New Features of the FIFRELIN Code for the Investigation of Fission Fragments Characteristics

The characteristics of the fission fragments (FF) as well as those of the prompt neutrons and gammas can be deduced using FIFRELIN Monte Carlo simulation code. The quality of the results obviously depends on the experimental entry data, the theoretical and phenomenological models, and the various assumptions done in the code. The goal of this paper is to highlight new features of the code and to present some selected new results focusing on the use of a temperature-dependent spin cut-off, the prompt gamma de-excitation capability, a ROOT-based tool for the analysis of the FF histories, the estimation of correlated quantities, and so on. The influence of some experimental data on the neutron multiplicity and the influence of the level density parameter models on fission observables are also presented. Finally a preliminary result concerning the neutron spectrum for the 238U(n,f) reaction at 1.8 MeV is shown.