Transverse energy distribution and the shape of blocking dips in real crystals

Abstract

Abstract The calculated shapes of blocking dips differ from the experimental ones since models for charged particle motion with in crystals assume a perfect lattice. In this paper we suggest that the difference between the transverse energy distribution π(E⊥) of the particles coming out from a real crystal and that calculated in a statistical equilibrum continuum model, corrected for thermal vibration effects by a diffusion equation, accounts for crystal defects and is approximately independent of the distribution of transverse energy before diffusion and of the energy of blocked particles. The extraction of π(E⊥) from experimental dips requires the inversion of an integral equation, that is analy = tically solved in a particular case of practical interest. This would provide a way of analysing nuclear reaction time measurements that makes use of the full shape of the blocking dips. An illustrative example of the method to a blocking lifetime measurement in 27A1 (p,α) 24Mg resonance reactions is presented.