Reports until 12:31, Friday 23 August 2024
H1 ISC
elenna.capote@LIGO.ORG - posted 12:31, Friday 23 August 2024 - last comment - 16:04, Friday 23 August 2024(79664)
Reducing time in lock acquisition

I am taking another look at what steps in lock acquisition take a very long time. See Georgia's previous alog on this: 76398

I noticed some of the power up steps seem to take longer than they should. I found some timers that are longer than necessary, so I am shortening them.

Just a note about many of the longer waits and tight convergence thresholds: powering up to 75 W was sometimes a very shaky process that required a much tighter convergence in the soft loops, otherwise runaway instabilities would often cause locklosses. We have previously relaxed some of these tight constraints to speed up lock but we didn't catch them all. This should take care of more of them (but maybe not all).

Comments related to this report
elenna.capote@LIGO.ORG - 16:04, Friday 23 August 2024 (79671)

I shortened lownoise ASC further. All the ASC loop changes happen in one step. The damping loops happen in two separate steps-- the combination of the damping loops the last time we made changes to this state caused problems so those still need to be separate.

This changed caused a lockloss. I have reverted the guardian code to break up these steps.