Lockloss @ 05/25 00:21 UTC

Starting 5 minutes before this lockloss, the ASC control and error loops suddenly became much larger, specifically MICH IN, and DHARD and CHARD OUT. The wind also jumped from ~17 to ~38(!!??) mph at EY right around that time, so I'll look into that

I'm currently working on relocking and we are in FIND_IR, but the wind at EY is still ~35mph so not sure how quickly we'll be able to get back up

On May 13th (as part of my DQ shift), I noticed a line of 4kHz glitches in the glitchgram, and they have appeared every day since then. Checking the summary pages revealed they’ve been intermittently present since Apr 8, 2024 but not previously (I checked from Dec 1, 2023 onwards). Fig. 1 shows an example glitchgram from May 13th. Figs. 2-4 show Omegascans for some of these glitches. I also created a spreadsheet to characterize these glitches, and did not find any pattern or regularity to their appearance.

I checked the aLogs for possible sources and found the SQZ angle was being tuned around the time the glitches started (aLog). I then compared the timing of the glitches to the SQZ: FC ASC channels and found a correlation between the deviation in the output and the strength of the glitches. See Figs 5-7 for examples, as well as the spreadsheet. I will be meeting with the LSC fellows on Tuesday to discuss these.

Sheila, Naoki

Today we found the excess noise from SQZ between 10-60 Hz as shown in the attachment. The yellow/purple show the DARM with/without SQZ. We think that the excess noise is scatter from SQZ and related to SQZ alignment. Since ZM4 yaw was close to saturation, we offloaded ZM4 yaw with SQZ ASC ON. The red shows the DARM after ZM4 move and the excess noise improved after ZM4 move. Although the excess noise improved, there is still excess noise compared with no SQZ and range is lower than May 8 when we had ~160 Mpc. 

Another notice from this plot is that PR2 spot revert yesterday in 78012 improved the noise below 20 Hz.

I took a long noise injection measurement of the MICH OLG, screenshot and template attached here. 

Anamaria had suggested that the ~17.75 Hz lump in our DARM spectrum could be due to BS bounce mode.  49643 has an old measurement of this frequency from before the bounce roll mode dampers were installed.

The second screenshot shows the MICH and PRCL error signals bandpassed with an elliptic bandpass from 15-20 Hz at a time when PRMI first catches lock.  The dominant frequency in the MICH error signal is in the right frequency region, 17.65Hz measured by the three cycles shown in the screenshot.

So perhaps this noise in DARM can be fixed with a notch in MICH.

TITLE: 05/24 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY:

Starting at 22:11 UTC we dropped out Observing again  to Corrective Maintenance to allow the SQZ team to try to resolve the intermittent low frequency noise issue that we have been seeing the last few weeks.

But on the bright side we made it through commissioning and we are now back to Observing as of 23:20 UTC. 

LOG:

TITLE: 05/24 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 13mph Gusts, 9mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.06 μm/s
QUICK SUMMARY:

We've been locked for over 10 hours, and are in Corrective Maintanance while squeeze team squeezes more range out of the squeezer.

Andrei, Sheila, Naoki

We analyzed the impact of ZM4 and ZM5 curvatures on squeezing level. We choose the channels H1:SQZ-DCPD_RATIO_#_DB_MON to analyze your squeezing.  Channel H1:GRD-IFO_OK was used to make a mask that will filter out all the data points that correspond to times when the measurements were not performed. The DBSCAN method from sklearn.cluster is used to cluster spatially separated data. Subsequent operations check for temporal cluster overlap and separate them.

Presumably, histogram plots can help determine the optimal parameters to achieve the best squeezing.

However, obviously, not only changes in ZM4 and ZM5 were made over the 200 days of observation. As seen from Figure_1.png, several peaks in histograms were likely caused by changes in other parameters. In the future, it would be nice to implement an additional parameter for clustering based on the squeezer phase or others.

Link to code: git.ligo.org/andrei.danilin/zm4-and-zm5-curvature-impact-on-squeezing-level

ZM4 and ZM5 curvatures channels could be easily swappped to others.

[Dave, Erik]

We installed power-over-ethernet injectors at both MY and MX to power the CDS wifi access points, which got them working again.

JeffK, FranciscoL [LouisD remote]

Finished characterizing the spare OMC DCPD whitening chassis (D2200215), S2300002.

• Voltage noise measurements:
  • Path to data directory:
    [CalSVN]/trunk/Common/Electronics/H1/DCPDWhitening/OMCA/S2300002/20240522/Data/
  • Plots are shown in:
    2024-05-22_OMCDCPDWhitening_D2200215_S2300002_OutputVoltageNoise.pdf
  • Measurement notes attached as 2024-05-22_OMCDCPDWhitening_S2300002_OutputVoltageNoise_MeasurementNotes.txt but also on data directory
• TF measurements:
  • Path to data directory:
    [CalSVN]/trunk/Common/Electronics/H1/DCPDWhitening/OMCA/S2300002/20240523/Data/
  • Plots shown in:
    2024-05-23_OMCDCPDWhitening_S2300002_TFs_finaldata.pdf
  • Measurement notes attached as 2024-05-23_OMCDCPDWhitening_S2300002_MeasurementNotes.txt but also on data directory

Noise is matching the expected performance. Transfer Functions look normal.

