Transport properties of a toroidal plasma at intermediate-to-high collision frequencies

Neoclassical transport coefficients are computed in a large aspect ratio toroidal magnetic confinement system in order to examine the transition between the plateau and Pfirsch-Schlüter regimes. The calculation employs a hybrid collision operator combining Krook and pitch angle scattering terms with the identical particle collision frequency taken to be a function of velocity which is determined from a fit to known exact results for classical transport. A simple approximate analytic form is presented which incorporates both these results and the results of Hinton and Rosenbluth for lower collision frequencies.