20180222

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Today's activities

Workers: Simon, Miyo, Akutsu

• (The WAB was locked yesterday.)
• Attached a reflector to the WAB -Y side, and the counter mass (the same shape as the reflector) +Y side.
• Installed three photosensors; positions were at +X, -Y, and the bottom, and they faced -X, +Y, and +Z, respectively, to look at the reflector.

  • To be reported: the distance from the sensor head to the reflector are ....

  • Due to the 50-mm pitch of the M6 screw holes on the optical table in the chamber, it was impossible to install the photosensor supports to the positions we like to put; so far a breadboard with 25-mm pitch M6 screw holes was inserted, and this will be replaced to a vacuum compatible one later.
  • Connected the pins.

• Attached a set of SmCo magnets for a coil-mag actuator; the magnets were attached at -X,-Y, about 45-deg clockwise from the bottom.

• Installed a coil magnet actuator in -X direction.
  • Before the installation, the coil's pins were connected to electric wires with copper pipes; because the net diameter of each pin was thicker than that of photosensor, new pipe (phi 1.2mm) was bought and adopted.
  • Connected the pins of the coil to U and V of P23.
  • The coil's resistance was measured as 13 ohm, while the resistance measured at the distributor was 75+75+13 = around 163 ohm due to the one-way 75 ohm electric wires.
• Unlocked the suspension; The WAB is now floating.
• Tried to exert a force by the coil-magnet actuator, but failed. This would be due to the too large total resistance so the current flow was not enough.
  • Should we use the other pins of 4-ohms, which are reserved for a thermometer???

• [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

• Complete the calibration of the oplev; the arm length was reported by Simon, so....
• 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.