REEMISSION TECHNIQUE FOR SYMMETRY MEASUREMENTS IN HOHLRAUM TARGETS CONTAINING A CENTERED HIGH-Z BALL

A technique for measuring time-resolved drive symmetry in a laser-irra diated Hohlraum is presented. Design considerations and experimental m ethod and results are emphasized. The experimental method involves x-r ay imaging a high-Z ball placed in the center of a laser irradiated Ho hlraum. We will show that the reemitted x-ray image can be measured as a function of time and that the images are directly related to the ra diation flux asymmetry within the Hohlraum. Results from a series of e xperiments performed on the Nova laser located at Lawrence Livermore N ational Laboratory will be presented as well as a method for comparing with theoretical calculations. Detailed comparisons between theoretic al calculations and experimental results will be given.