nutsinee.kijbunchoo@LIGO.ORG - posted 17:40, Sunday 15 January 2017 - last comment - 22:47, Sunday 15 January 2017(33317)
Ops EVE shift transition
Quick Summary: ALSY spot have fringes. ALSX can't be maximized. COMM beatnote wouldn't go beyond 5.6. TMS optics have been moved a lot before I got here. I'm putting the optics back to where they were 19 hours ago when we had th ebest range last night. Stay tuned.
Stopping at DC readout to damp Bounce, Roll, and 2nd harmonics violin modes
Something went unstable during Lownoise ASC. Then lockloss when Guardian moved up to Coil Drivers.
ITMY went all the way to -10 um after the lockloss. I had to bring it back by hand.
Since then I have been repeatedly losing lock at ALS_DIFF. I'm going through Jenne's troubleshooting document.
That StripTool image is pretty identical to the only semi-successful locking attempt that I had during my shift and also at the same stage. Comment to aLog 33292
So far with the ALS Diff checklist:
- ETMX ESD setting is correct
- H1:ALS-X_REFL_CTRL_OUTMON is between +/-10
- There's no way to tell if Bounce and Roll mode is not too high, it's burried in DARM spectrum. I damped them before the lockloss.
- ALS-[X,Y]_REFL_CTRL_OUT_DQ don't look glitchy while sitting at Locking Arms green.
I'm doing an initial alignment AGAIN since Patrick seems to make it work with that...
22:30 Bounce mode came back high. Stopped at DC readout transition to damp it.
22:39 Lockloss at LOWNOISE_ASC AGAIN. Similar behavior as last time.
I'm putting slide bars back to where they were 22 hours ago. I already did IM3 when I took this screenshot. Then I will trend oplevs and fine tune the alignment.