FAMIS 31106
PMC REFL has been continuing to increase, but nothing much of note this week otherwise.
Camilla, Sheila
We repeated a test similar to 78125, where we changed the SFI2 temperature and measured fringe wrapping by exciting ZM2 and ZM5. The temperature of SFI2 changes the backscatter shelf amplitude seen when exciting ZM2, but not ZM5, suggesting that the source of the scattering is upstream of the isolation of SFI2.
The attached plot shows ZM2 and ZM5 fringing measurements at LLO. The total OMC current is 50 mA.
Here's a model of our ZM fringe wrapping measurements (the same plot as in 86836, plotted with a model that's roughly emulating Valera's measurement above. It looks like LLO has about 200pW of interferometer light reaching the filter cavity, but none of the extra scatter we see from before SFI2.
TITLE: 10/06 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 3mph Gusts, 2mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY: H1 has been locked for 37.5 hours. Commissioning time scheduled today from 15:30 to 18:30 UTC.
TITLE: 10/06 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:
H1 has been locked for 28 hrs, currently Observing.
I Have nothing else to report.
LOG:
No Log
TITLE: 10/05 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 16mph Gusts, 10mph 3min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.11 μm/s
QUICK SUMMARY:
H1 is Locked and Observing & I've got no plans to change that.
TITLE: 10/05 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY: Very quiet day with H1 observing throughout; nothing of consequence to report. H1 has been locked for 22.5 hours.
State of H1: Observing at 158Mpc
H1 has been locked for 18 hours; quiet morning so far with no drops from observing.
Sun Oct 05 10:07:49 2025 INFO: Fill completed in 7min 45secs
TITLE: 10/05 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 13mph Gusts, 9mph 3min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.11 μm/s
QUICK SUMMARY: H1 has been locked for 13.5 hours. One drop from observing last night at 09:21 UTC from SQZ dropping out, but look like everything came back fine.
TITLE: 10/05 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:
One Lockloss @23:44 UTC & fairly easy relocked.
Back to Observing at 1:06 UTC.
H1 has been locked for 4 Hours.
LOG:
No Log
Unknown Lockloss.
H1:LSC-DARM_IN1_DQ seemed to be the first channel that takes an excursion.
Relocking notes:
Relocking was striaght forward, but had to send Y-ARM to Increase flashes. Otherwise it didn't give me any hassle.
TITLE: 10/04 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 74Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 10mph Gusts, 5mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.14 μm/s
QUICK SUMMARY:
H1 Has been locked for 27 Hours and is currently Observing.
The plan is to continue to Observe the universe for as long as possible.
TITLE: 10/04 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 150Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY: H1 remained lock the whole day with only a few drops from observing, most of which were intentional. After the squeezer relocked, the range was a bit low, but the SQZ angle servo eventaully brought it back up over the course of about an hour. I probably could have run a SQZ angle scan right before going back into observing to fix the range sooner. H1 has now been locked for 27 hours.
LOG:
This SQZ Lockloss was caused by the OPO PZT running out of range. Plot attached, when the OPO relocked with the PZT at ~100V, the SQZ angle servo worked as expected to bring the range back.
