Reversed current structure in a Z-pinch plasma

The current profile of a Z-pinch plasma is investigated using a one-dimensional magnetohydrodynamic code. Simulation results reveal the formation of a reversed current profile, its propagation, and an ejection of plasma at boundary region, which have been observed in previous experiments. A new physical mechanism is proposed to account for such phenomena. The physical mechanism involves the propagation of a shock wave. It is found that a reversed current profile appears when a shock wave reflected at axis expands in a compressing plasma column.