Intense ion cyclotron resonance heating can produce anisotropic non-Maxwellian velocity distributions with high energy tails. The distribution functions of the heated ions are determined by wave-particle interactions and Coulomb collisions. A quasi-linear diffusion theory for general wave-particle interaction in a fully toroidal geometry was developed by Kaufmann [1]. In contrast to the theory developed by Stix [2], Kaufmann's quasi-linear diffusion contains diffusion in real space as well as in velocity space. The RF-induced spatial transport as well as the finite orbit width are important for determining the velocity distribution, in particular for small and medium sized devices. Conference Table of Contents JET assigns a single Preprint number to a group of Conference Papers. The JET Preprints and Reports service holds Conference Papers in a dedicated Conference Papers section.