Radial structure of internal unstable ideal MHD modes in the range of intermediate toroidal wave numbers

Abstract

By extracting the ballooning phase factor from the displacement vector, the most unstable modes of the internal ideal MHD spectrum of two families of JET-like Tokamak configurations (with high shear and with low shear) can be calculated with a spectral code over a wide range of values of the toroidal wave number n. In the range of intermediate n-numbers (3<or=n<or=100), the authors present the radial and azimuthal structures of the amplitude of the displacement and the corresponding potential energy distribution. The eigensolutions behave qualitatively as expected from the ballooning mode theory.