Kinetic Analysis of the Localized Magnetohydrodynamic Ballooning Mode

A kinetic analysis of magnetohydrodynamic ballooning modes has been carried out in the limit of large toroidal mode numbers. At marginal stability, the mode acquires a real frequency. The finite ion Larmor radius and perturbed electron pressure anisotropy are stabilizing effects, whereas the perturbed ion pressure anisotropy and the longitudinal electric field are destabilizing. By minimizing the stability effect and maximizing the destabilizing effect, the critical $\beta$ may be 10% lower than that predicted by the magneto-hydrodynamic theory.