KAGRA Logbook

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VIS (EY)

koki.okutomi - 21:38 Wednesday 01 February 2017 (2423)

BF damper pre-assembling and protection net setup

[Takahashi, Ishizaki, Okutomi]

EYV:

Pre-assembling of the BF damper is ongoing
- Screws, washers and other small parts such as cable clamps are arranged
The palettes and the hand lifter washed yesterday are now wrapped and got ready to use

EYC 2F:

Stainless plates are laid on the floor
- They are not fixed yet, will be fixed with alminum tapes
The protection net is assembled but could not be installed into the cross chamber
- We check which dimension is wrong
- Anyway the flame of the net will be sent to Mitaka and go on a diet by additional machining

Photos >>> https://goo.gl/photos/ouqwj1FyvY3VNQR16

Images attached to this report

Comments to this report:

koki.okutomi - 23:49 Wednesday 01 February 2017 (2426)

The outer diameter of the protection net is designed as 900 mm to go through the flange with 914.4 mm diameter.
But the inner diameter of the flange is 898.4 mm on the drawings and 914.4 mm is the outer diameter of the flange.
Additionally, a measured diameter of the flange today was 890 mm.
So this problem originated from:

Misunderstanding the dimension of the flange
Incoincidence of the dimension of the flange between the drawings and the existing one
- I'm not sure about accuracy of the measurement but it's possible that they coincide within its error range
- If the difference of the dimension is true, the chamber somehow shrinked...?

Anyway, we need additional machining on the frame of the protection net.
Before doing that, we should also check whether the frame with reduced diameter can sit on the nominal position.