NEOCLASSICAL FLOW, CURRENT, AND ROTATION IN GENERAL TOROIDAL SYSTEMS

Neoclassical theories for the parallel flow, current and rotation are extended to a multispecies plasma in general toroidal systems. The extended theory is constructed in the Boozer coordinate system to be common in all collisionalities (1/nu, plateau, Pfirsh-Schluter regime) in terms of the geometric factor. It is shown that the decisive difference between axisymmetric and non-axisymmetric toroidal systems is attributed to the geometric factor which reflects the breaking of axisymmetry. As a result it is first found that the neoclassical current driven directly by the radial electric field can exist in the non-axisymmetric device, whereas such the current vanishes in the axisymmetric torus. Explicit expressions for poloidal and toroidal rotations are first derived for a multispecies plasma in the non-axisymmetric toroidal system. In the limit of small geometric factor, the poloidal and toroidal rotations of ions are reduced to the usual diamagnetic and E x B drifts.