Suppressing the asymmetrical structures of the wire array Z-pinch

A series of experiments have been carried out to suppress these asymmetrical structures of the wire-array Z pinch by applying a fast rising prepulse current and using insulated coatings. The single wire or a multiwire array load is investigated by a set of diagnostics with high temporal and spatial resolution including laser probing, high speed photography, and etc. Under a 1 kA, 100 A/ns current, corona free explosions of aluminum and tungsten wires are fulfilled by using the 2-3 μ m thickness dielectric coatings. Then these metallic vapors expand freely in the vacuum and two neighboring columns collide with each other, forming a stagnation region in the middle of the wires rather than a uniform gas shell. With the help of dielectric coatings, ablation and precursor plasmas are greatly suppressed for tungsten wires on a 100 kA facility. Based on the experimental results above, a dual-pulse generator “Qin-1” facility (a 10 kA prepulse and a 1 MA main pulsed) is designed and built up, and experiments on the implosion and stagnation stage of the preconditioned wire array Z-pinch will be conducted.