High-gradient acceleration of electron beam by superradiative microwave pulse

Abstract

For high-gradient acceleration of electron bunches by microwave superradiance pulses, a scheme is considered in which devices for the radiation generation and particle acceleration are combined. Two electron beams from coaxial cathodes powered by a single voltage pulse (–300 kV; 1.5 ns) are used. Outer tubular beam excites a relativistic superradiant Ka-band backward-wave oscillator (BWO), and paraxial beam is accelerated in a “pill-box” cavity positioned at the input of the BWO slow-wave structure. Formation of such beams is studied with the use a model cathode system. In calculations by particles-in-cells method, the rate of electron acceleration of up to 400 MeV/m was obtained and the role of nonsynchronous microwaves-to-bunches interaction was shown.