Visualization Interface for Single Crystal Neutron Spectroscopy

Analysis and visualization for single crystal neutron spectroscopy experiments have been historically performed using data pre-histogrammed in energy transfer. To obtain the dynamic structure factor, each histogram bin, for each detector, is transformed to energy and momentum transfer. For further analysis and visualization, the data is re-histogrammed in energy-momentum space, such that every reciprocal space region contains the average of the contributing histogram bins [1,2]. The main deficiencies of such existing approach are (i) the large amount of memory resources needed to store the histogram bins with zero neutron counts, and (ii) the difficulty of error propagation in re-histogramming, which result in the absence of weighting of contributions with different statistical significance. Based on the lessons learned from single crystal diffraction [3,4], we have developed a different approach, where the histogramming to energy-momentum space is based on neutron detection events and accounts for their statistical significance. The algorithm is implemented in the Mantid software [5] and provides options for processing and correcting both upolarized and polarized data. Here, we will emphasize the experience we gained with implementing straight forward python scripting based data processing and visualization, using the event approach. We will present plans for a future graphical user interface.

[1] R. T. Azuah et al., Journal of Research of the National Institute of Standards and Technology 114, 341 (2009)

[2] R.A. Ewings et al., Nuclear Instruments and Methods in Physics Research Section A 834, 132 (2016)

[3] T. Michels-Clark et al., J. Appl. Crystalography 49, 497 (2016)

[4] A. T. Savici et al., in preparation

[5] O. Arnold et al., Nuclear Instruments and Methods in Physics Research Section A 764, 156 (2014)

This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.