Agenda/Minutes of the VIS Meeting on 2018/4/27

2018/4/27 13:30 -

Participants:

Progress report

Schedule Chart

Type-A : (PDF/MPP)

Type-B: (PDF/MPP)

Type-A (Takahashi)

Past week report

[X-front]

• Suspended the filter chain from the TF.
• Attached two cross tubes and four feedthroughs onto the top chamber.
• Cabled from the upper small hexagon to the feedthroughs.
• Replaced the guide clamps for two blades with thin guards. Compressed the blades by 3~8mm respectively.
• Released the keystone of TF. The height of keystone was too low without additional load. Frequency was 1.4Hz (too high).
• Repaired the thread hole for the hook screw for the SF damper.
• Attached the EQ stop anchor. Adjusted the horizontal position of the EQ stop.
• Checked the LVDT signals. Found the F1 keystone touching to the secondary coil. When the F1 sit on the release sensor, it was free.
• Set the LVDT drivers to the rack. Calibrating the LVDTs for the BF damper.

Plan for coming weeks

[X-front]

• Solve the problem in the F1.
• Tune the IP.
• Set the ACCs.
• Set the LVDT coils for the BF damper.

Type B (Mark)

Past week report

• Made SRM model (Dropbox/Largefiles/Subsystems/VIS/Design/SR/Model/SRM-MetalMass_180426)

• Made 2D drawings of LBB ballast masses

Control Issue

• Resonant frequency table is ready for BS (BS suspension details)

• We found the inconsistency between local damping measurement and interferometer measurement. (klog4811)

  • The TF gains from IML to TML, and from TML to TML are different from the interferometer measurement.
  • I checked the TML gain, which are calculated from TMP and TMY measurements, and found EUL2COIL matrix was different from what I supposed.

    • --> Fixed it and updated the state space model. Might be OK now for TF from TML to TML. (Komori-kun will check it.)

  • I checked the calibration gain of OSEMs and found that the measured values are not used. But it makes only small difference.

  • Compare the TFs from BFGAS to BFGAS and BFGAS to IMV, and they are inconsistent for BS and PR2. (No data found for PR3)(klog4807)

  • Comparing TFs from IMP to TMP and from IMY to TMY also helps to check the OSEM calibration by comparing OSEM signals and Oplev signals.
    • Found the matrix to convert OSEM signals (um) to pitch (urad) is different from what I calculated. To be checked. The measurement will be done after phase-I.
• Constructing the tool to implement the current filterbank information to state space model.

Plan for coming weeks

Type-Bp (Shoda)

Past week report

Plan for coming weeks

OMMT & OSTM (Ohishi)

Past week report

• I have ordered some parts; stages, standoffs, and magnets.

Plan for coming weeks

• I will check the response of the vertical vibration isolation bellows and will order remaining 8 bellows.

Watchdog system (Tanaka)

Past week report

Plan for coming weeks

Other site works

Safety

• Incidents:
  • Type-A: When we replaced the guide clamp, the blade clamp slipped out.
• Foreseen risks
  • Type-A:
  • Type-B:
  • Type-Bp:

Discussion

Travel Plans

• Travel (Week of 4/30):
  • Takahashi:
  • Okutomi:
  • Sato:
  • Ishizaki:
  • Mark:
  • Hirata:
  • Enzo:
  • Shoda:
  • Ohishi:
  • Fujii:
  • Tanioka:
  • Tanaka:
  • Kozu (ICRR):
  • Arai (ICRR):
• Travel (Week of 5/7):
  • Takahashi:
  • Okutomi:
  • Sato:
  • Ishizaki:
  • Mark:
  • Hirata:
  • Enzo:
  • Shoda:
  • Ohishi:
  • Fujii:
  • Tanioka:
  • Tanaka:
  • Kozu (ICRR):
  • Arai (ICRR):

Next meeting

On 2018/5/11(Fri)