TITLE: 05/27 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Corey
SHIFT SUMMARY: locked most of the shift, issues listed below
LOG:
- handed off locked with violin damping
- Sheila called, scripts run to recover arm pointing likely removed a TRAMP time for TMSX, which is necessary for the stage INCREASE_POWER (was 0, now 30)
- Sheila restored the TRAMP time, I accepted it in SDF, H1 made it through INCREASE_POWER without issue, and then on to NLN
- (UPDATE: in DOWN, the SDF for the TRAMP was not saved, so came up as a diff, I accepted it, so it should not reappear)
- in NLN, H1 was very glitchy and SQZ lost lock a number of times, and the range ran low, between 80 Mpc and 90 Mpc for more than an hour
- Georgia called, and increased the FSS COMMON_GAIN from 23dB to 24dB, since the DC light level was down around 1.9V on the TPD
- this brought the high frequency noise in DARM back to a normal level
- during this time, winds increased and gusted up to around 38 mph (current max is holding steady at around 35 mph)
- at shift change, H1 was locked but SQZ was unlocked
- handed H1 off to Corey, and then H1 lost lock
- after lockloss, I realigned IM2 and IM3, which had shifted alignment when the ISI tripped (IM4 did as well, but since it's driven and the change was well withing the range that IM4 is typically pointing, I did not set IM4 back to the old values, however, it might need to be checked again once Corey gets to locking the arm in IR)
- I checked tht IM4 trans QPD, ISS Second Loop QPD, and confirmed the IM alignment changes were seen on these QPDs
- previous time when H1 was unlocked, to unlocked after the EQ, to now restored
- IM4 TRANS pitch: was ~1.6, then ~3.6, now ~0.17 -> change due to EQ(IMs) = 0.2
- IM4 TRANS yaw: was ~1.4, then ~1.5, now ~1.4
- ISS2 QPD pitch: was ~0, then ~0.56, now ~0 -> change due to EQ(IMs) = 0.6
- ISS2 QPD yaw: was ~-0.05, then ~0.0, now ~-0.07
- Corey's doing an initial alignment
changes in IM alignment shown in the attached plot: largest changes were IM2 pitch, delta -30 urad, and IM3 pitch, delta -10 urad
I was interested in what, if any, conferences changed between DARM and POP and REFL. I used skinny list of channels, and have included REFL in the first plot. Interestingly, the coherence with DARM today, in the lock after the EQ, are smaller than two days ago. The second plot is my first look at IMs to arms.