Reports until 16:32, Sunday 19 October 2025
LHO General
ibrahim.abouelfettouh@LIGO.ORG - posted 16:32, Sunday 19 October 2025 (87572)
OPS Day Shift Summary

TITLE: 10/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Wind
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

IFO is LOCKING at ACQUIRE_DRMI_1F

Bad day for the IFO due to the environment.

To start, the wind has not gone under 30Mph for the entire day, and has been over 35mph for the majority. It looks to be dying down now and will continue to do so this evening. Midshift report (alog 87565)

The microseism was sitting just at the 90th percentile point until 3 hrs ago when it started increasing.

We did get to NLN once but due to the known 1Hz CSOFT_P ringup (which previously was managed by increasing gain) but 4 minutes later, we had a Lockloss. (Lockloss alog 87571) This is an ongoing issue where it appears that long lock acquisitions experience the 1Hz ringup more violently than short acquisitions. Due to the microseism and wind, this has been the case for many of the recent locks. Ryan S has an alog about this correlation with a hunch that it is related to IFO thermalization (alog 87557)

In the next lock, since this is bound to happen again, we can either sit at MAX_POWER or increase the gain further (from 25 to 30) and see if either works. The former would test out the hypothesis in Ryan S's alog and the latter would just up the fix from before. 

14:30 UTC - shift start

14:54 UTC - TRANSITION_FROM_ETMX Lockloss

16:42 UTC - Initial Alignment - Fully Auto

17:12 UTC - IFO in IDLE due to WIND

18:36 - Lock Acquisition Attempt

19:35 - Succesful Lock Start

20:24 - NLN Reached (under 1 hr, fully auto)

20:28 - Lockloss due to 1Hz Ringup

22:07 UTC - IFO in IDLE due to MICROSEISM

22:54 UTC - Lock Acquisition Attempt

23:30 UTC - in DRMI, end of shift

LOG:

None