Numerical research of a 2D axial symmetry hybrid model for the radio-frequency ion thruster

Since the high efficiency discharge is critical to the radio-frequency ion thruster (RIT),a 2D axial symmetry hybrid model has been developed to study the plasma evolution of RIT.The fluid method and the drift energy correction of the electron energy distribution function (EEDF) are applied to the analysis of the RIT discharge.In the meantime,the PIC-MCC method is used to investigate the ion beam current extraction character for the plasma plume region.The beam current simulation results,with the hybrid model,agree well with the experimental results,and the error is lower than 11％,which shows the validity of the model.The further study shows there is an optimal ratio for the radio-frequency (RF) power and the beam current extraction power under the fixed RIT configuration.And the beam extraction efficiency will decrease when the discharge efficiency beyond a certain threshold (about 87 W).As the input parameters of the hybrid model are all the design values,it can be directly used to the optimum design for other kinds of RITs and radio-frequency ion sources.     

微电推进系统研制及应用现状

200kg以下的微小卫星的轨道维持、姿态控制、阻尼补偿、编队飞行等任务对微电推进技术及产品提出了明确的应用需求,不同类型的微电推进在不同功率范围内有着各自的优势。本文对中国微小卫星12U立方星LPPT-5脉冲等离子体电推进系统、150kg小卫星LPPT-25脉冲等离子体电推进系统、6U立方星LVAT-1真空弧电推进系统、引力波探测卫星LCT-10胶体电推进系统、低轨小卫星星座LHT-40霍尔电推进系统方案及研制进展进行了论述,最后对正在研制的LRIT-40射频离子电推进系统与LECR-50微波离子电推进系统研制情况及后续应用进行了展望。     

Kaufman放电室二次电子温度的计算方法研究

二次电子温度计算是研究Kaufman放电室的核心内容之一。针对Kaufman放电室建立稳态平板非均匀放电模型对二次电子温度进行求解。稳态平板非均匀放电模型从扩散方程出发,重点考虑离子漂移造成的扩散运动和双极性电场对放电室径向密度梯度造成的影响,进一步结合粒子数守恒方程,给出用于求解二次电子温度的方程的解析表达式。代入典型的Kaufman放电室结构参数进行计算的结果表明,用稳态平板非均匀放电模型计算出来的二次电子温度符合实验测量的范围,同时说明在中低压放电条件下,扩散运动和双极性电场是影响放电性能的关键参数。