10 MW, X- and Ka-band gyrotrons

Summary form only given, as follows. The results of the development of moderately relativistic X and Ka-band gyrotrons are presented. For the first time the high efficiency (about 50%) single-mode generation at the power level of about 5-10 MW was realized without recuperation at the beam energy of about 300 keV. The microwave pulse duration at the X-band gyrotron achieved 7 mcs, and at the Ka-band it was varied from 200 to 600 ns. Operation of the relativistic gyrotron was simulated by the method based on the stationary model with the selfconsistent, not-fixed structure of the field. It was found that additional optimization of the cavity profile and parameters of magnetron injection gun might increase relativistic gyrotron efficiency up to 50 %.