A ``Gatling" Micro-Pulse Gun for Microwave Frequency Multiplying

Proof-of-principle experiments are proposed to validate a new concept for a Gatling Micro Pulse Gun (GMPG) for a frequency-multiplying, high-power microwave generator. The concept utilizes a rotating cavity mode to generate a series of azimuthally distributed, bunched electron pulses. The bunch formation is based on the Micro Pulse Gun(J. Shiloh et. al., Observations of Electron Bunching in the MPG, this meeting.). A complete high-power amplifier consists of: an input cavity which comprises the GMPG source; (2) post acceleration; (3) radial compression of the micro bunches; and (4) an output cavity operating at an integer multiple of the input frequency. The GMPG depends on resonant amplification of electron current by secondary emission from prescribed emission areas in the input rf cavity. The GMPG produces very short electron bunches by virtue of a natural bunching process. The GMPG appears to be capable of producing high current densities (0.01-10 kA/cm^2) and short pulses (1-100 ps) for frequencies from 1-11 GHz. The bunch pulse width can be adjusted from 1.5-10% of the rf period depending on the rf voltage level and cavity gap spacing.