20180301

• http://klog.icrr.u-tokyo.ac.jp/osl/?r=4331

Today's activities

Workers: Simon, Miyo, Akutsu

• Fixed the WAB again.
• Checked and identified each thermometer on the WAB and the suspension.

  • Also checked wethere their thermal contacts were nice. Seemed are.

  • Each thermometer was fixed with a M3 short screw, the washer, and the spring washer.

• Lowered the WAB to the nominal position at the room temperature; details here.

  • First stood a vertical ruler and illuminated it with a laser leveler that was shooting the center of the WAB in the vertical direction.
  • Then lowered the laser lever by 2mm.
  • Loosened M3 screws on the top of the suspension, then rotated three vertical adjusters there, and then tightened the M3 screws.
    • The vertical adjusters were rotated in a single counterclock wise to lower the WAB while the WAB was fixed; meaning the vertical springs were slightly loosened at that time.
  • Removed the protectors so that the WAB was suspended again.
    • As foreseen (not wanted), one of the vertical spring said "beeeeeen" slightly but other than that, no big issues happened, fortunately.

  • Confirmed the again suspended WAB's center line was consistent with the laser leveler's illuminating line! WE DID IT!

    • Actually we should not/need not to do this work for the actual integration procedure of the WAB; it should be suspended in the position of the room-temperature nominal position. Otherwise it would be dangerous to do this kind of work with an actual sapphire mirror will be there...

• Found the optimal amount of the current to the coil in the current situation.

  • Because the distance between the coil actuator and the magnet on the WAB got close, the 1A would be too large.
  • Found 0.5A was sufficient. Less would work.

• [Ongoing] Need cares of water springs from anchor bolts for oplev pylons.

• [Ongoing] Need to confirm what are the scratch lines made by the measurement by the KEK team last week.

Next plan

• Make heat connection upper and lower part of the suspension by Cu wires.
• Make heat anchors for some electric wires in which large current will flow.
• Optimize the current amount to the coil.
• Complete the PS calibration.
• Complete the calibration of the oplev; the arm length was reported by Simon, so....
• Complete the signal matrix.
• Check the balance of the suspended WAB with some wires and sensors are attached.
• Check how the damping would be now after the replacement of the damping magnets.
• Check the reproducibility of the alignment of the suspension among several modes.
• Check heights of several points.
• Take care of water spring??

Wanted!

• Two burndy connectors, vacuum compatible.

• Stages outside the chamber to ease wiping our legs.

• Good rail(?) to move the WAB suspension in the cryostat in the main beam direction.

• Chain block? to support the load in the chamber.

• A clock to know the time easily.
• M6 screw set.