TITLE: 05/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Corey
SHIFT SUMMARY: Moved our SR3, SR2 alignment back to the "+Y" alignment (referencing from alog77694) that we had after the late April optical gain loss and subsequent SR Y movements. On Tuesday (alog78096) they moved to a "+P" position that didn't seem to help us much over the last few days, so today we tried to move to the "-P" location. We got past DRMI but then it looked like there was clipping in the SRC and we eventually lost lock trying to improve the buildups with SR3 movement. We decided to go back to known good place, the "+Y". As soon as we got to low noise and tried to adjust the squeezer, we lost lock when moving ZM4 to its old position. Currently relocking.
LOG:

• 1530 Out of observing for calibration measurement and commissioning time
• 1831 Lock loss
• 2238 Nominal Low Noise
• 2244 Lock loss  

TITLE: 05/30 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 6mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.06 μm/s
QUICK SUMMARY:

H1 was actively locking as I walked in (TJ mentioned Squeezer alignment knocked us out for the last lock) and this is with the OFI pointing reverting to a +Yaw spot.  Got the note that due to the SQZ alignment change, after NLN, take a locked squeezer to the two additional states scan_alignment_fds + scan_sqzang.

On Tuesday we moved the spot in the SRC to one of the spots (-P, second column) that TJ listed in 77694 .  This was partially motivated by some modeling that Alenna has done which suggests that our original (now possibly burned) spot in the OFI was below the center, so we might benefit from trying to move to a spot above the burned spot to be closer to center in the OFI.  Jenne measured the spot position on SR2 and SRM in  788119, minimizing the coupling of angle dithers to DARM, rather than SRCL, which indicated that we actually moved lower on SRM.  We'd like to check if we get the same result when measuring the A2L coefficient in using SRCL rather than DARM.

The second attached screenshot shows how our kappa C (normalized optical gain) has changed as we've moved in the SRC, with the inital recovery after the OFI damage shown at ~38 days, where the optical gain dropped to 96%, recovery to 98% with the large SR3 yaw move 35 days ago.  Around -29 days ago, Jennie Wright updated the OMC QPD offsets to bring kappa c back to near 1, as she noted in 78143 this change in offsets wasn't due to the damage of the Faraday, we had run a similar QPD spot scan before the OFI incident which indicated that we would have gained optical gain by moving to these same offsets before the OFI was damaged.  This implies that if we hadn't lost any optical gain due to the Faraday damage, we should now have 1.02 for kappa c with the optimized QPD offsets.  In the last few days when SR3 was at the -P position from 77694, we had slightly more optical gain (1.01 kappa C, meaning 2% better throughput.). 

In this -P position, the range was not as good as at the position we've been using since late April (+Y in 77694).  The first attachment shows a low frequency noise comparison.  Interestingly below 15Hz the noise was better in the -P alignment, but worse from 20-45Hz.  Some of this extra noise is from LSC FF which seems to need to be retuned at this alignment.  I did make an attempt yesterday to rescale the MICH FF, but this wasn't very sucsesfull as it seems that we would need to refit the filter to get good feedforward subtraction.  The LSC coherence though wouldn't explain all of this excess noise, especially not the 25Hz peak. 

Today, we decided to try the other pitch spot, to see if that would put us closer to the center of the OFI.  TJ moved us to the spot called +P in 77694 .  As soon as the ASC started to come on in full lock, it was clear that this is not a good location, with hughe power fluctuations in the PRC, POP 18 and POP90.  We were sitting in RF lock with this from 5/30 20:44-21:20 UTC.  During this time we injected a 31Hz line on SRM pitch, and adjusted P2L gain to minimize it's appearance in both SRCL and Rf DARM.  This wasn't a very precise measurement, but for both SRCL and DARM the line was smallest at -1.5 P2L gain (compared to -1 or -2), indicating that this position is closer to centered on SRM than the other two positions.

We've now gone back to the position that we had been using since late April, as that has the best range.  We may want to continue looking for better spots next week, to see if we can fully recover optical gain to 1.02. 

Camilla, Sheila, Robert

We successfully swapped from EX to IX ESD DARM control for Robert's bias sweep by manualling SUS_CHARGE to SWAP_TO_ITMX. On the swap back we again manualled SUS_CHARGE to SWAP_BACK_ETMX, this caused a lockloss as we forgot to return the ETMX bias to it's normal value so the BIAS MASTER_OUT_DCMON was around -487,000 rather than the nominal +170,000. Sorry.

TCS Chiller Water Level Top-Off (Bi-Weekly, FAMIS 27790)

• TCSx Chiller:  Had 29.5 cm - did not add any water
• TCSy Chiller:  Had 10.7 cm - did not add any water
• There was no water in the small cup under the slow leak.
• Recorded in T2200289 Google Sheets

Closes FAMIS 27790

Jennie W, Sheila

I compared the two OMC DCPD plots we made while rastering the QPD offsets on the 19th and 26th of April - ie. before (#77294) and after (#77440) we changed the alignment through the OFI.

