Plasma cathode electron sources and their applications

Summary form only given. The status of experimental research, ongoing development, and applications of plasma cathode electron sources is reviewed. The attractiveness of this kind of e-gun is due to its ability of producing high current, broad or focussed electron beams both in pulsed and steady state modes of operation. The absence of a hot filament in the plasma cathode e-gun leads to long lifetime and reliable operation, even in the presence of aggressive background gas media and at forevacuum gas pressures (such as obtained by mechanical pumps). Depending on the required beam parameters, different kinds of discharge systems can be used for the plasma cathode, including metal vacuum arcs and constricted gaseous arcs, hollow cathode glows, Penning and magnetron discharges in crossed E and B fields, and others. The specifics of the discharge systems required and the parameters achieved are discussed.