KAGRA Logbook

Reports 1-1 of 1

MIF (ITF Control)

takafumi.ushiba - 20:13 Monday 26 December 2022 (23377)

Strange oscillation of ETMX when FPMI is locked with at OBSEVATION state.

I found strange oscillation happened when FPMI was locked with observation state as like fig1.
As shown in fig2, the oscillation frequency is about 15 Hz.
I'm not sure the reason at this moment, so I will check it tomorrow if possible.

Note:
To keep avoid the oscillation during the obs. state, I changed the guardian not to requst OBSERVATION state to ETMX (L834, L835, L844, and L845 are modified).

Images attached to this report

23377_1672052965_Screenshot from 2022-12-26 20-08-40.png

23377_1672053202_Screenshot from 2022-12-26 20-09-12.png

Comments to this report:

takafumi.ushiba - 10:23 Tuesday 27 December 2022 (23385)

According to Yokozawa-san, he locked FPMI and requested observation state to ETMX guardian but oscillation didn't happen in this morning for about 3 hours.
There seems no difference except for the alignment (he did initial alignment before his work), it might be come from the alignment.
Anyway, I restored the change of LSC_LOCK guardian, so let's see what happens.