Vicky, Regina, Naoki, Sheila
We took squeeze data with PSAMs on ZM4 and ZM5 both at 120V, and four squeeze angles. Summary screenshot here, with these trends of squeezed BLRMS. All of the following data was done with frequency dependent squeezing.
With ZM4/5 at 120/120 V, +/- mid squeeze have noticibly different misrotations across the band. In alog 71902 from Aug. 2 with PSAMS at 200/200V, we didn't see strong misrotations down to ~80 Hz. From FDS data on Aug 2, compare today's green/blue lines to the green and yellow +/- mid squeeze lines in this plot.
DTT saved at $(userapps)/sqz/h1/Templates/dtt/DARM/PSAMS_tests_Oct112023.xml
For reference, with ZM4/5 PSAMS at 200/200V (what we've been operating with in O4).
H1:AWC-ZM4_PSAMS_STRAIN_VOLTAGE 7.52377
H1:AWC-ZM4_PSAMS_DEFOCUS_MON_MDIOPTER 201.544
H1:AWC-ZM5_PSAMS_STRAIN_VOLTAGE 3.49813
H1:AWC-ZM5_PSAMS_DEFOCUS_MON_MDIOPTER -1030.69
I took more data with PSAMS ZM4/5 = 200V/200V, using the same injected sqz angles as above.
See comparisons of anti-squeezing and squeezing with PSAMS @ 200/200V (dotted lines) vs. 120/120V (solid lines).
Notes / thoughts:
BLRMS trends here. All traces saved to same DTT file, $(userapps)/sqz/h1/Templates/dtt/DARM/PSAMS_tests_Oct112023.xml
Vicky, Sheila, Regina, Dorotea
We followed up by checking ZM Sliders to see if there is misalignment with different PSAMS was a factor in addition to the mode mismatches from changing PSAMS. There seems to be a large static alignment shift from changing PSAMS, we're not sure if it is fully compensated by ASC especially in yaw. We might do more measurements tomorrow to follow up.
| Squeezing | ZM4/ZM5 Voltage | Demod Phase (deg) | ZM4 P | ZM4 Y | ZM5 P | ZM5 Y | ZM6 P | ZM6 Y |
| +Mid SQZ | 120/120 | +200 | -41 | 255 | -176 | 339 | 780 | 805 |
| +Mid SQZ | 200/200 | +200 | -9.5 | 254 | -241 | 439 | 807* | 801* |
| -Mid SQZ | 120/120 | +32 | -12 | 257 | -176 | 351 | 753 | 793 |
| -Mid SQZ | 200/200 | +32 | -9.6 | 254 | -244 | 450 | 792 | 790 |
| ASQZ | 120/120 | +242 | -41 | 257 | -165 | 343 | 765 | 792 |
| ASQZ | 200/200 | +242 | -9.55 | 254 | -238 | 439 | 843 | 787 |
| FDS | 120/120 | +150 | -41 | 257 | -177 | 391 | 756 | 797 |
| FDS | 200/200 | +150 | -9.48 | 254 | -244 | 446 | 800 | 789 |
*+Mid SQZ: ZM6 was not flat for the 200/200 squeezing. It was increasing in P and Y for +Mid SQZ, didn't seem to reach the steady state. It seems like the ASC is keeping up better with 120/120 because the angles converged, whereas the angles of ZM5 and ZM6 for the 200/200 case kept increasing and did not reach steady state in the time given.
ASQZ: ZM5 pitch for 120/120 has some shaking, ZM6 pitch is rising and yaw is dropping
Full DQ shift report is at: https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20231002
Overall a relatively uneventful week.
Range frequently stable around 150 Mpc with some drops down to 140
Found that hveto was looking at unsafe channels to generate vetos, should be fixed now
Some safe channels also found by hveto as good witnesses:
H1:PEM-EX_EFM_BSC9_ETMX_Y_OUT_DQ
H1:SUS-ETMX_L3_OPLEV_PIT_OUT_DQ
H1:SUS-ETMX_L3_OPLEV_YAW_OUT_DQ
Glitches continue to be problematic, much higher glitch rate than L1.
Some of the glitches most affecting the PyCBC search have werd morphologies
Thu Oct 12 10:11:05 2023 INFO: Fill completed in 11min 1secs
Jordan confirmed a good fill curbside.
