Two-Dimensional Hollow Cathodes and Arrays of Cathodes
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-29
A two-dimensional hollow cathode has been developed for use as an electron emitter in a plasma or as an electron gun. The cathode utilizes a fundamental hollow cathode effect in what is essentially a two-dimensional enclosure. The hollow cathode effect has also been developed such that multiple-hold hollow cathodes are possible on a single device. The device consists of a sandwich of thin tantalum foils which are firmly attached at their edges. A gas supply in the form of a tube provides the increased gas density necessary for the hollow cathode effect to operate. On one surface of the sandwich, a small hole, or multiple holes, are drilled which then become the hollow cathodes. The internal Ta foils behind these holes are heated to thermionic temperatures by ion bombardment and become electron emitters.