young-min.kim@LIGO.ORG - posted 20:40, Tuesday 22 November 2016 - last comment - 21:43, Tuesday 22 November 2016(31759)
BruCo on Nov. 22
From Sheila's request, I ran BruCo on two times,
Nov. 22, 7:30:00, https://ldas-jobs.ligo-wa.caltech.edu/~youngmin/BruCo/ER10-O2A/H1/Nov22/H1-OMC-DCPD-1163835017-600/
Nov. 22, 13:26:24, https://ldas-jobs.ligo-wa.caltech.edu/~youngmin/BruCo/ER10-O2A/H1/Nov22/H1-OMC-DCPD-1163856401-600/
From quick view on the results, ASC CHARD looks concerns around under ~25Hz.
I've attached a screen shot of the DARM spectrum at the two times Young-min ran BRUCO for, the red trace is the worse time (13:26:24) while the yellow trace is the better time.
It looks like in the better of these two times (7:30 UTC) there was broad coherence between DARM and PCAL Y sensors; this is something I haven't seen before in BRUCO. Was something wrong with the optical follower servo last light? for example: CAL-PCALY_OFS_PD_OUT_DQ
At both times, we have broad coherence with jitter sensors at around 0.1.
It seems most likely that the board obvious noise from 50-120 Hz in the spectrum is some non linear coupling. This seems similar to the noise that is making our range low after maintence today.
There are a few more channels which I think could be added to the excluded channel list:
SUS-ETMY_L2_FASTIMON_UL_OUT_DQ
SUS-ETMY_L2_FASTIMON_UR_OUT_DQ
SUS-ETMY_L2_FASTIMON_LR_OUT_DQ