Agenda/Minutes of the VIS Meeting on 2019/3/8

2019/3/8 13:30 - 14:16

Participants: Mark, Takahashi, Okutomi, Aso, Hirata, Lucia, Terrence, Aso, Tanaka

Progress report

Site work schedule: [[|XLSX]]

Type-A : (PDF/MPP)

Type-B: (PDF/MPP)

Type-C: (XLSX)

[X-end]

The LVDT drivers have a steep line at 548Hz (by Lucia and Fujii).
The transfer functions of filters showed that the suspension is not healthy (by Lucia),
Checked the BF with opening the cross chamber. Any primary coils for BF damper were not touching to the secondary coils (by Tomaru).
The F0 keystone is too low. The F1-F3 keystones are closing to the upper receptacles.

On Monday, Mark helped Aso-san with PR3, and Monday, Tuesday and Wednesday, Fabian helped Fujii-kun with PRM.
Mark and Terrence attempted to offload some BS IM/IRM yaw adjustments that had been done by Enomoto-san last Friday. They rezeroed the OL and then opened the tank lid and did a compensating adjustment to the F0 yaw stepper, then undid the IM/IRM yaw with the pico. However this did not have the desired effect, probably because the buoyancy correction had not been cancelled when Enomoto-san was working and the BF keystone was very high, with the IM-V OSEMs way too far in and possibly touching. We did our best to back out all the adjustments but the roll TFs were still messy and there were signs that the IM was not free in yaw (the IM/IRM Y varied oppositely to IP Y, indicating that the IMR was free and the IM wasn't). We ended up deciding to have Mirapro remove the ducts on the ±X sides of the tank so we could go in and inspect.
Terrence tuned the SR3 LEN OL to be free of yaw cross-coupling.
Terrence and Enzo did a full set of filters and a Guardian for SR2 and SR3.
Terrence did health checks on SR2 and SR3.
Enzo measured mode Qs on SR2.

Mark at Kamioka full week.
Enzo at Kamioka Mon, Tue, then JPS.
Hirata-san at Kamioka from Monday lunchtime through Friday.
Fix BS.
Final test of stepper remote enable system (someone in cleanroom checks the lights go on/off).
Continue monitoring SRM yaw drift.
More mode Q measurements.
Work on Type B paper.

PR2:
- one channel of LVDT driver (for BF-LVDT-V2) did not seem to work properly. That board will be replaced.
- the satellite boxes looked still old type. They are to be replaced and checked.
PR3:
- the suspension became healthy again on Wed in terms of visual inspection.
- all the transfer functions will be measured in this weekend.
PRM:
- on Wed, we kicked IM and the followings were changed, and then we had to revisit the Tuesday’s starting point:
  - SF-GAS
  - BF-body height, its tilt in roll, its torsion in yaw.
- we already compensated the BF-body tilt by the picomotor on the BF-cap. Then the IM-yaw was tuned along with OSEM signals (and thus the QPD does not have the light on it now).
- we will compensate the yaw shift by the traverser so that the OpLev light is on the QPD.
- after these work, all the transfer functions will be measured.
- the satellite boxes looked still old type. They are to be replaced and checked.

Incidents: no incident
Foreseen risks
- Type-A: Crane work
- Type-B: Crane work, work in a confined space
- Type-Bp: Possible crane work

On 2019/3/15(Fri)

KAGRA/Subgroups/VIS/VISMinutes20190308 (last edited 2019-03-08 15:26:17 by YoichiAso)