Study of Formation and Propagation of Streamers in SF₆ and Its Gas Mixtures with Low Content of SF₆ Using a One-Dimensional Fluid Model

Using a hybrid Monte Carlo Collision/Fluid model, the formation and propagation of streamers in SF₆ and its gas mixtures are simulated. The simulation is based on an accurate numerical solution of Poisson’s equation in conjunction with the continuity fluid equation for electrons, negative ions, and positive ions. The factors that influence the formation and propagation of streamers are investigated. The electron density, positive and negative ion density, and electric field in the discharge channel are also presented, which are very important in understanding the phenomena of streamers and in assessing the insulation strength of the gas mixture.