Overview of 12-cm-Diameter, Argon Gas-Puff Experiments and Analyses with >200-ns Implosion Times at 3- to 6-MA Peak Currents

Abstract

This paper reviews the motivation for, results from, and analyses of 12‐cm‐diameter argon gas‐puff experiments carried out over the last four years on three generators at 3.2‐ to 6.5‐MA peak currents, all with implosion times ⩾200 ns. Using the argon K‐shell yield as a metric of implosion quality, high‐quality implosions are obtained for an appropriate initial radial mass distribution, i.e., a distribution that is peaked on axis. Higher compressed densities and smaller final radii are observed compared to shell‐like initial mass distributions. Theory and data suggest that these distributions mitigate the magnetic Rayleigh‐Taylor instability. An energy analysis shows that (1) significant electrical energy is directly coupled to the pinch during the K‐shell radiation pulse and (2) conversion of radially‐directed kinetic energy into thermal energy is not the dominant mechanism responsible for the pinch K‐shell radiation.