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为了系统地分析LIPS-200离子推力器交换电荷(CEX)离子对加速栅壁面的轰击溅射腐蚀机理,本文针对该推力器栅极系统最关键的两种磨损失效模式,即加速栅结构失效和电子反流失效,利用数值模拟Paritle-in-cell(PIC)和Monte-Carlo collision(MCC)方法,仿真模拟了束流引出过程中CEX离子的产生、加速及引出过程,得到了主束流离子空间位置分布、静电势分布、CEX离子分布和对应的密度分布。同时,采用数值仿真计算和理论分析相结合的方法对栅极寿命进行了评估。计算结果显示在现有几何结构和工作电参数一定的情况下,LIPS-200离子推力器栅极系统能很好地引出束流离子,无CEX离子直接轰击到加速栅壁面,程序统计到的整个栅极系统加速栅壁面截获的CEX离子电流约为9.76×10-4A。证明了加速栅电流的主要来源是冲击到壁面的CEX离子,计算得到的加速栅电流与束流电流比例为0.122%。LIPS-200离子推力器栅极寿命为11230.1 h,其对应的关键失效模式为加速栅结构失效。
In order to systematically analyze the mechanism of bombardment and sputter corrosion of accelerated gate wall by LIPS-200 ion thruster exchange charge (CEX) ions, this paper aims at the two most critical failure modes of the thruster gate system, ie, acceleration grid structure failure and The electron backflow is invalid. By using the Paritle-in-cell (PIC) and Monte-Carlo collision (MCC) methods, the generation, acceleration and extraction of CEX ions in the beam extraction process are simulated. Spatial distribution, electrostatic potential distribution, CEX ion distribution and corresponding density distribution. At the same time, the life of gate was evaluated by the method of numerical simulation and theoretical analysis. The calculation results show that the LIPS-200 ion thruster grid system can well extract the ion beam without the CEX ions bombarding the accelerating grid wall under the condition of the existing geometric structure and working electrical parameters, and the program statistics to the whole The CEX ion current intercepted by the gate system accelerating gate wall is about 9.76 × 10-4A. It is proved that the main source of accelerating gate current is CEX ion impinging on the wall. The calculated ratio of accelerating gate current to beam current is 0.122%. The lifetime of the LIPS-200 ion thruster grid is 11230.1 h, and the corresponding critical failure mode is the failure of the accelerating grid structure.