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 multiframe 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.
| Original language | English |
|---|---|
| Article number | 105109 |
| Journal | Review of Scientific Instruments |
| Volume | 90 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 1 2019 |
Funding
The authors thank J. M. Borreguero Calvo, A. T. Savici, T. E. Proffen, M. K. Stoyanov, and T. R. Charlton for fruitful discussions. The graphite sample of grade G347A was funded by Strategic Planning Partnership between ORNL and Tokai Carbon Co., Ltd. (No. NFE-09-377 02345) with the U.S. Department of Energy. The DFT simulations were performed at the High Performance Facility in the University of Sharjah. This work was supported by the Department of Energy, Laboratory Directed Research and Development SEED funding, under Contract No. DE-AC05-00OR22725. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.