DESIGN OF THE SPOKE CAVITY ED&D INPUT COUPLER*

The current design of the Accelerator Driven Test Facility (ADTF) accelerator contains multiple β, superconducting, resonant cavities. Spoke-type resonators (β = 0.175 and β = 0.34) are proposed for the low energy linac immediately following the radio frequency quadrupole. A continuous wave power requirement of 8.5 – 211.8 kW, 350 MHz has been established for the input couplers of these spoke cavities. The coupler design approach was to have a single input coupler design for beam currents of 13.3 mA and 100 mA and both cavity β’s. The baseline design consists of a half-height WR2300 waveguide section merged with a shorted coaxial conductor. At the transition is a 4.8-mm thick cylindrical ceramic window creating the air/vacuu