TITLE: 06/14 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 131Mpc
SHIFT SUMMARY:
Lock#1:
Lockloss at 07:41 due to PI29
Lock#2:
Yarm locked very nicely and quickly, unlike Xarm which went through increase flashes twice. Lost it at LOCKING_ALS (Xarm lost lock then Yarm). 2nd try locked als fine but couldn't get DRMI, went through PRMI and it took 2 attempts to lock. I tapped PRM in yaw by 6 microradians based on the AS_AIR image and it caught and stayed locked on the 2nd attempt, DRMI then locked quickly.
NLN at 09:00UTC, PI31 started to ring up almost immediately but was damped effectively by guardian.
In Observing at 09:08UTC
Another PI29 lockloss at 10:15
Lock#3:
Paused at DC_READOUT and let the PI DTT take a measurement, following the PI wiki to check and see if the mode had damped. Spent 20 minutes here before moving back up after not seeing any large peaks on the DTT or the 80kHz scopes.
NLN at 11:31UTC, in Observing at 11:39UTC
PI29 starting to ring up again at 12:54 (1:24 into the lock) but guardian succesfully damped it this time (yay!)
Handing off to Camilla
LOG:
No log for this shift
I looked at the "PI29" lockloss trends, with 2 unsuccessful and 1 damping successful-ish attempt. The channel for "PI29" damping looks at the DCPD output in a narrow band of ~5 Hz centered around 80.302 kHz. But it seems like the damping PLL now locks onto this new mode ~80.295 kHz, based on at trends of the damping PLL's frequency counter output. So, I'm wondering if this new mode causing locklosses is really at ~80.295 kHz, around 5+ Hz away -- if so, our damping PLL probably won't work. Looking around 80 kHz on the full spectrum DCPDs as the PI rings up, it looks like there are 3 narrow, distinct peaks between 80.295-300 Hz, so it's not crazy that there are additional distinct modes in the 80.3 kHz forest. The aliased-down 14.76 kHz monitor also sees this new problematic mode being several Hz off from where we're looking to damp.
Based on how the PI29 damping seemed correlated with "damping" it on the last attempt this morning, I think it'd worth trying a new PI damping path w/guardian for this new frequency, and on the same test mass, ETMX, though we'll only be able to fully confirm this by checking in full lock.