Alpha channelling is a possible mechanism to transfer the energy of the fusion generated alpha particles directly to the thermal ion population through a wave propagating in the plasma. The interaction of ion Bernstein waves with a population of alpha particles is investigated to determine the conditions that maximize the absorption of the wave by the thermal ions and minimize the absorption by the thermal electrons under reactor relevant conditions. The ray trajectories equations are analytically and numerically solved beyond the mode conversion layer and the optimal conditions for alpha channelling are determined.
Current drive by lower hybrid heating of thermonuclear alpha particles in tokamak reactors