iKAGRA ETM suspension preparation log

Schedule

• 12th Jan- (2 weeks) Disassembling, Washing, and transportation
• 25th Jan - (2 weeks) Assembling and Test Hanging with an Al dummy mirror
• 7th Feb- (1 week) coil winding, measurement of transfer function, transportation to the End area and installation test
• 15th Feb- (1 week)installation

Disassembling in the ATC clean booth at Mitaka [Ohishi] (12th-19th Jan.)

• Two nuts stuck. Hirata-san removed them.
• A Cu screw stuck. Hirata-san removed it.

Washing and transportation to Kamioka [Hirata-san]

• The ultra sonic washer at ATC was broken on 20th Jan. A new washer was ordered on 22th(Fri) and arrived at Mitaka on 25th(Mon).
• Eight screws for adjusting the IM holding plate was dirty. Takahashi-san ordered similar screws.

New parts

• Coil bobbin [Takahashi-san, Tatsumi-san]

  • coil bobbin

  • The outer diameter of the coil has been changed from 14.2mm to 14.5mm.
  • Due to this change, the number of winding becomes 39 from 41.
  • Delivered to Kamioka on 4th Feb.
• Coil winding [Kuwahara-san, and Ushiba-san from U-Tokyo, Lee-san from Okazaki, and Ohishi](8th-16th Feb.)
  • We used coil winding machine.
  • Lead wires from the bobbin to Dsub connector were too short (20cm). The length must be 40cm or more.
  • At the end of the lead wires, D-sub pins are swaged. We have run short of pins and waiting for delivery on 29th Feb(Mon).
  • Peeling off the coating of wires longer than the length of those pins make the wire broken easily.
• D-sub connector plates [Takahashi-san]

  
  

  • M3 holes were changed to phi3.1 holes. Yamamoto-san used drilling machine at Kamioka surface office.
  • One must be careful about the pillar position in order to attach this plate to the suspension.
• 15pin-9pin changer for coil driver output [Ushiba-san, Ohishi]
• Mirror container [Tatsumi-san]

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  • Some plates once used for transportation of MC mirrors were used
  • Two places of the container were cut to avoid standoffs.
• Attach magnets to dummy mirror (4 ; with the diameter of 2mm and the length of 5mm NdFeB magnets) [Tomaru, Yamamoto]
  • We used CLIO magnet fixture jigs.
• Screws in replace with Cu screws [Ohishi]
  • Replaced all Cu screws to stainless screws. Magnetism problem was indicated.

Pico-motors and PZTs

• We have 4 pico-motors except for x-axis (the direction of the light ) y, z, pitch, yaw

Coil drivers

• We use KAGRA coil driver; we need to cheek its performance.

Cables

Assembling [Tomaru-san, Ohishi, Yamamoto-san]

• On 21th, suspension frame, security frame, xy stages completed

Hanging

• Hanging jig preparation

Transfer Function Measurement

==== Transportation to the End [Prof. Kimura, Sawada-san, Tomaru-san(KEK),]====

• KEK

Mirrors

• Two TAMA PRM mirrors (with about 50% and 90% reflectivities each, resultant contrast becomes 96%) were delivered to Kamioka on 12th Feb.

Stages

• Condensation
• Vacuum compatibility?

Installation