Fission As a Relevant Probe of the Nuclear Level Density Away from Β-Stability

Fission at moderate to high excitation energy is proposed as an innovative approach to study the evolution of the nuclear level density (NLD) away from β-stability. A four-dimensional dynamical Langevin model, implementing various prescriptions of the asymptotic level-density parameter a˜, is employed to demonstrate the relevance of considering typical fission observables, and namely the pre- and post-scission neutron multiplicities, to investigate the evolution of a˜ with N and Z. The richness of fission is shown to offer an alternative route, that is very complementary to the conventional fusion-evaporation method from which no consensus emerged yet. In particular, to investigate the isospin-dependence of the NLD, the present calculations lead us to propose a series of fusion-induced fission measurements based on Ca + Pb collisions which are readily available at current experimental facilities. This set of reactions can be further enhanced with today, as well as future, radioactive beams.