cheryl.vorvick@LIGO.ORG - posted 00:29, Monday 09 September 2019 - last comment - 15:11, Tuesday 10 September 2019(51813)
OPS Eve Summary
TITLE: 09/09 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 118Mpc
INCOMING OPERATOR: Corey
SHIFT SUMMARY: dropped lock during EQ, relocked with small changes to IMs, in Observe
LOG:
- 04:20:17 - lockloss, SEI was in EQ, DCPD and EX verbal alarms
- plot attached shows that bounce mode for ETMX increased right before lockloss
- IX and EX bounce were hovering arounf 1.0, and about 8 seconds before lockloss EX bounce shot up to 1.7
- first attempt at relock ended before DRMI
- second attempt I made some small changes to IM1, IM2, IM3
- maximized to a smooth signal POPAIR_B_RF18_I_NORM_MON, minimized POPAIR_B_RF18_I_NORM_MON, maximized LSC_REFL_A_LF_OUT16
- third attempt didn't survive ENGAGE SOFT LOOPS
- fourth attempt went to NLN
- range is around 119Mpc
Images attached to this report
Comments related to this report
While I didn't plan to make any changes to the IMs, I am aware that the IMs haven't had their alignment looked at for a significant amount of time, while the input pointing, the IMC mirrors, and the rest of the optics in H1 have changed, so I made some very small changes, that imporved POPAIR_B_REF18_I_NORM, and REFL_A LF.
Changes made to IMs, which are 6.5urad or less.
Summary:
- IM1, IM2, IM3 changes are smaller than we have seen after some HAM2 trips
- IM4 alignment is different
- range it running at a level that's in line with the recent locks
- attached are a couple plots of coherence with POP, REFL, IM4 Trans, OMC A, NSIM and LF channels
- decrease in coherence just above 10Hz in Cal Delta
- increase in coherence above 20Hz
- coherence at 48Hz was elevated at the time of the measurement, but is at background now
- decrease in coherence with OMC A 6Hz to ~16Hz
- rest assured, all IMs can easily be resotred to the pervious alignments
Images attached to this comment
These IM alignment slider positions have been reverted -- see LHO aLOG 51858.