Multiple scattering of channeling ions in crystals-II. Planar channeling

Planar channeling is discussed. The Fokker-Planck kinetic equation is derived for charged particle scattering in planar channeling. The main factors that affect dechanneling are examined. Comparison of the obtained solutions with experimental data on dechanneling shows satisfactory agrceinent. The importance of nuclear scattering due to discreteness of the atomic plane is demonstrated. The depth-dependcncc of the flux peaking effect is investigated. Also, the dependence of a channeled ion profile on direction, energy, and temperature is studied. It is inferred that the approximation of monotonic gain of the transverse energy (that is commonly used in the interpretation of experiments and that docs not include the diffusion in the transverse energy space) proves to be unsatisfactory.