FAMIS 27375, last checked in alog86751
There are 13 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 2 DOF X/U = -1.57 [V]
ETMX T240 2 DOF Y/V = -1.466 [V]
ETMX T240 2 DOF Z/W = -1.024 [V]
ITMX T240 1 DOF X/U = -2.176 [V]
ITMX T240 1 DOF Z/W = 0.432 [V]
ITMX T240 3 DOF X/U = -2.304 [V]
ITMY T240 3 DOF X/U = -1.084 [V]
ITMY T240 3 DOF Z/W = -2.75 [V]
BS T240 1 DOF Y/V = -0.375 [V]
BS T240 3 DOF Y/V = -0.301 [V]
BS T240 3 DOF Z/W = -0.46 [V]
HAM8 1 DOF Y/V = -0.503 [V]
HAM8 1 DOF Z/W = -0.821 [V]
All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 1 DOF X/U = -0.091 [V]
ETMX T240 1 DOF Y/V = -0.146 [V]
ETMX T240 1 DOF Z/W = -0.159 [V]
ETMX T240 3 DOF X/U = -0.122 [V]
ETMX T240 3 DOF Y/V = -0.182 [V]
ETMX T240 3 DOF Z/W = -0.153 [V]
ETMY T240 1 DOF X/U = -0.029 [V]
ETMY T240 1 DOF Y/V = 0.131 [V]
ETMY T240 1 DOF Z/W = 0.192 [V]
ETMY T240 2 DOF X/U = -0.118 [V]
ETMY T240 2 DOF Y/V = 0.177 [V]
ETMY T240 2 DOF Z/W = -0.007 [V]
ETMY T240 3 DOF X/U = 0.187 [V]
ETMY T240 3 DOF Y/V = -0.021 [V]
ETMY T240 3 DOF Z/W = 0.078 [V]
ITMX T240 1 DOF Y/V = 0.223 [V]
ITMX T240 2 DOF X/U = 0.128 [V]
ITMX T240 2 DOF Y/V = 0.229 [V]
ITMX T240 2 DOF Z/W = 0.189 [V]
ITMX T240 3 DOF Y/V = 0.078 [V]
ITMX T240 3 DOF Z/W = 0.087 [V]
ITMY T240 1 DOF X/U = 0.022 [V]
ITMY T240 1 DOF Y/V = 0.077 [V]
ITMY T240 1 DOF Z/W = -0.058 [V]
ITMY T240 2 DOF X/U = 0.012 [V]
ITMY T240 2 DOF Y/V = 0.196 [V]
ITMY T240 2 DOF Z/W = 0.074 [V]
ITMY T240 3 DOF Y/V = 0.037 [V]
BS T240 1 DOF X/U = -0.122 [V]
BS T240 1 DOF Z/W = 0.121 [V]
BS T240 2 DOF X/U = 0.037 [V]
BS T240 2 DOF Y/V = 0.122 [V]
BS T240 2 DOF Z/W = 0.013 [V]
BS T240 3 DOF X/U = -0.204 [V]
HAM8 1 DOF X/U = -0.206 [V]
There are 2 STS proof masses out of range ( > 2.0 [V] )!
STS EY DOF X/U = -4.609 [V]
STS EY DOF Z/W = 2.244 [V]
All other proof masses are within range ( < 2.0 [V] ):
STS A DOF X/U = -0.456 [V]
STS A DOF Y/V = -0.864 [V]
STS A DOF Z/W = -0.523 [V]
STS B DOF X/U = 0.179 [V]
STS B DOF Y/V = 0.945 [V]
STS B DOF Z/W = -0.348 [V]
STS C DOF X/U = -0.692 [V]
STS C DOF Y/V = 0.751 [V]
STS C DOF Z/W = 0.533 [V]
STS EX DOF X/U = -0.214 [V]
STS EX DOF Y/V = -0.152 [V]
STS EX DOF Z/W = 0.079 [V]
STS EY DOF Y/V = 1.242 [V]
STS FC DOF X/U = 0.198 [V]
STS FC DOF Y/V = -1.122 [V]
STS FC DOF Z/W = 0.607 [V]
Following instructions from the TakingCalibrationMeasurements wiki, at 18:33 UTC I dropped H1 out of observing to run the usual calibration sweeps. Calibration monitor and report attached.
Broadband - 18:34:20 to 18:39:38 UTC
Simulines - 18:40:57 to 19:04:04 UTC
File written out to: /ligo/groups/cal/H1/measurements/DARMOLG_SS/DARMOLG_SS_20251004T184057Z.hdf5
File written out to: /ligo/groups/cal/H1/measurements/PCALY2DARM_SS/PCALY2DARM_SS_20251004T184057Z.hdf5
File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L1_SS/SUSETMX_L1_SS_20251004T184057Z.hdf5
File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L2_SS/SUSETMX_L2_SS_20251004T184057Z.hdf5
File written out to: /ligo/groups/cal/H1/measurements/SUSETMX_L3_SS/SUSETMX_L3_SS_20251004T184057Z.hdf5
Comparing the broadband from this Saturday to the previous broadband on Sept 27, there has been a significant change in the calibration uncertainty. We know that there was a small change in the overall calibration since the last model push on 8/28, which could be related to the power outage. However, I can't think of any significant change in the last week that could account for this difference.
We do know that:
However, both of those bullet points should be accounted for by the TDCFs.
