6.1: High current density - long life cathodes for high frequency applications

Sintered tungsten wire reservoir cathodes offer the promise of high current density operation with very long life time. The fabrication technique provides controlled porosity for diffusion of barium and oxygen to the emission surface to reduce the work function. The diffusion rate can be controlled depending on the current emission density requirement. The barium mixture is contained in a reservoir to provide extremely long lifetimes. This presentation will review the fabrication process and present the latest test results.