Mitigating background caused by extraneous scattering in small-angle neutron scattering instrument design.

Autor: Barker JG; NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899, USA., Cook JC; NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899, USA., Chabot JP; NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899, USA., Kline SR; NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899, USA., Zhang Z; NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899, USA., Gagnon C; NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Stop 6102, Gaithersburg, MD 20899, USA.
Jazyk: angličtina
Zdroj: Journal of applied crystallography [J Appl Crystallogr] 2021 Mar 03; Vol. 54 (Pt 2), pp. 461-472. Date of Electronic Publication: 2021 Mar 03 (Print Publication: 2021).
DOI: 10.1107/S1600576721001084
Abstrakt: Measurements, calculations and design ideas to mitigate background caused by extraneous scattering in small-angle neutron scattering (SANS) instruments are presented. Scattering includes processes such as incoherent scattering, inelastic scattering and Bragg diffraction. Three primary sources of this type of background are investigated: the beam stop located in front of the detector, the inside lining of the detector vessel and the environment surrounding the sample. SANS measurements were made where materials with different albedos were placed in all three locations. Additional measurements of the angle-dependent scattering over the angular range of 0.7π-0.95π rad were completed on 16 different shielding materials at five wavelengths. The data were extrapolated to cover scattering angles from π/2 to π rad in order to estimate the materials' albedos. Modifications to existing SANS instruments and sample environments to mitigate extraneous scattering from surfaces are discussed.
(© J. G. Barker et al. 2021.)
Databáze: MEDLINE
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