A single-crystal time-of-flight neutron diffractometer at a spallation neutron source

A single-crystal diffractometer using the time-of-flight (TOF) Laue technique had been operated for studies of structural and magnetic disorder and phase transitions in alloys and magnetic materials at the pulsed spallation neutron source facility of the KEK Neutron Science Laboratory (KENS). In various sample environments, the diffractometer has demonstrated its usefulness in measurements of diffuse scattering for studying local structures, and in surveys of reciprocal space for studying phase transitions and incommensurate structures under the conditions of varying temperature and magnetic field. Particular emphasis is placed on the fact that though the instrument did not receive high-flux neutrons for long wavelengths suitable for the studies of magnetic scattering, it gave good results on the observations of magnetic diffuse scattering and superlattice reflections. Remarks and future tasks of the TOF Laue technique are discussed in relation to the asymmetric pulse shape, separation of the inelastic scattering, and dependence of data correction on the sample quality.