Top/bottom asymmetry measured in axial radiation exiting dynamic-hohlraum X-ray source on Z

Summary form only given, as follows. A radiation source has been developed on the 20-MA Z facility that produces a high-power x-ray pulse, generated in the positive z direction primarily from the interior of a collapsing dynamic hohlraum The hohlraum is created from a solid cylindrical CH/sub 2/ target centered within an imploding tungsten wire-array z-pinch. This pulse, which exits a 4.5 mm/sup 2/ REH (radiation exit hole) centered above the target, begins /spl sim/5 ns prior to stagnation (as defined by radial-radiation power). The 5-ns interval leading to stagnation represents the duration the imploding tungsten plasma acts as a hohlraum, trapping radiation developed within its interior. The trapped radiation exiting the top hole is remarkably reproducible, having a risetime of 2.5/spl plusmn/0.2 ns, a pulsewidth of 4.6/spl plusmn/0.5 ns, and reaches a maximum intensity of 9.7/spl plusmn/1.8 TW (assuming Lambertian emission) 1.4/spl plusmn/0.3 ns prior to stagnation. This radiation pulse is useful for performing radiation-transport experiments in excess of 200 eV. By adding an identical REH at the bottom of the hohlraum, the radiation generated in the negative z direction through a bottom REH offers the possibility of doubling the utility of the hohlraum as a source of high-temperature radiation. Because of the up/down symmetry of the load about the mid-plane of the z-axis (aside from the power feed), a radiation pulse similar to that exiting the top-REH (anode) is expected from the bottom REH (cathode).