TITLE: 07/02 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
INCOMING OPERATOR: Oli
SHIFT SUMMARY: H1 has not been fully locked since before the maintenance period this morning, although I don't believe anything done during maintenance is to blame.
After maintenance, violin modes were very rung up, so we've been spending long stretches in OMC_WHITENING (when we've been able to get there) damping. Nominal violin damping settings have been working, it's just been taking a while to bring them down. On all three occasions where we've been damping violins here this afternoon and evening, there have been random locklosses (from sources I haven't been able to determine) before reaching NOMINAL_LOW_NOISE. Jitter noise injections were being run during one of these locklosses, but that didn't appear to be the cause, reinforced by the fact that these were run again the next time in OMC_WHITENING and there was not a lockloss. In addition, a few minor earthquakes and DRMI taking it's usual long time to catch have been making lock acquisition take seemingly longer than usual. I'm not sure what else there is to try as alignment has generally looked good this evening and overall I've been able to make locking progress before an inevitable out-of-nowhere lockloss happens.
H1 is currently trying to lock DRMI.