Plasma hollow cathodes

Hollow cathode plasma discharges are a fundamental part of large variety applications in industry, academia, and space. From surface processing coatings deposition to plasma–surface interaction research electric propulsion, advances hollow modeling performance critically important the progress evolution these other areas technology. This paper describes perspectives on that has been made recent years capabilities cathodes used discharges. While many developments have driven by demanding requirements propulsion applications, information provided applies all thermionic their applications. In paper, we describe status 2D global simulations plasmas, plume instabilities, development higher current low-current heaterless technologies. Advances our understanding technology some challenges still need be addressed solved discussed.