Reports until 03:22, Friday 30 September 2016
H1 ISC
stefan.ballmer@LIGO.ORG - posted 03:22, Friday 30 September 2016 (30080)
Tonights work

- Tried switching the guardian back to using REFL WFS instead of POPX WFS for PRC2. This is simply a boolean variable change in lscparams.py: use_popx_wfs = 0. We also updated the the beam diverter closing state to also use the same boolean variable.

- However, we need to retune the REFL WFS at the new modulation index - we saw the loop run away in Nominal Low Noise,

- We also tried to repeat the jitter coupling reduction with INP1 offsets. While the transfer function again was reduced, the ASC loops were having problems with the large offset - we saw CSOFT ring up at 1Hz. Also there was a 3Hzish signal visible in CHARD and CSOFT. So much for reproducability...

- Next we also tried a CHARD YAW offset. Indeed -3500ct in CHARD YAW started bringing down the IM4 YAW jitter coupling. As suspected this probably means we simply cancel an unknow coupling with a deliberate misalignment induced coupling.