Closes FAMIS#26482, last checked 72639
check_T240_centering.py - 2023-10-12 08:41:09.262244
There are 12 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 2 DOF X/U = -0.918 [V]
ETMX T240 2 DOF Y/V = -1.076 [V]
ETMX T240 2 DOF Z/W = -0.32 [V]
ITMX T240 1 DOF X/U = -0.87 [V]
ITMX T240 1 DOF Z/W = 0.428 [V]
ITMX T240 3 DOF X/U = -0.842 [V]
ITMY T240 3 DOF X/U = -0.56 [V]
ITMY T240 3 DOF Z/W = -1.111 [V]
BS T240 1 DOF Y/V = -0.456 [V]
BS T240 3 DOF Y/V = -0.358 [V]
BS T240 3 DOF Z/W = -0.573 [V]
HAM8 1 DOF Z/W = -0.306 [V]
All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 1 DOF X/U = 0.219 [V]
ETMX T240 1 DOF Y/V = 0.125 [V]
ETMX T240 1 DOF Z/W = 0.152 [V]
ETMX T240 3 DOF X/U = 0.1 [V]
ETMX T240 3 DOF Y/V = 0.114 [V]
ETMX T240 3 DOF Z/W = 0.097 [V]
ETMY T240 1 DOF X/U = -0.013 [V]
ETMY T240 1 DOF Y/V = 0.058 [V]
ETMY T240 1 DOF Z/W = 0.124 [V]
ETMY T240 2 DOF X/U = -0.082 [V]
ETMY T240 2 DOF Y/V = 0.146 [V]
ETMY T240 2 DOF Z/W = 0.028 [V]
ETMY T240 3 DOF X/U = 0.128 [V]
ETMY T240 3 DOF Y/V = 0.002 [V]
ETMY T240 3 DOF Z/W = 0.09 [V]
ITMX T240 1 DOF Y/V = 0.267 [V]
ITMX T240 2 DOF X/U = 0.086 [V]
ITMX T240 2 DOF Y/V = 0.217 [V]
ITMX T240 2 DOF Z/W = 0.188 [V]
ITMX T240 3 DOF Y/V = 0.107 [V]
ITMX T240 3 DOF Z/W = 0.112 [V]
ITMY T240 1 DOF X/U = 0.068 [V]
ITMY T240 1 DOF Y/V = -0.008 [V]
ITMY T240 1 DOF Z/W = -0.14 [V]
ITMY T240 2 DOF X/U = 0.061 [V]
ITMY T240 2 DOF Y/V = 0.13 [V]
ITMY T240 2 DOF Z/W = 0.014 [V]
ITMY T240 3 DOF Y/V = 0.039 [V]
BS T240 1 DOF X/U = -0.225 [V]
BS T240 1 DOF Z/W = -0.009 [V]
BS T240 2 DOF X/U = -0.184 [V]
BS T240 2 DOF Y/V = -0.084 [V]
BS T240 2 DOF Z/W = -0.226 [V]
BS T240 3 DOF X/U = -0.295 [V]
HAM8 1 DOF X/U = -0.131 [V]
HAM8 1 DOF Y/V = -0.094 [V]
check_sts_centering.py - 2023-10-12 08:43:32.265464
There are 2 STS proof masses out of range ( > 2.0 [V] )!
STS EY DOF X/U = -4.106 [V]
STS EY DOF Z/W = 2.601 [V]
All other proof masses are within range ( < 2.0 [V] ):
STS A DOF X/U = -0.614 [V]
STS A DOF Y/V = -0.874 [V]
STS A DOF Z/W = -0.437 [V]
STS B DOF X/U = 0.519 [V]
STS B DOF Y/V = 0.874 [V]
STS B DOF Z/W = -0.547 [V]
STS C DOF X/U = -0.365 [V]
STS C DOF Y/V = 0.808 [V]
STS C DOF Z/W = 0.217 [V]
STS EX DOF X/U = -0.246 [V]
STS EX DOF Y/V = 0.01 [V]
STS EX DOF Z/W = 0.059 [V]
STS EY DOF Y/V = 0.13 [V]
STS FC DOF X/U = 0.4 [V]
STS FC DOF Y/V = -0.74 [V]
STS FC DOF Z/W = 0.793 [V]
Closes FAMIS#26212, last checked 73167
Everything looking good besides ISS diffracted power low
Laser Status:
NPRO output power is 1.822W (nominal ~2W)
AMP1 output power is 67.6W (nominal ~70W)
AMP2 output power is 136.1W (nominal 135-140W)
NPRO watchdog is GREEN
AMP1 watchdog is GREEN
AMP2 watchdog is GREEN
PMC:
It has been locked 20 days, 1 hr 15 minutes
Reflected power = 16.57W
Transmitted power = 109.4W
PowerSum = 125.9W
FSS:
It has been locked for 0 days 10 hr and 20 min
TPD[V] = 0.7294V
ISS:
The diffracted power is around 1.7%
Last saturation event was 0 days 10 hours and 20 minutes ago
Possible Issues:
ISS diffracted power is low
TITLE: 10/12 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
OUTGOING OPERATOR: Ibrahim
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 3mph Gusts, 2mph 5min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.21 μm/s
QUICK SUMMARY: Locked for 9 hours, useism trending down to good levels.
