Analytical field-reversed equilibria derived from self-consistent particle orbits - Part 2

A further study of the field-reversed ion layer equilibria is presented (Part I was published in Nucl. Fusion 21 (1981) 1633). The formalism for introducing steady-state perturbations into the equilibria presented in Part I is applied to the problem of a perturbing rigid rotor ion current and analytic solutions are obtained. The problem of an equilibrium altered by a perturbing group of ions of differing canonical angular momentum is solved iteratively. The results of these studies are that the primary ion currents readjust so as to largely nullify the effect of the perturbations, tending therefore to preserve the unperturbed field reversal values. The effects of finite temperature electrons on the equilibrium are considered, using a 'Boltzmann model' for the electrons. As for the two perturbed cases, the field reversal ratio tends to be preserved at the value occurring in the unperturbed case. In support of the results, a variational principle is presented which shows the equilibria to be minima of magnetic and rotational kinetic energies. (author)