EFFECTS OF PLASMA FLOWS ON PARTICLE DIFFUSION IN STOCHASTIC MAGNETIC-FIELDS

The study of collisional test particle diffusion in stochastic magneti c fields is extended to include the effects of the macroscopic flows o f the plasma (drifts). We show that a substantial amplification of the diffusion coefficient can be obtained. This effect is produced by the combined action of the parallel collisional velocity and of the avera ge drifts. The perpendicular collisional velocity influences the effec tive diffusion only in the limit of small average drifts.