Reports until 14:49, Friday 29 September 2023
H1 TCS (ISC)
camilla.compton@LIGO.ORG - posted 14:49, Friday 29 September 2023 (73093)
TCS ETM Ring Heater 2-hour Change

After LLO's 67058 ring heater tests, we adjusted our ETM RHs, hoping to reduce our high frequency noise that LLO induced during their test.

We adjusted ETMX up from 0.9W to 1.1W and ETMY down from 1.0W to 0.9W/segment 19:02 to 21:05UTC.

No big changes seen, our range, circulating power and squeezing got worse and kappa_c slightly increased, plotted attached. No visible change in DARM. Our HOM peaks moved slightly towards each other as expected. We lost lock before we thermalized back to nominal RH powers and could check that the offloading of SQZ pointing Naoki was doing ( 73171) didn't have an effect on the IFO.

Interesting is that with our best low frequency noise in end of march 68491, our circulating powers with 60W input in were actually lowest they have been. Plot attached.

Images attached to this report