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Reports until 10:15, Saturday 27 May 2023
H1 SQZ
victoriaa.xu@LIGO.ORG - posted 10:15, Saturday 27 May 2023 - last comment - 22:53, Tuesday 30 May 2023(69965)
Lowered FC ASC trigger threshold, reset pump iss

I lowered the FC-ASC TRIGGER THRESHOLD's ON value from 0.8 to now 0.7, since it hadn't been triggering on during Friday's locks (trends). I noticed because the green beam spot on the FC green trans camera was clearly off from normal. This FC trans trigger was first setup in LHO:68587, where it said the trigger_on threshold was 0.6 -- but it was 0.6 for < 24 hours, then changed to 0.8, where it's been since. I have SDF'd the trigger_on threshold as 0.7.

Also, ISS tripped off again, so I reset it. From the SQZ_OPO_LR guardian, I requested "LOCKED_CLF_DUAL_NO_ISS" (which turns off ISS and resets lockloss counter), then requested "LOCKED_CLF_DUAL", so the guardian turns on ISS again. Sheila just did this a couple days ago 69890, but I didn't change the ISS setpoint this time. I think this is happening related to SHG output power drifts, we could check the on-table pump aom alignment. We shouldn't be driving the aom this marginally given the SHG power output and ISS setpoint, we used to be driving ~4-6V to maintain this trans power given even lower SHG output powers, and now we're driving often around 2-4V, so ISS is often in a marginal wayn now compared to before.

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camilla.compton@LIGO.ORG - 22:53, Tuesday 30 May 2023 (70031)

At the start of the 05:07UTC lock, Vicky realized the FC beamspot was not in the correct location on the camera so lowered FC_ASC the threshold further from 0.7 to 0.5. Accepted in sdf.

We decreased the OPO TEC temperature while maximizing CLF_REFL_RF6, see attached. We expect this needs changing more with the LVEA temperature fluctuations. Vicky noticed this needed to be done as WFS_A_Q wasn't low enough and RFL_QPD_A_SUM was lower than normal. See attached SQZ scopes at time of FC ASC turn on and OPO temperature improvement.

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