Transport Coefficient Sensitivities in a Semi-Analytic Model for MagLIF

In magnetohydrodynamics the magnetic field is obtained from an induction equation derived from an Ohm’s law for the electric field rather than Maxwell’s equations. As a result, magnetic-field evolution is determined from source, diffusion, and advection terms involving the magnetic field, plasma parameters, and proportionality constants called “transport coefficients.”¹ Thermal conduction in magnetized plasmas is also affected. The coefficients themselves have been the subject of repeated recalculation using various methods throughout the years. Using a semi-analytic MagLIF model (SAMM), ² we compare various fits to the electron and ion transport coefficients provided by Braginskii,¹ Epperlein, Haines,³ Ji, Held,⁴ and Davies et al.⁵ The choices modify magnetic flux losses caused by the Nernst thermoelectric effect and thermal conduction losses. We present results from a suite of simulations conducted to quantitatively compare the effects of the different fits on various values of interest, such as the fuel temperature over time and the total fusion yield.