These show the same trend for offsets in all four degrees of freedom - ie. PItch and YAW in OMC QPD A and B.

This seems to imply that we do not need to change the QPD offsets if we change the positions of SR3 and SR2 to move the spot on the OFI.

Vicky, Sheila, Camilla

Adjusted ZM2,3 alignment, see no clipping on this path (though VOPS). Moved Pitch then Yaw each around 40urad. Via moving ZM2, leting FC ASC move ZM3, FC1, FC2. I increased H1:SQZ-FC_ASC_INMATRIX_P,Y_RAMPING for INJ_ANG to speed up ZM3 control. 40urad  much more than usual fluctuation (comparison attached).

If we had been clipping, we had expected power on FC REFL WFS to change (Vicky showed they had drifted over past ~40 days) or for FC WFS Q to change. This didn't happen more than the original drift. Zoomed out plot. 

SFI2 temperature changes and injections were happening at the same time, plus some Robert stray beam watching. Unsure the reason for the CLF power decrease and WFS increase, seem not correlated with alignment change.

Naoki, Andrei, Sheila

To investigate the scatter noise from SQZ at low frequency, we excited the ZM2 or ZM5 length at 1 Hz with same amplitude. The attached figure shows the scatter shelf in DARM with ZM2 or ZM5 excitation.

The scatter shelf by ZM5 excitation is much larger than ZM2, which means that the origin of the scatter light is different for these two scatter shelves. The scatter light with ZM2 excitation should come from FC, but the scatter light with ZM5 excitation should come from between ZM2 and ZM5.

We also changed the SFI2 temperature. The scatter shelf does not change much with SFI2 25.2 and 35.2, but got worse with SFI2 20.2 for ZM2 excitation.

Ansel and Sheila following up on 77990. This work relates to the 9.5 Hz comb triplet .

Channels involved

• H1:PSL-ISS_PDA_REL_OUT_DQ - identified as a possible witness in 77990, which started the rest of the investigation. Does not see the 9.5 Hz combs when the ISS second loop is off.
• H1:PSL-ISS_PDB_REL_OUT_DQ - does see the 9.5 Hz combs (very clearly!) even when the ISS second loop is off, and even when the IMC is unlocked. Selected as best channel for tracking the time dependence of the comb (below).
• Other places the combs are seen, albeit not as clearly:
  • H1:PSL-PMC_HV_MON_OUT_DQ - also identified as a possible witness in 77990, combs are present here but much weaker.
  • H1:PSL-ISS_SECONDLOOP_PDSUMOUTER_OUT_DQ
  • H1:PSL-ISS_SECONDLOOP_PDSUMINNER_OUT_DQ
  • H1:PSL-PWR_NPRO_OUT_DQ (laser power before amplifier)
  • H1:PSL-PWR_HPL_DC_OUT_DQ (laser power after amplifier)

(Thanks to Sheila for guidance on channels and times here!)

Comb history

With this information in hand, it was possible to track the 9.5 Hz combs back to a likely start date on or near Sept 2, 2021. Details:

• I used the PDB channel first to determine that the combs appeared between August 30 and Sept 7, 2021. After that I switched over to some of the channels where the comb is more faint (H1:PSL-PMC_HV_MON_OUT_DQ, H1:PSL-PWR_NPRO_OUT_DQ, H1:PSL-PWR_HPL_DC_OUT_DQ), as there wasn't any good data from PDB (presumably due to the ongoing work), and found a distinct change point between the Sept 1 and Sept 2 daily spectra. A spreadsheet showing the dates & channels checked is attached.

Checking the alogs around that time, there was quite a bit of PSL upgrade work ongoing, as summarized in 59832.

This work is ongoing; as before, details and work-in-progress notes can be found on gitlab. Anamaria and Matt H have supplied a number of times to look at LLO data (recall that these combs have counterparts at LLO), particularly for dark spectra of the ISS PDs. This is next on the to-do list.

What about the 11.9 Hz comb mentioned in the previous alog?

It's also in a lot of these channels! However, unlike the 9.5 Hz, I don't see a notable change point in early September. This is not really surprising, since the 11.9 Hz comb was noted in O3. I'm focusing on the 9.5 Hz combs first, which are more pervasive, but keeping an eye out for more 11.9 Hz clues along the way.

Anybody interested in looking at the spectra can find the full set of plots here (more will be added as I work): https://ldas-jobs.ligo-wa.caltech.edu/~ansel.neunzert/iss_channels_combs/ .

Thu May 30 10:12:16 2024 INFO: Fill completed in 12min 12secs

Gerardo confirmed a good fill curbside.

Ran a broad band and simulines meaurement starting at 1531UTC.

