Trapped particle effects on ion velocity distributions in the presence of ICRH

An investigation is made of the influence of toroidal effects, in the form of trapped particles, on ion velocity distributions in the presence of ICRH. The analysis is based on a bounced averaged Fokker-Planck equation including RF-driven quasi-linear velocity space diffusion. A pitch angle averaged distribution, suitable for calculating weighted velocity space averages of the distribution, is derived under the assumption that the influence of anisotropy can be neglected. For a given absorbed power, this pitch angle averaged distribution is found to be independent of the aspect ratio. (author)