Noise without Squeezing improved in 80 to 190Hz band

I took some sqz and no sqz quiet times from yesterday to try and make a plot of the excess noise agaion as in this entry. As Vicky thinks this correlated (non-quantum) noise is getting better.

For the first image I compared calibrated DARM from  this week with the same measurement from March and from 04a.

 

Grey is from 04a, purple is from previous slide with March data, yellow and green are from this week.

 

What we can get from this plot is that this non-quantum noise is different from lock to lock and we are not sure why.

 

Between 80 and 190 Hz the excess noise seems to now be better relative to March and 04a.

 

But the fact the noise without squeezing changes so much in a week is confusing.

 

In the second plot I have just compared three no squeeze quiet times from this week and it easier to see that the noise is not consistent below 200Hz.

Fri CP1 Fill

Fri Apr 05 10:05:56 2024 INFO: Fill completed in 5min 53secs

Gerardo confirmed a good fill curbside. TCtrip raised to -100C while this cold spell lasts.

PSL Cooling Water pH Test

FAMIS 19972

pH of PSL chiller water was measured to be just above 10.0 according to the color of the test strip.

Updated POP_A_RF45 Dark Offsets for Input Alignment

S. Dwyer, R. Short

During H1's locking troubles this morning, we decided at one point to start an initial alignment from the start since DRMI was not locking. While the ACQUIRE_XARM_IR state was running during the input alignment steps, Sheila noticed the LSC-TR_X signal was far off from zero with no light, meaning there was a dark offset that needed to be fixed. I took the mode cleaner offline so we could observe the dark signal on the POP_A_RF45 photodiode and applied the negative value of that to the offset for both the I and Q segments. This allowed XARM IR to catch quickly, and input alignment completed without issue (contrary to its behavior in recent weeks). Sheila has updated the hard-coded offsets in ALIGN_IFO's PREP_ARM_IR state generator (lines 770-771) and included a note that these need to be updated periodically when input alignment has trouble.

This should fix the troubles we've been seeing with input alignment and serves as a reminder to check for any erroneous changes to dark offsets if we notice issues with alignment steps.

Coherences from last night

https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_1396341217_GDS_CALIB_CLEAN/
DHARD_Y is pretty bad, much worse than usual. Probably need a retuning of A2L

Ops Day Shift Start

TITLE: 04/05 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Earthquake
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 4mph Gusts, 3mph 5min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.32 μm/s
QUICK SUMMARY: H1 is currently running and initial alignment following downtime for about 5 hours from an earthquake (mentioned in the owl shift alog).

• Wind and microseism are low
• All other systems nominal

Ops Owl Report

The IFO lost lock at around 1015UTC, then while running an alignment, a 6.8M earthquake from the pacific rolled through, tripping ST1&2 ITMY ISI. This also put SEI_ENV into error for requesting the EARTHQUAKE state from SEI_CONF, which for reasons is actually EARTH_QUAKE. I'm waiting for the ground motion to come down a bit before finishing the alignment and starting to relock.

OPS Thursday EVE summary

TITLE: 04/05 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY: We've been locked for 23:18 as of 07:00UTC

Lock#1

• 23:00 UTC - 00:58 UTC Observing
  • SQZer unlocked possibly from the PMC-PZT voltage dropping too low, but the SQZ_MANAGER relocked everything then prompted me to "Return to FDS" so I requested FDS and was able to return to Observing at 01:14UTC. SQZing looked a little worse at high freq after the relock
  •  Reloaded SEI_ENV during this which caused it to lose FAIL/lose connection due to a TypeError of "NoneType is not iterable"
    • I think the error came from a small typo? An extra underscore?
• 01:14 UTC - 07:00 UTC Observing
• Two small local EQs came through around 1:45UTC, from 4.8 & 4.5 Northern California, not enough motion for SEI_ENV to transition

LOG:                                                                                                            

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
23:42	CAL	Francisco	PCAL lab	LOCAL	PCAL work	00:15

OPS Thursday EVE update

We briefly dropped from Observing due to the SQZer losing lock from 00:58 till 01:14 UTC. I reloaded SEI_ENV during this time which caused it to fail due to an index error, so Dave and I reverted the latest changes and restarted the node.

