Neoclassical flux-friction relations in arbitrary closed-end plasmas

By following the moment approach of neoclassical transport theory and introducing a vector field D determined by the magnetic field, flux-friction relations in arbitrary closed-end plasmas are derived. Unlike the conventional ones, which are based on the flux coordinates, the new formulas can be used with any coordinate system. They are therefore more convenient for systems with complicated magnetic axes, such as DRAKON's [in Controlled Fusion and Plasma Physics, 1981, Proceedings of the 10th European Conference, Moscow (European Physical Society, Budapest, 1981), Vol. 1, paper E-8; in Plasma Physics and Controlled Nuclear Fusion Research, 1982, Proceedings of the 9th International Conference, Baltimore (IAEA, Vienna, 1983), Vol. 3, p. 159], for which coordinates that follow the magnetic axes are more natural than the flux coordinates. As a simple application, the Pfirsch--Schlueter fluxes are obtained for arbitrary closed-end plasmas