Drift effects on the behavior of a low-beta axisymmetric toroidal plasma

Analysis of a low-β axisymmetric toroidal plasma is reported. This predicts shock structure in the presence of resistivity and viscosity. A one-fluid model is considered which includes the Hall terms in Ohm's law and gyroviscous corrections to the pressure tensor. In analyzing this behavior two orderings are used. For typical stellarator parameters, the first ordering (in which the mean free path is less than the connection length but greater than a critical value) leads to a stable rotational equilibrium with a positive potential on axis. In the second ordering the mean free path is less than this critical value and a shock develops toward the inside of the torus, leading to diffusion an order of magnitude larger than the Pfirsch-Schlueter value. A Korteweg-de Vries equation with an added dissipation term due to parallel viscosity governs the azimuthal density variation in the shock region. Agreement is found between theory and the results of a two-dimensional computer simulation of a toroidal plasma. 21 refs., 6 figs