On the magnetic drift deflection of plasma particles in axisymmetric tokamaks

The drift trajectories of untrapped (passing, circulating) and trapped particles have been analyzed in the axisymmetric tokamaks with circular and elliptic magnetic surfaces for arbitrary aspect ratios and elongation. Analytical expressions for the drift deflections and orbit-widths of plasma particles are derived using the self-consistent collisionless drift-kinetic equation for plasma particles in a tokamak with circular magnetic surfaces. The computational results demonstrate that the direction of toroidal magnetic drift of plasma particles is significantly influenced by the sign of their charge, the direction of their parallel velocity relative to the equilibrium magnetic field, and the particle's initial (starting) position on the magnetic surface. In the case of elongated tokamaks, the existence of the usual t-trapped particles and two groups of d-trapped particles on the elliptic magnetic surfaces is examined.