CDS Overview OK, no alarms
DIAG_MAIN - ITMY HWS code has stopped
TITLE: 10/12 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 148Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Two mystery locklosses with some opportunistic commissioning activities interspersed throughout the shift since L1 has been down.
HWS ITMX code is stopped and has been for the majority of this shift, tagging TCS.
LOG:
| Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
|---|---|---|---|---|---|---|
| 23:48 | PEM | Robert | CER | - | Adjust PSL chassis grounding | 23:57 |
| 00:28 | SQZ | Vicky, Naoki, Regina | CR | - | SQZ tests | 01:57 |
Lockloss @ 05:10 UTC - no immediately obvious cause. Another quick lockloss, no DCPD saturation this time.
Back to observing at 06:04 UTC
While L1 was down this evening, H1 dropped out of observing between 03:23 and 04:26 UTC to opportunistically continue SQZ tests (see alog 73408).
Tagging DetChar: although gwistat reported H1 was "Ready" for much of this time (where the GDS range was being computed since we could have flipped the intent bit to start observing), H1 was not observing between 03:23 UTC and 04:26 UTC for commissioning time.
H1 has just started observing at 146Mpc as of 02:54 UTC.
There's a M5.5 earthquake coming in from Alaska, so hopefully we can hold on through the rest of the evening.
Lockloss @ 01:50 UTC - no immediately obvious cause, happened quickly with a DCPD saturation.
H1 had reached NLN at 23:52 UTC and resumed with commissioning since L1 was not locked. There were SQZ-related tests being run at this time, but it's very unlikely they were the cause of this lockloss.
Back to observing at 02:54 UTC.
On Tuesday I tuned the periscope in the PSL by adjusting weights and Tyler and I shut down SF2, which was responsible for the new 120 Hz HVAC peak ( https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=73378 ). Figure 1 shows the reduction of the periscope peak from tuning, and from tuning plus the fan shutdown. The fan shutdown had the greatest effect.
Figure 2 shows the disappearance of the peak from the summary pages, as well as the 3+ MPc increase in range from the fan change only.
During commissioning today I looked for the source of the 13.1 Hz harmonics that began to appear on Oct. 3, by testing some of the things that were done that Tuesday. First I temporarily shut down the DC-DC converter and oplev laser for ITMX that had been worked on. But the noise, likely from the very high microseism, made my tests inconclusive. I also tried disconnecting the new grounding on the TCS and PSL chassis. Since DARM noise was too high for me to tell if this helped, I have left them disconnected and will reconnect the grounds when we can tell that they are not part of the problem.
Camilla, Jonathan, Dave:
h1hwsmsr had issues this afternoon, and then got stuck on reboot. Jonathan looked at the console and found it was reporting a SMART error on its hard disk drive. We will schedule a replacement.
Jonathan manually progressed the boot past this point and Camilla restarted the code. The EDC was disconnected from its 88 HWS ITMX channels between 16:15 - 16:48 PDT.
Camilla, Jenne. Started in 73345. H1 had been locked ~5 hours.
Didn't exactly follow instructions in lsc/h1/scripts/feedforward/README.md, as took residual measurements with no FF and took FF measurements with actuation through ETMY PUM rather than ETMX.
Gabriele helped fit the filters and we saved them to MICHFF and SRCLFF as 10-11-23-EY.
Vicky, Sheila, Camilla, Dorotea, Naoki
We went to SQZT7 this morning with the new homodyne (73241). In the end we wer able to see decently flat shot noise and decent visibility. On the way, we ran into some difficulties that caused some confusion:
In the end we have flat shot noise, and a visibility of 98.5% measured on PDA (3.07% loss) and visibility of 97.8% (4.44% loss) measured on PDB. The nonlinear gain of 11 measured with seed max/ no pump. A comment to this alog will contain the measured sqz/asqz/mean sqz.
Screenshot summarizing homodyne measurements today. With measured carrier NLG=11 (for generated squeezing ~14.7-14.8 dB), we observe
Comparing sqz/anti-sqz to generated sqz: ~7% unexplained homodyne losses. This is consistent with our last estimate of excess HD losses (8/29/2023, LHO:72802, ~7% mystery loss). Since then, we swapped the HD detector and improved readout losses (visibility). We now measure more homodyne squeezing at 6 dB, consistent with expected loss reductions. That is compared to 8/29 (LHO:72802), we have less total loss, less budgeted hd loss && more squeezing, but the same unexplained hd losses as before.
