Inclusion of sequential emission into the most probable fragmentation approach (Los Alamos model) and its validation

A new version of the Los Alamos (LA) model, based on more physical considerations than the previous versions by taking into account the sequential emission of prompt neutrons, is proposed. A residual temperature distribution for each emission sequence P$$_{\mathrm {k}}$$(T) is considered, so that this new version can provide the prompt neutron spectrum in the center-of-mass and laboratory frames of each neutron successively emitted from the light and heavy fragment. The LA model with sequential emission is applied on 15 fission cases which were not included in the 49 cases used in the elaboration of the systematics of different quantities of residual nuclei, on which the general form of $$\hbox {P}_{\mathrm {k}}$$(T) is based. The good description of experimental prompt neutron spectrum data of these fission cases by the model results constitutes a relevant validation of the LA model with sequential emission. Systematic behaviours of the average energies (in the center-of-mass and laboratory frames) provided by this model for each neutron sequentially emitted, are also emphasized