Reports until 11:06, Tuesday 19 August 2025
H1 SUS
oli.patane@LIGO.ORG - posted 11:06, Tuesday 19 August 2025 (86446)
Apparent alignment shift in PR3 due to OSEM calibration update

Like we did with SR3 (86070), I've updated the OSEM calibration for PR3. The updated OSEMINF values, along with the compensation gains that get put into the DAMP filter bank were calculated and put in (86222). Today I updated the PR3 OSEMINF gains and put the compensation gains into FM7 in the DAMP filter bank and turned them on. I've accepted these in the safe sdf.

The update to the OSEMINF calibration means that it will look like there is a change in alignment for PR3, but this is not real. Here is what the alignment change looks like: ndscope. These changes were made at 2025-08-19 16:27:57 UTC

OSEMINF changes

OSEM Old OSEMINF gain New OSEMINF gain
T1 1.161 2.055
T2 0.998 1.544
T3 1.047 1.511
LF 1.171 1.862
RT 1.163 2.063
SD 1.062 1.639

The compensation gains put in in the DAMP filter bank are in FM7, and they are the following:

L: 0.596
T: 0.648
V: 0.617
R: 0.617
P: 0.670
Y: 0.596

Images attached to this report