Laser-based foilless diode

Abstract

A new foilless diode has been developed that does not require an external magnetic field to control beam expansion of an intense relativistic electron beam (IREB). An ionized channel, formed with use of a laser, extends through the transport region and terminates at the cathode of an IREB accelerator. When a negative potential is applied to the cathode, channel electrons are expelled leaving a positive core that electrostatically attracts and focuses the emitted electrons. A 3.6-MeV, 25-kA electron beam has been generated and transported 1.3 m by use of this technique.