Reports until 00:36, Thursday 07 November 2024
LHO General
ibrahim.abouelfettouh@LIGO.ORG - posted 00:36, Thursday 07 November 2024 (81118)
OPS OWL Shift Summary

Tony texted me at 10PM and warned me of an unstable ALSY lock. After resding the alogs and enacting the changes that him and Keita made to manage to lock Y, I was still having issues.

For context, the ALSY laser had maintenance early today and since then has been having either multimode locking issues or more general laser performance issues according to Daniel. To tackle this, Keita and Tony lowered the ALSY locking thresholds in order to make it past ALS and while this worked once, was not repeatable. Their alogs: alog 81116, alog 81114. After some flailing, I decided to call for help.

Daniel came online and began to dianose the ALSY issues. The first guess was that it was a multimode issue, to which he began to change the ALS frequency to test it out. The final conclusion is that it's some tuning error where ALSY doesn't operate stably in its current frequency since being adjusted to PSL freq. Daniel's Alog 81117. Final recommendation is that corrective maintenance needs to be done on-site at EY. Since this is not possible now, with Daniel's recommendation, IFO will remain in LOCKING_ARMS_GREEN until tomorrow's DAY shift.