Development of 170 GHz/1 MW Russian gyrotron for ITER

The report presents the results of development of the 170 GHz/1 MW gyrotron s in Russia. The main problems of powerful gyrotrons at present (formation of a high quality helical electron beam, selection of a high efficiency cav ity mode, decreasing of inner converter losses, reliable collector and outp ut window) are discussed. The design versions of the main parts of gyrotron s including the short-pulse prototype, first and second versions of industr ial models and test set-up are presented. Advanced 170 GHz ITER gyrotrons w ere also investigated including a single-stage depressed collector versions (CPD) as well as an improved window (CVD diamond window from FZK). The pos sibility to make high efficient 170 GHz/1 MW gyrotron for ITER is proved by calculations and experiments. (C) 2001 Elsevier Science B.V. All rights re served.