Theory of semicollisional kinetic Alfvén modes in sheared magnetic fields

Abstract

The spectra of the semicollisional kinetic Alfvén modes in a sheared slab geometry are investigated, including the effects of finite ion Larmor radius and diamagnetic drift frequencies. The eigenfrequencies of the damped modes are derived analytically via asymptotic analyses. In particular, as one reduces the resistivity, it is found that, because of finite ion Larmor radius effects, the damped mode frequencies asymptotically approach finite real values corresponding to the end points of the kinetic Alfvén continuum.