Extended MHD Modeling of FRC Liner Compression

Abstract

Summary form only given. Compression of a field reversed configuration of plasma and magnetic field by a near-solid liner is an attractive path to fusion. We have previously developed the capability to model the formation and translation of an FRC into an imploding liner that subsequently compresses the magneto-plasma to fusion conditions aided by the magnetic inhibition of the thermal conduction. The model is embodied in a single, integrated simulation of the liner and FRC using the full power of MACH2, a 2 1/2-dimensional time-dependent arbitrary-coordinate, true ALE MHD code. The lifetime of the FRC undergoing relatively violent translation and subsequent compression is critical to the performance of the experiment. It is thought that extended MHD effects, such as the Hall effect, the thermoelectric effect, and finite Larmor radius effects may enhance or reduce this lifetime. While our previous simulations have used the Chodura subgrid turbulence model for enhanced resistivity -a nonclassical effect -the physics included has been standard MHD. The Hall and thermoelectric effects, introduced through generalization of the standard MHD Ohm's law, can produce toroidal field and rotation not shown by standard MHD FRC models; if sufficient bulk rotation develops, rotational interchange instability may reduce the FRC lifetime. Finite Larmor radius effects are generally diffusive, hence stabilizing, and may enhance the lifetime. We will show simulations of FRC formation and translation that include these extended MHD effects.