Explosive-Emission Plasma Dynamics in Ion Diode in Double-Pulse Mode

The results of an experimental investigation of explosive-emission plasma dynamics in an ion diode with magnetic self-insulation are presented. The investigations were accomplished at the TEMP-4M accelerator set in a mode of double pulse formation. Plasma behaviour in the anode–cathode gap was analyzed according to both the current–voltage characteristics of the diode (time resolution of 0.5 ns) and thermal imprints on a target (spatial resolution of 0.8 mm). It was shown that when plasma formation at the potential electrode was complete, and up until the second (positive) pulse, the explosive-emission plasma expanded across the anode–cathode gap with a speed of 1.3 ± 0.2 cm/μs. After the voltage polarity at the potential electrode was reversed (second pulse), the plasma erosion in the anode–cathode gap (similar to the effect of a plasma opening switch) occurred. During the generation of an ion beam the size of the anode–cathode gap spacing was determined by the thickness of the plasma layer on the potential electrode and the layer thickness of the electrons drifting along the grounded electrode.