We've been locked and observing since, lock time of 19:20 as of 03:00UTC

Evaluation of stray light work done during the break: desired reductions in vibration coupling attained for EX cryobaffle, and for input arm - after adjustment of ITMY CP yaw

EX Cryobaffle

In January we damped the EX cryobaffle through a viewport (75553) because it had not been available for damping during the O3-O4 break and because the scattering noise from it increased with beam power (70808). The baffle has a 4 Hz resonance that matched a 4 Hz mode of the isolation system of one of the HVAC fans, making it particularly noisy early in the run, until we switched fans.  Figure 1 shows that, after damping, about five times more motion of the beam tube is required to produce about the same level of noise in DARM.

Input Arm

During the break, we doubled the angle of the MC baffles in the input arm, so that there would be no specular reflection paths between optics, we added more damping to the MC baffles, added nozzle baffles to each of the nozzles with blank-off flanges, and added an unplanned baffle for a glint (75726).

Figure 2 shows a frequency sweep, injected by a speaker, and the resulting noise in DARM before and immediately after the break. The noise produced by injections above 15 Hz, is greatly reduced immediately after the break. However, we had also hoped to better reduce the noise produced by injections below 15 Hz. I spent last week looking into glints that I could see in the chamber and other potential sources of the residual coupling below 15 Hz. I found that  I could greatly reduce the residual coupling by changing the yaw of the ITMY compensation plate by 50 microradians. The last pair of spectrograms in Fig. 1 shows that this CP angling further reduced the coupling to levels that we had hoped to achieve. 

Figure 3 shows the elimination of noise for a 13.1 Hz injection after angling the ITMY compensation plate in yaw. The second page shows that there is repeatable structure at about 20 microradians in the coupling, suggesting that there are multiple ghost beams or, more likely, multiple retroreflecting structures.  The third page shows a bright light on the wall of a spool piece that bears further investigation.

OPS Thursday EVE shift start

TITLE: 04/04 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 11mph Gusts, 8mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.28 μm/s
QUICK SUMMARY:

• Winds calming down
• SQZ commissioning is wrapping up
• We've been locked for 15:18

PSAMS coarse scan trial (2)

Naoki, Eric, Camilla

We continued the PSAMS coarse scan in 76925. Yesterday, IFO was not thermalized, but today IFO is thermalized at least for 7 hours. It seems our nominal 140/90 (strain voltage 7.22/-0.71) would be close to optimal. The detail analysis will follow.

This time, after we moved PSAMS, we compensated the alignment change caused by the PSAMS change by looking at OSEM. This works well for ZM4, but not for ZM5 and we need to touch ZM5 in addition to the compensation. This might be related to the beam miscentering in ZM5 as reported in 75770.

no sqz (10 min)

PDT: 2024-04-04 08:06:30 PDT
UTC: 2024-04-04 15:06:30 UTC
GPS: 1396278408

asqz 200/115 (strain voltage 9.59/-0.702) (5 min)

PDT: 2024-04-04 08:41:34 PDT
UTC: 2024-04-04 15:41:34 UTC
GPS: 1396280512

sqz 200/115 (5 min)

PDT: 2024-04-04 08:49:14 PDT
UTC: 2024-04-04 15:49:14 UTC
GPS: 1396280972

asqz 200/200 (strain voltage: 9.59/2.67) (5 min)

PDT: 2024-04-04 09:28:12 PDT
UTC: 2024-04-04 16:28:12 UTC
GPS: 1396283310

sqz 200/200 (5 min)

PDT: 2024-04-04 09:36:04 PDT
UTC: 2024-04-04 16:36:04 UTC
GPS: 1396283782

asqz 100/200 (strain voltage 6.83/2.72) (5 min)

PDT: 2024-04-04 09:55:09 PDT
UTC: 2024-04-04 16:55:09 UTC
GPS: 1396284927

sqz 100/200 (5 min)

PDT: 2024-04-04 10:02:23 PDT
UTC: 2024-04-04 17:02:23 UTC
GPS: 1396285361

asqz 0/200 (strain voltage 2.2/2.72) (5 min)

