High current plasma electron emitter

Abstract

A high current plasma electron emitter based on a miniature plasma source has been developed. The emitting plasma is created by a pulsed high current gas discharge. The electron emission current is 1 kA at 300 V with a pulse duration of 10 ms. The prototype injector described in this paper will be used for a 20 kA electrostatic current injection experiment in the Madison symmetric torus reversed-field pinch. The source will be replicated in order to attain this total current requirement. The source has a simple design and has proven to be very reliable in operation. A high emission current, small size (3.7 cm in diameter) and low impurity generation make the source suitable for a variety of fusion and technological applications.