Cold and thermal neutron scattering cross sections of liquid H2 and D2 at temperatures between melting and boiling points

Cross section models for neutron scattering in liquid H-2 and D-2 are presented, which are applicable to a wide range of incident energies from 0.1 mu eV to 10 eV at all practical temperatures between the melting and boiling points. Typical cross-section results, both double-differential and total, are calculated to confirm the effects of nuclear spin correlations, i.e. ortho and para, and molecular translations and rotations. A slowing-down property is also analyzed in terms of the average cosine of scattering angle and the average energy of scattered neutrons. It is shown that the present models are able to serve for the generation of basic cross-section file in developing and advanced neutron source. (C) 2000 Elsevier Science Ltd. All rights reserved.