Experimental Research on the Neutralizer of Micro ECR Ion Thruster

微推力ECR离子推力器中和器实验研究

¹ School of Astronautics, Northwestern Polytechnic University, Xi'an 710072, China
² Shanghai Institute of Aerospace Control Technologyal Institute, Shanghai 201109, China

Received: 12 April 2017

Abstract

As the key component of micro electron cyclotron resonance (ECR) ion thruster, the initial gas discharge and electron beam extraction performance of ECR neutralizer plays an important role in the whole performance of ECR ion thruster. The experiment on the neutralizer is completed to study the influence of the antenna structure, cavity length and electronic extraction board on the performance. The experimental results show that, within a certain range, as the length of the cavity is longer, the annular segment of antenna is slightly higher than ECR zone and the width of annular segment is smaller, the performance of the neutralizer is better. There is a reasonable structure for the electronic extraction board to make the performance of the neutralizer better. According to the experimental results, the optimal structure of the neutralizer is determined. For Xe gas, when the microwave power is 2.0W and the gas flow rate is 0.2sccm, the best performances of the optimal neutralizer are that extracted electron beam and coupling voltage is 4mA and 31.5V respectively.

摘要

微推力电子回旋共振（ECR）中和器作为ECR离子推力器的关键组成部分，其初始放电及电子束流引出性能对离子推力器整体性能起着重要作用。研究对象为直径2 cm的ECR离子推力器中和器，根据中和器放电室内静磁场分布，选取不同结构的天线、腔体及电子引出板，并在真空环境下进行束流引出实验。实验结果表明：在一定范围内，腔体长度越长、天线环形段略高于ECR区且环形段宽度越小时，中和器性能越好；对于电子引出板存在一个合理结构使得中和器性能更佳。此外，在一定的偏压及气体流量范围内，无论采用哪种结构的腔体、天线及电子引出板，中和器引出的电子束流的大小均随偏压及气体流量的增加而增加。根据实验中不同组合结构中和器的气体初始放电以及电子束流引出性能的对比，最终得到较为合理的中和器结构。该中和器以氙气为工质，在微波功率2.0 W、流量0.2 mL/min的工作条件下，引出电子束流4 mA所需偏压为31.5 V。