首页 >

工质对射频放电模式转换特性影响的实验研究

张宇,方涛,王陈文,郑鹏,吴建军,钟宇轩   

  1. 国防科技大学
  • 收稿日期:2025-08-31 修回日期:2025-10-30 出版日期:2025-11-03 发布日期:2025-11-03
  • 通讯作者: 郑鹏
  • 基金资助:
    空天动力系统物质输运与能量转化

Experimental study on the influence of propellant on radio frequency dis-charge modes transition characteristics

  • Received:2025-08-31 Revised:2025-10-30 Online:2025-11-03 Published:2025-11-03
  • Contact: Peng ZHENG

摘要: 射频等离子体推力器作为一种无电极式电推力器,是超低轨道吸气式电推进系统长寿命运行的优选推力器方案。环境参数对射频等离子体推力器的放电模式及其转换特性影响显著,直接决定了推力器的宽范围工作稳定性。本文利用朗缪尔探针、发射光谱等实验测量装置,实验测量了不同工质种类、比例和流量工况条件下,等离子体密度和光谱强度随射频功率的变化规律,进而分析工质对于射频放电模式转换特性的影响规律。结果表明,氩气在300 W时发生放电模式CCP → ICP的转换,且等离子体密度和光谱强度跳变规律一致。氮气因电离能较高,放电模式转换所需射频功率阈值显著高于氧气,且在氮氧混合气体中,氧气比例增加可降低转换阈值,但高比例的氧气会因电负性效应易形成负离子,抑制自由电子密度。流量增加会导致气体驻留时间缩短,电子-中性粒子碰撞频率升高,电离效率降低,模式转换所需射频功率阈值升高。研究结果为揭示射频等离子体放电模式转换特性,优化宽域条件下射频等离子体推力器的工作参数提供了重要实验依据。

关键词: 射频等离子体, 工质, 放电模式, 朗缪尔探针, 发射光谱

Abstract: Radio-frequency plasma thrusters, as a type of electrode-less electric thruster, represent a preferred thruster solution for the long-duration operation of air-breathing electric propulsion systems in very low Earth orbits. However, ambient parameters significantly influence the radio-frequency discharge modes and the transition characteristics, which directly determine the thruster's operational stability with a wide range of conditions. This study employed experimental diag-nostic apparatus such as Langmuir probes and optical emission spectroscopy to measure the variations of plasma density and spectral intensity with radio-frequency power under different working conditions, including propellant type, mixture ratio, and flow rate. The influence of the propellant on the transition characteristics of radio-frequency dis-charge modes was subsequently analyzed. The results indicate that for argon, the discharge mode transition from CCP to ICP occurs at 300 W, accompanied by consistent jumps in plasma density and spectral intensity. Due to its higher ionization energy, the required radio-frequency power threshold for discharge mode transition is significantly higher for nitrogen than for oxygen. In nitrogen-oxygen mixtures, an increased oxygen proportion reduces the transition threshold; however, a high oxygen fraction can facilitate the formation of negative ions due to its electronegativity, thereby sup-pressing the free electron density. The threshold RF power for mode transition increases with gas flow rate, driven by the reduced gas residence time, the heightened electron-neutral collision frequency, and the consequent decline in ioni-zation efficiency. The results provide important experimental evidence for elucidating the characteristics of radio-frequency plasma discharge mode transitions and for optimizing the operational parameters of radio-frequency plasma thrusters under wide-range conditions.

Key words: Radio frequency plasma, Propellant, Discharge mode, Langmuir probe, Optical Emission Spectroscopy

中图分类号: