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Wavelength‐dependent reflectivities of a few neutron monochromators
Author(s) -
Malik S. S.
Publication year - 1976
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/s0021889876011357
Subject(s) - monochromatic color , bar (unit) , wavelength , optics , reflectivity , neutron , reflection (computer programming) , spectrometer , yield (engineering) , materials science , chemistry , physics , nuclear physics , computer science , meteorology , metallurgy , programming language
Wavelength‐dependent reflectivity measurements of neutron monochromators, Pb(200), Ge(111), Zn(100) and Be(100) were made with a triple‐axis spectrometer. The first two axes, in antiparallel arrangement, were employed to yield a monochromatic neutron beam. Pb(200) reflectivity was measured in reflection geometry. The other monochromators were studied in Laue (transmission) geometry. Experimental relative reflectivity values for Ge(111) for 0.83<λ<2.39 Å compare favorably with the corresponding calculated values. For all the other monochromators there is fair agreement for λ > 1.27 Å between the relative, measured and calculated, reflectivity values. The general behaviour of the experimental (reflectivity) values, both in the absolute and relative sense, is not in good agreement with the calculations. The measured integrated reflectivities of Ge(111), Pb(200), Zn(100) and Be(100) reflections are ≃0.1, 0.16, 0.5 and 0.9 of the respective calculated values.