TITLE: 05/08 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Jeff
SHIFT SUMMARY:
This shift went super fast....thanks to a dolphin crash! Ha. But it was actually kind of fun to go through all the problems; definitely a learning experience! Sadly, because I am slow I am only handing off an H1 with DRMI locked.
Back Story: Just as Niko was about to leave after his handoff from me, had a major dolphin crash in the LVEA (Dave will have a more informed entry on the specifics of the crash...he did mention we hadn't had one of these since January where we had been suffering from these fairly regularly before then).
I tried to post specifics & timing of events in other alogs for what I found and did during my shift for this recovery. In broad strokes, here were my method to the madness and areas I focused on in order through the night:
- Proceed as far as I could with locking as usual, until I ran into an issue. (I was stopped early due to IR cavity for X!)
- Alog search for similar issue (Basically looked at last instances for recovery from Dolphin recoveries (thanks, Sheila, Dan, & JimW for the two entries I found).
- Dark Offsets! (I should have realized this was an issue early on (TR_X [blue on striptool] was up at 0.3 instead of 0!)
- Check pit/yaw sliders for SUS (If I did this sooner (via Time Machine?) I could have saved some time scratching my head about why certain cavities were not locking.))
- ISI Config! (If I didn't read about this in the Dan/Jim alog, I would have been dead in the water.)
LOG:
- 7:04 Lockloss due to Dolphin crash
- 7:27 Recovery starts for CDS
- 7:35 Begin untripping stuff!
- 8:17 Begin first attempts at Locking (starting with the IMC).
- 11:05 Dark Offset investigation (because of previous dolphin recoveries Dec1, Jan17)
- Zeroed by hand: H1:LSC-TR_X_QPD_B_SUM_OFFSET (from alog 46124)
- Ran dark offset script: dark_offsets_exe.py (at /opt/rtcds/userapps/release/lsc/h1/scripts/dark_offsets/)
- Adjusted Xarm dark offset again by hand since it looks like it was changed during dark_offsets_exe.py script (from -1.1 to +0.1)
- Adjusted Yarm dark offset since I was at it.
- But I did both of these with IMC locked and ITMs aligned (i.e. not dark).....wonder if I need to back these out? ---->I don't think so, because I unlocked IMC & misaligned ITMs and dark offsets looked fine.
- 11:55 - 14:05 Initial Alignment
- 14:13 LLO going down a few hours for Ion Pump replacement
- 14:05 Starting to lock again
- IR was not found, so had to do by hand.
- Had to do a PRMI due to BS not being well aligned (even after the alignment!)
- DRMI eventually locked, but we were getting OPO saturations (!), then broke lock---So something is still awry.
- Looks like Ed/Richard fixed this by Clearing History for something on a Squeezer screen
- H1 is now past DRMI to PREP_DC_READOUT *crossing fingers*
- 14:35 Seismon note: Busy with recovery, but we noticed a sizeable Peruvian EQ roll through. didn't get Verbal. I didn't have seismon up to notice it.