Marc, Yuhang

We tried to recover the filter cavity following the earthquake of Friday night.

We used pico-motors to move back the mirrors to a good position.

However, we found out that the BS mirror can not be moved enough using only pico-motors.

The attached figure shows the BS pitch and yaw from the OpLev with the brown and green corresponding to reference spectra and red and blue the current situation.

We can see the appearances of several peaks that hint that the BS magnets are touching the coils.

It means that we will have to open this chamber.