R&D (FilterCavity)
YuhangZhao - 11:54, Wednesday 20 October 2021 (2719)
Comment to Filter cavity BS mirror is found to have some problems (Click here to view original report: 2712)

We have done some more check before opening the BS vacuum chamber.

1. Check BS P and Y transfer functions. They are similar with reference as shows in the fig1 and fig2.

2. Check coupling between P and Y. A substantial coupling increase is found as shows in the fig3.

3. We tried to close BS local control loop. But failed.

The results of test 2 and 3 make us really need to open BS chamber to check. The opening work is scheduled to be in this afternoon.

Images attached to this comment
2719_20211020045400_bsptf20211020.png 2719_20211020045405_bstf20211020.png 2719_20211020045411_bscoupling20211020.png