aLIGO LHO Logbook

H1 General

oli.patane@LIGO.ORG - posted 22:00, Tuesday 10 December 2024 - last comment - 10:59, Wednesday 11 December 2024(81757)

Ops Eve Shift End

TITLE: 12/11 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 102Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY: Currently Observing and have been Locked for almost 5 hours. Our range is still all over the place unfortunately. I jumped in and out of Observing a few times by turning squeezing on and off to check for differences with the range (81753), but didn't find anything.
LOG:

00:30 Relocking
01:08 NOMINAL_LOW_NOISE
01:14 Observing

   02:57 Went out of Observing and turned off SQZ to see if that fixes the mystery noise
   03:09 Back to FDS
   03:19 Turned off SQZ
   03:33 Back to FDS and back to Observing

Comments related to this report

camilla.compton@LIGO.ORG - 09:04, Wednesday 11 December 2024 (81760)ISC, SQZ

Link

Attached plot shows that the low range glitchy behavior happens independent of whether we have SQZ injected or not. Traces show the SQZ/NO SQZ times Oli noted in green/yellow with comparisons of good SQZ and NO SQZ times in blue and red.

Light and dark green = Squeezing injected. Can see 20-100Hz noise.
Yellow and orange = NO SQZ. Can still see 20-100Hz noise.
Blue = Squeezing injected. Good stable range.
Red = NO SQZ. No noise.

Yesterday, in 81724 it seemed like the behavior stopped before we took the no SQZ time. Each trace is: 0.1Hz 50% overlap 100 averages = 500 seconds ~10 minutes. /ligo/home/camilla.compton/Documents/H1_DARM_FOM_s_glitchy.xml

Conclusions:

The injected squeezed light or any backscatter from HAM7/8 in not causing low range times
Could still be a SQZ electronics issue? Due to hveto work that Detchar and gravity spy are doing linking to SQZ channels, links in chat and pasted here: hveto/Dec9/no_sqz/, wandering lines SQZ-FC, lines CO2, gravityspy, 20241209/detchar/hveto/, 81730, 81587
Even in good range times, SQZ is added noise 20-40Hz (compare red to blue): could retune FC de-tuning to improve.

Images attached to this comment

camilla.compton@LIGO.ORG - 10:59, Wednesday 11 December 2024 (81762)

Link

I ran BRUCOs on the bad (1417932916: 2024/12/11 06:14UTC) and good (1417949016: 2024/12/11 10:43UTC) times in the attached plot.

Main differences in 20-100Hz region:

Bad time has lots of coherence with PEM-EX_MAG_EBAY_SUSRACK_X_DQ compared to good time, but I expect if the ETMX suspensions is being actuated on, we could see signal noise in this rack to drive ETMX.
More coherence with LSC-POP_A_LF_OUT_256_DQ compared to good time. Again, could be due to feedback to keep IFO locked though glitches.
Other examples of channels that are probably seeing the glitches rather than causing them: ASC-X_TR_A_NSUM_OUT_DQ, OMC-ASC_QPD_A_PIT_OUT_DQ
In a few places, there is an increased coherence around 7-10Hz ISI-HAM2_MASTER_H1_DRIVE_DQ vs goodtime, SEI-EQ_ITMY_GND_X_SUM_OUT_DQ vs goodtime
Coherence bump 40-55Hz with PSL-ISS_SECONDLOOP_RIN_ERR2_OUT_DQ vs goodtime.
Lots of coherence 100Hz+ with PEM-CS_ADC_4_29_2K_OUT_DQ vs goodtime. Need to check what this channel is.
Little more coherence with SQZ-OPO_REFL_RF80_Q_NORM_DQ vs goodtime.

Images attached to this comment