Starting RH changes at 19:35UTC, turned up ITM RHs +0.1W and down ETM RHs -0.1W. Plots of DARM and HOM after 2 hours attached and ndscope trend. High frequency noise increased and the HOM moved higher in frequency. Circulating powers increased. After 3 hours at 22:35UTC I turned RHs back to nominal.
During this time Robert was doing some PEM injections and we had been locked at NLN for 5 hours so weren't completely thermalized at the start.
I added a 6600 to 6800Hz BLRM as H1:OAF-RANGE_RLP_8 to monitor high frequency noise, see attached, didn't prove very useful. H1:SQZ-DCPD_RATIO_6_DB shows trend better.
| Nominal (W/segment) | Test Values 19:35 to 22:35UTC | |
| ITMX | 0.44 | 0.54 |
| ITMY | 0.0 | 0.1 |
| ETMX | 1.0 | 0.9 |
| ETMY | 1.0 | 0.9 |
Last weeks test 73093. Future tests: Can't go the other direction as ITMY started with 0W RH. Could try commonly turning up just ETMs in a future while observing test as we had decreased high frequency noise with both ETM RHs ~1.4W/seg in February 67501, plot attached.
Updated plot showing thermalization back to nominal RH settings attached. Main changes were higher circulating power and more high frequency noise during the test.
