IDEAL MAGNETOHYDRODYNAMICS - GLOBAL MODE ANALYSIS OF 3-DIMENSIONAL PLASMA CONFIGURATIONS

The global magnetohydrodynamic (MHD) stability of three-dimensional (3-D) toroidal plasmas, investigated here by the ideal MHD energy principle formulated in magnetic coordinates, is studied by a Finite-Element-Fourier code, the Code for the Analysis of the Stability of 3-D equilibria (CAS3D) [Theory of Fusion Plasmas, Varenna 1990 (Editrice Compositori, Bologna, 1990), p. 667]. A first survey of the stability properties of 3-D equilibria clarifies structural characteristics of global MHD modes, such as the existence of separable mode families and the possibility of annihilating all compression terms, i.e., the fluid and the field compression, for the minimizing perturbation.