Abstract A heaterless plasma cathode using disc shaped C12A7 electride as emitter material is being developed for electric propulsion systems in space. C12A7 electride is a calcium-aluminate ceramic ( · ) with a low work function of about 2.4eV. The material has been optimized for improved thermionic emission and discharge stability. Due to the low work function of the emitter material, the cathode can be easily ignited from room temperature, eliminating the need of a complex and delicate heater. The cathode has been operated continuously for more than 950 h with the results being presented. After this endurance operation, a detailed material analysis (phase composition and microstructure) has been conducted and is presented.
Highlights An C12A7 electride cathode was operated for 950h at 2A discharge current. The copper body temperature of the cathode was only around 100°C. The surface of the electride emitter showed signs of degradation (melted phases). The bulk microstructure of the emitter was still as manufactured. From the microstructure analysis much higher operational times are anticipated.
Endurance operation of a heaterless C12A7 electride plasma cathode and post operation material analysis
Acta Astronautica ; 214 ; 231-239
2023-10-03
9 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
TIBKAT | 2023
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