Abstract: A technical proposal of using metal Ga instead of Cs was designed to solve the engineering problems of Field Emission Electric Propulsion(FEEP)caused by liquid metal propellant. On the basis of the comparison of physical property between Ga and Cs，the effects on the thrust，efficiency，specific impulse，emitter tip warming，thermal evaporation，oxidation and pollution were listed to indicate the pros and cons of Ga. By developing the principle prototype of Ga-FEEP，liquid metal Ga was successfully filled and wetted under air condition. Quasi-linear field emission was observed in ignition experiments. The results indicate that Ga is a good propellant substitution of FEEP.

Key words: FEEP；Cesium；Gallium；Wetting

摘要： 为解决场发射电推力器由于液态金属推进剂导致的工程化问题，分析并提出以金属镓替代现有推进剂铯的技术方案。基于推进剂镓铯物性对比，分析其对推力与比冲、发射尖端升温、热蒸发、氧化污染等的影响，论证了金属镓的工程化优势及缺点。通过研制金属镓场发射电推力器原理样机，探索并实现了液态金属镓在大气环境中的加注与润湿，在点火试验中获得准线性场发射形貌，表明金属镓是场发射推力器的良好推进剂替代物。

关键词: 场发射电推力器；铯；镓；润湿