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We will present experiments on the MAGPIE facility (1.5MA, 250ns) in which an inverse wire array [1] (with the wires acting as a return current cage placed around a central current conductor) operated as a fast current switch [2]. This allowed to significantly reduce the rise-time of the current pulse (< 100ns) delivered to a separate, standard imploding wire array z-pinch load. Experimental studies of the operation of this arrangement as a current switch will be discussed. In particular it was found that this arrangement generates a short current pre-pulse (∼5kA

End on Interferometric imaging is a useful technique for diagnosing the electron density distribution in the interior of wire array z-pinches during their ablation phase. These measurements are limited as there is often no known density reference point in the image. By using a time resolved, CW line integrated interferometry system, we can measure the electron density for a single point on the image. This allows us to calculate the density distribution across the remainder of the image. Two new quadrature interferometry systems are discussed, the first free space and the second fiber based. Also discussed is a new fiber based multipoint Heterodyne Velocimetry (HET-V) system, for the time resolved measurement of large velocities and accelerations, and a new faraday rotation current probe system, to measure rapidly rising currents in new switched mode wire arrays.

Coiled arrays, a cylindrical array in which each wire is formed into a single helix, suppress the modulation of ablation at the fundamental wavelength. Instead, ablation flow is modulated at the wavelength of the coil. Large wavelength coils produce wire beaks with sufficient axial separation that perturbations in the implosion sheath do not merge, producing an organized mode of implosion in which the global instability can be controlled and the perturbations correlated between all the wires in the array. The inductance of the current paths that may be established by an organized implosion are considered. This suggests that, for a given inductive voltage drop across the load, coiled arrays are capable of achieving significantly higher current convergence to the axis than straight arrays. These experiments were carried out on the MAGPIE generator at Imperial College. This research was sponsored by Sandia National Laboratories Albuquerque, the SSAA program of NNSA under DOE Cooperative Agreement DE-FC03-02NA00057.

Results of several recent experiments with wire array Z-pinches on the MAGPIE facility (1.5MA, 250ns) will be presented. This will include experiments with generation of supersonic radiatively cooled plasma jets using conical and radial wire arrays. We will also present measurements of the plasma parameters in standard wire arrays and wire arrays made of coiled wires, obtained with recently implemented diagnostics such as resistive voltage probe, CW laser interferometer and others.