Agenda/Minutes

Zoom Meeting

CRY+VIS Interface Meeting

Date: 2022/10/21 13:00-

Participants:

Post O3 Upgrade portal

Schedule

• Type-A: Test of the heater control in IY.
• Type-B: Optimization of the IP controls (Diagonalization, Calibration, Sensor correction).
• Type-Bp: Test of the strong damping in PRM.
• Type-C:

Status

• Replacement of cables: EXT remains.
• Oplev: Windshield in IMMT2.
• ACC: Repair of the geophone for spare.
• Commissioning:

• Acceptance check: DropboxPaper

• Vacuum system: Leak test in IMM, IFI, PRs, and TMSY.
• Heater control: Test in IY.
• TMS:

Discussion

VIS Meeting

Date: 2022/10/14 13:30-

Participants:

Summary Report

Type-A

• The BF GAS in IY had been saturated in the last weekend (not monitored). The setpoint of the heater control was changed from 30C to 25C. The BF GAS was recovered.

Type-B

• SR3:
  • IP LVDT and geophone diagonalization, actuation diagonalization.
  • Inter-calibration between LVDTs, geophones and ground seismometer.
  • Sensor correction with an improvement of 2.5 times in the integrated rms.
  • A bump appeared in the IP geophone TFs, very much like in SR2 in the past. New geophone calibration TFs were calculated, implemented in filter banks and are working fine.
  • Inter-calibration between geophones and LVDTs were calculated again but not yet written in filter banks.
• SR2:
  • It seems the resonance in IP-L appears at different frequencies, depending whether it's measured with the force TF or the IP free-swing ASD (66 and 80 mHz respectively). Double-checking this seems necessary.
  • I removed the sensor and actuation diagonalization matrices that I had implemented last week because they introduced large coupling at some frequencies. Nevertheless, Lucia realized that diagonalization of only actuation is beneficial.
  • I implemented inter-calibration with the seismometer on the ground and then implemented the LVDT sensor correction. With the microseimic conditions at the time, the seismoc noise in the LVDT decreased by 5.8 and 6.6 in L and T respectively, without increasing the rms.
• Beam splitter:
  • Lucia tested the blending of the geophones with the corrected LVDTs,and the inertial dampiong. It seems to be working fine.
  • Ushiba-san implemented low noise control for the payload.

Type-Bp

Type-C

Electronics

• Repaired the broken geophone pod which was replaced with the spare geophone in SR2. We had three geophone pre-amps as spares, but they are the old type boards with opposite side sockets for the feedthrough. I made a special ribbon cable to connect to the feedthrough.

Control

Schedule

• Type-A:
• Type-B: Optimization of IP controls.
• Type-Bp:
• Type-C:

Safety

Discussion

Travel Plans

(Date in Kamioka)

The week from 10/24

• Hirata: 10/25-28

The week from 10/31

• Takahashi:
• Hirata:
• Sato:

Next meeting

• 2022/10/28(FRI) 13:30