HIGH POWER RF COUPLER FOR ADS ACCELERATING CAVITIES

An accelerator driven system (ADS) requires a highpower CW proton accelerator with proton beam energies near 1 GeV. High-gradient superconducting TEM-cavities are a natural choice for the front end of the linac. This paper presents the design of superconducting low-beta half wave resonators operating at 162 MHz frequency for ADS, as well as, a new 75 kW power coupler. This coupler would permit operations with an accelerating voltage of 3.0 MV per cavity with a beam current of 25 mA. The coupler includes a cold RF window which cools the antenna by conduction and a variable bellows section to adjust the coupling factor. The importance of these features for reliable operation will be discussed in detail.