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A new model for the description of X‐ray diffraction from mosaic crystals for ray‐tracing calculations
Author(s) -
Schlesiger Christopher,
Anklamm Lars,
Malzer Wolfgang,
Gnewkow Richard,
Kanngießer Birgit
Publication year - 2017
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s1600576717012626
Subject(s) - mosaicity , ray tracing (physics) , diffraction , reflection (computer programming) , optics , crystal (programming language) , distributed ray tracing , x ray , gaussian , physics , specular reflection , computational physics , x ray crystallography , computer science , quantum mechanics , programming language
This paper presents the development of a new reflection model for describing X‐ray diffraction from mosaic crystals. In contrast to the well established diffraction model of Zachariasen [Zachariasen (1994), Theory of X‐ray Diffraction in Crystals . Mineola: Dover Publications], it gives additional information on the spatial reflection behaviour and not just on the depth‐integrated reflectivity of the crystal material. The new reflection model enables a concrete description of mosaic crystal performance in an arbitrary X‐ray spectrometer configuration. Multiple reflections inside the crystal are described by splitting the calculation into a discrete number of reflections. Hence, the influence of each number of reflections is investigated, leading to a laterally resolved solution for the reflectivity. In addition, the model can use a mosaicity of arbitrary shape. This is important because the present work uses a Lorentzian‐shaped mosaicity instead of a Gaussian one, which is usually the case in the most widely used simulation programs. A comparison between the new model and that of Zachariasen is performed, and it predicts a similar integrated reflectivity with a deviation lower than 0.7%. Further, a ray‐tracing simulation with multiple reflections based on the new model is compared with a measurement, showing a deviation of lower than 5%.