Reports until 09:28, Thursday 25 July 2019
H1 ISC
georgia.mansell@LIGO.ORG - posted 09:28, Thursday 25 July 2019 - last comment - 09:58, Thursday 25 July 2019(50810)
Possible problem: Falling off QPDs again

Maybe someone has already looked into this but one of the first things we do in the INCREASE_POWER state is add an offset to TMS_X in pitch, to recenter the beam on the transmon QPDs

I had a look at one of the locklosses, and it looks like maybe the offset is too much, and when we turn it on we are falling off the transmon QPDs (see bottom plot of the attachment). I can have a look at other locklosses and see if that is not a fluke but maybe something to try, if it hasn't been done already, is to reduce this offset by ~ half?

Images attached to this report
Comments related to this report
jeffrey.kissel@LIGO.ORG - 09:49, Thursday 25 July 2019 (50813)
THAT WAS IT!

More details to come...
georgia.mansell@LIGO.ORG - 09:58, Thursday 25 July 2019 (50814)

Whew!! yesyesyes

 

(The long term solution to this problem is to pico on the transmon so we don't have these sneaky hidden offsets in guardian)