Spatial diffusion of charged high-energy fusion products by shear Alfven perturbations

The interaction between shear Alfven perturbations and the charged high-energy particles produced by fusion reactions is investigated. The aim is to evaluate the conditions that must be realized in order for the quasi-linear diffusion flux of the fusion products to become significant. It is found that in the most relevant cases a severe deterioration in the confinement properties of the fusion products is not to be expected. This result follows from taking explicitly into account the spectral properties of shear Alfven perturbations in a toroidal configuration with magnetic shear. (author)