camilla.compton@LIGO.ORG - posted 12:04, Friday 13 October 2023 - last comment - 11:51, Thursday 09 November 2023(73445)
ETM RHs turned up 0.1W at 19:03UTC.
Both ETM RH turned up from 1.0W to 1.1W/segment at 19:03UTC, plan to increase another 0.1W later this afternoon. Follow on from 73437. Will stay in observing during this test.
Made another step up of +0.1W to 1.2W/Segment on ETMX and ETMY at 21:07UTC.
Plots attached of HOM, DARM and ndscopes. Jenne pointed out we should use GDS-CALIB for DARM as it isn't effected bt the calibration changing with the RH changes. On ndscopes, not that at -4hours theres a step in SQZ that effects the range 73446.
High frequency noise reduce, DARM maybe better in in the bucket but circulating power down 7kW and Kappa_C down 0.8%.
This doesn't seem to be doing anything bad to the range so we can leave the ETM Ring Heaters in this 1.2W setting for the weekend. If Operators have any troubles, they can reduce H1:TCS-{ETMY,ETMY}_RH_SET{UPPER,LOWER}POWER from 1.2W to 1.0W.
Adding plots of 11:00UTC,13h30 after ETM RH change. DARM ~1000Hz looks like it thermalized worse than 2 hours after the RH change. 6kHz DARM continued to reduce, but it started that lock particularly high. Circulating power settled at 367kW, 7kW less than nominal. KAPPA_C dropped nearly 1%.
These RH changes were reverted 16 October 2023 73503.