Reports until 19:22, Sunday 31 July 2016
H1 ISC
stefan.ballmer@LIGO.ORG - posted 19:22, Sunday 31 July 2016 (28763)
Test mass ASC offloading x-over at 0.1Hz

Sheila, Stefan

Based on yesterday's measurement, the ASC PUM to TOP x-over was at 0.002Hz and 0.0029Hz (before the 10dB increase in the script).

I added gains of 50 for pitch and 34.5 (for now in the L1_LOCK modules) to move this x-over to 0.1Hz.

The only loops for which this 0.1Hz offload is critical are the soft loops. Thuis I added z=0.01Hz:p=0.1Hz lead filters to all soft loops. I also turned the soft loop bandwidth up by 3x.

The guardian now sets those gains before turning on the soft loops - and sets them back in the down state.

We still should do some more loop tuning for the soft loops - their response should be sped up

We got to 50W - but lost it when moving the PRM - the soft loops seem to be still too slow to follow, resulting in the Izumi-Ballmer instablility.