Comparative Study of Pulsed Dielectric Barrier Discharges in Argon and Nitrogen at Atmospheric Pressure

In this paper, the mechanisms and characteristics of the pulsed dielectric barrier discharges in Ar and N₂ at atmospheric pressure are analyzed and compared by means of numerical simulation based on the 1-D fluid model. Under different operating conditions, including gap width d_g, dielectric thickness d_s, and relative dielectric constant ε_r, the important characteristic quantities of describing the discharge, i.e., maximum discharge current density J_m, averaged electron density N_e-ave, and averaged dissipated power density Pave, are observed and studied in detail. This paper gives the following significant results. In Ar, the discharge occurs after the gap voltage has reached its maximum and is in the form of two short discharge current density pulses. In N₂, the discharge starts from the increase of the gap voltage and presents the smooth development in a longer time being nearly equal to the pulsewidth. For the two gases, J_m, Ne-ave, and Pave decrease with the increase of d_g, and these characteristic quantities decrease with the increase of d_s, or with the decrease of ε_r. In addition, the discharges in Ar maintain in the atmospheric pressure glow discharge (APGD), but the discharges in N₂ operate in the varying discharge modes, including the APGD, the weak APGD, and the atmospheric pressure Town send discharge. The development of the APGD in N₂ requires the smaller gap width, the thinner dielectric thickness, and the larger relative dielectric constant.