Sheila, Kiwmau, Jenne
Once the IFO relocked after our unexplained alignment change, we did a few quick tests. We opened and closed shutters on the DBB, and looked for coherence between DARM and the rack power monitor that we set up yesterday. The DARM noise no longer changes with the state of the DBB shutters, this may be due to the alingment and TCS changes that got rid of our lump in DARM (even at 50W), or due to the PMC realingment that reduced the PMC HV noise in DARM.
However, there is non neglible coherence between the rack power monitor and DARM, from about 320 to 380 Hz. The spectrum of the rack voltage isn't especially noisy at these frequencies.
An attempt to re-measure the PMC HV noise broke the lock when I enabled the excitation.
For Jenne:
Injection for iterative tuning of SRCLFF: started at 8:08:33, went until 8:11:00 UTC on October 27th.
Is this 19V power that only PSL uses?