Numerical Methods for Plasma Astrophysics:
From Particle Kinetics to MHD

CSIC Building (#406), Seminar Room 4122.
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Kinetic MHD and Nonlocal Fluid Models of Long-Mean-Free Path Physics

Dr. Greg Hammett

Princeton Plasma Physics Lab at Princeton University

Abstract:   For the benefit of a broader audience, I will first review the formulation of kinetic MHD (Kulsrud, Handbook of Plasma Physics, 1983), which results from expansion of the collisionless Vlasov-Boltzmann kinetic equation in the limit of slow dynamics compared to fast particle gyration in the magnetic field. This is in some sense the first step beyond MHD to include kinetic particle effects in the long mean-free-path limit. I will compare these equations with gyrokinetic and full kinetic equations and discuss the implications of various orderings. I will next discuss Landau-fluid approximations to kinetic MHD (Snyder, Hammett, Dorland, Phys. Plasmas 1997). An n-pole Pade approximation to the linearized closure problem is employed, which leads to a non-local heat-conduction expression that differs from some earlier semi-empirical formulas. Some of the relative advantages and disadvantages of Landau-fluid and fully kinetic solutions will be discussed.