Reports until 08:08, Thursday 25 July 2019
H1 General
yannick.lecoeuche@LIGO.ORG - posted 08:08, Thursday 25 July 2019 - last comment - 10:16, Thursday 25 July 2019(50804)
Shift Summary - Owl

TITLE: 07/25 Owl Shift 07:00 – 15:00 (00:00-08:00), all times posted in UTC

STATE of H1: Corrective Maintenance

INCOMING OPERATOR: TJ

SHIFT SUMMARY: Still working to recover from power glitch yesterday. Locklosses continue at INCREASE_POWER, despite trying a few recommended changes by commissioners. Since my mid-shift post, I tried letting the violin modes ring down before increasing power (only got down to ~4.5 and lasted the longest of any attempts), realigned the OM’s to previous lock values, and tested that the IMC stays locked when powering up to 10 W (and that PWR_SCALE matches power).

LOG:

07:00 (00:00) Start of shift

07:16 (00:16) Starting initial alignment

07:36 (00:36) Initial alignment complete, starting re-lock

07:55 (00:55) Lockloss at CARM_TO_TR, looks like we lost DRMI while ramping down LSC-REFL_SERVO_IN2GAIN.

08:43 (01:43) Lockloss from INCREASE_POWER, after waiting at ENGAGE_DC_VIOLINS for ASC channels to converge

09:38 (02:38) Lockloss from INCREASE_POWER after reducing MICH_P gain by 70%

13:04 (06:04) Lockloss from INCREASE_POWER after waiting for violins to go down a bit

14:47 (07:47) Lockloss from INCREASE_POWER after aligning OM’s to previous config (to reduce AS_A_NSUM)

15:00 (08:07) End of shift

Comments related to this report
jeffrey.kissel@LIGO.ORG - 10:16, Thursday 25 July 2019 (50815)ISC, OpsInfo, SUS
Link 

Once we regained Nominal Low Noise, one of the OBSERVE SDF DIFFs was in the OM3 alignment offsets. Niko comments about that he restored to previous lock's values, but those values appear to be quite different from what it's been for months.

While in NLN, I set the offset's tramp to 360 seconds (6 minutes), and restored the offsets VERY SLOWLY. Then reverted the ramp time to its normal 2 seconds.
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