Dependence on the incident angle of the electronic energy loss of planarlychanneled fast ions

The angular dependence of the electronic energy loss of fast ions was calcu lated. Models for the transitions from axial to planar channeling and from planar channeling to a random direction are discussed in terms of a simple generalization of the Lindhard-Jin-Gibson Model for the axial-random transi tion. In order to compare these models with experimental data, the energy l oss of 2.0 MeV He ions channeled through a thin silicon crystal into direct ions that scan the {001} plane from the [110] axis to the [100] axis was me asured. (C) 1999 Elsevier Science B.V. All rights reserved.