corey.gray@LIGO.ORG - posted 10:43, Saturday 06 July 2024 - last comment - 13:14, Saturday 06 July 2024(78904)
Lockloss & Locking Notes
h1 just had a lockloss and green arms looked decent, but it kept hanging up with locklosses (6 so far) with the LOCKING ALS.
- Paused at LOCKING ARMS GREEN and it was fine there for a couple of minutes,
- Paused at LOCKING ALS for atleast a minute but then started seeing glitches/drops in power in both arms (with Y-arm being bigger and then another lockloss) (see attached).
- Will now try an Intial Alignment.
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- Initial Alignment was fully automated & no issues.
- Paused at problem spots earlier (LOCKING ALS & also FIND IR---no issues.
- DRMI immediately locked, BUT
- lockloss at DRMI_LOCKED_CHECK_ASC
- 2nd DRMI lock took around 4-minutes. Held at drmi locked prep asc a few minutes & then moved to engage drmi asc....
- lockloss as the ASC control signals were being offloaded (probably same happened for previous lock).
- Will investigate steps of ENGAGE DRMI ASC.
Will attempt to tweak up SRM (maybe PRM/BS) at ACQUIRE DRMI 1F to help ease ASC for DRMI.
- SRM made no change
- PRM pit 2-clicks positively (dropped POP18 & lockloss)
Attempt #2: automatically taken to check mich fringes then back to drmi...
- I took to PRMI since drmi looked bad, but then a lockloss.
Attempt #3: Went to PRMI fine.
- Lockloss at engage drmi asc.
Attempt #4: DRMI ASC completed FINE this time! (I had phoned Camilla before before this lock with fears I'd need help! Luckily, we both watched it get past DRMI.)
- Went back to OBSERVING at 1:11pm (2011utc)....just as Fred was giving a tour to a high school class from Aukland New Zealand!