Identifying the Spin-Incoherent Contribution to Quasielastic Neutron Scattering with a Cold Triple-Axis Spectrometer

Abstract

Polarisation analysis for neutron scattering experiments is a powerful tool suitable for a wide variety of studies, including soft-matter samples which have no bulk magnetic behaviour and/or a significant hydrogen content. Here, we describe a method to leverage the versatility and spin-polarisation capabilities of a cold triple-axis spectrometer to perform a measurement to separate coherent and incoherent neutron scattering for a non-magnetic sample in the quasielastic neutron scattering (QENS) regime. Such measurements are complementary to unpolarised QENS measurements, which may typically be performed on a backscattering or time-of-flight spectrometer instrument where polarisation analysis can be significantly more difficult to achieve, and utilise the strengths of each type of instrument.

Keywords

• quasielastic neutron scattering
• polarised neutron scattering
• triple-axis spectrometry
• incoherent neutron scattering