Content area
Abstract
The kinetic theory of ion transport in axisymmetric tokamak plasmas has been extended to include the effects of strong plasma rotation and radial viscous momentum transfer due to unbalanced neutral beam injection. To accommodate particle flow speeds which are comparable in magnitude to the ion's thermal velocity, the kinetic analysis is carried out in a coordinate frame which is moving with the plasma. As a result, the kinetic transport equations are a simple generalization of the kinetic equations valid for non-rotating plasmas with the radial gradient of the toroidal angular velocity appearing as a driving term like the temperature gradient.
An ordered hierarchy of kinetic equations are obtained for both the gyroangle dependent and gyrotropic components of the particle distribution function by expanding the particle distribution function, electric field vector and particle flow in powers of the gyroradius parameter. The lowest order kinetic equation governing the gyroangle dependent component of the particle distribution function is solved and the result is used in conjunction with the definition of the toroidal viscosity to obtain the functional structure of the gyroviscous momentum drag force.
The collisional response of the plasma to intense momentum injection is obtained by use of a linearized Fokker-Planck collision operator which accounts for both the direct and indirect effects of beam particle collisions with the background plasma species. This operator is used in the O$(\delta\sp{f1})$ drift kinetic equation to obtain a solution for the gyroaveraged component of the particle distribution function in all collision frequency regimes. The lowest order neoclassical friction-flow and parallel stress constitutive relationships are computed from a knowledge of the O($\delta\sp{1}$) particle distribution function.
Finally, the fluid equations are used in conjunction with the kinetically derived constitutive relationships to obtain an expression for the radial particle flux for a mixed regime beam injected plasma. In this regard, the theory of particle transport in the presence of an external beam momentum source is evaluated for a two specie plasma composed of a high Z impurity ion and a dominant hydrogenic ion species.
