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Plasma Sci. Technol. ›› 2019, Vol. 21 ›› Issue (7): 074003.doi: 10.1088/2058-6272/ab10a7

• 2018 National Conference on High Voltage and Discharge Plasmas • Previous Articles     Next Articles

Influence of nitrogen impurities on the characteristics of a patterned helium dielectric barrier discharge at atmospheric pressure

Yuhui ZHANG (张雨晖), Wenjun NING (宁文军), Dong DAI (戴栋) and Qiao WANG (王乔)   

  

  1. School of Electric Power, South China University of Technology, Guangzhou 510641, People’s Republic of China
  • Received:2018-11-15 Published:2019-03-14
  • Supported by:

    This work is supported by National Natural Science Foundation of China (Grant No. 51877086).

Abstract:

In this paper, a two-dimensional axisymmetric fluid model was established to investigate the influence of nitrogen impurity content on the discharge pattern and the relevant discharge characteristics in an atmosphere pressure helium dielectric barrier discharge (DBD). The results indicated that when the nitrogen content was increased from 1 to 100 ppm, the discharge pattern evolved from a concentric-ring pattern into a uniform pattern, and then returned to the concentricring pattern. In this process, the discharge mode at the current peak moment transformed from glow mode into Townsend mode, and then returned to glow mode. Further analyses revealed that with the increase of impurity level, the rate of Penning ionization at the pre-ionization stage increased at first and decreased afterwards, resulting in a similar evolution pattern of seed electron level. This evolution trend was believed to be resulted from the competition between the N2 partial pressure and the consumption rate of metastable species. Moreover, the discharge uniformity was found positively correlated with the spatial uniformity of seed electron density as well as the seed electron level. The reason for this correlation was explained by the reduction of radial electric field strength and the promotion of seed electron uniformity as pre-ionization level increases. The results obtained in this work may help better understand the pattern formation mechanism of atmospheric helium DBD under the variation of N2 impurity level, thereby providing a possible means of regulating the discharge performance in practical application scenarios.

Key words: pattern, dielectric barrier discharge, impurities, Penning ionization, discharge uniformity, seed electron