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High Flux Backscattering Spectrometer (HFBS)

 The NCNR backscattering spectrometer is one of the highest intensity instruments of its kind. It enables very high energy resolution studies of the low frequency dynamics of many systems. Applications of backscattering spectroscopy are numerous and include molecular reorientations, dynamics of adsorbed systems, and viscous liquids. To learn about the instrument, and about experiments that have been performed on the HFBS, please use this link to visit our webpages.


At the center of the beam, the neutron fluence rate is 3 x 105 n cm-2 s-1 as determined by gold foil activation measurements. A high-speed Doppler-driven monochromator system allows energy transfers up to ±50 µeV (though this energy range is not advisable). The instrumental energy resolution is a Gaussian-like lineshape, with a full-width-half-maximum (FWHM) about 1 µeV.

Created April 18, 2011, Updated January 20, 2022