General theory of kinetic ballooning modes

Abstract

The ’’ballooning mode formalism,’’ previously developed for the ideal magnetohydrodynamic problem, is applied to the kinetic problem in tokamaks. The general two-dimensional equation governing drift and trapped-electron eigenmodes reduces to a one-dimensional integral equation along the lines of force with the radial structure determined by a WKB procedure. Comparisons made between the present one-dimensional code and a previous two-dimensional code embodying identical physical assumptions indicate reasonable agreement. This correspondence holds both for the structure along the field line and for the radial structure in the special case of closely spaced turning points.