Agenda/Minutes of the VIS Meeting on 2018/9/7

2018/9/7 13:30 -

Zoom Meeting

Participants:

Progress report

Schedule Chart

Type-A : (PDF/MPP)

Type-B: (PDF/MPP)

Type-A (Takahashi)

Past week report

[Y-end]

• Transported the parts of DP. Assembled the DP.
• Disassembled the junction box and removed the suspension wires.
• Installed the DP into the EQ stop. Suspended the DP from the BF.
• Tuned the BF. The optimal load was 204.7kg.
• Tuned the F3. The F3 can work for the BF with above optimal load. The height of keystone is closing to the upper limit.
• Replaced the side stoppers for BF.
• Tuned the TF. The TF was in bi-stable. Set the height of keystone to the lower position.

[X-front]

• Found a leak in the feedthrough flange. A tag plate for the connector was put between the gasket and the knife edge. The gasket was replaced.

Updates

• A (large) drift was observed in BF-Yaw DoF. We have to rotate the F0-Y adjusting system when we open the top-chamber *BY HAND* since we do not have the stepping motor for F0-Y for the time being.
• The resonant frequency of the horizontal IP motion was about 100 mHz and this looked a bit high. We will also wan to add the tuning mass on the IP stage when we open the top-chamber.

• This week was a week for ITMX measurement

• IP-diagonalization for sensors(LVDTs)/actuators was done with the method used in Virgo (LVDT sensor mat was calculated from the actual positions. the actuator matrix was done by injecting 3Hz line at each coil and then using the transfer functions at the frequency).

  • -> looks well. Now the sensor matrix diagonalization for ACCs are ongoing (measurement has done and the calculation is ongoing).

• BF diagonalization for sensors/actuators is ongoing.

  • -> For sensor diagonalization, we will want to set the BF-L axis along to IP-L. One idea: move IP in L-DoF and then align the BF-L axis. (I gave up to do this for the moment.. I ran out of time; due to the black-out prep, also we have to pass ITMX to cryo-people in the next week.

• TF measurement except for BF-GASexc is done. The identification of the resonances will be done soon.
  • (IP-stage is already dinagonalized though the BF-LVDTs are not. It is confirmed that we can damp the lowest yaw mode by BF-LVDT with current matrices (and current matrices will not disturb the lock-acquisition work), we will refine the matrix)

Problems

• It seems that:

  • -> F3 is at the edge of the linear range.

    • -> The injection signal were observed at the LVDT though, the amplitude was small.

    -> BF is out of the linear range.

    • -> Even though the injection was applied, the signal were not observed at the LVDT.

• [Note]

We could not adjust the height of BF(/F3) by the stepping motors. (F2 had been also at the edge of the linear range though we could adjust the position by the STM. All the cabling for the STMs has no problem btw. When we measured the transfer functions from F1-GAS, 4 peaks were observed and thus the all the GAS filters should be freely suspended properly since we have F1/F2/F3/BF now.)

[Y-front]

• We could not start the measurements since one issue on the digital system, i.e. IRIG-B 9999xx issue. We will do in the next week.
• We prepared for the power outage.

Plan for coming weeks

[X-end]

• Preparation for repairs of the actuator coil in the TF.

[Y-front]

• Setting of controls.

Type B (Mark)

Past week report

Plan for coming weeks

Type-Bp (Shoda)

Past week report

Plan for coming weeks

OMMT & OSTM (Ohishi)

Past week report

• Still waiting for the quotation of mechanical parts.

Plan for coming weeks

• Preparation for guleing.

VIS electronics (Tanaka)

Past week report

Plan for coming weeks

Other site works

• Sept 10(Mon): Planned power outage

Safety

• Incidents:
• Foreseen risks
  • Type-A:
  • Type-B:

Discussion

• Preparation for the power outage

Travel Plans

• Travel (Week of 9/10):
  • Takahashi:
  • Okutomi:
  • Sato:
  • Lucia:
  • Fabian:
  • Mark:
  • Hirata:
  • Enzo:
  • Shoda:
  • Ohishi:
  • Fujii:
  • Tanioka:
  • Tanaka:
  • Kozu (ICRR):
  • Arai (ICRR):
• Travel (Week of 9/17):
  • Takahashi:
  • Okutomi:
  • Sato:
  • Lucia:
  • Fabian
  • Mark:
  • Hirata:
  • Enzo:
  • Shoda:
  • Ohishi:
  • Fujii:
  • Tanioka:
  • Tanaka:
  • Kozu (ICRR):
  • Arai (ICRR):

Next meeting

On 2018/9/14(Fri)