Numerical Simulation of a High-Repetition Nanosecond Pulsed Glow Nitrogen Discharge Plasma

Nanosecond pulsed glow discharges under atmospheric and sub-atmospheric pressure have attracted attention in various fields because of their ability to generate high-density non-equilibrium plasma. This study reports numerical simulation results of a high-repetition nanosecond pulsed nitrogen glow discharges. In the simulation, a pair of parallel plate electrodes with a gap length of 30 mm was placed inside a cylindrical vessel. The upper electrode was grounded, and a repetitive pulsed negative voltage with a pulse width of 200 ns was applied to the bottom electrode at a frequency of 600 kHz. The gas pressure is 0.5 kPa. The dynamics of the discharge was described by a fluid (drift-diffusion) model consisting of the continuity equation for electron transport, the Maxwell-Stefan equation for the transport of ions and neutral species, and the Poisson’s equation for the space charge electric field. These equations were numerically solved by the finite element method. It was shown that the electron temperature and electron density of the afterglow plasma are about 0.5 eV and 0.5×10¹⁸ m^-3, and the next pulsed voltage is applied before the afterglow decays, resulting in the quasi-steady generation of low-temperature and high-density plasma.