A Generalized Model for the Elastic and Inelastic Slowing Down of Fast Neutrons

For the determination of fast neutron spectra, we propose a slowing down operator model whose number of terms increases with the needed accuracy without theoretical limit. This method can be used for elastic and inelastic slowing down and needs only the choice of an arbitrary fitting flux and the determination of some functions from this flux. Applications to the determinations of spectra and reaction rates are studied in various media including resonantelements. The practical interest of this method is its rapid convergence.