ryan.short@LIGO.ORG - posted 07:40, Monday 15 September 2025 - last comment - 09:48, Monday 15 September 2025(86921)
Ops Day Shift Start
TITLE: 09/15 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: 6mph Gusts, 3mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY: I'll start by taking H1 through an initial alignment then relock up through CARM_5_PICOMETERS, since it sounds like that's still the latest stable state H1 can get to.
Attempt 1:
CARM_5_pm by guardian. TR_CARM offset -52, could then set TR_CARM gain to 2.1, then could step TR_CARM offset to -56. Then could set DHARD P gain to -30 and DHARD Y gain to -40.
Then ran CARM_TO_TR with the guardian. We could step the TR_REFLAIR9 offset to -0.03 and things looked stable, things started to ring up at 2Hz when we stepped to -0.02.
It seems like the increased DAHRD gain helped keep things more stable than last night.
Plot attached of the lockloss, Elenna pointed out we need to look at the faster channels. The oscillation started once the REFLAIR9 offset was -0.02 and higher. It's a 17Hz to 18Hz woble, also seen growing in all the LSC signals, which makes more sense for the fast frequency.
This same 17Hz LSC wobble was seen in the last lockloss last night too, plot.