부산대학교 도서관

Previously, relativistic gyrotrons with thermionic magnetron-injection electron guns have been demonstrated successfully to produce radiation in the cm and long-mm wavebands with the pulse power exceeding 10 MW. This brief presents a new step toward generating higher-frequency microwaves with a relativistic gyrotron operated in the 3-mm wavelength band. The gyrotron employed with a 250 kV, 100 A, $1~\mu \text{s}$ helical electron beam. The operating wave was the rotating TE 12,5,1 mode of a circular waveguide cavity. The mode was transformed into the Gaussian wave beam by a built-in mode converter. In the optimized single-mode regime, the gyrotron delivered 5.6 MW of the peak power in pulses with durations of about 0.5 $\mu \text{s}$ .