Generalisation of opacity formulas for neutron transport
1 CEA/Saclay, DEN/DM2S/SERMA, 91191 Gif-sur-Yvette Cedex, France
2 Laboratoire Physique Théorique et Modèles Statistiques (UMR CNRS 8626), Université Paris-Sud, Orsay Cedex, France
In the context of reactor physics, one is often called to relate the physical properties of a medium to the statistics of the random trajectories of the neutrons flowing through it. For instance, Cauchy’s formula establishes a link between the average length of the neutron paths (which is proportional to the medium opacity) and the volume-to-surface ratio of the traversed medium. In this work, we consider some extensions of such results for neutrons undergoing scattering, absorption and branching. A validation of the proposed formulas via Monte Carlo simulations is discussed.
Key words: Monte Carlo / opacity / branching processes / exponential flights
© Owned by the authors, published by EDP Sciences, 2014