Megavolt, multikiloamp <i>K</i> <i>a</i> band gyrotron oscillator experiment

Abstract

A Ka-band gyrotron oscillator experiment using a 1–1.35 MeV, multikiloampere beam from a pulse line accelerator has produced approximately 250 MW at 35 GHz in a circular TE62 mode with a peak efficiency exceeding 10%. Time-dependent simulation studies have been used to predict the behavior of a high-peak-power, short-pulse gyrotron in this parameter range. The simulations demonstrate the occurrence of such phenomena as hard excitation of the gyrotron as a result of the time dependence of the voltage pulse. The experimental results are in reasonable agreement with the predictions of theory.