Overmoded GW-class surface-wave microwave oscillator

Abstract

Results of theoretical and experimental studies of a GW-class, large diameter microwave oscillator are presented. The device consists of a large cross-section (overmoded), slow-wave structure with a unique profile of wall radius specifically designed to support surface waves and to provide a strong beam-wave coupling at moderate voltage (500 kV), an internal adjustable microwave reflector, a coaxial microwave extraction section, and a coaxial magnetically insulated field emission electron gun. In preliminary experiments carried out at 8.3 GHz, the power level exceeding 0.5 GW and efficiency of 15% have been measured calorimetrically.