Design of a movable synchrotron radiation mask with SIC absorber for the Photon Factory Advanced Ring (PF-AR)

We have six rf cavities in the photon factory advanced ring (PF-AR) at KEK. One of them was seriously damaged by the synchrotron radiation (SR) from the upstream of the cavity in 2003. In order to protect the cavities from the SR, we developed movable SR masks that have SiC absorber to protect an RF contactor from HOM of the cavity. The mask head is made of Alumina dispersion-strengthened copper to block high power from the SR. It will be installed nearby the cavities in this summer. We report the design of the movable SR masks and the results of high power test.