J. Kissel

Following up on all the work from yesterday replacing the V2 OSEM on H1SUS OPO (ID of problem: LHO aLOG 41468, Replacement LHO aLOG 41470), I've had a bit of time between HAM6 SQZ Team Closeout Activity to grab a set of undamped Euler basis TFs.

Attached are the results.

One can see -- especially in pitch -- that swapping the V2 OSEM has moved out the PD-to-Coil cross-coupling zero to the typical ~10 Hz, and fixed the problem.

The TFs are pretty noisy, but not unexpectedly so: while the ISI was unlocked, the chamber was still half-open letting in SQZ light, so I expect purge was still flowing heavily over the OPOS.

I'd like to get
    - A Repeat of the Euler basis TFs,
    - OSEM basis TFs,
    - Damped TFs,
one morning when we have the chamber door parachutes completely closed, and pulled away from the ISI (as was true for the 2018-04-02 data).