DESIGN OF HIGH-POWER ELECTRON LINAC AT PNC

A high power CW (Continuous Wave) test electron linac was designed to develop a higher power linac to transmute radioactive wastes. The test linac is energized by two 1.2 MW CW L-band klystrons to produce an el ectron beam with the energy of 10 MeV and current of 100 mA. The avera ge beam power is 200 kW approximately 1 MW for the duty factor 20 appr oximately 100%. In designing such a high power linac, authors selected a traveling-wave accelerator with TWRR (Traveling Wave Resonant Ring) . This is to enhance the threshold current of BBU (Beam Break-Up) and to get high accelerator efficiency that results from the low value of attenuation constant tau and high field multiplication factor M which are permitted only with TWRR. A kind of efficient cooling structure is adopted to an accelerator structure in order to disperse the generate d heat by RF (Radio Frequency). The variational method is used to calc ulate the sizes and parameters of the disk-loaded accelerator structur e employed. There is a discrepancy of the order of a few hundredth of one percent between the calculated sizes and the experimental ones. Th e M determined in the design agreed well with those measured in low an d high power tests.