed by AS_A and AS_C getting noticeably quieter. This is only two minutes before the next AS_AIR image is saved, which is the first one where we can no longer see the beamspot.
        - Keita and I checked the driftmon and sliders for the optics around this time and saw that, to correlate with the work going on at sqzt7, some of the optics were being aligned and misaligned around this time, but it didn't look like any of those would've affected the beam on AS_AIR. Our best guess is that something else we didn't check was changed during that time or them walking around the area was putting the beam in a different spot.
    Actually for sure: 
    - At 23:10 UTC HAM5/6 were taken to DAMPED for HEPI to be locked, and when trending the SR3 oplevs, we found that at this time the oplev values for Y changed by ~1.5urad and P by 0.1urad. Using the sliders, we adjusted the pitch and yaw until the oplev values were back to what they had been before this time, and we got our beamspot back!**
    **This does mean that once HEPI is unlocked, we'll need to adjust SR3 back!**

LOG:

23:00 Detector in IDLE

00:35 Went into MANUAL_INITIAL_ALIGNMENT to SR2_ALIGN to verify that current alignment has same values on AS_{A,B}_DC_NSUM_OUT_DQ and AS_C_SUM_OUT_DQ
    - 10W
    - Opened fast shutter
    - Verified SRM misaligned
    There was no light on AS_AIR, and AS_{A,B,C} channels read 0 (attachment1 - AS_A and AS_C traces are very dim and at 0)
    - Took ALIGN_IFO to DOWN and saw beam swing across AS_AIR, but after settling we are back to black screen
01:10 - 04:07 Trying to find AS_AIR
04:08 Went into MANUAL_INITIAL_ALIGNMENT and TO SR2_ALIGN in ALIGN_IFO to compare current ASC_AS values to previous
04:55 Put detector in IDLE