Dispenser cathodes: The current state of the technology

This paper describes the present technology of dispenser cathodes with emphasis on emission characteristics and life capabilities of the various types. The differences between the "B" the "S" the "L" the "M" the "MK", the "CPD" the "MMM" (Mixed Metal Matrix), the scandate and "CPD" Cathodes are described. Work is going on in several locations in the U.S., the U.K., Germany, Holland and France on dispenser cathodes. The primary purpose of this paper is to distinguish between the characteristics of the dispenser cathodes that are presently or soon to be available to potential users such as tube designers and the update the status of the technology.