aLIGO LHO Logbook

LHO General

corey.gray@LIGO.ORG - posted 08:51, Friday 18 September 2015 - last comment - 10:13, Friday 18 September 2015(21647)

OWL Ops Summary

TITLE: 9/18 OWL Shift: 7:00-15:00UTC (00:00-8:00PDT), all times posted in UTC

STATE OF H1: In Observation Mode with a range which was trending down.

SUPPORT: Most of the shift solo.

SHIFT SUMMARY: Other than the 2hrs of downtime due to low frequency seismic, the shift went fairly smoothly, and was nice to take H1 into O1 in Observation Mode!

Incoming DAY Operator: Patrick T.

DAY'S ACTIVITIES:

9:34 Lockloss: (see entry)
- Lock Attempt #1:
  - Xarm ALS took a while to lock (tweaked etmx around)
  - Broke lock in DRMI1F acquisition while locked and ASC optimizing
- Lock Attempt#2: Straight to DRMI. ASC completed. Broke lock at DRMI3F
- Ultimately waited for seismcic to drop to 0.1um/s
10:03 Switched Operating Mode to Earthquake since the 0.03-0.1 blrms seismic band continues it's upward trend.
Switched ITM ISIs to HI gain & thus ACCEPTED new OBSERVE.snaps for the ITM ISIs
Took snapshot of Verbal_log_only.py on video5 (emailed to TJ) and restarted
11:18 DRMI finally locks (0.03-0.1 down to 0.1um/s)
11:35 Observation Mode
12:04 Lockloss. Does NOT look like Chile quake (nothing on our seismometers, so this is an unknown lockloss.)
- Attempt#1: Had to assist in DIFF IR by moving DIFF OFFSET slider
12:39 Back to Observation Mode & this is where H1 rode out the rest of the shift.

Comments related to this report

eleanor.king@LIGO.ORG - 10:13, Friday 18 September 2015 (21652)

Link

I was curious what caused the lock loss at 12:04 (1126613091.1). There is an oscillation that starts in ASC-AS_B_RF36_I 0.5s before lockloss, and SRC2 and the SRM start to wiggle at ~4Hz. An 8Hz oscillation starts in DHArd and CHard 0.25s later, and ITMY followed by ITMX L2 stages saturate just before the lockloss.

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