Design and cold-testing of a high gain, Ku-band gyroklystron

At the University of Maryland, we have been evaluating the use of gyroklystrons to drive RF accelerators. In order to use our 500 kV, 500 A system to energize a 17 GHz accelerator structure built by the Haimson Research Corporation, we need a large-signal gain of nearly 50 dB. To accomplish this goal, we have designed a six-cavity circuit in which the first three cavities operate near the cyclotron frequency and the last three cavities operate near the second harmonic. Adequate efficiencies and gains are predicted via numerical simulations with the MAGYKL code, even for average perpendicular to parallel velocity ratios (alphas) as low as one.