Finite beta stabilization of the kinetic ion mixing mode

The full finite-β local dispersion relation of the ion mixing mode is derived and analyzed, using kinetic theory. The physical mechanism of finite-β stabilization of a single (i.e., fixed wavenumber, kzrn and bi constant) ion mixing mode is discussed. The distortion of the resonant region, in velocity space (by ∇B drifts) and the coupling to the shear Alfvén wave are shown to be the important stabilization mechanisms. It is found that high values of β (β>βc, where βc =0.1→1.0, for relevant parameters) are necessary for stabilization.