微波驱动的电子回旋共振阴极研究综述

The microwave-driven electron cyclotron resonance(ECR)cathode is a type of plasma cathode that generates high-density plasma through ECR heating,capable of extracting electron currents ranging from several milliamperes to over 1 ampere. It features a simple structure,easy operation,and stable performance, with advantages such as strong propellant adaptability and low operating temperature(room temperature). This cathode is well-suited for low-power electric propulsion systems of up to 100 W,demonstrating significant appli⁃ cation potential in microsatellites,deep space exploration,and very-low Earth orbit(VLEO)air-breathing pro⁃ pulsion missions. Starting from the operating principle and primary processes of ECR cathodes,this paper system⁃ atically reviews the core research advances of microwave ECR cathodes:First,it clarifies the operating principle (multi-physical field coupling process involving ECR resonant heating,magnetic mirror confinement,ionization collision,and electron extraction)and characteristics(high current density and broad propellant compatibility). Second,it summarizes key technological breakthroughs at home and abroad from four aspects:prototype develop⁃ ment(Japanese μ1/μ10 models,improved models in China),simulation studies(PIC/MCC models revealing plasma generation and electron extraction mechanisms),lifetime reliability(effects of sputtering contamination and spacecraft surface conditions),and multi-propellant feasibility(performance differences among propellants such as xenon,argon,krypton,nitrogen,and water). Finally,it discusses remaining issues and challenges for microwave cathodes. Research indicates that microwave ECR cathodes have gradually transitioned from laborato⁃ ry validation to engineering applications. Future efforts should further deepen multi-physical field coupling mech⁃ anisms,material anti-erosion design,and multi-propellant adaptation technologies to support their deployment in more complex space missions.