Numerical and experimental modeling of subnanosecond plasma closing switches in gases

In this paper, a 2-D Finite Element Time Domain (FETD) model is presented for analyzing sub nanosecond plasma closing switches in gases, based on the Matlab Partial Differential Equation (PDE) toolbox. We will present the basic features of the model, as well as the results of validation studies on simple problems such as switch closure in an ideal, infinite, conically symmetric test volume. The physical model is then modified to simulate a test cell that had been previously used to collect experimental data. The dynamic channel current and its rate of the switch were evaluated based on the numerical model for different gases in different pressure regimes. The dynamics of the switch closure are greatly affected by the gas species and pressure used for insulation in the experiment.