Axially resolved temperature and thermal transport observations in MagLIF implosions at Z

In a series of MagLIF experiments performed at the Z pulsed power machine of Sandia National Laboratories, Kr was added as a spectroscopic tracer to the deuterium fuel to assess the temperature conditions achieved in the compressed core. The experiments used a ~10 mm Be liner that was imploded by the JxB force due to a 20 MA current along the axis of the cylinder. In addition, a10 Tesla azimuthal magnetic field was applied to inhibit radial heat losses. Time-integrated, spatially resolved Kr K-shell x-ray spectra was recorded with the CRITR-AR transmission crystal spectrometer. Detailed analysis of the spatially resolved Kr emission spectra including collisional-radiative atomic kinetics produced the spatial distribution of the electron temperature along the axis of the plasma. In turn, these measurements enabled the estimation of thermal transport along the z-axis of the imploded plasma. Results are discussed for six experiments where deuterium fill pressure, and liner diameter and thickness were changed in order to assess the impact on core plasma conditions and neutron yield.