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Investigating time‐of‐flight spin‐echo modulation for small‐angle neutron scattering through experiments and simulation
Author(s) -
Sales Morten,
Plomp Jeroen,
Habicht Klaus,
Strobl Markus
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/s1600576714025916
Subject(s) - neutron spin echo , optics , physics , neutron time of flight scattering , neutron , neutron scattering , spallation , scattering , larmor precession , small angle neutron scattering , monte carlo method , wavelength , time of flight , computational physics , neutron detection , detector , magnetic field , nuclear physics , statistics , mathematics , quantum mechanics
A spin‐echo‐modulated small‐angle neutron scattering (SEMSANS) instrument in a time‐of‐flight (TOF) mode will be able to excel at pulsed neutron sources such as the European Spallation Source (ESS), currently under construction. This work compares experimental data from a TOF SEMSANS setup, where a spatial beam modulation of a white beam is obtained using triangular field coils, with Monte Carlo ray‐tracing simulations. The experiments and simulations in accordance demonstrate that a good contrast can be achieved when using a constant field in the triangular coils. In the reported setup only neutrons with certain wavelengths rotate by a Larmor precession angle that spatially modulates their polarization to coincide with the period of a grating installed at the detector position. This is shown by measuring with a broad wavelength range while scanning the echo condition.