Impurity outward particle flux from externally applied torque

Abstract

Abstract In this work a term in the impurity particle flux expression, which arises from the externally applied angular momentum torque, is rederived and analyzed in detail. This contribution to the species particle flux is found to be directed outward for co-current injected torque in conditions pertinent to present devices, which could explain the increasing hollowness of light impurity density profiles observed experimentally as neutral beam injected power is increased. This result is obtained by revisiting the fluid framework to compute the particle flux of a generic ion species.