Trends in 3D Simulations of MagLIF

Two-dimensional magneto-hydrodynamics (MHD) simulations, with codes such as HYDRA, are the primary tool for designing Magnetized Liner Inertial Fusion (MagLIF) [1] experiments on the Z machine at Sandia National Laboratories. However, experimental stagnation conditions and associated structures are better described by three-dimensional simulations that include the magneto-Rayleigh-Taylor instability (MRTI). Findings from a series of 3D HYDRA simulations will be shown that study how MagLIF target performance varies with initial seed on the liner surface as well as initial axial magnetic field strength. Results suggest that MRTI can explain experimental yield variability, although general matches with experiment are achieved without considering other degradation mechanisms such as mix. As the Bz field was scanned in 3D, the ion temperature increased with field strength, however the yield was essentially flat or reduced beyond 15 T which is unlike 2D simulations that generally show higher yield. The simulations suggest residual azimuthal flow in the fuel due to the laser deposition is responsible for a twisted Bz distribution in the fuel which leads to a much lower plasma beta (P_therm./P_mag. < 10) at stagnation.