Disk-type input coupler with a HOM damper for the PLS storage ring cavity

A disk-type input coupler for the Pohang Light Source (PLS) storage ring cavity was fabricated and tested up to 60 kW. A coaxial adapter is required for this system which should have an exit for the loop coupling tubes. Since this input coupler can extract HOMs better than the cylinder-type one out of the cavity, a specially designed HOM absorber was implemented in the design of the adapter. A characteristic of the system is simulated by the HFSS code. The result of the simulation and a preliminary measurement are presented.