Peter, Anamaria
We swept the MICH and SRCL loops at 50W input power, and then cross-checked the calibrations in CAL-CS. They were close, a small adjustment was made in the ERR filter bank. PRCL still to be done, but likely less important to DARM. Perhaps the PRCL subtraction matrix element for SRCL should be rechecked (it can change with different buildups, etc).
MICH UGF is 9.5 Hz, so CAL CS MICH ERR gain should be 1.15;
SRCL UGF is 20 Hz, so CAL CS SRCL ERR gain should be 1.075.
I forgot to save them in SDF.
Dtt templates are in userapps directory lsc/h1/scripts/ with today's date in the file name.
We found some inconsistencies in the the SRCL CTRL that are still to be resolved, in that the drive is way too large for what the filter and signal chain appears to be. We will continue the investigation later.
After damping sufficiently the rms dominating violin mode19, we were able to power up all the way from 30 to 50W and get to low noise, where it was left undisturbed for the night.
My curiosity got the best of me: The full location and name for these MICH and SRCL open loop gain TFs lives here /opt/rtcds/userapps/release/lsc/h1/scripts/ 221118_Mich50W.xml 221118_Srcl50W.xml (I'll leave it for others to manage, but these have not been committed to this location.) I attach screenshots of the open loop gain TFs as well as the loop suppression, since the phase margins were at best 30 deg (SRCL) and not so great ~25 deg (MICH). Turns out that even with this little phase margin, the loop suppression remains below 3.0.The changes were confirmed in SDF.