Production and Diagnostic Measurements of Kilovolt High-Density Deuterium, Helium, and Neon Plasmas

Abstract

This paper reports successful production and diagnostic measurements of kilovolt high‐density plasmas of deuterium, deuterium‐helium mixtures, helium, and neon. Particular attention was given to obtaining a systematic understanding of the electron and ion heating and cooling processes, as well as the attendant equilibration processes. These plasmas typically psosessed 1<T_e19 <n_e20 cm⁻³, 2×10¹⁸ <n_i20 cm⁻³, copper contamination levels of n_Cu∼5×10¹⁷ cm⁻³, energy densities ∼10⁵ J/cm³, and effective lifetimes ∼0.5 μsec. Diagnostic measurements were made with absolute time‐resolved x‐ray and neutron detectors, magnetic and electric probes, and high‐speed visible photography. The plasmas were generated in a coaxial discharge tube, with the ions being heated primarily through collapse of the quasicylindrical current sheet, in a manner reminiscent of the linear pinch effect. The electrons rapidly achieved kilovolt temperatures via collisions with the energetic ions; radiation cooling of the electrons was observed, late in time, particularly for those plasmas consisting of high‐Z ions.