12 cm diameter gas puff density profile measurements using planar laser induced fluorescence

Abstract

Summary form only given. The technique of Planar Laser Induced Fluorescence (PLIF) has been applied to characterize the initial gas distributions produced by 12 cm diameter nozzles, as used on recent Decade Quad and Double-EAGLE Ar Z-pinch experiments. This information is required to understand and simulate the implosion dynamics. A 266 nm, /spl sim/5 ns, /spl sim/5 cm line-focused laser beam passes through the Ar gas puff, which is mixed with a few percent acetone by volume. A gated intensified CCD camera views the fluorescence of the excited acetone molecules from the side. The acetone emission has a short, intense pulse, coincident with the exciting laser pulse, and a weak, slowly decaying phosphorescence. The gas density profiles are obtained from the fluorescence images recorded coincident with the laser. Flow velocities of the gas puff are obtained by capturing the images of the phosphorescence at several delay times relative to the laser pulse. The distribution of the clusters is determined by comparing the PLIF signal with 2-D Rayleigh scattering from the gas puff. These measurements are compared with computer simulations to benchmark and refine the 2-D fluid dynamics models.