Reports until 07:41, Saturday 13 September 2025
LHO General
ryan.short@LIGO.ORG - posted 07:41, Saturday 13 September 2025 - last comment - 08:43, Saturday 13 September 2025(86898)
Ops Day Shift Start

TITLE: 09/13 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 4mph Gusts, 1mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.17 μm/s
QUICK SUMMARY: I will start H1 running an alignment then try locking to see where we're still having trouble.

Comments related to this report
ryan.short@LIGO.ORG - 08:16, Saturday 13 September 2025 (86899)

The SEI and SUS trips from the EQ moved alignment of the IMs quite a bit, so to lock XARM_IR, I restored these alignments based on top-mass OSEMs to what they were pre-trip. This was the only intervention needed for initial alignment. Starting main locking now.

ryan.short@LIGO.ORG - 08:43, Saturday 13 September 2025 (86900)

Lockloss at DHARD_WFS. After locking DRMI, I tried moving PRM, SRM, and IM4 to get the buildups better, but I could not. I then was stepping through the following states slowly to see if an issue cropped up, and sure enough, after DHARD_WFS had completed I was waiting for DHARD to converge, and alignment was pulled away to eventually cause a lockloss; screenshot attached. I believe this was happening yesterday also. POP18/90 had been slowly degrading since locking DRMI, which may be because only MICH is enabled during DRMI ASC.

Images attached to this comment