KAGRA Logbook

Reports 1-1 of 1

VIS (IX)

takafumi.ushiba - 15:43 Saturday 10 July 2021 (17468)

MNH1 actuator of ITMX seems to have an issue.

I tried to perform the coil blancing of ITMX and found that MNH1 actuator efficiency is so small compaired to H2 an H3 coils.
I checked the TF measured by Miyo-kun on 2 of July and found that the actuator efficiency has already been strange at that time (fig1).

I tried to look for the much older TF but I coudn't because I don't know well about which directory stores the old TF measurement result.
Anyway, I will investigate it on Monday.

Images attached to this report

17468_1625899344_PLANT_HDIAG_MN_TYPEA_COILOUTF2OSEMINF.png

Comments to this report:

takafumi.ushiba - 15:23 Sunday 11 July 2021 (17472)

I found the healthy TF in klog17158, which is measured on 18 of June.
So, this actuator efficiency drop must be occurred between 18 of June and 2 of July.

According to the klog, there is a work for repairing the BF actuator cables.
So, the first step is to check the cable around the BF.