Effects of electrostatic trapping on neoclassical impurity transport in a collision-dominated plasma

It has been shown by Hazeltine and Ware that the existence of a reasonable high-Z impurity species can produce electrostatic trapping and drift comparable to the magnetic effects, assuming that the main plasma components are in the plateau regime. The calculation is extended to the collisional regime, modeling the edge region of the tokamak column and significant modification to the neoclassical impurity transport coefficients is found. A fluid approach is developed and the transport coefficients are found to be nonlinear in density and temperature gradients.