Ryan S, Camilla. Followed 90783.
ZM4 and ZM5 PSAMS were set at 100V, strain gauges for ZM4 0.4V and ZM5 -4.5V. I turned on the servos.
Dither locked the OPO with 75mW SEED power. Had 1.1mW on SQZT7 IR PD.
Set ASC back to settings as in 90742.
When we opened the beam diverter, we could not see the SQZ beam, tried moving SRM back to alignment as in vent. Turned out Travis still needed to open a Relay tube GV, after the gate value was opened, we saw the SQZ beam and reverted SRM to nominal.
Needed to reduce H1:SQZ-ASC_TRIGGER_THRESH_ON to get the sQZ ASC to turn on. Turning on SQZ ASC dropped all powers, attached, so we must be clipping. Turned off ASC and cleared SUS histories.
Ryan then did a walk of ZM5 for AS_C and ZM6 for AS_A. Once we were closer, we turned on the SQZ ASC and it worked. We put in the H1:OMC-ASC_QPD_A/B_PIT/YAW_OFFSET we had in 91371. The OMC ASC went to these values when turned on.
We then turned off ASCs and ran /sqz/h1/Templates/dtt/OMC_SCANS/Sept25_2026_OMC_scan.xml (after taking H1:OMC-PZT2_OFFSET to -50). We got 00 peaks of max height 0.5V whereas before Sheila got 0.6V 90783, we are not sure why, the SEED power injected is the same. Initially had asymmetric peaks, checked whitening as in 90612, adjusted H1:OMC-DCPD_{A,B}_GAINSET to be HIGH. Peaks were then symmetric, we followed 91371 to lock OMC and tweak OM3 and OMC to slightly improve TEM00 mode. Our misalignment peak to was then ~1%, plot.
Ryan checked the ZM4 and ZM5 strain gauge ranges (from 5V to 195V avoiding 0 and 200V edges):
| Strain Gauge Reading | ||
| 5V on PZT | 195V on PZT | |
| ZM4 | -3.9V | 3.2V |
| ZM5 | -9.5V | -1.2V |
Ryan then adjusted 4x4 grid of PSAMS settings and ran: /ligo/gitcommon/squeezing/sqzutils/omc_scans_psams/ham7_psams_sweeo_QPD_centering.py
The data looked good with misalignments <1.5% and the best mismatch <1%. Plot attached. The analysis may need some tweaking by Sheila, the misalignment peak was not identified in all scans so I did not include it in the total of some to give us the mismatch values, edit attached.
We reran the OMC scans, zoomed in around our best area, results attached.
