Paramagnetic scattering of neutrons by rare-earth oxides

Thermal region neutrons are scattered by the paramagnetic moment of rare-earth oxides such as Gd2O3 which are contained in nuclear fuels as burnable poison. The scattering is atomic process and not a nuclear process, so the data are not included in the nuclear data files such as ENDF/B and JENDL. The cross sections and angular distributions of the elastic scattering are calculated using the existing theory and ENDF/B type files are made for oxides of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb. in the incident neutron energy range from 10-5 to 1.0 eV at the room temperature and the temperature dependences in the paramagnetic region are also given. (author)