TITLE: 08/09 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 53Mpc
INCOMING OPERATOR: Patrick
LOG: N/A

SHIFT SUMMARY:

Mid_Shift Summary (never got posted)

After many failed attempts to recover lock after the EQ(s), I performed initial alignment. The furthest I've been able to get thus far is LOWNOISE_ESD_ETMY. I had to pause at DC readout to tame some ETMX violin modes.

Lockloss problems included:

• LOWNOISE_ESD_ETMY - consistent problem
• Trouble with ALS - intermittent problem; still not reconciled.
• CARM_ON_TR - random. Happened once. Not atypical.

ETMX Violin Mode damping:

• I noticed that the VIOLIN_MODE_DAMPING_1 default gain for mode 4 was causing that mode to ring up.
  • it starts at 50 but this seems to cause it to ring up a bit. I immediately turned it down to 20 while damping mode 2...segue
  • mode 2 has no gain on it and has been ringing up higher than mode 4 according o the new DTT template. I immediately set this gain to 50 and perhaps this should be hard coded. After this damping takes effect mode 4 can be turned up to 50. It will need to be.
  • the screen shot below is how modes 1-5 should look ( at least for now?)
  • also, PEM awg was left running and had to be halted in order to set the intention bit.

Lots of phone time with Sheila got H1 back in business.

I'd like to suggest that next time an earthquake takes us down we wait to re-lock and assess any artifacts from the event before beginning maintenance on the IFO and then take it down on our own terms to begin making changes.

06:27 H1 back to Observing