ryan.short@LIGO.ORG - posted 15:47, Thursday 22 June 2023 - last comment - 09:46, Friday 23 June 2023(70739)
ISS Second Loop Gain Updated Following Power-down to 60W
R. Short, J. Driggers
Daniel had noticed that the ISS secondloop gain had been set back to -5 dB when the IFO relocked to 60W last night. Since we now want this at -2 dB in our 60W configuration (alog 70684), I've updated the ISS_acquisition_gain in lscparams.py to be -2 and committed to svn. While we were out of Observing this afternoon starting at 22:45 UTC, I changed the gain to -2 dB, accepted the change in SDF, and reloaded the IMC_LOCK guardian.
This usually doesn't work without adjusting the input offset. Also, you would want to test this with the IMC alone, since the AC-coupling is finicky. On the other hand, changing the gain after the servo is engaged is trivial.