Author: Jacob R King
Requested Type: Poster
Submitted: 2017-03-17 17:54:55
Co-authors: K. Beckwith, S. Kruger, P. Stoltz, R. Masti, B. Srinivasan, D. Hansen, E. Held
5621 Arapahoe Ave Suite A
Boulder, CO 80303
Recent results from experiments and simulation [1,2] of magnetically driven pulsed power liners have explored the role of the early-time electrothermal instability in the evolution of the magneto-Rayleigh-Taylor instability. Our focus will be on understanding the development of such instabilities and the potential stabilization mechanisms, which we expect could play a significant role in supporting the success of the MagLIF (Magnetized Liner Inertial Fusion) program. Better understanding of magneto-Rayleigh-Taylor instabilities through advanced modeling will improve the MagLIF concept. The ultimate goal of this work is to provide increased understanding of these experiments by employing simulations with a multi-fluid extended-MHD model, which uses kinetic closures for thermal conductivity, resistivity, and viscosity. The results of this modeling will be compared to that computed with standard MHD equation-of-state (EOS) modeling. We discuss the approximations and implementation of equation-of-state models for MHD. In particular, we describe the generalized expression for the sound speed and the implementation of the MHD EOS model within a Godunov-type finite-volume scheme. Finally, we argue that a kinetic approach for closure is required given the large thermodynamic drives that result from the extreme gradients present during liner implosions. These large gradients cause any model that assumes a local-therodynamic equilibrium to breakdown. We discuss future plans for this kinetic modeling.
1. K. J. Peterson, et. al., “Simulations of electrothermal instability growth in solid aluminum rods”, Phys. Plasmas 20, 056305 (2013).
2. K. J. Peterson, et al., “Electrothermal instability growth in magnetically driven pulsed power liners”, Phy. Plasmas 19, 092701 (2012).