HIGH-POWER OPERATION OF AN X-BAND GYROTWISTRON

We report the first experimental verification of a gyrotwistron amplif ier. The device utilized a single 9.858 GHz, TE011 cavity, a heavily a ttenuated drift tube, and a long tapered output waveguide section. Wit h a 440 kV, 200-245 A, 1 mus electron beam and a sharply tapered axial magnetic field, peak powers above 21 MW were achieved with a gain nea r 24 dB. Performance was limited by competition from a fundamental TE1 1 mode. A multimode code was developed to analyze this system, and sim ulations were in good agreement with the experiment.