TITLE: 09/14 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: None
SHIFT SUMMARY:

IFO is in IDLE and CORRECTIVE MAINTENANCE

The "good" news:

DHARD P loop has been successfully automatic since closing it this afternoon. We can lock all the way to CARM_5_PICOMETERS quite quickly. DRMI has also been good to me this evening.

The bad news:

We thought we were losing lock at RESONANCE, but we were really losing lock at CARM_5_PICOMETERS.

Stepping through this state has showed that its only at the end of this, where the matrix involving REFL_BIAS, TR_REFL9 and TR_CARM is loaded, we lose lock roughly 10s later due to SRM becoming unstable quickly.

I investigated this via alogs 86909, 86910, 86911, 86912, which are comments to my OPS shift start (alog 86908). After being led down a rabbit hole of ramp times, from 3 other times where that was the problem, I can confirm that this isn't it. Curiously, lock was lost faster with a longer ramp time.

With confirmation from TJ and Jenne, I'm leaving IFO in IDLE with the plan being to solve this problem in tomorrow's shift.

I do feel like we're close to solving this problem or at least figuring out where the issue lies. Specific details are in the alogs listed below.

LOG:

None