New modes of X pinch backlighting on cobra

Summary form only given. X pinch backlighting is a useful imaging technique whereby two or more wires are crossed at a single point and driven with a high current (300-500 kA). At the crossing point, a micron-scale sub-nanosecond X-ray source is produced that acts as a point source and can be used for point-projection imaging. Three new modes of X pinch imaging on COBRA have been implemented. One of these techniques involves coupling the point-projection imaging with an MCP camera. This method is in development in the hopes that it can be used to take high resolution images of imploding (i.e. strongly radiating) wire-array Z pinches by time-gating out the radiation from the Z pinch. Previous attempts resulted in low contrast, blurry images. Presented here are new results which show an improvement in image quality. Another recent development involves a new large format imaging camera which allows point-projection imaging with high magnification. This new camera can be used to take backlighting images of wire arrays with ~34times magnification. Presented here are recent images of dense wire cores and coronal plasma, both showing significant axial modulation. Finally, for the first time on COBRA, a technique is in development for end-on X pinch backlighting. Preliminary results from this new method will be presented.