Title :
Top/bottom asymmetry measured in axial radiation exiting dynamic-hohlraum X-ray source on Z
Author :
Sanford, T.W.L. ; Mock, R.C. ; Chandler, G.A. ; Leeper, R.J. ; Lemke, R.W. ; Mehlhorn, Thomas A. ; Nash, T.J. ; Sarkisov, G.S. ; Waisman, E.M. ; Chrien, R.E. ; Idzorek, G.C. ; Peterson, D.L. ; Watt, R.G. ; Chittenden, J.P. ; Haines, M.G. ; Lebedev, S.V. ;
Author_Institution :
Sandia Nat. Labs., Albuquerque, NM, USA
Abstract :
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).
Keywords :
Z pinch; exploding wires; plasma X-ray sources; 20 MA; Z facility; axial radiation exiting source; collapsing dynamic hohlraum; dynamic-hohlraum X-ray source; imploding tungsten wire-array z-pinch; radiation source; soft X-rays; solid cylindrical target; top/bottom asymmetry; trapped radiation; Contracts; Laboratories; Laser modes; Laser theory; Physics; Plasma measurements; Plasma temperature; Pulse shaping methods; X-ray imaging; X-ray lasers;
Conference_Titel :
Plasma Science, 2002. ICOPS 2002. IEEE Conference Record - Abstracts. The 29th IEEE International Conference on
Conference_Location :
Banff, Alberta, Canada
Print_ISBN :
0-7803-7407-X
DOI :
10.1109/PLASMA.2002.1030255