Fluid description of a magnetized toroidal plasma
A closed system of fluid equations to describe the evolution of a weakly collisional toroidal plasma is presented. The primary physical phenomena incorporated are gyration, guiding center motion, and parallel flows of particles and heat. The systematic use of the drift ordering allows for faster dynamics that in a transport context, and in order to capture important spatial variation, no flux-surface average is taken. A notable feature of this model is a generalized bootstrap current: applying the neoclassical limit and flux-surface average to the expression for the parallel current annihilates more general terms, leaving the canonical bootstrap current as the result. Thus, the model reduces to neoclassical transport in the proper limit, but generally includes more physical effects.