Breakdown phenomena in ultra-fast plasma closing switches

An experimental investigation into the rate of voltage collapse in plasma closing switches has been undertaken. A transmission line test switch, using a radial/conical topology to minimise wave reflections, has been used for this investigation. The results described in this paper were obtained from experiments using hydrogen. The results show that there is a distinct difference in behaviour between low pressure (5 bar) breakdown. Comparatively high values of dV/dt were obtained at both low and high pressures, whereas a low dV/dt was observed at intermediate values of pressure.