Aso, Fujii with help of Ito, Shimizu from MPC, Y. Enomoto,

= What we did =
-- We opened a bellows at PR2 chamber (BS side) in order to fix the PR2 rubbing issue.
-- We found that the BF-primary-coi cylinder (inner cylinder) was touching to the york not at the botom but at the side part (It smmed).
-- We slightly shifted the inner cylinder so that the cylinder did not touch to the york.
-- Then once we successfully found the position and we could find a BF-GAS signal which was freely swinging :)
-- HOWEVER, a few ten minutes later, we found that the keystone looked rubbing and it did not oscilate freely
-- After this, we tried to find the sweet point though, consequently we failed: we could not get the freely-swinging BF-GAS signal. It was oscillating indeed, though its Q factor was quite low.
  -- the mystery was, sometimes we found free-swing when we slightly touch the BF-body. This free swing vanished when we released the IRM for example. BF-GAS signal looked much sensitive to the BF-tilt.
  -- Also we found that the BF-GAS was freely swinging when we were moving the picomotor on BF (BF-yaw) as attached.
      (Green: BF-GAS, red: SF-GAS, blue: BF-V, yellow: IMV in the mov, and I was moving BF-Yaw pico.)
-- We gave up  to find good position for BF-keystone, and we set the keystone at middle of the EQ stopper screws.
  -- We might have to adjust the OSEM positions instead of GAS-keystone.
-- After this inspection, we found 5 OSEMs out of 6 went outside the linear range and thus we have to tune the position again.
-- Then we restored the optic postion as reference of Opev signal by the traverser, IM-pios.

   --> we went back to the today's starting point (or more)

= Note =
-- The photos are stored in:
https://photos.app.goo.gl/ZRvmcyjmNmaFSmLh9
-- BFVDT-V2 signal

= Next =
-- Measure the TFs
-- Adjust the OSEMs after double-checking if the P.PR2-OpLev is reliable.
-- invectigate the BFLVDT-V2 is from circuits or anything else.