4. Modeling nuclear data: reaction cross sections

Calculating nuclear data involves using a succession of nested theoretical models. Today, it is impossible to obtain a satisfactory result for application calculations without including adjustments derived from experimental results. However, the predictive power of models taken independently of each other is progressing to the point where they are generally qualitatively acceptable.

The models presented in the following pages may appear complex, but they are in fact the approximations needed to perform the calculations. They still need to be refined to provide a faithful description of physics in all circumstances. The real-life examples presented in section 6 will give you a better understanding of these refinements.

In the energy range of reactor physics, up to a few tens of mega-electronvolts (MeV), the calculation of neutron cross sections...