• LCGT
• subgroup
• AOS
• WideAngleBuffle
• 2018-01-26

20180126

http://klog.icrr.u-tokyo.ac.jp/osl/?r=4036

Today's activities

Workers: Akutsu, Simon, Miyo, Hasegawa

• Set a laser marker in the cryostat and roughly checked the relative position of the WAB's nominal position and the duct.

  • Today we utilized a marker scratch at the duct aperture in the 3 o'clock direction, assuming this is the level of the interferometer's main beam... (or a horizontal diameter line of the duct aperture... whichever!); need to be confirmed.

  • Note: took about 10 minutes to set up the laser marker in the cryostat chamber (by Miyo and Hasegawa); the legs of the tripod supporting the laser marker were covered by aluminum foil, as it seemed dirty.
• Moved the WAB suspension to the nominal position of the saving mode (make WAB escaped), as the relative positions of the WAB and the duct were confirmed in the manner described above.
  • Positioning: I (Akutsu) stood on the optical table in front of the WAB, Simon and Hasegawa stood in -X direction, and Miyo in +X direction.

  • Method: I was just an observer, saying something; the others moved the WAB suspension to the position for the saving mode shown here.

  • Result: ignoring some issues described below, finally the WAB suspension was lead to the planned position in the saving mode.

  • Issues:
    • The base beams, i.e. just misumi bars, which were not fixed, so the beams moved easily during the WAB moved; for example, we found one of the beams almost fell (but not... we modified the postion) because the friction during the WAB moving also moved the beams. At least the beams should be somehow fixed onto the cryostat shield (not happened... thanks to the workers' carefulness!!).
    • To move the WAB suspension, we cannot avoid yawing of the WAB during the WAB move efforts; due to this yawing, sometimes the WAB tended to hit the inner surface of the duct connected to the cryo-shield.
  • Discussion:
    • Making some slits under the misumi beams or some modifications would be required to somehow "fix" the beams...
    • A rail would be preferable.
    • Hanging from the top would not help the situation...
    • Today we did not recover the WAB position from the saving mode to the nominal position. It can be done, but considering the actual commissioning situation, it would become more more difficult when a cryopayload would be existing.

• [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

• Check the reproducibility of the alignment of the suspension among several modes.
• Take the WAB suspension back to the table and detach some guard parts and check the balance, and attach them back;
• Attach heater plates?
• Try to connect bundy pins to the heaters??
• Place bundy cables toward outside?

• [Slightly done] Check tilt of the basement optical table in the IYC chamber.

• Check heights of several points.
• Wash the coil in ethanol at Univ. of Toyama...?

• Pick up OptoSigma parts sent to Akutsu.

• Take care of water spring??

Wanted!

• 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.

• Cutters and scissors!!
• A clock to know the time easily.

• A fiber cleaner to connect oplev source parts; need to get back from Yend.

• M6 screw set.