Comparing FLAG Magnetohydrodynamics Simulations to Cylindrical Liner Implosions on Sandia’s Z machine
Maren Hatch, University of New Mexico
The magneto-Rayleigh-Taylor instability (MRT) is an acceleration-driven instability that limits performance of magnetically-driven applications, including Magnetized Liner Inertial Fusion (MagLIF) experiments on the Z machine at Sandia National Laboratories. Previous experiments generated radiographs that observed the growth of such instabilities in fast Z-pinch plasmas, seeded by sinusoidal perturbations on the surface of solid aluminum liners. Secondary jet formation along the outer surface were also observed. The application of the Los Alamos National Laboratory Advanced Simulation and Computing Multiphysics FLAG code, an arbitrary Lagrangian-Eulerian (ALE) code with magnetohydrodynamics and advanced material models, was used to compare simulations to results from these cylindrical liner implosions. This multi-dimensional, multi-material, multi-temperature code has been used to study fundamental electrothermal instability (ETI) physics and continues to evolve to address more topics in the high energy density regime. Direct comparisons of FLAG calculations to sinusoidally perturbed target designs have been well-suited to address the role of dominant, localized Joule-heating and ETI in plasma formation in high-current conductors. Jet formations due to preferential Joule-heating in the troughs of sinusoidal perturbations are identified, sourced from smaller wavelength perturbations. Studies show first order convergence under spatial refinement of the initial mesh, producing good agreement between simple theory and simulation in the demonstration of MRT evolution.
References:1D.B. Sinars et al., Phys. Rev. Lett. 105, 185001 (2010)
Work supported by DOE NNSA Laboratory Residency Graduate Fellowship, in partnership with Los Alamos National Laboratories.
Authors: M.W. Hatch1, C.L. Rousculp2
1Sandia National Laboratories, New Mexico, USA
2Los Alamos National Laboratory, New Mexico, USA
Abstract Author(s): (see above entries)