Numerical analysis of the effect of surface recombination on N-atom in discharge and post-discharge region

In this paper, the effect of surface recombination on N-atom production is discussed through a one-dimensional simulation of Townsend dielectric barrier discharge in pure N₂ based on a fluid model. By comparison of the experimental results, the recommended value of the sticking coefficient of N–N surface recombination is 0.5–1. The spatial-temporal distribution of N-atom of simulation results in discharge and post-discharge agree with experimental results. When the sticking coefficient is 0.5, the primary active species include N, N₂(A), and N₂(a′). N₄⁺ is the densest positive ion, which can reach 4.77 × 10⁹ cm⁻³. N-atom can reach the saturation level within about 30 ms. The highest number density is 3.14 × 10¹⁴ cm⁻³ at the position 0.25 mm away from the surface. The numerical simulation results are very consistent with the experimental results. The contribution of surface recombination and three-body recombination for the decay of N-atom are roughly equal in the post-discharge region.