Neutral gas heating effects and streamer branching in short and long gaps

For the plasma multiphysics fluid analysis, the avalanche and streamer propagation in point plane DC long gaps of 5 cm, as well as the neutral gas heating effects in the post-streamer discharge in short DC parallel plates, have been successfully simulated. AVALANCHE AND STREAMER PROPAGATION The avalanche and streamer discharges have been analysed in very long gaps of the order of 5 cm in positive point-plane gap geometries with the tip radius being 50 µm in two dimensional axisymmetric coordinates (1). An applied direct current voltage of 130 kV was applied at the anode tip, with the parallel plane at 0 V. The discharge was initiated from a single electron released close to the anode tip. The phenomena simulated within the discharge include two-dimensional radial and axial electric fields as shown in Figs. 1 and 2 respectively, one-dimensional axial electric fields as shown in Fig. 3, streamer branching, streamer speeds as shown in Fig. 4, radial and axial expansion of the streamer towards the outer boundaries and the cathode, as well as electron, positive and negative ion densities. The streamer branching phenomenon, as well as the numerical analysis of very long gaps of the order of 5 cm, have been performed for the first time, which demonstrates the capability and efficiency of the algorithm to go beyond other existing software discharge packages.