After tonight's Initial Alignment, H1's been fairly good with getting through the bulk of ISC_LOCK, but have had 2 consecutive locklosses a couple of states after MAX POWER:
- 1st lockloss was ASC-related
- 2nd lockloss was possibly an FSS/IMC glitch
Locking Notes:
0003-0043 INITIAL ALIGNMENT (w/ ALSy needing touch up by hand)
0044 LOCK#1
- 0122: LOCKLOSS at LOW_NOISE_ESD_ETMX [558] due to ASC ring up (happened before the new T-Ramp change) ---> In the Control Room we saw ASC ring up for a few seconds before the lockloss ("it was DHARD PIT ringing up at 1Hz; probably a not great alignme," according to Elenna).
- For next lock, will pause at LOWNOISE COIL DRIVERS [552] to make sure ASC looks ok.
LOCK #2: DRMI looked its ugly self. Needed to run CHECK MICH FRINGES and the BS was definitely the culprit for the nasty alignment and was fixed. PRMI & DRMI both locked immediately.
- 0205 LOCKLOSS while holding at TRANSITION FROM ETMX [557] to look for the ASC ring-up....but while here, there was NO ring up and it looks like an FSS (or IMC?) glitch lockloss (see attached plot by Elenna from Sheila's template), BUT....
- There was NOT an FSS or IMC tag on the Lockloss page
Will continue locking for the next 2.5-3hrs, and then take H1 to IDLE and leave FSS & PMC -ON- for the night.
But if H1 makes it to NLN, will contact Louis or Joe B for a ~15min calibration check.
Vicky, Ryan, Sheila
Zooming in on this 2:05 UTC lockloss, MC2 trans dropped about 150ms after the IFO lost lock, so we think this was not due to the usual PSL/IMC issue, even though there was a glitch in the FSS right before the lockloss.
