HIGH-EFFICIENCY RELATIVISTIC BACKWARD-WAVE OSCILLATOR - THEORY AND DESIGN

Backward wave oscillators (BWO's) driven by high-current relativistic electron beams are capable of producing high-power coherent radiation in the centimeter and millimeter wavelength regions, However, the effi ciency of these devices is usually limited to 15-20% when a homogeneou s slow-wave structure is used, Utilizing a two-section slow-wave struc ture, where the spatial period of the second section is larger than th at bf the first section, a BWO efficiency of greater than 50% was calc ulated, A conceptual design of a high efficiency S-band BWO driven by a 500-kV 5-kA electron beam has been developed and analyzed.