射频离子推力器束流特性数值模拟

为了分析射频离子推力器束流特性,基于二维流体模型对自研的11 cm射频离子推力器开展放电室等离子体数值模拟,获得给定电气参数下离子密度、电子温度等关键参数的分布特性;研究了等离子体参数和束流大小与射频功率间的函数关系;以等离子体参数和栅极参数为输入,基于离子光学系统模型获得不同工况下的单孔离子引出轨迹.研究结果显示:离子密度和电子温度分别沿放电室径向逐渐减小和增大,有利于获得更好的束流均匀性及更大的束流;束流大小与射频功率呈线性正相关关系,有利于实现束流连续精确可调;屏栅上游鞘层的形成与离子密度、离子种类、栅极电压组合相关,综合考虑以上因素获得最佳束流聚焦和引出特性.

Numerical Simulation of Beam Characteristics of RF Ion Thruster

In order toIn order to analyze the beam characteristics of RF ion thruster, the plasma numerical simulation of 11cm RF ion thruster was carried out based on a two-dimensional fluid model, the distribution characteristics of key plasma parameters including ion density and electron temperature were solved under certain gas and electrical parameters. The relationship between plasma parameters, beam current and RF power were studied. The ions extraction trajectories of single hole under different working conditions were obtained based on the ion optics system model by using plasma parameters and grids parameters as inputs. The results show that the ion density and electron temperature decrease and increase along the radial direction of the discharge chamber respectively, which is beneficial to achieve better beam uniformity and larger beam current. There is a linear positive correlation between beam current and RF power, which is beneficial to realize the continuous and accurate adjustment of beam current. The formation of upstream sheath is closely related to ion density, ion type, and grids voltage, these factors need to be considered to obtain the best focusing and extraction characteristics.