Neutron data

Interaction of neutrons with matter is of great importance when evaluating the safety and risks related to operation of nuclear power plants, nuclear waste management, or new concepts of nuclear power production. Smaller uncertainties in the neutron cross section data can result in enhanced safety of the present and future plants.

Databases of neutron-induced reaction cross sections are maintained by the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD). The NEA databank maintains a high-priority request list (HPRL) of the most important nuclear data requirements. In particular, the Joint Evaluated Fission and Fusion (JEFF) project of evaluated neutron data maintains a comprehensive database for routine applications in various areas of science and technology.

IRMM measures neutron cross-sections of the relevant nuclei to improve the existing files. IRMM focuses on neutron data for
For accurate neutron data two energy domains need to be distinguished:
  • the resolved resonance region, where the neutron cross-sections reveal a complicated resonance structure. Here, experiments with very high energy resolution are required. This is only possible at dedicated time-of-flight facilities such as the linear electron accelerator (GELINA) facility at IRMM.
  • the unresolved resonance region, where the width of the resonances is larger than the resonance spacing, and the overlapping cross-sections exhibit a smoothed energy dependence. In this energy region measurements with mono-energetic neutrons are preferable, which are usually obtained using nuclear reactions. At IRMM, these measurements can be carried out at the 7 MV Van de Graaff accelerator (VdG).


On-going work table

Training in the nuclear field is an important part of the IRMM work programme.
Access to IRMM accelerators can be applied via the EUFRAT project.




Last Update 23/10/2008