Reports until 05:23, Sunday 24 November 2024
H1 General (SQZ)
thomas.shaffer@LIGO.ORG - posted 05:23, Sunday 24 November 2024 - last comment - 08:12, Sunday 24 November 2024(81442)
Ops Owl Update

The SQZ OPO is struggling to stay locked. We've dropped Observing 7x so far in the last hour. So far it has been able to recover itself, but now it seems to be struggling. If it can't recover itself soon, I'll be calling for help.

On the bright side, H1 has been locked for over 13 hours.

Comments related to this report
thomas.shaffer@LIGO.ORG - 06:36, Sunday 24 November 2024 (81443)

Looks like the SQZ sorted itself out out at 1422 and has stayed locked for 15 min so far.

victoriaa.xu@LIGO.ORG - 08:12, Sunday 24 November 2024 (81446)SQZ

Since IFO was down, I tried to fix this. SHG output power dropped >30% overnight, and ISS ran out of range trying to follow (so not necessarily a pump iss alignment problem). See trends in first attachment.

1) I turned the pico-waveplate before the ISS AOM to sent more power to the fiber (aka reject less green power). This pico worked.

2) Adjusted SHG temperature from 35.95 C --> 35.3 C to optimize output green power, which is a surprisingly big move. See second attachment of trends to optimize temperature. Not sure why the setpoint temperature changed so much, and I wonder if it will change back to "normal" later.

Conservatively, even though 35.3 C was best for SHG green power, I set the SHG TEC setpoint inbetween at 35.5 C, and accepted this in SDF.

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