Neoclassical Heat Flux Due to Poloidally and Toroidally Varying Electrostatic Potential in Nonaxisymmetric Toroidal Plasmas

抄録

A poloidally and toroidally varying electrostatic potential due to the perpendicular ion drift and its effect on the radial heat flux are studied in the plateau regime for a nonaxisymmetric toroidal plasma. This potential produces an enhancement by one order of magnitude in the electron heat flux, whereas an increase of the ion heat flux is modest. Moreover, these radial electron and ion heat fluxes due to this potential are found to be inward in a stellarator satisfying the conditions mε_h²>2ε_t² and nq−m>0, where q is the safety factor, n and m are the numbers of the toroidal field periods and the helical field coils, and ε_t and ε_h are the toroidal and the helical magnetic field modulations.