Sat Oct 04 10:07:34 2025 INFO: Fill completed in 7min 30secs
Today I began calibrating the camera servo signals into spot positions. I ran the A2L script at the nominal camera spot positions. Then, I changed the camera offset and waited for the camera servo to converge. Then I remeasured the A2L gain. Using the a2l_lookup function in /opt/rtcds/userapps/release/isc/common/scripts/decoup/BeamPosition the A2L gain can be converted into a spot position in mm. This is a slow process so it will take time to get the conversions for all.
| Camera offset | A2L gain | Conversion | |
| ETMY Pitch | start: -230, end: -231 | start: 5.62, end: 5.92 |
(-23.2 mm - -21.8 mm)/-1ct = 1.4 mm/ct |
| ITMX Pitch | start: -230, end: -231 | start: -0.45, end: -0.56 |
(6.46 mm - 5.96 mm)/-1ct = -0.5 mm/ct |
I continued today following the same process stated above.
| Camera offset | A2L gain | Conversion | |
| ETMX P | start: -173, end: -172 | start: 3.04, end: 2.92 |
(-9.38 mm - -9.93 mm)/ 1ct = 0.55 mm/ct |
| ETMY Y | start: -349.5, end: -348.5 | start: 1.41, end: 1.06 |
(3.90 mm - 5.18 mm) / 1ct = -1.28 mm/ct |
| ETMX Y | start: -422, end: -421 | start: 4.85, end: 4.68 |
(17.22 mm - 17.84 mm) = -0.62 mm/ct |
I reran the ITMX beam spot calibration following the same method described above, but this time I checked how the beam spot moved on both ITMX and ITMY when I changed the BS camera offset. Turns out, they give the same answer, so that's good.
| Camera Offset | A2L gain | Conversion | |
| ITMX P (ITMY P) | start: -230 ct, end: -231 ct | start: -0.45 (0.19), end: -0.55 (0.09) |
(6.41 mm - 5.96 mm)/-1 ct = -0.45 mm/ct |
| ITMX Y (ITMY Y) | start: -236 ct, end: -237 ct | start: 3.18 (-2.75), end: 3.06 (-2.63) |
(11.26 mm - 11.70 mm)/ -1ct = 0.44 mm/ct (-0.44 mm/ct for ITMY) |
Sheila, Camilla. Saved to camilla.compton/Documents/sqz/templates/dtt/Fringe_wrapping.xml
ZM2,5 Fridge Wrapping with No SQZ light
As Sheila suggested in 86836, the amount of backscatter we are seeing from SQZ should be due to light from the IFO being backscattered rather than any excess SQZ light. To confirm this I took SQZ DOWN, mis- aligned FC, blocked all three SQZ beams on SQZT0 and re-opened the beam-diverter so that the IFO light could get into HAM7 but there was no SQZ generated light. The ZM2 and ZM5 scatter shelves were the same in both this and the nominal SQZ configurations, confirming all backscattered light is coming from the IFO. Plot attached. This plot does show our ZM5 scatter has increased since 2024, ZM2 is the same.
I did the same with the 30Hz injection too, saved to Fringe_wrapping_nosqz.xml, refs 0-8 are no sqz beams, refs 9-17 are nominal FDS. Plot attached, if anything, the shoulders of the 30Hz peak are larger with no sqz beams, so again, there is no difference.
ZM2,5 Fridge Wrapping with Different Alignments on OFI_PD_A
In FRS # 35457 and 87071, we theorized that the backscatter could be off the OFI_PD_A which we shows out beam is clipping, when we change the alignment to this PD using ZM4/5, we change the level of light on OFI_PD_A, showing we are clipping and not centered on the PD, but this also changes the level of SQZ so it's hard to compare. Unsure if there's a real difference, plot attached and ndscope. It's possible that with more light on PD_A (less clipping) there is a more scatter and a secondary ZM5 scatter shelf ~25-40Hz. Would want to repeat or misalign more to confirm.
| References on Fringe_wrapping.xml | No Injection | ZM5 Inj | ZM2 Inj |
| Nominal FDS (ZM5 Yaw -460urad, -4.6dB, OFI_PD_A = 0.031) |
0 | 1,2 | 3,4 |
| No SQZ light, BeamDiv Open to IFO | 5 | 6,7 | 8,9 |
| FDS, ZM5 Yaw -510urad, -3.4dB, OFI_PD_A = 0.024 | 10 | 11,12 | 13,14 |
| FDS, ZM5 Yaw -440urad, -3.4dB, OFI_PD_A = 0.033 | 15 | 16,17 | 18,19 |
Other ideas that haven't been done yet: change the temperature of SFI2 and repeat backscatter measurements, repeat above with increased alignment changes the OFI_PD_A changes.
Elenna realized while I was doing this that we should turn off the 13Hz Roll mode damping before injecting into ZM2/5 as this increased DARM noise might confusing the damping signals.
To turn off the roll mode damping: sitemap > SUS > Bounce Roll > DAMPING Filters. Then turn the gain of the one damping to zero (already should be a 10s Tramp).
