Reports until 18:18, Monday 07 January 2019
H1 ISC (GRD)
sheila.dwyer@LIGO.ORG - posted 18:18, Monday 07 January 2019 (46272)
changes to ASC engaging for dithers

Jenne, Craig, Georgia, Sheila, Kara

We had a couple of locklosses this afternoon when the dither/soft loops were engaging.  We have made some changes in the guardian that we think will help prevent this in the future.

We see that spot positions on the TR QPDs are rather different now than they were before the dither loops were commissioned (attachment), especially the Y B QPD.  We would like to try moving these spots while in low noise to see if we can reduce the fringe wrapping we are seeing, but in the past we have difficulty moving our spots after powering up because of the dP/d angle instability.  Georgia is trying right now to move the spot while we are at 2W to be more similar to the old spot. 

Images attached to this report