Fission Dynamics of Compound Nuclei: Pairing versus Fluctuations

Phys. Rev. C 103, 031304 (2021) Energy dependence of fission observables is a key issue for wide nuclearapplications. We studied real-time fission dynamics from low-energy to highexcitations in the compound nucleus $^{240}$Pu with the time-dependentHartree-Fock+BCS approach. It is shown that the evolution time of the laterphase of fission towards scission is considerably lengthened at finitetemperature. As the role of dynamical pairing is vanishing at high excitations,the random transition between single-particle levels around the Fermi surfaceto mimic thermal fluctuations is indispensable to drive fission. The obtainedfission yields and total kinetic energies with fluctuations can be divided intotwo asymmetric scission channels, namely S1 and S2, which explain wellexperimental results, and give microscopic support to the Brosa model. Withincreasing fluctuations, S2 channel takes over S1 channel and the spreadingfission observables are obtained