Four-fluid Model and Radial Transport Equation for Toroidal Momentum in Tokamak Plasmas

摘要

Mechanically, the usually assumed transport equation of the toroidal momentum in tokamak plasmas seems to be questionable since it fails to consider constraint conditions on the motion of the trapped particles. In this paper, starting from the so-called four-fluid model which can make up the above-mentioned deficiency of the ordinary MHD model and can correctly and effectively describe the relations between the particle flows and the acting forces, a more reasonable radial transport equation for the toroidal momentum is derived on the basis of the ambipolarity of the radial particle fluxes.