Inelastic Thermal-Neutron Scattering by Liquid D₂O

The General Atomic Neutron Velocity Selector was used to study the details of neutron scattering in liquid D₂O maintained at 300° K. The scattering into various angular directions between 30 and 120° is studied for incident neutrons with energies ranging up to ∼0.65 eV. The energy-transfer cross sections, corrected for plural scattering effects, are evaluated to provide data in regions of large energy and momentum transfers not previously available and not readily accessible to experimenters using a reactor as a source of neutrons. The present results agree satisfactorily with the previous results but indicate that the previous results contain effects due to plural scattering in the sample. The present results also are compared with theory. Although there are some regions of acceptable agreement, other regions of poorer agreement indicate that each of these theoretical treatments may need further attention.