aLIGO LHO Logbook

H1 General

ryan.crouch@LIGO.ORG - posted 07:36, Tuesday 11 August 2026 - last comment - 08:48, Tuesday 11 August 2026(91474)

OPS Tuesday day shift start

TITLE: 08/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 9mph Gusts, 4mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.06 μm/s
QUICK SUMMARY:

A few CDS tasks on the docket for today
CRS work as well
Optics lab and EX dust alarms
The AQI is decent this morning at good/28, but it's predicted to worsen to moderate

Comments related to this report

ryan.crouch@LIGO.ORG - 08:09, Tuesday 11 August 2026 (91475)SUS

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The M2 stage of the BS has been moving a lot since yesterday afternoon ~21:17 UTC, the oplev damping has grown with it.

Images attached to this comment

louis.dartez@LIGO.ORG - 08:42, Tuesday 11 August 2026 (91476)

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The BS oplev damping was turned back on by me inadvertently yesterday. The OLDAMP Gain increases happened right as I requested DOWN from the ISC_DRMI guardian. Masayuki and I did notice additional motion on the BS yesterday but we didn't know at the time whether it was due something we did or from something someone else was doing. Now, looking at the timing of the grd state request and confirming by looking at ISC_DRMI.py, I can say that the BS oplev damping was 1.) turned on by accident and 2.) can be / should be turned back off.

Images attached to this comment

elenna.capote@LIGO.ORG - 08:48, Tuesday 11 August 2026 (91477)

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I tried to SDF the oplev damping off, see 91267, but I never checked what the guardians do. I recommend we change the guardian code to not engage oplev damping until we can diagnose why it isn't working, specifically, saturating the suspension.