Estimation of densities of active species in an atmospheric pressure N2DBD flowing afterglow using optical emission spectroscopy and analytical calculations

In this work the densities of active species in an atmospheric pressure N 2 dielectric barrier discharge (DBD) flowing afterglow are experimentally investigated. The main objective of this work is to propose a rather simple method for the estimation of the densities of these species via analytical calculations and optical emission spectroscopy results. The method described here could be of significant practical importance, for example in the optimization of surface treatment processes. Based on this method, under the conditions investigated here, it has been found that (i) densities of UV-emitting radiative states are below 3 × 10 8 cm −3 , (ii) free radical densities of ∼2 × 10 15 cm −3 and ∼10 11 cm −3 are found, respectively, for atomic nitrogen and atomic oxygen, (iii) for the N 2 ( X , v > 4) and N 2 ( A ) long-living particles the densities are, respectively, of the order of 10 15 cm −3 and 10 13 cm −3 .