Effects of a weakly 3-D equilibrium on ideal MHD instabilities
نویسنده
چکیده
The effect of a small three-dimensional equilibrium distortion on an otherwise axisymmetric configuration is shown to be destabilizing to ideal MHD modes. The calculations assumes that the 3-D fields are weak and that shielding physics is present so that no islands appear in the resulting equilibrium. An eigenfunction that has coupled harmonics of different toroidal mode number is constructed using a perturbation approach. The theory is applied to the case of tokamak H-modes with shielded resonant magnetic perturbations (RMPs) present indicating RMPs can be destabilizing to intermediate-n peeling-ballooning modes. Pacs. nos. 52.30.Cv, 52.35.Py, 52.55.-s, 52.55.Fa
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