Benchmarking Kinetic and Fluid Neutral Models with Drift Effects

Abstract

AbstractA kinetic neutral model and a fluid neutral model have been benchmarked under the detachment condition. The upstream radial profiles of basic plasma and neutral parameters with the fluid neutral model are carefully fitted to that with the kinetic model, while no such an attempt has been made in the divertor region as a first step of the benchmark study with the effects of drifts. At the mid‐plane, no significant effects of the drifts on the radial profile of the basic plasma parameters are seen. However, in the divertor region, large differences of the benchmark result are seen even without the effects of drift. Effects of drift tend to enlarge the difference. Therefore, improvement of the fluid neutral model or optimizations of the free parameters are needed to analyze the effects of drifts in the divertor region, especially for the detached state. Otherwise, the kinetic model should be used to analyze the divertor characteristics even without the effects of drifts. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)