Prebreakdown Evolution of Field Emission-Induced Breakdown Under Impulse Voltage

Physical evolution during the prebreakdown process of field emission-induced breakdown (FEBD) reveals the mechanism of how the breakdown is caused, which has theoretical significance for the vacuum interrupter’s insulation improvement. In this article, an impulse voltage conditioning experiment is carried out between pure copper electrodes and applied voltage, and the corresponding prebreakdown current of FEBD is obtained. A particle-in-cell with direct simulation Monte Carlo (PIC-DSMC) model which considers two dimensions in space between electrodes and three dimensions in particles’ velocity (2D3V) is proposed and established with the obtained experimental data. The distributions, densities and numbers of electrons, Cu neutrals, and Cu+ ions over prebreakdown voltage are obtained to display the physical evolution during the prebreakdown process. The field emission current from the PIC-DSMC model is consistent with that measured from the experiment, which validates the simulation method. It provides a novel insight into FEBD’s prebreakdown process through physical evolution between electrode gaps.