Investigations of chaotic particle transport by drift waves propagating in the edge plasma of
tokamaks with poloidal zonal flow are described. For large aspect ratio tokamaks, the
influence of radial electric field profiles on convective cells and transport barriers, created by
the nonlinear interaction between the poloidal flow and resonant waves, is investigated. For
equilibria with edge shear flow, particle transport is seen to be reduced when the electric
field shear is reversed. The transport reduction is attributed to the robust invariant tori that …