The use of cold neutrons (E < 10meV) significantly improves the quality of neutron X-ray images and the performance of small-angle neutron scattering (DNPA) devices. The majority of research reactors and spallation sources active in these fields are equipped with them. Numerical models predict a significant increase in the performance of cold moderators using para hydrogen when their dimensionality is reduced (3D – 2D – 1D). The European spallation source will for example use a two-dimensional flat cold moderator to increase the brightness of the source by a factor of 4. Simulations suggest that switching to one-dimensional geometry potentially gains an additional 7 factor on brightness. These developments around cold moderators therefore have very strong implications for the potential performance of neutron sources at very high costs.
The objective of the CONEMO project is to develop all the tools and methods for modeling the integration of these moderators around neutron sources based on the use of accelerators, to build and integrate a prototype of a one-dimensional moderator and to validate its performance for neutron radiography and scattering experiments at small angles. Neutron radiography techniques will make it possible for example to carry out experiments on the problems of hydruration of fuel elements as well as on measurements of homogeneity of boron content. For the CEA, diffusion measurements at small angles will allow the continuation of experiments on the ageing of nuclear steels.
In a particularly active international context, this project will place the CEA as a major player in the supply of components for compact neutron sources, beyond its recognized expertise in accelerators and the work already done on targets. Various institutes are considering the construction of compact sources to replace research reactors. In Europe alone, we can mention the SONATE project in France, HBS in Germany, ARGITU in Spain, LvB in Hungary and SARAF in Israel.