Comparing mean-squeezing to generated sqz: could be consistent with sqz/asqz losses. I think there is a mis-estimate of the generated squeezing level from non-linear gain. If we ignore our NLG11 measurement, and instead use the generated squeezing level to match observed 13.5 dB of anti-squeezing, then we allow losses to determine the measured 6 dB squeezing level, we would have an NLG=10 (not 11) for a generated squeezing level of 14.5 dB. This would suggest 7% unexplained losses, same as the sqz/asqz measurements.
For ~7% mystery losses, this is compared to total HD losses of 21%, of which we budget 15% losses. From the sqz wiki, the budgeted losses are:
If we include phase+dark noise that degrades squeezing but is not loss, then 21% total loss can explain the 6dB measured squeezing, see e.g. from the gsheet calculator (edited to include ranges for NLG=10 and NLG=11):
| SQZ | ASQZ | |
| NLG | 10 - 11 | |
| x | (0.68, 0.70) | (0.68, 0.70) |
| gen sqz (dB) | (-14.5, -15.01) | (14.5, 15.01) |
| with throughput eta = | 0.79 | |
| meas sqz (dB) | (-6.24, -6.29) | (13.54, 14.03) |
| with phase noise (mrad) = | 20.00 | |
| meas sqz (dB) | (-6.08, -6.11) | (13.54, 14.03) |
| with dB(Vtech/Vshot) = | -22.00 | |
| var(v_tech/v_shot) | 0.0063 | 0.0063 |
| meas sqz (dB) | (-5.97, -6.00) | (13.54, 14.03) |
DTT homodyne template saved at $userapps/sqz/h1/Templates/dtt/HD_SQZ/HD_SQZ_101023.xml .
Edited to include some history of homodyne measurements:
It could still be interesting to vary NLG to see if we can obseve any more squeezing, or if an additional technical noise floor (aside from dark noise) is needed to explain the NLG sweeps.
We revised the sqz loss wiki table again today, and are including it to explain what we think our current understanding of losses is.
It seems likely that the 7% extra losses we see on homodyne measurements are in HAM7, so we've nominally added that to the loss budget.
In addition to this, there would be an additional 8% loss on the sqz beam if we didn't correct it's linear polarization with a half wave plate. 72604 At the time of the chamber close out, (65110) we measured throughput from HAM7 to HAM5 that would implies that two passes through the OFI were giving us 97.6% transmission, so this is not compatible with the polarization being wrong by this much. We haven't included this as a loss in the loss budget because it seems incompatible with our measurement in chamber.
The wiki currently lists the OMC transmission as 92%, and the PD QE as 98%. The PD QE may be worse than this (see 61568), but measurements of the product of QE and OMC transmission for 00 mode seem to indicate that is in the range 90-92%, so this is close.
With the infered losses of from the measured sqz/anti-sqz in the IFO, the plausible range of losses is 30-35%, we are using 32%. With only known losses (including the values for OMC trans and PD QE), we have 14% unexplained loss. If we include the 7% apparent HAM7 losses, we have 9% unexplained losses in the IFO. This does seem similar to the 8% polarization problem, but it would also include SQZ-OMC mode matching.
Possible future scenarios: We may be able to reduce the 7% HAM7 losses, and we may be able to swap the OMC to reduce those losses from 92% to 97%.
| total efficiency | resulting sqz measured without subtraction (technical noise -12dB below shot, 20mrad phase noise) | if technical noise is 20dB below unsqueezed shot noise | |
| fix HAM7 losses | 0.73 | 4.4dB | 5dB |
| swap OMC (92%-> 97%) | 0.71 | 4.14dB | 4.8dB |
| swap OMC and fix HAM7 losses | 0.77 | 4.85dB | 5.6dB |
| swap OMC, fix HAM7 losses, and fix 8% from polarization issue (if that is real) | 0.84 | 5.83dB | 6.8dB |
These numbers come from the aoki equations that Vicky added to the google sheet here: gsheet
Don G. and Sheila have very likely resolved the homodyne polarization issue as being due to the SQZT7 periscope. So, the mis-polarization is likely not an issue for squeezing in the interferometer.
The sqz beam leaves HAM7 via reflection off the sqz beam diverter. From the latest CAD layout from Don, the outgoing reflected beam (blue) is ~75.58 degrees from global +X. The periscope re-directs the beam to travel along SQZT7, approximately along +Y. The CAD layout thus suggests that the SQZT7 periscope re-directs the beam in yaw (counter-clockwise) by an estimated 90 - 75.58 = 14.4 degrees.
From recent homodyne measurements LHO:72604, of the sqz light leaving HAM7 and arriving on SQZT7, ~8% of the power was in the wrong polarization, this calculates to a ~16.5 degrees polarization misrotation. Compared to this 16.5 degree misrotatation we were searching for, the 14.4 degrees polarization rotation induced by the periscope image rotation can plausibly explain the misrotation.