As fusion-generated alpha -particles of RF-heated minority ions in a fusion plasma collide with impurity ions, the latter can be accelerated to energies of several MeV, a fact which may be useful for diagnostic purposes. The source strength and the distribution function of the hot ion population thus created is calculated. Account is taken of the effects of nuclear elastic scattering and velocity-space anisotropy. In addition, the distribution of near 7 MeV alpha -particles formed in close collisions between 3.5 MeV alpha -particles is determined.