Contents
Agenda/Minutes
CRY+VIS Interface Meeting
Date: 2021/12/24 13:00-13:35
Participants: Takahashi, Aso, Ushiba, Ikeda, Sato, Akutsu, Uchiyama
Schedule
- IX: Pump down on 12/23. Investigating the glich in the F3 signals. Go to the health check.
- EX: In vacuum. Go to the health check.
- IY:
- EY: Recovery of the BF problem. Implementing the damping controls.
Status
- Replacement of flip cables:
- TM height setting: ITMY.
- Oplev: Setup of the TM Oplev in IY after the TM alignment.
- ACC: Experiments in IX/EX. Assembly for EY.
- Commissioning in air: Return of GRY.
- Commissioning in vacuum: Pump down of IXC/IXV on 12/23.
- Overall commissioning:
- Acceptance check:
- PF actuator: At the in-vacuum commissioning.
- New vacuum pumps for V-chambers:
- Heater control:
- Power source for Oplev: SLD was broken due to pulling the cables.
Discussion
VIS Meeting
Date: 2021/12/24 14:00-14:25
Participants: Takahashi, Fabian, Sato, Terrence, Aso, Ushiba, Ishizaki, Uchiyama
Summary Report
Type-A
- Monitored and offloaded the displacement of the IXV during the pump down.
- Investigating the glitch of F3 signals in IX.
ETMY
- Coil direction check for IP, GAS, and BF.
IP H1 H2 and H3 coils are all inverted. https://klog.icrr.u-tokyo.ac.jp/osl/?r=19295
F2, F3, BF GAS coils are inverted. https://klog.icrr.u-tokyo.ac.jp/osl/?r=19303
BF V1, V3, H2 coils are inverted. https://klog.icrr.u-tokyo.ac.jp/osl/?r=19309
- Is there any reason why some of them are inverted? The coil output gains are now kind of messy.
IP LVDT sensing and actuation diagonalization. https://klog.icrr.u-tokyo.ac.jp/osl/?r=19301, https://klog.icrr.u-tokyo.ac.jp/osl/?r=19302
- Some questions
- BF LVDT readouts are very large, they read a few thousand um/urad. Are they calibrated?
- Some GAS filters are some thousand microns away from the setpoint. Can I simply use the stepper motors to offload them? Is there anything I should pay attention to?
What is the oscillation/pump at 20 mHz? It appears in many DoFs, e.g. IP L, BF L. (except GAS DoFs).
.
Type-B
Type-Bp
PR2
We glued back the magnets onto the mirror.
- It was not necessary to remove the mid-size baffle. It was possible to do visual inspection of magnets within coil bodies with an inspection mirror.
- Because the RM is not designed to be a positioning jig for the mirror, a concern was the relative alignment of the two bodies.
- The method that we used was to release both bodies and lock them, as much as possible, to the position in which they hung free.
- Despite the absence of two magnets, this method work, likely because the any imbalance affects the RM and mirror in equal amounts becuase they both hang from the IM.
- During the course of this work, we security structie locking screws were withdrawn by defined distances, not like before.
After the gluing, procedure I measured a few transfer functions of the IM and the sysytem seemed to be healthy. However, we should do a more comprenhensive set of measurements. I didn't do it becuase IFO alignment has a higher priority.
PRM
During IFO alignment work, we realized the traverser was far away from its centre. Likely, a similar error as PR2 one was made in PRM on Thursday last week.
- At the begining it moved, but later it jammed.
- We realized the problem was that some locking assemblies had not been removed and two of them seemed locked. It seems no other suspension has this locking system.
- We removed them and the traverser now moved smoothly.
- During the course of this work, we security structie locking screws were withdrawn by defined distances, not like before.
It would be good to buy more sligs so we don't have to go back and forth between clean booths to pick them up, please.
Type-C
Electronics
Control
Schedule
See Schedule
- Type-A team: ACC in EY, Heter test in IXV/EXV
- Type-B team: Calibrate BF LVDT in BS
Safety
Discussion
Travel Plans
(Date in Kamioka)
The week from 12/27
(Holidays in 12/29-1/3)
The week from 1/4
- Takahashi: 1/5-7
- Sato: 1/5-7
- Hirata: 1/5-7
Next meeting
- 2022/1/7(FRI)