Recent Advances in Research and Development of Emissive Materials forHollow Cathodes of Electric Propulsion Systems

Hollow cathode is the core component of an electric thruster, and the research and development of its emitter material has been a hot spot in the field of electric propulsion. From the point of view of the application of hollow cathode at present, BaO-W cathode has been widely used in electric thrusters and has shown excellent performance because of its characteristics of high emission current density and long service life. The research and application of LaB₆ cathode, due to its excellent thermal electron emission characteristics and high stability, further promote the development of electric propulsion technology. The C12A7 electride cathode shows excellent thermal electron emission performance and low work function, which makes it a potential application in the field of electric propulsion. In the future, further research and development work will contribute to its application in a wider range of fields, such as aerospace, satellite and deep space exploration. In summary, BaO-W cathode, LaB₆ cathode and then C12A7 electride cathode with great application potential, the service characteristics of the emitter, such as thermal electron emission performance, discharge behavior in the working medium and working life are the key factors determining the working performance of hollow cathode. Therefore, the research status and development progress of emitter materials at home and abroad are summarized in this paper, and their future development prospects are prospected.