Benchmark of the GEF code for fission-fragment yields over an enlarged range in fissioning nucleus mass, excitation energy, and angular momentum
Résumé
The GEneral description of Fission observables (GEF) code was developed to produce fission-related nuclear data which are of importance for basic and applied nuclear physics. The investigation of the performance of the GEF code is here extended to a region in fissioning system mass, charge, excitation energy, and angular momentum, as well as to new observables, that could not be benchmarked so far. More specifically, benefiting from recent and innovative measurements, the work focuses on fragment mass and isotopic distributions for fission of various heavy actinides, with excitation energies from threshold up to ≈60MeV and angular momenta up to ≈20ℏ. The approach reveals a high degree of consistency and provides a reasonable description of the new data. The physics behind specific discrepancies is discussed, with emphasis on the challenging modeling of the competition between the symmetric and asymmetric fission channels. Comparison of the calculation with experiment permits us to highlight the influence of the system intrinsic properties, their interplay, and the importance of experimental aspects such as mass, charge, and excitation-energy resolution. All together points to the necessity of measuring as many observables as possible in one experiment with the highest possible accuracy, for proper unfolding of involved correlations and robust interpretation. The GEF code has become a widely used tool for this purpose.