Super-resolution energy spectra from neutron direct-geometry spectrometers

Fahima Islam; Jiao Y. Y. Lin; Richard Archibald; Douglas L. Abernathy; Iyad Al-Qasir; Anne A. Campbell; Matthew B. Stone; Garrett E. Granroth

doi:10.1063/1.5116147

arXiv · 1906.09482

Super-resolution energy spectra from neutron direct-geometry spectrometers

Fahima Islam·Jiao Y. Y. Lin·Richard Archibald·Douglas L. Abernathy·Iyad Al-Qasir·Anne A. Campbell·Matthew B. Stone·Garrett E. Granroth

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Abstract

Neutron direct-geometry time-of-flight chopper spectroscopy is instrumental in studying fundamental excitations of vibrational and/or magnetic origin. We report here that techniques in super-resolution optical imagery (which is in real-space) can be adapted to enhance resolution and reduce noise for a neutron spectroscopy (an instrument for mapping excitations in reciprocal space). The procedure to reconstruct super-resolution energy spectra of phonon density of states relies on a realization of multi-frame registration, accurate determination of the energy-dependent point spread function, asymmetric nature of instrument resolution broadening, and iterative reconstructions. Applying these methods to phonon density of states data for a graphite sample demonstrates contrast enhancement, noise reduction, and ~5-fold improvement over nominal energy resolution. The data were collected at three different incident energies measured at the Wide Angular-Range Chopper Spectrometer at the Spallation Neutron Source.

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Fahima Islam, Jiao Y. Y. Lin, Richard Archibald, Douglas L. Abernathy, Iyad Al-Qasir, Anne A. Campbell, Matthew B. Stone, Garrett E. Granroth. 2019-06-22. Super-resolution energy spectra from neutron direct-geometry spectrometers. https://doi.org/10.1063/1.5116147

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