New developments in the simulation of Rutherford backscattering spectrometry in channeling mode using arbitrary atom structures
Résumé
As Rutherford backscattering spectrometry in channeling mode (RBS/C) is an efficient technique for characterizing crystallographic defects, its computational simulation has drawn attention over the past several decades. Recently, a RBS/C simulation code based on the binary collision approximation called Rutherford backscattering simulation in arbitrary defective crystals has been suggested and successfully applied to predict the RBS/C spectra from different damaged materials, whose structures were generated in high-dose ion irradiation atomistic simulations. In the present paper, we introduce new developments improving the flexibility of the developed software and its applicability to different types of materials. More precisely, we modified the algorithm describing the slowdown process of backscattered ions, added fitting parameters in the collision partner search routine, modified the routine taking into account target atom thermal vibrations and provided new descriptions of the ion beam divergence. As an example, the effect of the modifications on simulated RBS/C spectra is shown for an 〈011〉-oriented UO2 crystal analyzed with a 3.085 MeV He2+ ion beam. Some of these changes proved necessary to achieve satisfying agreement between simulations and experimental data. Similar observation was made for 〈001〉-oriented Si and 〈001〉-oriented GaAs crystals analyzed with a 1.4 MeV He+ ion beam. In these simulations, the modifications have also resulted in good agreement with experiment