thomas.shaffer@LIGO.ORG - posted 12:24, Thursday 19 September 2024 - last comment - 12:32, Thursday 19 September 2024(80186)
Ops Day Mid-Shift Report
Commissioning is complete and we have relocked. Observing at 1923UTC
SQZ ADS dithers are now OFF during observing. See SDFs accepted - the ADS dither gains are set to 0 (so it is off), and the ASC gains and sensing matrix have bene reverted to the previous settings for AS42 ASC.
This should resolve the dithers being accidentally left on the past few days, see Sheila lho80185.
We lost lock during commissioning because of a big (100 cts) PIT step of ZM4, when it's TRAMP = 0.1. That TRAMP being too short was due to a guardian setting bug during SCAN_ALIGNMENT, which is now fixed. We tried the big ZM4 step in an attempt to re-measure the AS42 sensing matrix using ZM4 instead of ZM5, since the ZM5 steps gave very small changes in AS42 WFS with significant P/Y coupling. Measuring the AS42 sensing matrix with ZM4+6 might be worth trying again in the future (especially - check that ZM4 slider TRAMPS are >1 second).
The TRAMPs for ZM4,5,6 slider offsets are all set to 3 seconds now, and that has also been saved in SDF.