aLIGO LHO Logbook

LHO General (PSL)

ibrahim.abouelfettouh@LIGO.ORG - posted 07:37, Saturday 19 October 2024 - last comment - 08:15, Saturday 19 October 2024(80755)

OPS Day Shift Start

TITLE: 10/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Aligning
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 19mph Gusts, 11mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.21 μm/s
QUICK SUMMARY:

IFO was sitting in SRC_ALIGN part of initial alignment unable to lock the IMC, with MC2 saturations every few seconds.

This issue has happened before and it's becauser the LASER_PWR was not able to revert to 2W so was sitting at 10W - this is related to FSS glitching it seems from Ryan C's OWL alog 80754. Will set the power to 2W and attempt initial alignment again after the IMC locks.

Comments related to this report

ibrahim.abouelfettouh@LIGO.ORG - 08:15, Saturday 19 October 2024 (80756)

Link

What seems to be happening is FSS glitches and unlockes the IMC, but the power doesn't go down to 2 - this happens during MICH_FRINGES and MICH_BRIGHT_ALIGNING.

The solution that seems to work:

Manually set PWR to 2
Go to DOWN, wait for IMC to lock
Go to ALIGN_IFO and select PREP_FOR_SRY (I think manual initial alignment into SR works too)
Once there, select SRC_ALIGN_OFFLOADED and wait for it to finish.
Once offloaded, try locking full IFO again.

I had the FSS glitch out on me twice during this process meaning I had to repeat it, but it worked eventually. I think this is a temp solution.