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Dynamical theory calculations of spin‐echo resolved grazing‐incidence scattering from a diffraction grating
Author(s) -
Ashkar Rana,
Stonaha P.,
Washington A. L.,
Shah V. R.,
Fitzsimmons M. R.,
Maranville B.,
Majkrzak C. F.,
Lee W. T.,
Schaich W. L.,
Pynn Roger
Publication year - 2010
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/s0021889810010642
Subject(s) - grating , diffraction , bloch wave , physics , scattering , neutron scattering , neutron diffraction , polarization (electrochemistry) , neutron spin echo , optics , neutron , echo (communications protocol) , computational physics , small angle neutron scattering , quantum mechanics , chemistry , computer network , computer science
Neutrons scattered or reflected from a diffraction grating are subject to a periodic potential analogous to the potential experienced by electrons within a crystal. Hence, the wavefunction of the neutrons can be expanded in terms of Bloch waves and a dynamical theory can be applied to interpret the scattering phenomenon. In this paper, a dynamical theory is used to calculate the results of neutron spin‐echo resolved grazing‐incidence scattering (SERGIS) from a silicon diffraction grating with a rectangular profile. The calculations are compared with SERGIS measurements made on the same grating at two neutron sources: a pulsed source and a continuous wave source. In both cases, the spin‐echo polarization, studied as a function of the spin‐echo length, peaks at integer multiples of the grating period but there are some differences between the two sets of data. The dynamical theory explains the differences and gives a good account of both sets of results.