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Reports until 14:48, Tuesday 07 April 2026
H1 SUS (SUS)
ryan.crouch@LIGO.ORG - posted 14:48, Tuesday 07 April 2026 - last comment - 13:31, Friday 10 April 2026(89809)
OPLEV charge measurements, ETMX, ETMY

We ran the OPLEV charge measurements this afternoon. We had a env / package issue trying to start the script, it was complaining about the scipy sin function, I ended up changing from the default cds env to the aligoNB using "conda activate aligoNB" after doing a pip env search to find which environment had the needed packages, I still had scipy sin issues but they were depreciation warnings. To fix this script we may be to rewrite the scipy parts with numpy. The End Stations SEI configuration was ISI_DAMPED_HEPI_OFFLINE. This was a pretty good measurement unlike a few of the previous ones, I didn't get any saturations on either QUAD and the coherence was pretty good.

ETMY's charge is a little high (above 50 on half of the plots) but it is trending to zero or is mostly static near zero (UR P).

ETMX's charge is high (above 50 on all but 2/8 plots but not quite at 100) and is trending away from zero, increasing. The ETMX_L3_LOCK_BIAS_OFFSET value has been at its "unlocked" value of -8.9 during the break, it flips to ~+6 when we are in full lock.

We are still fully processing and thinking about the results, more to come.

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rahul.kumar@LIGO.ORG - 14:53, Tuesday 07 April 2026 (89811)SUS

Our plan is to it to switch the sign and take another measurement this week (and then once every week now) to see if that is helping ETMX or not. 

Will be posting the bias sign and values once we have settled with one which works.

rahul.kumar@LIGO.ORG - 13:31, Friday 10 April 2026 (89858)

Sheila, Rahul

Since charge for EY is trending down, hence will switch off (digitally) HV for this one.

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