相邻栅孔不同直径作用下的等离子体动态行为和自洽电势演化研究  

Investigation on the Plasma Dynamic Behavior and the Electric Potential Evolution of the Variable Aperture

作　　者：陈娟娟[1] 王江伟 谷增杰 耿海[1] 贾艳辉[1] 胡竞[1] 徐金灵[1,2] CHEN Juanjuan;WANG Jiangwei;GU Zengjie;GENG Hai;JIA Yanhui;HU Jing;XU Jinling(Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics,Lanzhou 730000,China;Hangzhou Institute,China Academy of Space Technology,Hangzhou 310000,China)

机构地区：[1]兰州空间技术物理研究所真空技术与物理重点实验室,兰州730000 [2]中国空间技术研究院杭州中心,杭州310000

出　　处：《真空与低温》2025年第2期177-186,共10页Vacuum and Cryogenics

基　　金：国家自然科学基金(62371213)。

摘　　要：离子推力器具有比冲高、寿命长、推力连续可调等显著技术优势,已成为了卫星位置保持和轨道转移的最佳动力选择。但推力小的特点使得卫星要求推力器在轨工作几千甚至上万小时。变孔径栅极是一种新型的栅极组件,它是通过减小屏栅孔直径,降低栅极中心区域的束流离子密度,提高束流平直度,从而达到延长推力器工作寿命的目的。本文构建了两个相邻的栅孔不同直径下的栅极组件数值仿真计算模型,采用仿真手段模拟了两个栅极孔同时引出束流时孔内的电势分布和束流离子密度分布,旨在获得变孔径栅极对束流离子聚焦特性和电场畸变的影响。研究结果表明,变孔径栅极组件因分区耦合区间的上游等离子体密度相同,屏栅孔直径的大小不会影响栅极组件内的电势分布和束流离子聚焦行为。但是,屏栅孔直径的大小会直接影响栅极组件的性能和工作寿命。栅极组件中心区域的屏栅孔直径减小5.2%将使推力器的平均引出束流下降2.7%、屏栅上游等离子体密度增大1.2%。屏栅孔直径从32.36增至34.26,将使CEX离子的密度从0.19增至0.22,增加13.6%,加速栅的最大溅射腐蚀深度增加11.1%。Due to its high specific impulse,long lifetime and continuously adjustable thrust,the ion thruster has been applied to the satellite position maintenance and orbit transfer.The ion thruster has become the best choice of the dynamic system for position maintenance and orbit transfer missions.But its thrust is so small that it is asked for working thousands or even tens of thousands of hours,which will be more for the deep space missions.Variable aperture,a new concept of the ion optics,could improve the plasma flatness and increase the lifetime.By artificially decreasing the aperture diameter of the screen grid,the plasma density of the grid center will be reduced and it could make the thruster lifetime longer.This paper establishes an ion optics numerical model.Two adjacent apertures with different diameters are chosen and their interactions are taken into account.A simulation method is used to simulate the electric potential distribution and the beam ions density distribution,where the ions from two apertures are extracted simultaneously.This paper aims at investigating the effects of the variable apertures on the perveance characteristics and the changes of the electric field.The simulation results show that the screen grid diameter could not have an influence on the electric potential distribution and the beam ion perveance when the plasma density upstream of the screen grid is constant.However,the screen grid diameter directly impacts on the ion optics performance and lifetime.If the diameter of the screen grid is decreased by 5.2%,the average beam current extracted is reduced by 2.7%and the plasma density upstream of the screen grid is increased by 1.2%.The CEX ion density is increased from 0.19 to 0.22,about 13.6%if the screen grid diameter increases from 32.36 to 34.26,and the maximum erosion depth of the accelerator grid increases by 11.1%.

关 键 词：离子推力器 变孔径栅极组件 束流 工作寿命 

分 类 号：TB71[一般工业技术—真空技术] V439[航空宇航科学与技术—航空宇航推进理论与工程]