STRUCTURE OF SHORT-WAVELENGTH DRIFT MODES AND TRANSPORT IN A TOROIDALPLASMA

Short-wavelength fluctuations, such as electron and ion drift waves, m ay be one cause of anomalous transport in toroidal plasmas. The purpos e of this paper is to establish the radial structure of these modes an d to clarify some discrepancies in the literature. The conventional fo rm of toroidal drift modes can occur only at isolated plasma radii and are unlikely to be the source of a universal transport. electron and ion drift modes can occur at all plasma radii. They have a structure c onsistent with an anomalous transport exhibiting the Bohm scaling with magnetic field and decreasing with plasma rotation.