camilla.compton@LIGO.ORG - posted 14:18, Thursday 20 April 2023 - last comment - 09:49, Friday 21 April 2023(68875)
Increased EY Ring heater 0.1W so that ETMX RH at 1.3 W and ETMY RH at 1.2 W.
Increased EY Ring heater 0.1W so that ETMX RH at 1.3 W and ETMY RH at 1.2 W. This is after ~24 hours with settings ETMX RH at 1.3 W and ETMY RH at 1.1 W. See Elenna's alog 68842.
Using thermalized data (6hr30m after NLN), I compared the ETMY RH 1.0W to 1.1W settings. EX RH at 1.3W for both and CO2s both at 1.7W.
2023 Apr 16 10:44:22 UTC
The high frequency noise plots traces with squeezing are the same times (PURPLE, GREEN), without squeezing are different times: for LIME GREEN 20/04, in the same lock just 3 hours before, for PINK 15/04 was 1day 9 hours before purple, with the same thermal settings but ETMY was reduced from 1.1W only 4 hours before.
These hint that the high frequency noise is getting worse but are less trustworthy than Elenna's frequency noise injection plots (alog 68860) as we don't know if the exact squeezing state and the DARM calibration changed between the two times. We didn't do a frequency noise injection plot with the 1.0W, 1.3W settings and 75W PSL input. We will wait for the IFO to thermalize with these 1.3, 1.2W RH settings are re-take the injections.
This move improved our frequency noise further.
And moved the lower mode-separation peak lower in frequency. See attached. Purple and green traces are the same locks as above plot but only 3h30 into the locks. Nothing else is changed, this was before the SR3 change.