High-power operation of a K-band second-harmonic gyroklystron.

Abstract

Amplification studies of a two-cavity second-harmonic gyroklystron are reported. A magnetron injection gun produces a 440 kV, 200--245 A, 1 \ensuremath{\mu}s beam with an average perpendicular-to-parallel velocity ratio slightly less than 1. The ${\mathrm{TE}}_{011}$ input cavity is driven near 9.88 GHz and the ${\mathrm{TE}}_{021}$ output cavity resonates near 19.76 GHz. Peak powers exceeding 21 MW are achieved with an efficiency near 21% and a large signal gain above 25 dB. This performance represents the current state of the art for gyroklystrons in terms of the peak power normalized to the output wavelength squared.