TITLE: 11/07 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:
ALS-Y is not correct and is very time consuming to trick into working correctly.
Please see alog https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=81114
Once locking , I took ISC_LOCK to Green arms manual, Keita lowered the Threshold even further: H1:ALS-Y_REFL_LOCK_TRANSPDNORMTHRESH -> 0.40 which is even lower than initial alignmnet. We did this because the Diff beatnote that we were seeing was -41 dbm
We also increased the gain H1:ALS-Y_REFL_LOCK_LOCKEDGAIN from 6 to 12.
Line 921 in ALS_ARM.py was changed:
if ezca['ALS-C_TR%s_A_LF_OUT16'%self.arm] < 0.5: # WAS Changed From 0.5 to 0.3
We then just waited and eventually it went to LOCKING_ALS !
I then reverted all my changes in ALS_ARM.py and save and reloaded ALS-Yarm as soon as we made it past Locking ALS.
Got all the way up to LOW_NOISE_ETMX[558] before some oscillation seen on ASC Chard P inmon unlocked it again.
The IFO is still very difficult to lock beyond ALS-Y, See the attachment for help finding these channles.
LOG:
Keita went out on the floor to work on the Lockloss Monitor.