中国物理B ›› 2024, Vol. 33 ›› Issue (10): 105201-105201.doi: 10.1088/1674-1056/ad6250

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Experimental studies of H2/Ar plasma in a cylindrical inductive discharge with an expansion region

Shi-Bo Li(李世博), Si-Yu Xing(邢思雨), Fei Gao(高飞)†, and You-Nian Wang(王友年)   

  1. Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, China
  • 收稿日期:2024-05-07 修回日期:2024-06-20 接受日期:2024-07-12 出版日期:2024-10-15 发布日期:2024-10-15
  • 通讯作者: Fei Gao E-mail:fgao@dlut.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11935005 and 12075049) and the National Key Research and Development Program of China (Grant No. 2017YFE0300106).

Experimental studies of H2/Ar plasma in a cylindrical inductive discharge with an expansion region

Shi-Bo Li(李世博), Si-Yu Xing(邢思雨), Fei Gao(高飞)†, and You-Nian Wang(王友年)   

  1. Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, China
  • Received:2024-05-07 Revised:2024-06-20 Accepted:2024-07-12 Online:2024-10-15 Published:2024-10-15
  • Contact: Fei Gao E-mail:fgao@dlut.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11935005 and 12075049) and the National Key Research and Development Program of China (Grant No. 2017YFE0300106).

摘要: The electrical parameters of H$_{2}$/Ar plasma in a cylindrical inductive discharge with an expansion region are investigated by a Langmuir probe, where Ar fractions range from 0% to 100%. The influence of gas composition and pressure on electron density, the effective electron temperature and the electron energy probability functions (EEPFs) at different spatial positions are present. In driver region, with the introduction of a small amount of Ar at 0.3 Pa, there is a rapid increase in electron density accompanied by a decrease in the effective electron temperature. Additionally, the shape of the EEPF transitions from a three-temperature distribution to a bi-Maxwellian distribution due to an increase in electron-electron collision. However, this phenomenon resulting from the changes in gas composition vanishes at 5 Pa due to the prior depletion of energetic electrons caused by the increase in pressure during hydrogen discharge. The EEPFs for the total energy in expansion region is coincident to these in the driver region at 0.3 Pa, as do the patterns of electron density variation between these two regions for differing Ar fractions. At 5 Pa, as the discharge transitions from H$_{2}$ to Ar, the EEPFs evolved from a bi-Maxwellian distribution with pronounced low energy electrons to a Maxwellian distribution in expansion region. This evolve may be attributed to a reduction in molecular vibrational excitation reactions of electrons during transport and the transition from localized electron dynamics in hydrogen discharge to non-localized electron dynamics in argon discharge. In order to validate the experimental results, we use the COMSOL simulation software to calculate electrical parameters under the same conditions. The evolution and spatial distribution of the electrical parameters of the simulation results agree well with the trend of the experimental results.

关键词: inductively coupled plasma, transmission and distribution, energy distribution functions

Abstract: The electrical parameters of H$_{2}$/Ar plasma in a cylindrical inductive discharge with an expansion region are investigated by a Langmuir probe, where Ar fractions range from 0% to 100%. The influence of gas composition and pressure on electron density, the effective electron temperature and the electron energy probability functions (EEPFs) at different spatial positions are present. In driver region, with the introduction of a small amount of Ar at 0.3 Pa, there is a rapid increase in electron density accompanied by a decrease in the effective electron temperature. Additionally, the shape of the EEPF transitions from a three-temperature distribution to a bi-Maxwellian distribution due to an increase in electron-electron collision. However, this phenomenon resulting from the changes in gas composition vanishes at 5 Pa due to the prior depletion of energetic electrons caused by the increase in pressure during hydrogen discharge. The EEPFs for the total energy in expansion region is coincident to these in the driver region at 0.3 Pa, as do the patterns of electron density variation between these two regions for differing Ar fractions. At 5 Pa, as the discharge transitions from H$_{2}$ to Ar, the EEPFs evolved from a bi-Maxwellian distribution with pronounced low energy electrons to a Maxwellian distribution in expansion region. This evolve may be attributed to a reduction in molecular vibrational excitation reactions of electrons during transport and the transition from localized electron dynamics in hydrogen discharge to non-localized electron dynamics in argon discharge. In order to validate the experimental results, we use the COMSOL simulation software to calculate electrical parameters under the same conditions. The evolution and spatial distribution of the electrical parameters of the simulation results agree well with the trend of the experimental results.

Key words: inductively coupled plasma, transmission and distribution, energy distribution functions

中图分类号:  (Plasma properties)

  • 52.25.-b
52.25.Fi (Transport properties) 52.50.-b (Plasma production and heating)