Impacts of External Momentum Torque on Impurity Particle Transport in LHD

Abstract

Particle transport processes of impurity ions in a multi-ion-species plasma in the Large Helical Device are investigated by neoclassical transport simulations. While the quasi-linear gyrokinetic analyses indicate that the anomalous contribution of the impurity particle transport is radially inward-directed, it is found that the external momentum sources can cause the existence of the electron root with positive radial electric field and outward-directed neoclassical particle flux of the impurity ion.