alan.weinstein@LIGO.ORG - posted 12:21, Monday 16 December 2019 - last comment - 07:54, Tuesday 17 December 2019(53923)
DQ shift report December 9 - December 15
- LHO completes 113+ hour lock stretch! With only brief periods outside of observing mode, ending for Tuesday maintenance (shortly after 1260000000 turn-over): alog 53781 , alog 53788
- PSL chiller leak brought down the PSL for much of Wednesday (~16 hours) - alog 53831, alog 53846
- Duty cycle: 80.5% (low noise, ISC_LOCK_NOMINAL), 78.7% (Observing).
- Range: Steady at 110-115 Mpc throughout observing time.
- ETMY violin modes 18 & 20 (at 1kHz) were ringing up; much effort put into damping them. It produced lots of omicron glitches at 1 kHz, through Wednesday Dec 11. Much reduced after PSL chiller recovery.
- Lock stretches on Thursday through Saturday (Dec 12-14) had greatly elevated noise and glitchiness in the 20-35 Hz band (around ASC dither system (ADS) lines), associated with high microseism -induced scattering arches.
- Lock losses on Thursday, Friday and Saturday; cause unknown. Lock loss on Sunday due to mag 6.9 EQ in Phillipines. All four recovered low noise in ~2 hours.
- Readout of squeezer BP3 (500-900 Hz) still corrupted by excess noise.
- Four CBC public alerts, two were retracted. S191215w is a nice BBH.
- EX wind fence complete, pics in alog 53826.
- For more information see https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20191209
Expanding on this comment:
ETMY violin mode damping of modes 18 and 20 was completed early on Friday, Dec. 13th (Pacific), alog 53875.