Negative corona discharges in SF6

Corona discharge in SF₆ is analyzed avoiding the equilibrium assumption. This is accomplished by a Monte Carlo simulation of electrons, considering the ionization, attachment, and photoionization processes, and finding the solution to Poisson´s equation for the space charge field. The current pulses simulated at various voltages are found to have more than one peak. This agrees with experimental observation. The current lasts several nanoseconds depending on the voltage. The development of electron avalanches due to ionization and photoionization are displayed in great detail. The quenching of the electrons at later surges is due to space-charge field suppression