KAGRA Logbook

CAL (General)

darkhan.tuyenbayev - 15:02 Tuesday 07 April 2020 (14021)

DARM transfer function measurements April 7

YamamotoT, Darkhan

We took a set of "weekly" DARM transfer function measurements on the April 7 (morning).

The set of measurements include:

Step 8: DARM OL TF (with both ETMX and ETMY actuators),
Step 9: DARM with PCALX
Step 10: DARM with ETMX
Step 11: DARM with ETMY
Step 12: DARM with PCALY
Step 13: PCALX OFS open-loop TF

All measurements were taken during a single lock stretch of the interferometer.

On steps 9 and 12 reduced both of the Pcal excitations to 3 Vp to reduce chances of lock loss (our first attempt at Step 9 resulted in lock loss when exciting w/ PCALX at around 1 kHz). DARM lock was lost during Step 13, we believe that this lock loss was not caused by the PCALX measurement because the excitation level for this measurement was only 0.02 Vp, which is 1/100 of normal PCAL TF measurements.

The measurements were saved in:

CAL/current/measurements/weekly/2020/04-07

Images attached to this report

Comments to this report:

yuki.inoue - 16:49 Tuesday 07 April 2020 (14023)

Member: Yuki

The estimated parameters are followings:

Hx=( 4.6540392623763 pm 0.03648068596648561 )x1e-12
Hy=( 4.02311196507028 pm 0.030453634607333604 )x1e-12
tau_ax=( 12.389945826930383 pm 1.931409586806943 )x1e-6
tau_ay=( 11.222519904792978 pm 2.1027147133617587 )x1e-6
Hc=( 0.2166946103962428 pm 0.005590270922039493 )x1e8
fcc=( 22.575454402768454 pm 0.39237048337550345 )
tau_c=( -40.79154603879509 pm 4.89177030720717 )x1e-6

takahiro.yamamoto - 18:23 Tuesday 07 April 2020 (14026)

This is the quick check of online calibration.
UGF is around 70Hz
Consistency of C00_STRAIN and H_err is within 5% in gain and 3deg. in phase in the range of the target frequency (30-1500Hz)

Images attached to this comment

yuki.inoue - 10:14 Wednesday 08 April 2020 (14037)

Member: Yuki and Takahiro
We updated the parameters by replacing the Trans comp filter.

Hx=( 4.656490188294972 pm 0.030713099239283195 )x1e-12
Hy=( 4.026427682080395 pm 0.024961137039447488 )x1e-12
tau_ax=( 11.139905933469702 pm 1.9333971140709563 )x1e-6
tau_ay=( 9.893051071603125 pm 2.0255092342030174 )x1e-6
Hc=( 0.06210972131797969 pm 0.0014651839346088089 )x1e8
fcc=( 21.14772475402097 pm 0.39746326908662566 )
tau_c=( -39.31445087696091 pm 4.637879163199134 )x1e-6