Experimental research of electron magneto-hydrodynamics effects in microsecond POS

The paper presents new data aimed at understanding and characterizing of microsecond Plasma Opening Switch (POS) plasma. In planar geometry both optical and probe experiments were carried out in two regimes. Erosion regime with sharp current interruption is characterized by current penetration with a velocity 10⁸ cm/s through plasma having its impedance at several Ohms from current beginning. Ion probes show substantial ion current along all POS cathode area. In another regime with higher plasma concentration there is no sharp switching, plasma has high conductivity and current penetrates into plasma an order as slow. Electron-image frames show instabilities at the last stage of rising current that could be important illustration when considering Electron magneto HydroDynamic (EHD) effects.