In the pedestal of a tokamak, the sharp radial gradients of density and
temperature can give rise to poloidal variation in the density of impurities.
At the same time, the flow of the impurity species is modified relative to the
conventional neoclassical result. In this paper, these changes to the density
and flow of a collisional impurity species are calculated for the case when the
main ions are in the plateau regime. In this regime it is found that the
impurity density can be higher at either the inboard or outboard side. This
finding differs from earlier results for banana- or Pfirsch-Schl\"uter-regime
main ions, in which case the impurity density is always higher at the inboard
side in the absence of rotation. Finally, the modifications to the impurity
flow are also given for the other regimes of main-ion collisionality.Comment: 15 pages, 5 figures, submitted to Physics of Plasma
