Experimental Simulation of High Energy-Density Plasma Interaction with Liquid Metal Media for Inertial Fusion Reactor First Wall Studies

Inertial confinement fusion (ICF) is a promising technology positioned to address the future energy needs of the world.An advanced design concept for ICF reactors is to use a circulating liquid barrier to protect the first wall of the target chamber.With the impaction of the high energy-density plasma on the liquid barrier, sputtering and vaporization can occur causing particulate matter to enter the target chamber interior volume.In order to best engineer the design of the target chamber, this interaction must be well characterized.A small-size experimental facility was designed, constructed, and operated at NC State University to simulate the interaction of high energy-density plasma with liquid metals.This study focuses on characterization of the plasma-liquid metal plume.Characterization of the generated plumes shape and size of evolved vaporized liquid metal particulates; density and other plasma parameters were studied in this research.Electrical and spectral data were obtained for each experiment to obtain the plasma parameters including total power, impedance, electron temperature and density and identification of species.It was determined that a typical plasma generated from a 2 kV discharge has a temperature of 1.0 ± 0.3 eV and a density of 4.2 ± 1.7 x 1017 cm-3.The height and geometric configurations of the collection substrates were changed to produce a model of the generated metallic plume.Data analysis of the substrates indicates that the plume has a higher density profile and smaller particulates at distances closer to the point of impact, and the particulate size increases and the particulate density profile decreases with increased distance from liquid metal pool.