Reports until 12:06, Tuesday 09 September 2025
H1 SUS (SUS)
ryan.crouch@LIGO.ORG - posted 12:06, Tuesday 09 September 2025 (86806)
ETMX OPLEV charge measurement

I was getting lots of overflows when I started the measurement, I tried lower the drive_amp by 20% and retrying. This didn't work, I went from the usual 11000 down to under 100 and still saw lots of overflows. Rahul suggested to halve the gain of the ESD output filters with the original 11000 drive_amp, from 1.0 to 0.5 and this stopped all the overflows during the measurements. I got a few thousand overflows when the script ended and was restoring settings though.

This measurement like previous recent ones (since the ESD bias voltage increase?) has very large errors, there wasn't any work going on at EX and the wind wasn't too bad, gusting up to 20mph.

Despite the huge error bars the charge generally seems lower than the last measument in most quadrants/dofs.

Images attached to this report