Fission Dynamics of Compound Nuclei: Pairing versus Fluctuations

Abstract

Energy dependence of fission observables is a key issue for wide nuclear applications. We studied real-time fission dynamics from low-energy to high excitations in the compound nucleus ${}^{240}$Pu with the time-dependent Hartree-Fock+BCS approach. It is shown that the evolution time of the later phase of fission towards scission is considerably lengthened at finite temperature. As the role of dynamical pairing is vanishing at high excitations, the random transition between single-particle levels around the Fermi surface to mimic thermal fluctuations is indispensable to drive fission. The obtained fission yields and total kinetic energies with fluctuations can be divided into two asymmetric scission channels, namely S1 and S2, which explain well experimental results, and give microscopic support to the Brosa model. With increasing fluctuations, S2 channel takes over S1 channel and the spreading fission observables are obtained.

arXiv comment5 pages, 4 figures

References in corpus (29)

• Pairing gaps from nuclear mean-field models
• Microscopic Theory of Nuclear Fission: A Review
• Time-dependent density-functional description of nuclear dynamics
• Induced Fission of ${}^{240}$Pu within a Real-Time Microscopic Framework
• The TDHF Code Sky3D
• The Role of Fission in Neutron Star Mergers and its Impact on the r-Process Peaks
• Review on the progress in nuclear fission
• Heavy-ions collisions and fission dynamics with the time-dependent Hartree-Fock theory and its extensions
• Future of Nuclear Fission Theory
• Canonical-basis time-dependent Hartree-Fock-Bogoliubov theory and linear-response calculations
• Fission fragment charge and mass distributions in 239Pu(n,f) in the adiabatic nuclear energy density functional theory
• A Stochastic Mean-Field Approach For Nuclear Dynamics
• Fission Barriers of Compound Superheavy Nuclei
• Potential energy surfaces of superheavy nuclei
• Fission Dynamics of 240Pu from Saddle-to-Scission and Beyond
• Fission dynamics within time-dependent Hartree-Fock: deformation-induced fission
• Stochastic quantum dynamics beyond mean-field
• Microscopic modeling of mass and charge distributions in the spontaneous fission of 240Pu
• Timescales of quantum equilibration, dissipation and fluctuation in nuclear collisions
• Microscopic self-consistent description of induced fission dynamics: finite temperature effects
• Pairing dynamics in particle transport
• Microscopic predictions for production of neutron rich nuclei in the reaction ${}^{176}\mathbf{Yb}+{}^{176}\mathbf{Yb}$
• Unitary evolution with fluctuations and dissipation
• Pairing interactions and the vanishing pairing correlations in hot nuclei
• Thermal fission rates with temperature dependent fission barriers
• A Statistical Approach to Describe Highly Excited Heavy and Superheavy Nuclei
• Efficient method for estimation of fission fragment yields of r-process nuclei
• Pairing Reentrance Phenomenon in Heated Rotating Nuclei in the Shell Model Monte Carlo Approach
• Superfluid dynamics of 258Fm fission

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• Bayesian evaluation of charge yields of fission fragments of 239U
• Microscopic analysis of induced nuclear fission dynamics
• Optimizing multilayer Bayesian neural networks for evaluation of fission yields
• Energy and pairing dependence of dissipation in real-time fission dynamics
• Fission dynamics, dissipation and clustering at finite temperature
• Microscopic description of the torque acting on fission fragments
• Nuclear Quantum Many-Body Dynamics: From Collective Vibrations to Heavy-Ion Collisions (2nd edition)
• Modeling survival probabilities of superheavy nuclei at high excitations
• Correlations between nuclear landscape boundaries and neutron-rich r-process abundances
• Time-dependent density functional theory study of induced-fission dynamics of ${}^{226}$Th
• Postfission properties of uranium isotopes: A hybrid method with Langevin dynamics and the Hauser-Feshbach statistical model
• Microscopic self-consistent description of induced fission: dynamical pairing degree of freedom