Agenda/Minutes

Zoom Meeting

CRY+VIS Interface Meeting

Date: 2021/10/15 13:00-13:25

Participants: Takahashi, Hirata, Miyoki, Yasui, Ikeda, Ushiba, Uchiyama, Yokozawa, Sato, Node

Post O3 Upgrade portal

Schedule

• IX: Health check. F0 behavire.
• EX: Health check.
• IY: (LVDT driver. Cable check.)
• EY: H4 geophone. F0 FR. Height adjustment. LVDT driver. IP position. Insulator repair.

Status

• TM height setting: ITMY
• Commissioning in air: Health check.
• Commissioning in vacuum:
• Overall commissioning:
• Acceptance check:
• PF actuator: At the in-vacuum commissioning.
• New vacuum pumps for V-chambers: Under the bidding process.
• Heater control: To PRs in the next.

Discussion

VIS Meeting

Date: 2021/10/15 14:00-

Participants:

Summary Report

Type-A

Type-B

• BS: We tested the robustness of the outer frame
  • Resolution of the dial gauge: 0.01 mm.
  • Weight added to the frame: ~71 kg.

  • Corner (-X,-Y) : -3 um

  • Corner (-X,+Y): -10um

  • Corner (+X,+Y): it didn't seem to move much.

  • Corner (+X,-Y): -8 um

• SR2: The geophone theoretical noise was calculated (shown in this meeting last year also). The noise is higher than expected.

• SR3: The geophone theoretical noise was calculated.

  • Below 500 mHz, the calculated and measured values seem to coincide.

  • As far as I remember being told, these geophones have been very noisy after installation on the IP table. I need to measure the IP free swing displacement ASD on a day with low micro-seismic in order to compare.

Type-Bp

• SR2: We fixed the BF picomotor cable.
• PR3:
  • On monday we moved the V1 OSEM within range. We left it at ~9940 cnt. Although I don't expect this to happen, let's see if the OSEM remains in range after the next eathquake.
  • We assesed whether is possible to lower the SF keystone by 5.2 mm: it seems possible.
    • The concern was cables underneath the BF touching the security structure ring, but there are functional gaps after we lowered it.
    • First we moved the keystone using the lock screws, but later we used 405 grams.
    • Lowering the SF yoke-coil assembly might damage cables around, but I guess we can fix them if such a thing happens.
    • It's better to add mass on the keystone rather than on the BF. Hirata-san has designed an adapter.

Type-C

Electronics

Control

Schedule

See Schedule

• Type-A team:
• Type-B team:

Safety

Discussion

Travel Plans

(Date in Kamioka)

The week from 10/18

• Hirata: 10/18-22
• Yano: 10/18-22

The week from 10/25

• Takahashi: 10/26-29
• Sato: 10/26-29
• Hirata: 10/26-29
• Yano: 10/25-29

Next meeting

• 2021/10/22(FRI)