KAGRA Logbook

VIS (EY)

masahide.tamaki - 6:23 Tuesday 08 November 2022 (22824)

Type-A control update (ETMY MN P)

I made OBS filter (ETMY MN OLDAMP P FM2).
► I Applied 4-oder eliptic filter from 0.4 Hz.
► Notches were put in against the peaks (around 0.37 Hz, 0.62 Hz, 0.99 Hz).
► Control was chaged as shown in Fig1 → Fig2 (UGF changed 0.0614 Hz → 0.175 Hz).

As for 0.85 Hz peak, I made DAMP filter in ETMY MN MNOLDAMP filter bank.
► I measured TF from ETMY_MN_TEST_P_IN2 to ETMY_MN_MNOLDAMP_P_IN1_DQ (.xml file is in /users/tamaki/low_noise/ETMY) and made SUSMod (Fig3).
► I have implemented DAMP filter (FM3) and notch filter(FM6) (Fig4).

I updated Guardian.
► {'MN_OLDAMP_P':(['FM2'], True)} was added to {ITMX 'ENGAGE_LOWNOISE_CTRL'} part in NEW_paramsA.py.
► Comment out mark before {'MN_MNOLDAMP_P' : (['GAIN', -1.0, 3.0], True)} in same part was removed.

I could only get about 20 minutes to LSC/CAL work, so I will check the stability in a little longer time scale (So far, it's been okay).

Images attached to this report

22824_1667854373_Screenshot from 2022-11-08 05-49-19.png

22824_1667854377_Screenshot from 2022-11-08 05-45-35.png

22824_1667855231_Screenshot from 2022-11-08 06-06-35.png

22824_1667855347_Screenshot from 2022-11-08 06-06-58.png

Comments to this report:

masahide.tamaki - 8:05 Tuesday 08 November 2022 (22827)

It oscillates at 0.8639 Hz, so there must be a problem somewhere.
I will fix it tonight.
(You may request Observation state since the relevant section in the Guardian has been commented out.)

Images attached to this comment

22827_1667862213_Screenshot from 2022-11-08 08-01-49.png

22827_1667862216_Screenshot from 2022-11-08 08-01-13.png

masahide.tamaki - 16:33 Saturday 12 November 2022 (22895)

I really wondered why this control was not working, I tried various thing, but all to no avail.
However, I stupidly forgot to turn on K1:VISETMY_MN_MNOLDAMP_P_SW2 (i.e. damping filter I put in MN OpLev filterbank was meaningless) (Fig1).
Once I realized that, the problem was solved in an instant.

(A small change, but I increased the gain of the damping filter in the MN OpLev by 5 dB. (Fig2))

Anyway, now the OBSERVATION mode lasts over 30 mins without oscillation (Fig3).

I will do noise budget and post about it tomorrow (maybe).

Images attached to this comment