R&D (FilterCavity)
MarcEisenmann - 10:31, Wednesday 01 March 2023 (3186)
Green alignment to filter cavity

[Marc, Michael, Rishabh, Shalika]

We tweaked the last mirror on green injection into PR and recovered targets on PR tank.

We moved PR coils and recovered BS target. Actually, the gate valve between BS and INPUT is open so we could not use it to fine tune this alignment.

However, we found out that centering the beam on the 2inch mirror inside BS chamber was also a good way to have the beam centered on the first target.

We tried to control the 2nd target and look at its camera from remote but we could not connect to them. Maybe related to the on-going fiber installation in the arm?

We went to 2nd target and could recover alignment by moving BS pitch and PR yaw. It now seems that at least one of the yaw magnet of BS fall down as the beam is not moving properly.

Then we tuned END to recover the back-reflection on the 2nd target. However, it also seems that END yaw is not working properly..

We tweaked a bit INPUT and the green beam is now back to the injection FI.

We will have to offload several suspension using pico-motors as current coil offset is quite large for several dofs.