Particle-in-cell simulations of the runaway breakdown of nitrogen

The runaway breakdown initiated by a mono-energetic beam of runaway electrons propagating through a cathode-anode gap filled with nitrogen at atmospheric pressure is studied using the one-dimensional particle-in-cell numerical model. It is shown that the breakdown is strongly influenced by the amplitude of the beam, its duration, and the electric field in the vicinity of the cathode. In addition, the simulation results showed that, in spite of the formation of rather dense plasma inside the cathode-anode gap by runaway electrons, the electric field is not screened because of frequent electron-neutral collisions. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4769748]