KAGRA Logbook

Reports 1-1 of 1

VIS (IY)

yoshinori.fujii - 18:11 Monday 10 June 2019 (9172)

ITMY Investigation (cont'd)

= ITMY =

For further investigation, I push/set IP to some points and measured BF-Yaw excited transfer function.
The issue still remains.
- This is for an investigation for the friction between the frame and the suspension.
  - The noiminal position is (K1:VIS-ITMX_IP_DAMP_L_IN, K1:VIS-ITMX_IP_DAMP_T_IN) := (L, T) = (0, 0) [um].
- The tested points were:
  - (L, T) = (0 ,0), (-100, 0), (-200, 0), (+100, 0), (+200, 0), (+100, -100), (+100, -200), (+100, +100), (+100, +200).
  - At (-200, 0), the TF became much weird.
  - At (+100, +100), the gain at about 0.2-0.3Hz was slightly improved.
- However, again, the critical stuff was not found.
- Figure1: (L, T) = (0 ,0), Figure2: (L, T) = (-200 ,0), Figure3: (L, T) = (+100 , +100)

Next is to use GAS more drastically, and also try to use the moving mas for payload.
I would say opening the chamber is much much easier to push this issu to the end.

Images attached to this report

Comments to this report:

yoshinori.fujii - 17:13 Tuesday 11 June 2019 (9192)

= ITMY =

Chaging the payload height by using BF-GAS fishing rod did not solve this issue.
- The vertical shift always coupled to MN-P oplev signal. (This did not improve the TM/MN spectra)
  - I measured just one TFs for this reson, and the shape was not as designed.
- This adjustment was done ising MN-/TM-oplev and thus checking this again in the mine might be more helpful.
Changing the MN tilt in Roll by the moving mass improved the coulping between MN/TM-Pitch and Yaw. From one point, only MN-oplev Pit signal was changed. but the TF of BFY was not improved.
moving the MN in R or P more, trying to use the PF-moving mass would be the next.
Some screen shots are in
- /users/VISsvn/TypeAtower/ITMY/Measurements/20190611/