Simulines start:

PDT: 2024-05-30 08:37:11.822463 PDT
UTC: 2024-05-30 15:37:11.822463 UTC
GPS: 1401118649.822463

End:

2024-05-30 15:58:42,508 | INFO | File written out to: /ligo/groups/cal/H1/measurements/DARMOLG_
SS/DARMOLG_SS_20240530T153713Z.hdf5
2024-05-30 15:58:42,515 | INFO | File written out to: /ligo/groups/cal/H1/measurements/PCALY2DA
RM_SS/PCALY2DARM_SS_20240530T153713Z.hdf5
2024-05-30 15:58:42,520 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_
L1_SS/SUSETMX_L1_SS_20240530T153713Z.hdf5
2024-05-30 15:58:42,524 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_
L2_SS/SUSETMX_L2_SS_20240530T153713Z.hdf5
2024-05-30 15:58:42,529 | INFO | File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_
L3_SS/SUSETMX_L3_SS_20240530T153713Z.hdf5
ICE default IO error handler doing an exit(), pid = 1172966, errno = 32
PDT: 2024-05-30 08:58:42.575781 PDT
UTC: 2024-05-30 15:58:42.575781 UTC
GPS: 1401119940.575781
 

TITLE: 05/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 4mph Gusts, 2mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.07 μm/s
QUICK SUMMARY: Locked for 13 hours, range around 150+. Planned calibration and commissioning today from 830-1200PT.

TITLE: 05/29 Eve Shift: 2300-0800 UTC (1600-0100 PST), all times posted in UTC
STATE of H1: Observing at 148Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

Decent shift with more Observing time compared to last night's shift.  Notables for locking was the continue locklosses for FIND IR (even after an alignment).  Pausing seemed to help.  There was also a superevent as well (102nd of O4).
LOG:

• 2340 Lockloss
  • Locking notes:
    • Several locklosses at early state (FIND IR)---during Diff Beatnote sweeps
    • 2358 Started Initial Alignment
      • For ALS it only took about 7min to complete (but while waiting for offload x-arm would lose lock randomly even with the good transmitted power)...Ryan S mentioned a very long ALS step (over 40min!) which ended up sending him a wake-up call during his Owl shift.
      • Continued to have a couple more FIND IR loclosses.  So, waited at LOCKING ALS for 2min, and then watched both ALS COMM & DIFF guardians.  And finally made it past FIND IR.  (Should also mention wind speeds have been increasing.)
      • 0116 OBSERVING
• 0120-0141 Washington teachers tour in Control Room (Cassidy)
• 0124 S240530a

Decent night even with winds and a lockloss.  (H1 had issues getting past FIND IR.)  Also managed a super event at the very beginning of this current 2+hr lock.

Jennie W, Sheila

Summary: We need to rerun this test with slightly different starting QPD offsets and a different amplitude to get a meaningful measurement of how the optical gain would be affected by changing the OMC alignment.

I started an injection into the OMC ASC loops (which feed back to the OMC and the OM3 pitch and yaw to keep the beams centred to specific offsets on OMC QPD A and B.

With this we can raster the OMC alignment and find which QPD offsets allow us to maximise optical gain.

The injection started at about 20:30 UTC while no squeezing was injected.

I used this template at /ligo/home/jennifer.wright/Documents/OMC_Alignment/20240419_OMC_Alignment_EXC.xml with amplitudes of 3 counts in all four degrees of freedom.

Within one cycle the OMC suspension saturated.

Why did we saturate with an injection amplitude of 3 as this ran the last time we did this test without any saturations?

Decreased amplitude to 1 to run it without saturating the OMC suspension.

Restarted at 20:39:07 UTC roughly.

Stopped injecting after 21:06:00 UTC.

Results inconclusive as changing the QPD in offset does not seem to change the noise injected around the calibration line between 410 to 411 Hz, so maybe we need to have higher injection amplitudes but start raster from different QPD offset set points so we don't staurate the suspension.

Looking at ndscope of the channels when they saturated.

OMC T2 and T3 saturated (this is an18 bit DAC). This is OMC pitch degree of freedom, which corresponds to Y direction in the OMC ASC loop basis.

Looking at the top left plot the POS Y DOF seems to correspond to the time of saturation and is the highest Y channel so we want to put in a +0.5 offset to this before the next time we run this raster to bring the input to the POS Y loop down in magnitude.

As I logged in this morning, the  SQZ ASC and FC ASC offload and graceful clear history scripts that I  ran and left open yesterday (whoops) reran. 15:16UTC. Before I could save sdf diffs, we went though DOWN SDF revert. There was nothing in SQZ ASC, but FC ASC got cleared. As squeezing hasn't been in a good alignment over the last 12 hours, this doesn't really matter. But if  we were in observing it would have knocked us out.

Reminder to close scripts once used. CDS is there a way we can disable this from happening?

Andrei, Sheila

We've analyzed the time-traces of the effective range (H1:CDS-SENSMON_CAL_SNSW_EFFECTIVE_RANGE_MPC) along with the alignment channels FC_WFC_A(B) and AS_A(B)_RF42 (see attached figures). We found no observable dependance between those.