中国空间科学技术

中国空间科学技术 ›› 2022, Vol. 42 ›› Issue (5): 65-77.doi: 10.16708/j.cnki.1000-758X.2022.0068

• 论文 • 上一篇    下一篇

空心阴极羽流形态与热特性的变化机理

于博，徐亚男，康小录   

  1. 上海空间推进研究所，上海201112
  • 出版日期:2022-09-09 发布日期:2022-09-09

Changing rules of plume pattern and thermal characteristics in discharge modes of hollow cathodes

YU Bo，XU Yanan，KANG Xiaolu   

  1. Shanghai Institute of Space Propulsion，Shanghai 201112，China
  • Published:2022-09-09 Online:2022-09-09

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摘要： 空心阴极的放电模式主要有点状和羽状两种，为研究两种模式的转变机理，采用PIC/PCD（单元粒子/等离子体化学动力学）混合算法对阴极内部等离子体流场进行计算，以辐射传递系数处理阴极内部的热辐射计算，并且在通过流场与热场的多次迭代计算后达到收敛。为验证数值模型的计算精度，考察阴极表面5个测点的计算结果与试验数据对比，计算误差在5%以下，并且以羽流光色计算图与试验照片作对比，定性验证模型对放电模式的模拟精度。在此基础上，对不同气体流量下、不同阴极顶孔径的阴极内部各类等离子体参数分布进行计算，通过分析阳极电压、羽流形态变化的内在原因，获得点-羽放电模式的转变机理，可为阴极优化提供理论支撑。

关键词: 空心阴极, 放电模式, PIC/PCD, 羽流形态, 优化设计

Abstract: There are mainly two discharge modes in hollow cathodes，namely the spot mode and the plume mode.In order to study the transition mechanisms of the two modes，a hybrid model of the PIC（particle in cell）/PCD（plasma and chemical dynamics）was established.This model can solve the plasma parameter distribution in the hollow cathodes，and the heat radiation process can be solved by the radiation transportation coefficient.The solution can be converged after several iterations of the flow-heat coupling calculation.To verify the accuracy of the numerical model，the comparison of the calculation and test results of the 5 measurements on the cathode surface was conducted by a discharge test，and the relative error was less than 5%.Meanwhile，the comparison of the calculated color patterns and the photographs of the cathode plume showed that the numerical model could qualitatively capture the transition of the discharge mode.Based on those，the plasma parameters of the hollow cathode were solved with the PIC/PCD model under the condition of different gas flow rates and different orifice diameters.The mechanisms of the transition mode of the spot-plume discharge were obtained by analyzing the rules of the anode voltage and the plume pattern.This paper can provide the theoretical support for the cathode optimization design.

Key words:  , hollow cathode；discharge mode；PIC/PCD；plume pattern；optimization design