By making use of a general formulation of the MHD energy theorem the power deposited by ideal-MHD waves in a stable plasma is calculated in a straightforward way. When applied to very-low-frequency waves with is the wave vector and the Alfvén velocity vector), the principle shows that heating at the shear Alfvén wave resonance is inefficient. Then, a low-frequency heating scheme which, unlike the different kinds of TTMP studied so far in the literature can have substantial overall efficiency in thermonuclear toroidal devices is considered. It makes use of purely poloidal m ≠ 0, n = 0 RF-coils, which can be located so close to the vacuum wall that the plasma cross-section is not appreciably reduced.
Torsional Alfvén wave excitation by mode conversion in a tokamak plasma