A method for calculating the neoclassical transport coefficients in a nonaxisymmetric multispecies plasma is developed by employing a momentum conserving collision operator. In this method, the parallel current, and the radial particle and heat fluxes are expressed in terms of the transport coefficients which can be obtained by solving the drift kinetic equations with the pitch-angle scattering collision operator. These expressions can be easily incorporated into the existing numerical codes including the pitch-angle scattering collisions only.

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The current drive by electron cyclotron resonance heating (ECRH) is investigated in a Tokamak with arbitrary aspect ratio. The r.f. power is assumed to be weak and the wave-induced current is calculated by using an adjoint equation to the steady-state linearized Fokker-Planck equation with a quasi-linear diffusion term. The trapped electrons and the modification of electron cyclotron resonance condition by the relativistic mass increase are shown to have significant effects on the efficiency of this current drive. The efficiency strongly depends on the values of the parallel velocity uo of resonant electrons, the inverse aspect ratio E , the poloidal angle Bo of the absorption point, and the relativistic parameter Swhich represents the strength of the relativistic correction to the resonance condition. It is also pointed out that the electronelectron collisions enhance the trapping effects compared with those of the Lorentz gas model.

A method for calculating the ion thermal conductivity and the ion distribution function in the banana regime is formulated for an axisymmetric toroidal plasma of arbitrary aspect ratio. In the limits of large and small aspect ratios. the computed thermal conductivity agrees with the results of ROSENBLUTH et al. (1972, Physics Fluids 15, 116) and HAZELTINE et al. (1973, Physics Fluids 16, 1645. A simple expression for this conductivity is also derived.

An approximate expression for the beam driven current in which the trapping effects of fast ions and electrons are included is derived by means of a variational principle, The beam driven current due to arbitrary fast ions can be calculated easily from this expression in an axisymmetric magnetic field with finite aspect ratio. It is shown that in a tokamak with circular cross-section this expression gives a good approximation to the results obtained by numerically solving the Fokker-Planck equation. The beam driven current due to energy diffusion, which is neglected in the approximate expression, is also estimated.