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, incorporating a radial/conical topology to minimize wave reflections, has been used for this investigation. The results described in this paper were obtained from experiments using hydrogen, helium, nitrogen, and SF6, The results show that there is a distinct change in breakdown behavior as the pressure increases. At the lowest tested pressures, there is a rapid voltage collapse phase. This phase reduces at intermediate pressures before recovering at higher pressures. This transition from low-pressure behavior to high-pressure behavior occurred in all the tested gases, although the transition pressure values were dependent on the gas type.