Physics of a highly nonequilibrium ion distribution: The Polywell trademark/SCIF

The Polywell trademark/SCIF fusion confinement concept, in which magnetically confined electrons form a spherical potential well which causes the ions to flow to the center of the sphere, is characterized by a highly nonequilibrium ion velocity distribution. This distribution must in fact be maintained in a state far from thermal equilibrium in order for the ions to converge to a dense core at the center of the sphere, which is required for the success of the concept. In this paper the authors calculate the effects of some of the processes which tend to drive the ions toward thermal equilibrium. These processes include collisional upscatter in energy, collisional isotropization, and turbulent distortion and relaxation of the ion distribution. The problem is made more complicated and much more interesting from a theoretical point of view because of the strong variations in the density and velocity distributions at different radii. The authors present an analytic model for this variation, which is the starting point for the other calculations. 1 ref