Recent Progress in NEO-2 — A Code for Neoclassical Transport Computations Based on Field Line Tracing

Abstract

NEO-2 is a code for the computation of neoclassical transport coefficients and current drive efficiency in toroidal devices which is based on the field line integration technique. The possibility to use the complete linearized collision integral is realized in this code. In this report the results of comparison of the full matrix of transport coefficients in a tokamak with analytical models are presented. Effects of simplifications of the linearized collision model (e.g., reduction to a Lorentz model) are studied in order to provide a comparison with various momentum correction techniques used for the computation of transport coefficients in stellarators.