Self-bunching micro-pulse guns for high-power RF generation

Schemes for the generation of high-power microwave using the micro-pulse electron gun (MPG) technology are presented. The MPGs, with their short electron bunches, are especially well-suited for power tube applications. The main objective of the MPG work is to develop novel electron guns which produce self-bunched high-current density beams and have cold emission, long life, and are non-contaminating. The cold emission process is based on secondary electron emission operating in the reflection mode. Traditional power tube technology employs thermionic cathodes which are easily contaminated. Furthermore, the high temperature required for their operation causes additional problems such as distortion of grids and limited cathode lifetimes. Cold cathodes can potentially eliminate these problems and achieve a similar beam emittance at the same current density as thermionic cathodes.