SKIN SIZE ELECTROMAGNETIC DRIFT MODE AND ANOMALOUS TRANSPORT

A low-beta tokamak discharge is unstable against skin size electromagnetic drift modes. The growth rate peaks at k perpendicular-to congruent-to omega-pe/c with a maximum growth rate of the order of the ion acoustic transit frequency. The quasilinear particle flux is radially inward (anomalous pinch) if eta (the temperature gradient) greater-than-or-similar-to 1. The proposed anomalous electron thermal diffusivity exhibits a good agreement with those inferred from several tokamaks both in magnitude and in reproducing the radial profile, and predicts that the energy confinement time should improve in discharges with heavier ions (the isotope effect).