Eric, Sheila, Jennie, Naoki, Camilla
Aiming to repeat 68814 O4a FIS SQZ, SCRL offset data set. Nominal H1:LSC-SRCL1_OFFSET = -175, previously looked at in 74373.
Using data from our PSAMS scan 76986, we're set ZM4 to 8.8V (175 offset), leaving ZM5 with -0/7V (100 offset). Reran alignment scripts following 76986. Accepted PSAMs sdf, and alignment sliders.
For FIS took SQZ_MANGER to AUTO to stop ISC_LOCK bringing it to FDS.
PSAMs at 8.8/-0.7
- 15:23:30 - 15:42:00UTC No SQZ time
- 16:04:45 - 16:10:00UTC FDS SQZ
- 16:13:00 - 16:21:30UTC FIS SRCL1_OFFSET -175, SCAN_SQZANG tuned to 350Hz: 193deg CLF Phase
- 16:30:20 - 16:36:00UTC FIS SRCL1_OFFSET -225, hand tuned SQZ angle to 2kHz: 208deg CLF Phase
- 16:39:00 - 16:45:00UTC FIS SRCL1_OFFSET -275, hand tuned SQZ angle to 2kHz: 212deg CLF Phase
- 16:49:00 - 16:54:30UTC FIS SRCL1_OFFSET -325, hand tuned SQZ angle to 2kHz: 217deg CLF Phase
- 16:57:30 - 17:04:00UTC FIS SRCL1_OFFSET -375, hand tuned SQZ angle to 2kHz: 223deg CLF Phase
- 17:07:00 - 17:12:30UTC FIS SRCL1_OFFSET -425, hand tuned SQZ angle to 2kHz: 228deg CLF Phase
- 17:13:10 - 17:18:30UTC No SQZ time (to check for SRCL offset causing technical noise but DARM looks the same as previous)
- 17:25:30 - 17:31:30UTC FIS SRCL1_OFFSET -175, hand tuned SQZ angle to 2kHz: 192deg CLF Phase
- 17:35:00 - 17:41:00UTC FIS SRCL1_OFFSET -125, hand tuned SQZ angle to 2kHz: 186deg CLF Phase
- 17:43:00 - 17:48:30UTC FIS SRCL1_OFFSET -75, hand tuned SQZ angle to 2kHz: 168deg CLF Phase
Data with different angles (+/-10deg from SQZ and ASQZ, and +/- midsqz aimed to match no SQZ level) with SRCL1_OFFSET -175. Plot attached.
- 17:59:30 - 18:04:30UTC FIS SRCL1_OFFSET -175, 192deg CLF Phase
- 18:05:30 - 18:10:30UTC FIS SRCL1_OFFSET -175, 182deg CLF Phase
- 18:11:20 - 18:16:30UTC FIS SRCL1_OFFSET -175, 202deg CLF Phase
- 18:18:30 - 18:23:30UTC FIAS SRCL1_OFFSET -175, (neg sign) 108deg CLF Phase
- 18:24:35 - 18:29:40UTC FIAS SRCL1_OFFSET -175, (neg sign) 98deg CLF Phase
- 18:30:00 - 18:35:00UTC FIAS SRCL1_OFFSET -175, (neg sign) 118deg CLF Phase
- 18:41:00 - 18:46:00UTC FIMS SRCL1_OFFSET -175, 140deg CLF Phase (-Mid SQZ aimed to match no SQZ level)
- 18:55:00 - 19:00:00UTC FIMS SRCL1_OFFSET -175, 220deg CLF Phase (+Mid SQZ aimed to match no SQZ level)
Data with different angles (+/-10deg from SQZ and ASQZ) with SRCL1_OFFSET -275.
- 19:10:30 - 19:15:30UTC FIS SRCL1_OFFSET -275, 207deg CLF Phase
- 19:16:00 - 19:21:00UTC FIS SRCL1_OFFSET -275, 197deg CLF Phase
- 19:21:30 - 19:24:00 [glitch] 19:24:35 - 19:27:40UTC FIS SRCL1_OFFSET -275, 217deg CLF Phase
- Lockloss before completing data set
Additional plots for data above:
- SRCL_TUNE_FIS_2.png: This shows how FIS changes as a function of SRCL detuning (-175 is our current nominal value). We see that when increasing the SRCL detuning, we initially see significant improvement at lower frequencies with a slight rise in midband.
- SRCL_TUNE_FIS_3.png: This shows how FIS changes as we change the SRCL detuning in the other direction. Everythihng appears to get worse.
Note: As a sanity check, we took another NoSQZ trace at H1:LSC-SRCL1_OFFSET = -= -425 and saw that it looked idential to NoSQZ at H1:LSC-SRCL1_OFFSET = -175.
After looking at this scan, we were wondering if H1:LSC-SRCL1_OFFSET = -275 might be a more optimal operating point than H1:LSC-SRCL1_OFFSET = -175. We decided to do a few more FIS measurements at the two candidate operating points:
- FIS_SRCL_neg175.png (Attached above in Camilla's post): shows FIS, FIAS and FIMid Squeezing and nearby squeezing angles for a H1:LSC-SRCL1_OFFSET = -175
- VARY_SQZANG_SRCL_275 shows FIS and +/- 10 degrees for H1:LSC-SRCL1_OFFSET = -275. Unfortunately we lost lock before taking the remaining points.
After rethermalizing, we plan to look at FDS at H1:LSC-SRCL1_OFFSET = -275 and perhaps tweak the filter cavity a bit to see if this SRCL detuning is better or worse in terms of range.
An alternate version of one of the plot from the original post. A few intetrmediate traces are removed and replaced w reference FDS and No SQZ traces.
