Axial channeling and blocking with restricted equilibrium in phase space

The influence of planar channeling on axial channeling and blocking dips has been studied. An equilibrium in phase space restricted by exclusion of planar channeling trajectories was introduced previously for axial blocking, and this model is formulated for channeling and compared with backscattering experiments. A depression of the yield in the shoulder region, caused by planar effects, is accounted for by the model. The restriction of phase space is the main cause of the ''Barrett factor'', on the minimum yield, and the depth dependence of this factor is studied by comparison of the model with computer simulation. The enhancement is found to disappear quickly with depth, being reduced from a factor of 2-3 to a correction of the order of 10%, only when χmin reaches a value of 0.1. (orig.)