Two-dimensional simulation of the negative streamer in N2 between parallel-plate electrodes

With the purpose of deeply understanding behavior of streamer discharge in nitrogen-dielectric, the two-dimensional and self-consistent fluid model of the gas discharge was established based on the electron and ion continuity equations coupled to Poisson's equation. The plasma channel of the negative streamer discharge is studied in this paper by numerical simulation. A program based on the finite element method in its full two-dimension form is developed and employed for the solution of continuity equations of charged particles under the effect of space-charge electric field. Results of two-dimensional simulation of cylindrically symmetric streamer in pure N2 between parallel-plate electrodes are presented. The formation and propagation of negative streamer in numerically was observed. The space electric field distribution, space ions distribution and drift velocity were predicted by the model. The influence of initial conditions and applied voltages on the streamer characteristic was also investigated. The results show that the space electric field and electrons and ions density at the tip of the streamer increase with the propagation of negative streamer. The space electrons density and electric field at the tip of streamer increase, when the ionization density in the initial increase. The propagation velocity and other characteristics of the streamer are influenced by the diameter of the initial charge distribution. For negative streamer, the ionization density and electron density gradient and electric field at the tip increase with increasing applied field.