TITLE: 10/25 OWL Shift: 07:00-15:00UTC (00:00-08:00PDT), all times posted in UTC
STATE of H1: ETMy violin mode issues. H1 currently down.
Incoming Operator: Cheryl
Support: Kiwamu (drove onto site)
Quick Summary: ETMy violin mode (2nd harmonic) has been ringing up over last 2 days.
Shift Activities:
- ETMy Saturations: 8:00, 8:09, 8:37, 8:41, 9:25,
- The main activity for today were the issues with the ETMy violin mode. Over the last few days, it has been slowly ringing up and last night it reached a point to drastically affect H1 sensitivity & it will continue to do so until it is damped out. Damping out violin modes is a slow-going process where one makes a subtle change (waits 20-30min) and then one watches to see if there has been an improvement.
- I made a few gain changes to the ETMy MODE 3, but then H1 dropped out of lock.
Handing off H1 to Cheryl. H1 should be able to get up to Engage ASC3 or DC Read out and then one can continue work on damping ETMy violin. Cheryl will contact Sheila when she gets a chance. She has experience working on damping these modes, but will give Sheila a call this morning.
Notable changes:
anti whitening (FM1) OFF for OMC DCPDs (A&B)....as Kiwamu notes.
ETMy MODE3 currently at gain of 50 (100 is what used to be nominal, but this rings up ETMy).