Agenda/Minutes on 2020/11/13

CRY+VIS Interface Meeting

13:30-13:50

Participants: Takahashi, Hirata, Ikeda, Hagiwara, Aso, Yano, Kimura, Sato, Ushiba

Post O3 Upgrade portal
Disassembly of the Type-A tower was finished in Y-end (11/11). Evacuation of IYC will be started on 11/18.
Schedule: Wire disconnection (IX 11/13, EX 11/19), Chamber evacuation (IY 11/20).
Jig for the FC painting: Hirata-san made the 3D model of jigs for SR and BS.
PF actuator: Measurement of coefficients --> calculation of the noise (by mid Dec.).

14:00-15:00

Participants: Takahashi, Hirata, Aso, Yano, Sato, Fabian, Washimi, Terrence, Tanaka, Sugiyama

With Washimi-san.

We inspected the BS BF in order to decide the size of a SDC M6 screw to buy. Hirata-san ordered a few (klog 15435).
We connected the cables for the SRM OSEM and the IM picomotors. An adapter for the IM picos broke and I borrowed from SR3 for now.
As preparation we turned on the optic fibre camera and realized it's missing a microSD card. Takahashi-san ordered one already.
I reported to Yokozawa-san that the temperature in SRM was about 21.8 degrees Celsius. We need it warmer next week.
SRM new problem: F1 fishig rod jammed at the lower end of its range. See klog 15447.
- Some FRs don't jam when reaching the end of ther ranges, but others do.
- The expeced position of the keystone at 23 degrees in vacuum is -980 um (klog 15461), which is likely too large to bring the keystone to zero with the coil-magnet actuator.
- What to do? Following our current line of thought, we should remove mass from the BF. Another option would be:
  - Hope fo the best next week and fix the BF.
  - Leave the SF wherever it lands (at -980 um presumably),
  - Set the BF at zero and
  - Compensate the height of the mirror with at the F0 keystone or the IP jacks (better).
Recovery of SRM still continues: I need to check why IM-Y is about -3 mrad whereas it should be close to -65 urad. Unfortunately we don't have the oplev for visual inspection of the beam.See klog 15463.

Washimi-san, Akutsu-san, Miyo-kun, Sugiyama-san, Fabian.

After Shimode-san fixed a minor problem with one of PR2 LVDT drivers, we installed it back and it worked!
We measured the phases again. The results of almost all LVDT drivers used in PR suspensions are reported in klog 15457.
- PRM BF recoil mass LVDT cards have not been examined because we need the problem with the misconnected cables solved.
- One resistance in PRM SF GAS LVDT channel seems anomalous: it's value is only 1.2 Ohm whereas typical values are larger than 5 kOhm.
PRM oplev breadboard with optics was installed on the pylon. They will turn the SLED on next week. See klog 15449.

The circuit boards for new combiner prototype were delivered. The circuit parts have not yet.
Considering the mass production of new combiner using ICRR/NAOJ budget.
No stock of Murata inductor in the market.
We asked AEL to modify 16 LVDT cards (AD630 grounding and on-board D-sub connectors).

The week from 11/16

The week from 11/23

KAGRA/Subgroups/VIS/VISMinutes20201113 (last edited 2020-11-13 15:19:31 by RyutaroTakahashi)