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Title: Wavelength-independent constant period spin-echo modulated small angle neutron scattering

Spin-Echo Modulated Small Angle Neutron Scattering (SEMSANS) in Time-of-Flight (ToF) mode has been shown to be a promising technique for measuring (very) small angle neutron scattering (SANS) signals and performing quantitative Dark-Field Imaging (DFI), i.e., SANS with 2D spatial resolution. However, the wavelength dependence of the modulation period in the ToF spin-echo mode has so far limited the useful modulation periods to those resolvable with the limited spatial resolution of the detectors available. Here we present our results of an approach to keep the period of the induced modulation constant for the wavelengths utilised in ToF. This is achieved by ramping the magnetic fields in the coils responsible for creating the spatially modulated beam in synchronisation with the neutron pulse, thus keeping the modulation period constant for all wavelengths. Such a setup enables the decoupling of the spatial detector resolution from the resolution of the modulation period by the use of slits or gratings in analogy to the approach in grating-based neutron DFI.
Authors:
 [1] ; ;  [2] ;  [3] ;  [4] ;  [1] ;  [5]
  1. Nano-Science Center, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark)
  2. Faculty of Applied Sciences, Delft University of Technology, 2629 JB Delft (Netherlands)
  3. Helmholtz-Zentrum Berlin für Materialen und Energie GmbH, D-14109 Berlin (Germany)
  4. Space Sciences Laboratory, University of California at Berkeley, Berkeley, California 94720 (United States)
  5. (Sweden)
Publication Date:
OSTI Identifier:
22597913
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BEAMS; DECOUPLING; FREQUENCY DEPENDENCE; GRATINGS; IMAGES; MAGNETIC FIELDS; MODULATION; NEUTRON DIFFRACTION; NEUTRONS; PULSES; SIGNALS; SMALL ANGLE SCATTERING; SPATIAL RESOLUTION; SPIN; SPIN ECHO; SYNCHRONIZATION; TIME-OF-FLIGHT METHOD; WAVELENGTHS