Diffuse Scattering Spectrometer

 D7 has been dismantled.  The new permanently-polarized diffuse scattering spectrometer D007 will deliver its first neutrons in 2024.

Inelastic Magnetic Scattering

Polarization analysis separates magnetic from nuclear scattering, which is particularly necessary when the nuclear and magnetic scattering are weak, diffuse, and overlapping.  This occurs in diffuse elastic scattering from disordered materials, and also in inelastic scattering.

In the example shown here, D7 was used to measure the magnetic spectra from a Tb2Sn2O7 magnetic pyrochlore. The compound has magnetic frustration, but it does partially order if the temperature is low enough. D7 was used in both diffraction and time-of-flight modes to differentiate between the elastic and inelastic magnetic scattering, leading to a better understanding of the magnetic structure and energy scales.

Ref: K. C. Rule, G. Ehlers, J. R. Stewart, A. L. Cornelius, P. P. Deen, Y. Qiu, C. R. Wiebe, J. A. Janik, H. D. Zhou, D. Antonio, B. W. Woytko, J. P. Ruff, H. A. Dabkowska, B. D. Gaulin, and J. S. Gardner, Phys. Rev. B. 76 212405 (2007)