Agenda/Minutes on 2021/1/22
CRY+VIS Interface Meeting
13:30-14:00
Participants: Takahashi, Sato, Hirata, Ikeda, Miyo, Ushiba, Tomaru, Kimura, Aso
- Schedule for IX: Cabling for the payload is scheduled from 1/26. Connection is scheduled in the week of 2/8.
- Schedule for IY: Cooling of payload was started from 1/18.
- Schedule for EX: Connection of ETMX was scheduled in the week of 3/15.
- Corrugate tube fixing jig: Re-measurement at the beginning of March (3/1-3) in IYV is planed. Deformation of the bottom ring of top-chamber would be large.
- Commissioning in vacuum:
- Acceptance check: Cryo-payload in IX and Type-A tower in EY are on going.
- Jig for FC painting: Under manufacturing.
- PF actuator: by the end of January.
VIS Meeting
14:00-15:30
Participants: Takahashi, Sato, Hirata, Miyo, Aso, Iguchi, Ishizaki, Tanaka, Washimi, Terrence
Progress report
General
Type-A
- Installation in EYV.
- Going to the F3 stage.
- Blades for FR in the F3 was replaced. Checked the motion of FR.
- Measured the spectrum of BF LVDT.
- Mounted the F3 on the EQ stop. The BF was suspended by the F3.
- Prepared the cables between the BF and F3.
- The cabling work from BF to F3 was completed.
- Stepper motor driver in EYV
One channel of the stepper motor driver for GAS had failed. k-log
Type-B
Albums
Week of the 18th of January
Hirata-san worked in the design of the thermistor holder, cabling, etc.
SRM
I disconnected SRM picomotor drivers to move them away from the assembly frame. I failed to report it in a klogin due time.
BS
Miyo-kun, Hirata-san and I reviewed the IP transformation matrices from IP LVDTs to L, T and Y and from actuation in L, T and Y to real coil-magnet actuator. We found a few of inconsistencies in existing documents. See klog reports 15769 and 15776.
- We recovered the IP alignment:
See klog 15782.
- I updated the medm screen with these matrices. Diagonalization is pending.
- I moved the IP close to the setpoint using horizontal FRs.
- I turned the control system on by hand and works fine. (I tried using Guardian but it keeps using the old setpoint values despite I took a snapshot.)
- I moved BF keystone to around zero. (F1 keystone has been in midrange for a long time and we should not move it unless it's absolutely necessary.)
- We went to the tunnel and recovered the oplev readout. We had to move the suspension in yaw by a lot (mrad maybe) using the new F0-Y stepper motor.
- After recovery I measured TFs in the IP. They look fine, but in IP-L and IP-T the coherence is low from 150 mHz to 400 mHz. Terrence suggested to check coherence with ground motion and we cna also increase the amount of actuation.
- We finally got to add ballast mass on top of BF:
When we began working the temperature was 23.1 degrees but when we finished it was 23.5 degrees (klog 15809), likely due to the coach filters (klog 15810), but this morning it was 23.0 degrees.
- The final result is that the keystone is now about 16 um above the goal. It requires -1,100 counts of coil-magnet actuation to reach it. After pump down we can use the FR to move it closer if we think it's suitable.
- The aligmment of the OSEMs didn't change much.
- IM TF measuements reveal that the system is healthy.
- Things left to do in BS suspension:
- In F0 adjust ballast mass, FR position and limit switch positions.
- Tune IP resonant frequency.
- Measure IP-LVDT sensitivity.
- Install oplev box (what is the status?)
- Install outer frame large beam? (what is the status?)
Plan for next week
SR3
- Alignment recovery after cabling (it seems they want to use it next week for injecting green light.)
- Preparation for ballas mass adjustment.
Type-Bp
[Fabian] What's the plan for next week? It is something like this:
- Traverser cable change?
- Gluing wire in PR3?
Type-C
Controls
Although I told you that I explain my document for Suspension Commissioning, I should write more information. here
Electronics
- Compared the TFs of modified LVDT board with the original board. Reduction of 50dB in the TF was found.
- Actual effect should be measured using the BF damper in PR.
Towards O4
- Type-B remedy work is on going.
- Installation of Type-A is on going in EY.
- Schedule.
- Procedure documents.
- Criteria in the acceptance test.
Safety
Discussion
- BS control noise
Travel Plans
The week from 1/25
- Takahashi: 1/25-29
- Sato: 1/25-29
- Hirata: 1/25-29
- Yano: 1/25-29
The week from 2/1
- Takahashi: 2/1-5
- Sato: 2/1-5
- Hirata: 2/1-5
- Yano: 2/1-5
Next meeting
- On 2020/1/29(Fri)