Generation of neutron multigroup constants in the energy range –10 MeV for light and heavy water at four different temperatures

On the basis of the cross section models of neutron scattering in liquid H2O and D2O, which have been developed in the previous papers, we have generated eight sets of multigroup constants (energy-averaged cross sections) for each liquid at 5, 27, 52 and 77 ∘ C . The multigroup constants cover a wide energy range 0.1 μ eV –10 MeV with 140 energy groups at equal logarithmic intervals and represent an angular scattering distribution by the Legendre polynomial expansion up to order 3. Major characteristics of neutron scattering inherent to liquid water are fully included in terms of coherent and incoherent properties and temperature-dependent quasi-elastic and inelastic scattering. These characteristics are assured by comparison with relevant experimental results of scattering cross section and also by neutron slowing-down and thermalization analysis in liquid H2O and D2O. It is shown that the present multigroup constants serve for analysis of neutron moderation from fission/spallation to ultra-cold energies, in combination with the already-generated ones for liquid 4He, H2, D2 and CH4 and solid CH4.