Experimental study of the dynamics of planar wire array Z-pinch preconditioned by a controlled prepulse current

The influences of the prepulse current on the implosion dynamics of planar wire array were investigated. The time-delay between the prepulse current and the main current (Tdelay) was able to be controlled manually based on the double pulse current generator “Qin-1.” In the precondition stage by the prepulse current, the corona plasma, aluminum vapor, and residual wire cores formed during the explosion of the wires, and ∼40% (±10%) mass of the wires was in a gaseous state at ∼425 ns after the prepulse. After the main pulse was applied, the low-density corona plasma was first imploded and then collided with the aluminum vapor and residual dense cores. Then, the further implosion of the preconditoned wires closely related to their mass distribution, which was determined by the duration of Tdelay. The residual dense wire cores had a significant impact on the implosion when Tdelay was ∼200 ns. When Tdelay increased to ∼> 500 ns, the mass distribution gradually became uniform, and the implosion of the preconditioned wires showed no ablation and no trailing mass.