Drift Alfvén Waves in Tokamaks

Abstract

A new branch of solutions of the finite-beta drift-wave radial eigenmode equations has been found. The branch is heavily damped in the low-beta regime and identified with the shear Alfv\'en wave. This branch and the usual electrostatic branch are damped in a collisionless plasma. Including trapped electron effects introduces an instability which is potentially harmful to plasma confinement.