Cold and thermal neutron scattering in liquid water-II: Scattering laws and group constants for H2O and D2O

On the basis of the cross-section model of liquid H2O, which has been developed in the previous paper, cold and thermal neutron scattering in liquid D2O is described. The dynamics of liquid molecules, together with their static distribution, is fully taken into account so that various results of neutron experiments and computer simulations are well reproduced especially in terms of coherent scattering like the diffuse Bragg one. The model covers a wide range of neutron incident energies from 0.1μeV to 10eV at many different temperatures between 0 and 100∘C. Double-differential and total scattering cross sections are calculated by the use of a generalized frequency distribution and, equivalently, a velocity auto-correlation function. Furthermore, a set of scattering laws and group constants for liquid H2O and D2O is generated, which will be useful for research and development of an advanced neutron source and a nuclear power reactor.