Thermal neutron cross-section data for the design of cold and superthermal neutron sources

Abstract

For the relevant materials used in cold and superthermal neutron sources the database for design studies was considerably improved. For D 2O at room temperature the intra and inter molecular interaction with neutrons were included using realistic structure factors S( κ). These effects are also taken into account for the cold moderators liquid H 2 and D 2 by deriving improved S( κ). The neutron interaction in solid materials and neutron filters as Al, Pb and Bi is treated exactly at low temperatures, especially for coherent neutron scattering in the tetragonal and FCC lattices. For superfluid 4He cross-section data for ultracold neutron production were derived as well as data for neutron transport considering diffusive motions and intermolecular scattering. Validation of the generated cross-sectional data was realized by comparison with differential and integral neutron scattering experiments so far available. These thermal neutron data can be used for both multigroup S N and Monte-Carlo methods solving the neutron transport equation.