PDT: 2024-04-04 10:27:25 PDT
UTC: 2024-04-04 17:27:25 UTC
GPS: 1396286863

sqz 0/200 (5 min)

PDT: 2024-04-04 10:35:27 PDT
UTC: 2024-04-04 17:35:27 UTC
GPS: 1396287345

asqz 140/90 (strain voltage 7.22/-0.71) (5 min)

PDT: 2024-04-04 11:04:22 PDT
UTC: 2024-04-04 18:04:22 UTC
GPS: 1396289080

sqz 140/90 (5 min)

PDT: 2024-04-04 11:12:41 PDT
UTC: 2024-04-04 18:12:41 UTC
GPS: 1396289579

asqz 170/90 (strain voltage 8.80/-0.70) (5 min)

PDT: 2024-04-04 11:55:59 PDT
UTC: 2024-04-04 18:55:59 UTC
GPS: 1396292177

sqz 170/90 (5 min)

PDT: 2024-04-04 12:03:26 PDT
UTC: 2024-04-04 19:03:26 UTC
GPS: 1396292624

asqz 75/90 (strain voltage 5.77/-0.71) (5 min)

PDT: 2024-04-04 12:24:44 PDT
UTC: 2024-04-04 19:24:44 UTC
GPS: 1396293902

sqz 75/90 (5 min)

PDT: 2024-04-04 12:31:39 PDT
UTC: 2024-04-04 19:31:39 UTC
GPS: 1396294317

asqz 130/125 (strain voltage 7.21/0.26) (5 min)

PDT: 2024-04-04 14:58:24 PDT
UTC: 2024-04-04 21:58:24 UTC
GPS: 1396303122

sqz 130/125 (5 min)

PDT: 2024-04-04 15:06:03 PDT
UTC: 2024-04-04 22:06:03 UTC
GPS: 1396303581

asqz 130/83 (strain voltage 7.22/-1.2) (5 min)

PDT: 2024-04-04 15:39:41 PDT
UTC: 2024-04-04 22:39:41 UTC
GPS: 1396305599

sqz 130/83 (5 min)

PDT: 2024-04-04 15:46:36 PDT
UTC: 2024-04-04 22:46:36 UTC
GPS: 1396306014

Attached are the averaged squeezing and anti-squeezing DARM spectra for each PSAM value we've measured so far.  Based on the course scan, we see that our initial PSAM values (strain voltages of 7.22/-0.71 for ZM4/ZM5) appear to be roughly optimal, giving roughly -5.2 dB of squeezing and 15.6 dB antisqueezing at 2 kHz.  So far we've noticed that any significant movement of the PSAM setting for ZM5 seems to de-optimize things and we are relatively insensitive to changes in ZM4 when ZM5 is held fixed at its initial value.    

Values from yesterday afternoon are also included.

moving input pointing and BS camera set point

Jennie W, Sheila, Gabriele remotely

Summary:  With the ISS second loop open, we were able to move the IMs without loosing lock.  We realized that the BS camera set point is not ideal for power recycling gain, and that is the reason that the IM moves seemed to improve build ups.  After reseting the camera servo set point, we were able to increase power on the ISS array and IM4 by moving IM1 yaw in the opposite direction from past moves ( 76534 and 76607 ). 

Details:

We moved IM1 and 3 with the ISS second loop open (take IMC_LOCK to LOCKED), this allowed us to move the input pointing without loosing lock. 

We believe that the improvements in build ups seen in 76534 and 76607 were due to the spot on the ITMs/BS moving. When Jennie moved the IMs in the same direction as these earlier attempts, the build ups increased in both arms and LSC POP, but once the CAM1 YAW servo converged the build ups where back to where they started (screenshot).  The IM move also decreased the power on the ISS second loop array (in and out of loop sums) and IM4 trans QPD dropped, indicating that this move may have been the wrong direction to reduce any clipping in HAM2.  We then moved the CAM1 YAW set point to where the error signal was at the maximum build up time, and this restored the build ups.  

