Localized resistive modes (resistive interchange and resistive ballooning modes) are investigated for self-consistent Tokamak equilibria which have circular cross-sections near the magnetic axis. The second region of stability (which is stable with respect to ideal ballooning modes at high poloidal beta beta p) proves to be unstable when resistive effects are taken into account as well. In the low beta p stability region, the stability boundaries are shifted toward lower beta p values. The magnitude of the shift depends on the degree of localization of the perturbation around the field line, highly localized perturbations being the most unstable ones.
Magnetohydrodynamic stability of high-beta tokamak equilibria with force-free currents