A 4-megavolt, 5-kiloampere pulsed-power high-brightness electron beam source

The REX machine at Los Alamos National Laboratory is being used to generate a 4-MV, 5-kA, 50-ns electron beam. The beam is produced by a planar velvet cathode, accelerated through a foilless anode aperture, and transported by an air core magnetic lens. Extensive measurements of the time-resolved (<1 ns) properties of the beam using a streak camera and high-speed electronic diagnostics have been made. These parameters include beam current, voltage, current density, and emittance for a single cathode-anode configuration. Results indicate beam brightness in excess of 10⁸A/m²-rad². Numerical simulations of the experiment have been performed with ISIS, a time-dependent particle-in-cell code, and are in good agreement with the measurements. This electron beam source is being considered as an injector to a linear induction accelerator and can be operated at higher voltages and currents than a stand-alone flash X-ray machine