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Summary form only given. Ablation of a wire in the wire-array Z-pinch discharged on MAGPIE has been simulated in a two-dimensional domain of finer grid resolution using a magnetohydrodynamic code, GORGON. For accurate description of ohmic heating at high densities, an electrical conductivity model for nonideal plasma has been incorporated in the code. Emissions of line radiation as well as blackbody radiation are taken into account based on an astrophysical model in order to show the radiation cooling effect. Starting from the wire core assumed as warm dense plasma initially, the expansion and implosion dynamics of coronal plasma are demonstrated and basic plasma parameters are calculated as a function of time. Computed profiles of electron density are compared with data measured by laser interferometer at a certain point of time. The level of electron densities predicted by simulation appears reasonably compatible with measurements despite some discrepancies found in regions away from the initial wire core position. A few physical points are discussed regarding nonideal plasma and radiation emission models.

Summary form only given. Recent experiments on the MAGPIE (IMA 250ns) have used an inverse cylindrical wire-array configuration in which plasma is ablated radially outwards. The improved diagnostic access allows detailed quantitative probing of the ablation structure and radial profiles of electron density to be taken using interferometry and XUV framing cameras. In addition the magnetic field geometry of this setup allows the local inductance of the wires to be calculated using an inductive probe and the size of the current carrying region through the wires to be deduced.

Coiled arrays, a cylindrical array in which each wire is formed into a helix, suppress the modulation of ablation at the fundamental wavelength. Outside the vicinity of the wire cores, ablation flow from coiled arrays is modulated at the coil wavelength and has a 2-stream structure in the r,thetas plane. Within the vicinity of the helical wires, ablation is concentrated at positions with the greatest azimuthal displacement and plasma is axially transported from these positions such that the streams become aligned with sections of the coil furthest from the array axis. The GORGON MHD code accurately reproduces this observed ablation structure, which can be understood in terms of axial JxB forces that result from the interaction of the global magnetic field with radial components of a helical current path as well as additional current paths suggested by the simulations. With this ability to control where ablation streamers occur, large wavelength coils were constructed such that the breaks that form in the wires had sufficient axial separation to prevent perturbations in the implosion sheath from merging. This produces a new, organised mode of implosion in which the global instability can be controlled and the perturbations correlated between all the wires in the array. For large wavelength 8-wire coiled arrays, this produced a dramatic increase in x-ray power, equaling the x-ray power of a 32-wire straight array. These experiments were carried out on the MAGPIE generator (IMA, 240ns) at Imperial College, London.

Summary form only given. Radial wire array Z-pinches - array configurations where the wires stretch radially outwards from a central cathode - may present several advantages over cylindrical wire array Z-pinches for driving HEDP experiments. In particular, the implosion of a radial wire array results in the formation of a much smaller, yet still highly emitting, column of stagnated plasma that could be coupled to a compact hohlraum, increasing drive temperatures. Also during implosion this column of plasma is projected above the electrodes, allowing unrestricted diagnostic and experimental access over 2pi steradians. Finally, the radial wire array presents a relatively low inductance load to the pulsed power generator and may be used on long-pulsed, low cost machines. On the 1 MA MAGPIE facility we have explored the implosion and stagnation of radial wire arrays. Here the dependence of the array dynamics and X-ray emission on parameters including cathode diameter, array mass and wire number will be discussed. Initial nested radial wire array experiments that aim to provide shaping of the X-ray pulse will also be presented. Finally predictions of scaling of the radial array to larger current facilities including Saturn and Z will be presented, along with possible hohlraum configurations for HEDP including ICF experiments.

Summary form only given. Experiments with the aim of studying the dynamics of a ~mum thick radial metallic foil subject to the current from the MAGPEE generator (peak current of 1 MA in 250 ns) have been performed at Imperial College. After the start of the current pulse the foil is ohmically heated and then is driven by the JtimesB force in the axial direction, which is reasonably described by 0-D equations of motion. Data on the parameters of ablation from the foil will be presented as well as evidence of azimuthal current filamentation. The pressure of the toroidal magnetic field detaches the foil from the electrode creating a gap and allowing the formation of a "magnetic tower" similar to what it is observed on radial wire arrays. Current reconnection across the gap leads to the formation of subsequent outflows which are characterized by emission of soft x-rays as sharp pulses. This experimental configuration can be also used to drive strong shock waves through neutral gases. Results of these experiments will also be presented.

Wire array z-pinches are the world's most powerful laboratory X-ray source, however the large volume required for them to work efficiently requires the use of a large hohlraum for inertial confinement fusion applications. This hohlraum size limits the temperature achievable using present pulsed power capabilities. Whilst work is continuing to improve the efficiency of cylindrical wire arrays, an alternative is to use an array configuration that is better suited to a smaller hohlraum. Radial wire arrays have been shown to have similar emitted power and radiated energy to cylindrical wire arrays, however occupy a volume which is a factor of >4 smaller. We will discuss plans for radial wire array experiments on the multi-MA Saturn facility at Sandia, along with the results of MHD simulations and initial data.