High Power Test of the Prototype Cryomodule for ADS Superconducting Linac

A prototype cryomodule containing two 9-cell superconducting cavities of β=0.725 and fo=972MHz had been constructed under the collaboration of Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) on the development of superconducting LINAC for Accelerator Driven System (ADS). Cool-down tests to 2K of the cryomodule and high power rf tests with a 972MHz pulsed klystron have been carried out. Rf power of 350kW in pulsed operation of 3msec and 25Hz was transferred to a nine-cell cavity through an input coupler. Accelerating gradients of 14MV/m higher than the specification of 10MV/m have been achieved in both cavities. Compensation of Lorentz-force detuning by a piezo tuner was successfully demonstrated.