中国物理B ›› 2015, Vol. 24 ›› Issue (12): 125202-125202.doi: 10.1088/1674-1056/24/12/125202

• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇    下一篇

A computational modeling study on the helium atmospheric pressure plasma needle discharge

钱沐杨a, 杨从影b, 刘三秋a, 王震东a, 吕燕a, 王德真c   

  1. a Department of Physics, Nanchang University, Nanchang 330031, China;
    b School of Medical, Nanchang University, Nanchang 330031, China;
    c School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023, China
  • 收稿日期:2015-07-12 修回日期:2015-08-15 出版日期:2015-12-05 发布日期:2015-12-05
  • 通讯作者: Qian Mu-Yang E-mail:qianmuyang@ncu.edu.cn
  • 基金资助:
    Project supported partly by the National Natural Science Foundation of China (Grant No. 11465013), the Natural Science Foundation of Jiangxi Province, China (Grant No. 20151BAB212012), and in part by the International Science and Technology Cooperation Program of China (Grant No. 2015DFA61800).

A computational modeling study on the helium atmospheric pressure plasma needle discharge

Qian Mu-Yang (钱沐杨)a, Yang Cong-Ying (杨从影)b, Liu San-Qiu (刘三秋)a, Wang Zhen-Dong (王震东)a, Lv Yan (吕燕)a, Wang De-Zhen (王德真)c   

  1. a Department of Physics, Nanchang University, Nanchang 330031, China;
    b School of Medical, Nanchang University, Nanchang 330031, China;
    c School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023, China
  • Received:2015-07-12 Revised:2015-08-15 Online:2015-12-05 Published:2015-12-05
  • Contact: Qian Mu-Yang E-mail:qianmuyang@ncu.edu.cn
  • Supported by:
    Project supported partly by the National Natural Science Foundation of China (Grant No. 11465013), the Natural Science Foundation of Jiangxi Province, China (Grant No. 20151BAB212012), and in part by the International Science and Technology Cooperation Program of China (Grant No. 2015DFA61800).

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摘要： A two-dimensional coupled model of neutral gas flow and plasma dynamics is employed to investigate the streamer dynamics in a helium plasma needle at atmospheric pressure. A parametric study of the streamer propagation as a function of needle tip curvature radius and helium gas flow rate is presented. The key chemical reactions at the He/air mixing layer which drive the streamer propagation are the direct ionization via collision with electrons, the Penning effect being not so crucial. With increasing the gas flow rate from 0.2 standard liter per minute (SLM) to 0.8 SLM, however, the emissions resulting from reactive oxygen and nitrogen species change from a solid circle to a hollow profile and the average streamer propagation velocity decreases. Air impurities (backdiffusion from ambient air) in the helium jet result in a significant increase in the streamer propagation velocity. Besides, with decreasing the tip curvature radiusfrom 200 μ to 100 μ, the electron avalanche process around the near-tip region is more pronounced. However, the spatially resolved plasma parameters distributions (electron, helium metastables, ground state atomic oxygen, etc.) remain almost the same, except that around the near-tip region where their peak values are more than doubled.

关键词: atmospheric pressureplasma needle, fluid model, streamer propagation

Abstract: A two-dimensional coupled model of neutral gas flow and plasma dynamics is employed to investigate the streamer dynamics in a helium plasma needle at atmospheric pressure. A parametric study of the streamer propagation as a function of needle tip curvature radius and helium gas flow rate is presented. The key chemical reactions at the He/air mixing layer which drive the streamer propagation are the direct ionization via collision with electrons, the Penning effect being not so crucial. With increasing the gas flow rate from 0.2 standard liter per minute (SLM) to 0.8 SLM, however, the emissions resulting from reactive oxygen and nitrogen species change from a solid circle to a hollow profile and the average streamer propagation velocity decreases. Air impurities (backdiffusion from ambient air) in the helium jet result in a significant increase in the streamer propagation velocity. Besides, with decreasing the tip curvature radiusfrom 200 μ to 100 μ, the electron avalanche process around the near-tip region is more pronounced. However, the spatially resolved plasma parameters distributions (electron, helium metastables, ground state atomic oxygen, etc.) remain almost the same, except that around the near-tip region where their peak values are more than doubled.

Key words: atmospheric pressureplasma needle, fluid model, streamer propagation

中图分类号:  (Plasma sources)

  • 52.50.Dg
52.65.Kj (Magnetohydrodynamic and fluid equation) 52.80.-s (Electric discharges)