Nuclear data generation & implementation for analog Monte Carlo simulation

Université Paris-Saclay, CEA Service d’études des réacteurs et de mathématiques appliquées, 91191 Gif-sur-Yvette France

^* e-mail: camilo.corderoramirez@cea.fr
^** e-mail: cedric.jouanne@cea.fr

Published online: 26 May 2023

Abstract

Nuclear data is in constant evolution as more experimental data is gathered, computational capabilities increase, and evaluators verify its validity by means of stochastic and deterministic simulations. The focus here is on the analog Monte Carlo simulation of nuclear reactions that produce more than two particles in the outgoing channel, which needs specific considerations to ensure the correlations between the particles and thus the conservation of energy and of translational and angular momenta. It is possible to adapt nuclear data and its exploitation to implement realistic reactions from the phenomenological point of view (as opposed to the historical need of variance reduction techniques), which increases computation time but allows the expansion of the transport codes capabilities. Simulation anomalies were found concerning the kinematical calculations of photon energies emitted from neutron-induced inelastic scattering (n,n’γ), as well as concerning the photon multiplicity of ¹⁵⁵Gd(n,γ) due to the presence of a rotational band in ¹⁵⁶Gd. Recommendations are given for potential solutions for both anomalies.