Energetic high current density electroniion beam generation in Plasma Opening Switches

In this paper we present experimental results on the generation of high energy ion/electron beams generation during operation of microsecond/nanosecond Plasma Opening Switch (POS). For the nanosecond POS, a coaxial configuration with negatively charged central electrode was used. For the microsecond POS, a strip-line geometry was investigated. Different arrays of magnetically insulated Collimated Faraday Cups (CFC) were used to observe energetic electron/ion flows towards the anode/cathode POS electrodes and towards the load. It was shown that in both nanosecond and microsecond cases, high-energy high current density axial ion flows are generated downstream towards the load at the load side edge of the plasma. The main axial ion acceleration occurs in the first few cm downstream with respect to the load side edge of the plasma at the beginning of the POS opening. Data observed by the anode CFC array show fast axial propagation of a radial electron flow along the anode electrode towards the load which is accompanied by an ion flow that first appears at the generator side of the plasma.