Neoclassical Transport Coefficients for Tokamaks with Bean-Shaped Flux Surfaces

Abstract

Simple analytic representations of the neoclassical transport coefficients for indented flux surfaces are presented. It is shown that a transport coefficient for an indented flux surface can be expressed in terms of a linear combination of the previously known transport coefficients for two nonindented flux surfaces. Numerical calculations based on actual equilibria from the PBX-M tokamak [Phys. Fluids B 2, 1271 (1990)] indicate that, even for modestly indented flux surfaces, the ion neoclassical thermal transport can be over a factor of smaller than in a circular plasma with the same midplane radius or with the equivalent area.