Fabian, Yoshinori,

Log on March 11th, 2019,


= PRM =
-- As reported in the previous log, we tried the following*
  > == Next ==
  > -- we will compensate the yaw shift by the traverser so that the OpLev light is on the QPD.
  > -- after these work, all the transfer functions will be measured.

  -- By following the procedure reported in klog#581, we slided the traverser in +Yaw by 156 mdeg('= 30mdeg*6 - 10mdeg*3 +3mdeg*2) si that the oplev was centered.
    -- The used script was the followinfg:
        /kagra/Dropbox/Subsystems/VIS/TypeBp/Traversers/cont_serial.py
  -- Then we measured some transfer functions of the IM-stage, and found some weird stuffs:
    -- one wierd peak in a vertical transfer function (This looked a coupling from IM-L or T).
      -- Actually, one OSE flag was close to the cavity though we cannot shift the OSEM plase anymore (There was no torelance anymore). Tilting BF-body from client machine could not solve this issue. The actual flag position should be checked visually.
    -- the peak at 4.1 Hz was shifted to 4.4 Hz which was RM-P mode. and the frequency of the notch in damping filter was changed along with this, and the gain was slightly changed (from 1 to 0.8).

  -- Now all the filters can be closed though, this system seems to include weird issues. Some more (visual) check would be necessary.