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Reports until 17:20, Tuesday 16 May 2023
H1 SQZ (PEM)
camilla.compton@LIGO.ORG - posted 17:20, Tuesday 16 May 2023 - last comment - 18:27, Tuesday 16 May 2023(69671)
SQZT0, Increased SHG input power and moved temp IR PD

Naoki, Vicky, Camilla  

At the end of maintainance:

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victoriaa.xu@LIGO.ORG - 18:27, Tuesday 16 May 2023 (69673)

Some interesting trends to see what SHG output is sensitive to, knowing that SQZT0 hasn't fully theramlized yet after just 30 minutes of closing up. So far, I tried things with marginal gains like pico-ing the input IR alignment (marginal gain), tweaking SHG CMB servo gain (marginal, but bad if too high > -9), SHG TEC temperature (marginal gain, original setting was pretty close), as well as things which surpringly had an effect like changing the SHG common servo offset. We can get to higher NLGs now, and will work on this soon, in coordination with PEM work.

In addition, the opo pump aom's diffraction efficiency is still reasonbly good, see trends from varying the pump power. With no diffraction, there's about 21mW through the AOM 0-order (which goes to the OPO). With full diffraction drive, there's ~8mW in the 0-order which is dumped. This is like (21-8)/21 ~ 62% diffraction efficiency of the pump aom, so PUMP ISS should have sufficient range.

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