The discharge selectivity in an atmospheric pressure helium–argon dielectric barrier discharge

In this paper, an atmospheric pressure polyethylene terephthalate dielectric barrier discharge is produced in a helium–argon mixture. The influences of the electrode voltage on the discharge mode are experimentally investigated. The results show that, at a fixed argon content of 50%, the discharge transits from local uniform, through the isolated pattern, to whole uniform with the increase in the electrode voltage. Both the peak value of current pulse and argon spectra (696.54, 763.13, 772.09, 811.17, and 911.81 nm) intensities are captured to clarify the characteristics of the discharge mode transition. The different discharge characteristic regions are obtained by varying the argon content. In addition, the influence of the argon content on the above-mentioned argon spectra intensities is also researched. The spectra intensities enhance at 696.54, 763.13, and 772.09 nm but weaken at 811.17 and 911.81 nm with the increase in the argon content when the discharge operates in the whole uniform mode. The physical reasons for these results are discussed.