微牛级射频离子推力器结构优化研究

Structure Optimization of Micro-Newton Class Radio-Frequency Ion Thruster

关键词:  空间引力波探测  电推进  射频离子推力器  结构优化  微牛级

Key words:  Space gravitational wave detection  Electric propulsion  Radio-frequency ion thruster  Structure optimization  Micro-Newton class

摘要:

为了满足中国科学院空间引力波探测——“空间太极计划”对航天器推进系统提出的微牛量级推力高精度控制需求，基于感性耦合等离子体自持放电，设计了一套微牛级射频离子推力器（μRIT-1）。通过理论分析与实验验证，完成了μRIT-1关键结构组件优化工作，包括射频天线、放电室及离子光学系统。根据实验结果，μRIT-1采用7匝线直径为1.6mm的紫铜管作为射频天线，匝间距为2.0mm；放电室材料为氧化铝陶瓷，内径为1.0cm，长径比为1.5；离子光学系统采用双栅极结构，材料为金属钼，栅极透明度为18.05%。经过结构优化，μRIT-1可以实现5~100μN可调推力输出，比冲可达1275s。

Abstract:

In order to meet the micro-newton level thrust high-precision control requirements of spacecraft propulsion system， which was proposed by the space gravitational wave detection program of the Chinese Academy of Sciences called “Space Taiji Project”， a micro-newton level radio-frequency ion thruster （μRIT-1） was designed that was based on the inductively coupled plasma self-sustaining discharge. Through the theoretical analysis and the experimental verification， the optimization of key components of the μRIT-1 was completed， including RF antenna， discharge chamber and ion optical system. According to the experimental results of the μRIT-1， the RF antenna was 7 turns and 2.0mm pitch with 1.6mm diameter copper tube. The material of discharge chamber was alumina ceramic， the inner diameter was 1.0cm and the length to diameter ratio was 1.5. The ion optics system was two grids structure with molybdenum， and the gird transparency was 18.05%. After structural optimization， the thrust range of the μRIT-1 was 5~100μN， and the maximum specific impulse was 1275s.