Energy dependence studies of channelling critical angle and de-channeling probabilities were essential for defect analysis. Present study reveals the fact that the well known energy dependence relations were not always applicable, particularly for the case of light relativistic particles. Here the energy dependence for positron channelling angular scans and de-channeling probability due to stacking faults was obtained using quantum mechanical models. The channelling critical angle calculated using this method (about 1.1 for 1MeV e+ in Au along (111) planes) was consistent with the experimental value measured by Andresen et al. (1971). New energy dependence relationships derived here were found to be consistent with standard formulae as and when the system enters into classical regime.

Energy Dependence Relations for Positron Channeling Critical Angle and Dechanneling Probability due to Stacking Faults. V.S.Vendamani, S.V.S.Nageswara Rao: Nuclear Instruments and Methods in Physics Research B, 2010, 268[14], 2312-7