High-Power Operation of a Three-Cavity X-Band Coaxial Gyroklystron

Abstract

Experimental studies of high-power amplification in a novel three-cavity X-band gyroklystron are reported. The electron gun produces a 520 A beam of 470 keV electrons. The voltage flat top is nearly $2\ensuremath{\mu}\mathrm{s}$ and the beam's average velocity ratio is about 1. All cavities are designed to operate in the ${\mathrm{TE}}_{011}$ coaxial mode near 8.6 GHz. Peak powers of 75--85 MW are measured. The resultant efficiency is near $32%$ and the gain is near 30 dB. This performance is in good agreement with simulations and represents nearly a threefold increase in the peak power capability of pulsed X-band gyroklystrons.