Lindhard's multiple scattering description justifies axial and planar dechannelling data |
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| Authors: | S. U. Campisano G. Foti F. Grasso M. Lo Savio E. Rimini |
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| Affiliation: | 1. Centro Siciliano di Fisica Nucleare e di Struttura della Materia , I-95129, Catania, Italy;2. Gruppo Nazionale di Struttura della Materia del Consiglio Nazionale delle Ricerche , I-95129, Catania, Italy;3. Istituto di Struttura della Materia, Università di Catania , I-95129, Catania, Italy;4. Istituto Nazionale di Fisica Nucleare, Sezione di Catania , I-95129, Catania, Italy |
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| Abstract: | The dechannelled fraction vs. penetration depths X(z) has been measured for 0.3 to 1.5 MeV protons impinging along the {110} plane of Si and Ge. The experimental results show an exponential trend of X(z) vs. the penetration depth and a very small dependence on the crystal temperature. The theoretical model previously proposed to describe the axial dechannelling in terms of changes in the ion transverse energy has been extended to the planar case. Due to the difference in symmetries between planes and axes, the change of transverse energy gives rise to a diffusion equation. The analytical form of the diffusion coefficient has been obtained taking into account the Lindhard's description of nuclear and electronic reduced multiple scatterings. A comparison between the planar and the axial case brings into light the different role played by nuclear and electronic scatterings in dechannelling. |
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