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The High-Flux Backscattering Spectrometer at the NIST Center for Neutron Research

A. Meyer·R. M. Dimeo·P. M. Gehring·D. A. Neumann
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Abstract

We describe the design and current performance of the high-flux backscattering spectrometer located at the NIST Center for Neutron Research. The design incorporates several state-of-the-art neutron optical devices to achieve the highest flux on sample possible while maintaining an energy resolution of less than 1mueV. Foremost among these is a novel phase-space transformation chopper that significantly reduces the mismatch between the beam divergences of the primary and secondary parts of the instrument. This resolves a long-standing problem of backscattering spectrometers, and produces a relative gain in neutron flux of 4.2. A high-speed Doppler-driven monochromator system has been built that is capable of achieving energy transfers of up to +-50mueV, thereby extending the dynamic range of this type of spectrometer by more than a factor of two over that of other reactor-based backscattering instruments.

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A. Meyer, R. M. Dimeo, P. M. Gehring, D. A. Neumann. 2002-09-06. The High-Flux Backscattering Spectrometer at the NIST Center for Neutron Research. https://doi.org/10.1063/1.1568557

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