Discrete Alfvén eigenmode spectrum in magnetohydrodynamics

Abstract

The conditions for the existence of global Alfvén eigenmodes below the continuum are investigated, and an analytical dispersion relation describing the modes is obtained. In cylindrical geometry, the curvature together with gradients of the equilibrium current (magnetic shear), and finite ω/ωci effects are responsible for these modes which could play an important part in Alfvén wave heating of tokamak plasmas.