Diffraction of H from LiF(001): From slow normal incidence to fast grazing incidence

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:382

Article; Proceedings Paper

Muzas, A. S.¹  Gatti, F.²  Martin, F.^1,3,4  Diaz, C.^1,4 

[1] Univ Autonoma Madrid, Dept Quim Modulo 13, E-28049 Madrid, Spain

[2] Univ Montpellier 2, Inst Charles Gerhardt, CTMM, UMR 5253, Pl Eugene Bataillon, F-34009 Montpellier, France

[3] Inst Madrilerio Estudios Avanzados Nanociencia IM, Madrid 28049, Spain

[4] Univ Autonoma Madrid, Condensed Matter Phys Ctr IFIMAC, E-28049 Madrid, Spain

关键词: Grazing incidence;    Diffractive scattering;    Quantum dynamics;   

DOI  :  10.1016/j.nimb.2016.04.031

来源: Elsevier

【 摘 要 】

Describing diffraction of atomic and molecular projectiles at fast grazing incidence presents a real challenge for quantum theoretical simulations due to the high incidence energy (100 eV-1 keV) used in experiments, This is one of the main reasons why most theoretical simulations performed to date are based on reduced dimensional models. Here we analyze two alternatives to reduce the computational effort, while preserving the real dimensionality of the system. First, we show that grazing incidence conditions are already fulfilled for incidence angles <= 5 degrees, i.e., incidence angles higher than those typically used in experiments. Thus, accurate comparisons with experiment can be performed considering diffraction at grazing incidence, but with smaller total incidence energies, whilst keeping the same experimental normal energy in the calculations. Second, we show that diffraction probabilities obtained at fast grazing incidence are fairly well reproduced by simulations performed at slow normal incidence. This latter approach would allow one to simulate several experimental spectra, measured at the same normal incidence energy for several incidence crystallographic directions, with only one calculation. This approach requires to keep the full dimensionality of the system. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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