Jennie moved the IMs back to their starting place, which restored the power on IM4 trans and the ISS array, then we walked the CAM1 YAW offset (BS camera feeds back to PRM) to maximize the POP and arm powers, we found that an offset of -236 counts seemed best.   This is consistent with what Jennie and Camilla found with the stepper scripts in 76770.  In 76695, Camilla looked at how the camera offsets change from lock to lock, when they are set after ADS converges. This gave us a roughly 0.5% more power in the arms. We want to change the guardian to use this set point in every lock, and retune the ITMs A2L gain for this new set point, but we haven't done that today.

Next Jennie moved IM1 yaw in the positive direction, which increased the power on IM4 trans and ISS second loop array PDs screenshot and here.  While she was doing this the sqz team was injecting anti-sqz, but when they were done we had a quick quite time for a DARM comparison, it appears that we might have made the noise worse.  We wll double check as we revert this move after the squeezers are finished.

New Improved MICH FF on at 19:45UTC

Turned on new MICH FF at 19:45UTC, details and plot in 76956. Updated safe and observe sdf's and ISC_LOCK.

Took SRCL measurements 19:50-20:05UTC.

Pushed Updated Cleaning

Jennie, Jenne, Sheila

 

I pushed Jenne's updated cleaning but cannot check if this is better or worse until our problems getting data from nds2 are fixed.

I ran the following:

cd /ligo/gitcommon/NoiseCleaning_O4/Frontend_NonSENS/lho-online-cleaning/Jitter/CoeffFilesToWriteToEPICS/

python3 Jitter_writeEPICS.py

I accepted these DIFFS in OAF model in OBSERVE.snap but we might have to revert them before finish of the commissioning period today if we find out the cleaning is worse.

GPS 139627823 - 16 mins quiet time from last night.

11:12:41 UTC - 11:18:38 UTC quiet time just before cleaning implemented.

11:19:55 UTC new cleaning drops.

11:31:30 UTC end of quiet time.

Unsqueezed DARM excess noise getting lower, more similar to O4a

Attachment 1 - Unsqueezed (left) vs. squeezed (right) DARMs in ER16, with respect to O4a. Like Gabriele's plots, the ratios on the bottom show a given trace / O4a reference, so ratio > 1 means more noise now than O4a.

• (left) Last night's no-sqz time 76872 looks quite similar to O4a around 100 Hz, so maybe any excess non-quantum noises around 100 Hz are improving?
   
• (right) Squeezing does not look super optimal right now - definitely would be interesting to do more optimization.. It both looks highly frequency-dependent, and SQZ possibly even lossier now than earlier in ER16, though this is very difficult to say. Recently we've been optimizing SQZ around 350 Hz for range, so it's hard to evaluate high-freq SQZ, since it is misrotated due to the strong frequency-dependence. But even recent ASQZ efficiency could use another look. Maybe we could check OPO temperature, try re-running alignment scripts, etc. General SQZ efficiency is worth some investigations, alongside optimizing PSAMS or SRCL.

Colors: Rainbow colors are ordered past to present: e.g. Red = O4a, ... Purple = now.

Attachment 2 - SQZ dBs after subtracting non-quantum noise, with various recent PSAMS settings. Upper subplot: Anti-SQZ, Lower subplot: SQZ. Lines are a moving average of the data. Some caveats for the subtraction: here I am using the same H1 unsqueezed quantum noise model for all subtractions; this may not be the most accurate, but I think it should be fairly close.

 

Reference alogs wth times that I used to grab GDS_STRAIN_CLEAN:

• O4a references - 74935 and Gabriele's times from 76825
• 76434 - PSAMS 120/120, March 17
• 76540 - PSAMS 150/90, March 20
        --> corresponding SQZ data set saw ~10-15% higher frequency-dependent losses at 100 Hz vs. kHz unlike earlier Mar16, possibly due to PSAMS settings following 76507
• 76777 - PSAMS 100/100, March 29
• 76798 - PSAMS 125/125, March 29  low-freq glitch in this short SQZ time, difficult to compare. Expect it is similar to 120/120 data?
• 76825 - PSAMS 100/100, March 30  - Gabriele showing total DARM at 100 Hz similar to O4a
• 76872 - PSAMS 100/100, April 2 - opportunistic NO SQZ from last night.