Recent progress in research and development of hollow cathodes for electric propulsion

• Published in: Reviews of modern plasma physics Vol. 3; no. 1
• Main Authors: Lev, Dan R., Mikellides, Ioannis G., Pedrini, Daniela, Goebel, Dan M., Jorns, Benjamin A., McDonald, Michael S.
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 03.06.2019
• Subjects: Astronomy; Astrophysics and Cosmology; Lasers; Nuclear Fusion; Optical Devices; Optics; Photonics; Physics; Physics and Astronomy; Plasma Physics; Recent Progress in Physics of Plasma-Based Space Propulsion; Topical Collection: Review Paper; Electric propulsion; Hollow cathodes; High power; Heaterless; Low power; Instabilities; Electron emitter
• ISSN: 2367-3192; 2367-3192
• DOI: 10.1007/s41614-019-0026-0

Electric thrusters are finding increasing usage worldwide in spacecraft applications. Significant progress has been made in recent years in the modeling and performance of thermionic hollow cathodes used in flight thrusters, such as Hall and ion thrusters, or other types of plasma sources, such as for technological plasmas. The recent progress is surveyed in this paper through the discussion of six areas: hollow cathode modeling and simulation, low-current hollow cathodes, high-current hollow cathodes, heaterless hollow cathodes, new thermionic insert materials, and plasma oscillations. This includes descriptions of hollow cathode designs capable of < 1 A to over 300 A, advances in electron emitter and heating/starting technologies, and modeling and simulation of the plasma properties, thermal behavior and instabilities in the discharge. Advances in the understanding and technology in these areas and challenges that still need to be addressed and solved are discussed.