Controlled porosity dispenser cathode: Iridium-barium oxide

This paper discusses the development of a novel technique of fabrication of a porous metal matrix dispenser cathode based on the iridium-barium oxide system. Studies at the Naval Research Laboratories utilizing surface analysis techniques determined many of the critical parameters such as pore size and matrix thickness and their effect on work function, surface coverage and evaporation rate. These studies led to the development of a cathode that utilized as a matrix a foil of iridium containing an array of holes produced by photolithographic techniques. Cathodes were fabricated and tested in a specially designed vehicle which simulated a real tube environment.