Atomic pair distribution function analysis from the ARCS chopper spectrometer at the Spallation Neutron Source

Neutron powder diffraction based atomic pair distribution functions (PDFs) are reported from the new wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The spectrometer was run in white-beam mode with no Fermi chopper. The PDF patterns of Ni and Al2O3 were refined using the PDFfit method and the results compared to data collected at the NPDF diffractometer at Los Alamos National Laboratory. The resulting fits are of high quality demonstrating that quantitatively reliable powder diffraction data can be obtained from ARCS when operated in this configuration. Neutron powder diffraction measurements can be carried out routinely using timeof-flight (TOF) instruments at spallation sources such as the NPDF at the Los Alamos PREPRINT: Journal of Applied Crystallography A Journal of the International Union of Crystallography