射频离子推力器由于其推力连续可调、寿命长，比冲大和工质利用率高等 优点，成为电推力器研究的一大热点。目前射频离子推力器主要使用的推进工 质为氙气、氪气等稀有气体，但这类气体地球储量极少并且价格昂贵。为了降 低成本并优化推进系统结构，研究者们尝试使用固体碘作为推进工质，相继开 展了固态工质射频离子推进技术研究。目前此类型推进工质的应用技术，需要 推进系统具有工质加热单元和流量控制单元，整体系统复杂性仍然较高。为了 进一步降低系统复杂度，本文参考烧蚀型固态工质电推力器，开展无固态工质 气化供给单元的固体烧蚀型射频离子推力技术研究。 首先，利用放电室内径为 4cm 射频离子推力器（Radio frequency ion thruster，RIT）RIT-4研究了其以聚四氟乙烯（Polytetrafluoroethylene，PTFE）为工质 的稳定工作模式。在点火时通入一定量 Xe 气并维持功率不变，推力器的离子束 流呈先上升后下降的变化趋势，当离子束流趋于稳定时即可将氙气流量降至0， 完全依靠 PTFE分解出的气体来实现等离子体的自持放电，推力器可以持续稳定 的工作。 然后，使用平面探针测试了 RIT-4 分别以氙气和 PTFE 作为工质时的离子束 流密度和等离子体特性。发现在没有中和器的情况下，以 PTFE为工质时的离子 束流悬浮电位比以 Xe 气为工质时的离子束流低很多，而 PTFE 的离子束流发散 角要更大，约为 20°。通过测量参数评估出 RIT-4 以 PTFE 工作时当前能达到的 指标：推力为 1.02mN，比冲为 1236.17s，功推比为 93.14 W/mN，电效率为 44.5 %，工质利用率为 14.1%。 最后，实验研究了射频等离子体桥中和器 RPN-4 电子引出特性，实验发现 发射孔径的变化，会对中和器电子引出电压、饱和电流和工质利用系数产生较 大的影响，且在部分孔径下发现了电子束流随引出电压上升时出现二次跃变现 象。根据工质利用系数和电子引出功耗比分析得到中和器最优发射孔径为 1.5 mm，当电子束流引出为 1 A 时，工质利用系数达到 27.7，电子引出功耗比为 94.6 W/A。

Radio frequency ion thruster has become a hot spot in the research of electric thruster because of its advantages such as continuously adjustable thrust, long life, high specific impulse and high efficiency of working medium. At present, rare gases such as xenon and krypton are mainly used in radio frequency ion thrusters, but these gases are rare and expensive. In order to reduce the cost and optimize the structure of the propulsion system, researchers tried to use solid iodine as the propellant, and successively carried out the research on radio frequency ion propulsion technology of solid refrigerant. At present, the application technology of this type of propellant requires that the propulsion system has a working fluid heating unit and a flow control unit, and the overall system complexity is very high. In order to further reduce the complexity of the system, this paper refers to the ablation solid working medium electric thruster to carry out the solid ablation type radio frequency ion thrust technology without solid working medium gasification supply unit. Firstly, the stable working mode of polytetrafluoroethylene (PTFE) was studied by using 4cm radio frequency ion thruster (RIT-4) with inner diameter of discharge chamber. When a certain amount of xenon is injected during ignition, the ion beam current of the thruster with constant power increases at first and then decreases. When the ion beam current tends to be stable, the xenon flow rate can be reduced to 0. The plasma self-sustaining discharge can be realized completely by relying on the gas decomposed by PTFE, and the thruster can work continuously and stably. Then, the ion beam density and plasma characteristics of RIT -4 with xenon and PTFE as working fluids were measured using a planar probe. It was found that in the absence of a neutralizer, the suspension potential of the ion beam with PTFE was much lower than that with xenon, and the divergence angle of the PTFE ion beam was about 20 ° . Based on the measured parameters, the thrust, specific impulse, work-to-thrust ratio, electrical efficiency, and working PTFE utilization of Rit-4 were estimated to be 1.02 mN, 1236.17 s, 93.14 W/MN, 44.5% , and 14.1% respectively. Finally, the electron extraction characteristics of the radio frequency plasma bridge neutralizer RPN-4 are studied experimentally. it is found that the change of the emission aperture will have a great influence on the electron extraction voltage, saturation current and working medium utilization coefficient of the neutralizer, and the second jump of the electron beam with the increase of the extraction voltage is found under the partial aperture. According to the analysis of the working fluid utilization coefficient and the electron extraction power consumption ratio, the optimal emission aperture of the neutralizer is 1.5 mm. When the electron beam extraction is 1 A, the working medium utilization coefficient is 27.7, and the electron extraction power consumption ratio is 94.6W/A