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Influence of polychromaticity on particle structure determination in small‐angle X‐ray scattering
Author(s) -
Wang Wenjia,
Shtykova Eleonora V.,
Volkov Vladimir V.,
Chang Guangcai,
Zhang Lianhui,
Dong Yuhui,
Liu Peng
Publication year - 2015
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/s1600576715019214
Subject(s) - small angle x ray scattering , scattering , wavelength , optics , beam (structure) , materials science , cylinder , small angle scattering , monochromatic color , physics , computational physics , geometry , mathematics
Pink beams are now widely used for small‐angle X‐ray scattering (SAXS) data collection owing to their high intensity. However, the wavelength spread of a pink beam is a factor of 100 higher than that of a monochromatic beam, thus causing the experimental data to be smeared. To reveal the influence of polychromaticity on shape reconstruction, four geometric bodies (sphere, cube, helix and long cylinder) were used for SAXS data analysis. The results reveal that the influence of polychromaticity on the process of shape reconstruction is significantly more dependent on the geometry of the body than on its size. Scattering objects with smoothed scattering curves can tolerate a higher wavelength spread than those with tortuous curves. It is further demonstrated that the structural parameters calculated from the smeared data sets have little deviation from the ideal ones, which indicates the possibility of using a light source with a greater wavelength spread than a conventional pink beam for special time‐resolved SAXS experiments. Finally, it is concluded that SAXS data collected in pink‐beam mode can be used directly for structural calculations and model reconstructions without a desmearing procedure.