Computational and experimental research on the performance of ECRIT ion source with nitrogen propellant

氮工质ECRIT离子源性能计算与实验研究

¹ School of Astronautics, Northwestern Polytechnical University, Xi'an 710072, China
² Lanzhou Institute of Physics, Lanzhou 730000, China

Received: 8 June 2022

Abstract

Electron cyclotron resonance ion thruster (ECRIT) with a diameter of 2 cm has the characteristics of no hot cathode and high specific impulse, which is suitable for the air-breathing electric propulsion system. In order to adapt to the atmospheric composition characteristics of nitrogen and oxygen in low orbit, the computational and experimental research on the performance of the ECRIT ion sourse with nitrogen propellant is an important basis for analyzing the feasibility of applying ECRIT to the air-breathing electric propulsion system. In this paper, the global model of the nitrogen ECRIT ion source with a diameter of 2 cm is established to calculate its performance. Then, the computational results are compared with the experimental results to analyze the difference. The research results show that when the input power of the ion source is 8 W and the gas flow rate is 2 ml/min, the computational and experimental results of the extracted ion beam current and thrust reach the maximum with the extracted beam current of 16.2 and 12.5 mA and the thrust of 476.6 and 368 μN, respectively. When the input power is 8 W and the gas flow rate is 0.6 ml/min, the computational and experimental results of the specific impulse are 2 095.8 and 1 855.6 s, both reaching the maximum value. The relative errors between the computational and experimental results of the extracted ion beam current, thrust and specific impulse all range from 2% to 32%. When the input power and gas flow rate used are 8 W and 1 ml/min in calculation, and 8 W and 0.8 ml/min in experiment, the ion source is on the optimal operating state. At this situation, the computational and experimental propellant utilization efficiencies with 17.8% and 16.2% respectively are high, and the ion energy loss with 443.9 and 596.2 W/A respectively is low.

摘要

2 cm电子回旋共振离子推力器(electron cyclotron resonance ion thruster, ECRIT)具有无热阴极、比冲高等特点, 适用于吸气式电推进系统。为了适应低轨道氮氧混合大气成分特点, 开展氮工质ECRIT离子源的性能计算与实验研究, 是分析ECRIT应用于吸气电推进系统的可行性的重要基础。建立了氮工质2 cm ECRIT离子源的整体模型并计算其性能, 再与实验结果相互对比, 分析两者差别。研究结果表明: ①当离子源的输入功率为8 W, 气体流量为2 ml/min时, 离子引出束流和推力的计算与实验结果均达到最大值, 引出束流分别为16.2与12.5 mA, 推力分别476.6与368 μN。②当输入功率为8 W, 气体流量为0.6 ml/min时, 比冲的计算与实验结果为2 095.8与1 855.6 s, 均达到最大值, 离子引出束流、推力和比冲的计算与实验结果的相对误差变化范围均为2%~32%。③当计算采用的输入功率为8 W, 气体流量为1 ml/min, 实验采用的输入功率为8 W, 气体流量为0.8 ml/min时, 离子源都处于最优工作状态, 此时推进剂利用效率较高, 分别为17.8%和16.2%;离子能量损耗较低, 分别为443.9和596.2 W/A。