TITLE: 12/11 Eve Shift: 00:00-08:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Corey
SHIFT SUMMARY: locked in Observe most of the shift, lockloss near the end of the shift, loss of light on the PSL, error message about the PMC High Voltage, and the Diode Chiller tripped off, more detailed info in other alogs by me and Corey
LOG:

H1 activities (out of Observe):

• 00:38:42 - H1 reached NLN, with asistance from Jenne, JeffK, and others
• JeffK worked on calibration
• 02:33:17 - H1 into Observe
• 03:51:43 - verbal alarm for DCPD
• 07:20:39 - lockloss, which included no IMC, no FSS, no PMC
• I looked to see if we'd tripped a shutter, and that was not the case, since the 70W and tne NPRO were both showing 0W of power
• I called Jason, and then I went to check on the PSL power supplies
• Corey arrived for his shift, and he and he checked the diode chiller, and found what appears to be a leak
• Corey has contacted Keita
• assessment continues, though any further entry into the CER or LVEA are not expected

H1 activities (In Observe):

Violin Damping went well tonight, and the results are posted in my alog, alog 53827.

• Highlights:
  • yesterday, ETMY mode 20 was damped in the 100+ hour lock, enough that there was no peak in DARM
  • today, I damped ETMY mode 18, using a negative gain.  Once I changed the gain to a negative value, the damping effect was easy to see
  • today, damping mode18 contributed to the damping of mode20 and mode12, though the effect was not big, clearly damping mode18 was not ringing up other modes
  • H1 lost lock as I was testing higher damping gains for ETMY mode 18.
    •  I also turned off damping to ETMY mode12 because there was no longer a peak in DARM
    • I was about to turn off damping to ETMY mode 11 for the same reason, when H1 lost lock