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In transport barriers, particularly H-mode edge pedestals, radial scalelengths can become comparable to the ion orbit width, causing neoclassicalphysics to become radially nonlocal. In this work, the resulting changes toneoclassical flow and current are examined both analytically and numerically.Steep density gradients are considered, with scale lengths comparable to thepoloidal ion gyroradius, together with strong radial electric fields sufficientto electrostatically confine the ions. Attention is restricted to relativelyweak ion temperature gradients (but permitting arbitrary electron temperaturegradients), since in this limit a delta-f (small departures from a Maxwelliandistribution) rather than full-f approach is justified. This assumption is infact consistent with measured inter-ELM H-Mode edge pedestal density and iontemperature profiles in many present experiments, and is expected to beincreasingly valid in future lower collisionality experiments. In the numericalanalysis, the distribution function and Rosenbluth potentials are solved forsimultaneously, allowing use of the exact field term in the linearizedFokker-Planck collision operator. In the pedestal, the parallel and poloidalflows are found to deviate strongly from the best available conventionalneoclassical prediction, with large poloidal variation of a different form thanin the local theory. These predicted effects may be observable experimentally.In the local limit, the Sauter bootstrap current formulae appear accurate atlow collisionality, but they can overestimate the bootstrap current near theplateau regime. In the pedestal ordering, ion contributions to the bootstrapand Pfirsch-Schluter currents are also modified.

Local and global Fokker-Planck neoclassical calculations showing flow and bootstrap current modification in a pedestal