A fit of the TF data is pending and will be added as a comment.

TITLE: 05/24 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 12mph Gusts, 7mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.06 μm/s
QUICK SUMMARY:

15:00 UTC Dropped out of Observing due to the following SDF Diffs .

Once I was able to take a screen shot of them they were gone.
15:01 UTC  back to Observing

15:31 UTC Happened again. Tj check out the TCS scopes to make sure TCS was ok.
Back to Observing 15:40 UTC

Dropped to Commissioning from 1600 to 1900 UTC

Back to OBSERVING at 19:02 UTC

I engaged the boost filter that Gabreile desgined 77865, the attached screenshot shows that this reduced the DHARD P rms by amost half. 

With this boost engaged I ran the same SRCL excitiation as in 77648 at 18:45:59- 18:55:00 UTC 5/24/24. 

Next week we can add this DHARD P boost into the guardian at LOWNOISE_ASC. 

After this I quickly adjusted the SRCL FF gain to reduce the coupling to DARM at 30Hz a little, screenshot attached.

After the PR2 spot move last night we have some CHARD Y coherence around 20 Hz, so we ran the A2L script in commissioning time today.

Want to change gain from 3.22 to 3.19, rounded to 2 decimal places. St.Div is 0.57. Change of 0.034
H1:SUS-ETMX_L2_DRIVEALIGN_P2L_SPOT_GAIN => 3.19
Want to change gain from 4.87 to 4.89, rounded to 2 decimal places. St.Div is 0.946. Change of -0.018
H1:SUS-ETMX_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 4.89
Want to change gain from 4.43 to 4.39, rounded to 2 decimal places. St.Div is 0.823. Change of 0.041
H1:SUS-ETMY_L2_DRIVEALIGN_P2L_SPOT_GAIN => 4.39

Want to change gain from 1.03 to 0.98, rounded to 2 decimal places. St.Div is 0.159. Change of 0.049
H1:SUS-ETMY_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 0.98

Want to change gain from -0.99 to -1.01, rounded to 2 decimal places. St.Div is 65.221. Change of 0.015
H1:SUS-ITMX_L2_DRIVEALIGN_P2L_SPOT_GAIN => -1.01

Want to change gain from 2.82 to 2.83, rounded to 2 decimal places. St.Div is 0.512. Change of -0.006
H1:SUS-ITMX_L2_DRIVEALIGN_Y2L_SPOT_GAIN => 2.83

Want to change gain from -0.37 to -0.35, rounded to 2 decimal places. St.Div is 0.134. Change of -0.015
H1:SUS-ITMY_L2_DRIVEALIGN_P2L_SPOT_GAIN => -0.35

H1:SUS-ITMY_L2_DRIVEALIGN_Y2L_SPOT_GAIN => -2.47
Want to change gain from -2.47 to -2.47, rounded to 2 decimal places. St.Div is 1.043. Change of 0.003

SDF screenshot attached, these values have been updated in lscparams

Fri May 24 10:08:05 2024 INFO: Fill completed in 8min 2secs

Gerardo confirmed a good fill curbside.

Out of observing times: 1500-1501, 1531-1540 UTC

The TCSX laser had to relock two times in the past half hour. The first time was because it ran out of PZT range (#1 on the screenshot), not uncommon and something that happens from time to time. ~20 minutes after it relocked the chiller temperature got a bit warmer for an unknown reason (#2 & #3). This caused it to unlock and then relock again, this last time everything seems stable (#4).

Out of paranoia I when to check on the chillers and didn't notice anything odd - water levels ok, filters ok, no leaking water/coolant, no critters making nests inside that I could see.

TITLE: 05/24 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 6mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.07 μm/s
QUICK SUMMARY:
H1 is currently locked and Observing for over an hour and a half.
Everything looks good for continued Observing.
 

Naoki, Karmeng, Andrei, Sheila

We did NLG sweep on DARM at NLG 16.9 (nominal) and 42. The IFO was locked for more than 20 hours and well thermalized. We also tried NLG of 65.9, but the squeezing level was not stable so we gave up this NLG. We will take the third NLG data tomorrow if IFO is thermalized. 

Previous NLG sweep on DARM: 73747

How to measure NLG: 76542

How to change NLG: 73801

Note:

• Requesting SQZ_MANAGER guardian from FDS to FIS does not work. We need to request DOWN and then request FIS.
• With NLG 42, as soon as the seed was injected, the pump ISS failed. We reduced ISS gain from 31dB to 21dB to avoid it.
• With NLG 65.9, reducing ISS gain did not help, so we measured NLG without pump ISS. We requested OPO guardian to LOCKED_CLF_DUAL_NO_ISS and adjusted the OPO trans by changing the drivepoint of ISS.

Since we are considering reverting the PR2 spot move, I measured the spot positions by adjusting A2L gains for PR2, PRM, and PR3.  The first attached screenshot shows the current sliders and pico position, the second screenshot shows the A2L gains in SDF.