A particle simulation of negative corona discharge in SF6 gas

In order to study partial discharge phenomena in a gas-insulated system, we have developed a simulation code using the MC-PIC (Monte Carlo Particle-in-Cell) method. The MC-PIC code can simulate ionization and attachment in a nonuniform unsteady electric field with sufficient quantitative accuracy by considering collision cross-section data as close as possible to the real data. A negative DC corona discharge in SF6 is simulated. The electric field is distorted near the rod electrode once the corona discharge starts, because the positive ions and negative ions are polarized near the rod electrode after the electron avalanche ends. The electric field strength decreases in comparison with the initial condition due to the negative space charge. The image current due to the motion of electrons dominates the current pulse. The simulation result agrees Well with the experimental result. (C) 2002 Wiley Periodicals, Inc.