Characterization of a Fixed-Volume Release System for Initiating an Arc Discharge in a Heaterless Hollow Cathode

Ham, Ryan K ; Williams, John D ; Hall, Scott J ; Benavides, Gabriel F ; Verhey, Timothy R

关键词: ARC DISCHARGES;    BIAS;    CATHODE GLOW;    ELECTRIC POTENTIAL;    ELECTRIC PROPULSION;    FAILURE MODES;    FLOW VELOCITY;    HALL EFFECT THRUSTERS (HET);    HOLLOW CATHODES;    IGNITION;    PLASMA JETS;    PLASMAS (PHYSICS);    PROPELLANTS;    SPACECRAFT PROPULSION;    XENON;   

RP-ID  :  GRC-E-DAA-TN72605

学科分类：航空航天科学

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Heaterless hollow cathodes may provide improved reliability, simplicity, and portability when compared with traditional heater-equipped hollow cathodes, traits which are well suited for low-power Hall-effect thrusters that are currently being developed for small satellite propulsion. Despite the advantages, there are concerns that the ignition process in heaterless hollow cathodes may impose an excessive burden on the propellant feed and/or electrical systems of a small satellite. To address this concern, a fixed-volume release flow protocol, which can be used to temporarily increase the propellant mass flow rate, was developed, modeled, and experimentally evaluated. The new protocol allowed for a heaterless hollow cathode to be ignited reliably with a moderate bias voltage and a minimal electrical power requirement. Specifically, a xenon fed heaterless hollow cathode was ignited with a 375 V bias using 17.3 mg of propellant. Repeating the tests with krypton showed that ignition could be achieved in the same heaterless hollow cathode assembly with a 300 V bias using 13.1 mg of propellant. We judge that a fixed-volume release system could be implemented in a satellite feed system while introducing minimal additional complexity.