Time-dependent generator coordinate method study of mass-asymmetric fission of actinides

Abstract

Low-energy positive and negative parity collective states in the equilibrium minimum, and the dynamics of induced fission of actinide nuclei are investigated in a unified theoretical framework based on the generator coordinate method (GCM) with the Gaussian overlap approximation (GOA). The collective potential and inertia tensor, both at zero and finite temperature, are computed using the self-consistent multidimensionally constrained relativistic mean field (MDC-RMF) model, based on the energy density functional DD-PC1. Pairing correlations are treated in the BCS approximation with a separable pairing force of finite range. A collective quadrupole-octupole Hamiltonian characterized by zero-temperature axially-symmetric deformation energy surface and perturbative cranking inertia tensor, is used to model the low-lying excitation spectrum. The fission fragment charge distributions are obtained by propagating the initial collective states in time with the time-dependent GCM+GOA that uses the same quadrupole-octupole Hamiltonian, but with the collective potential and inertia tensor computed at finite temperature. The illustrative charge yields of ${}^{228}$Th, ${}^{234}$U, ${}^{240}$Pu, ${}^{244}$Cm, and ${}^{250}$Cf are in very good agreement with experiment, and the predicted mass asymmetry is consistent with the result of a recent microscopic study that has attributed the distribution (peak) of the heavier-fragment nuclei to shell-stabilized octupole deformations.

10 pages, 8 figures. arXiv admin note: text overlap with arXiv:1809.06144

References in corpus (9)

• Relativistic Continuum Hartree Bogoliubov Theory for Ground State Properties of Exotic Nuclei
• New parametrization for the nuclear covariant energy density functional with point-coupling interaction
• Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies
• Beyond the relativistic mean-field approximation (III): collective Hamiltonian in five dimensions
• Fission Barriers of Compound Superheavy Nuclei
• Microscopic study of induced fission dynamics of ${}^{226}$Th with covariant energy density functionals
• Excitation energy dependence of fission in the mercury region
• Multidimensionally-constrained relativistic mean-field study of triple-humped barriers in actinides
• Spectroscopy of reflection-asymmetric nuclei with relativistic energy density functionals

Cited by in corpus (11)

• The time-dependent generator coordinate method in nuclear physics
• Nucleosynthesis and observation of the heaviest elements
• Ground state properties and potential energy surfaces of ${}^{270}$Hs from multidimensionally-constrained relativistic mean field model
• Time-dependent generator coordinate method study of fission: dissipation effects
• Angular momentum and parity projected multidimensionally constrained relativistic Hartree-Bogoliubov model
• Scission configuration of ${}^{239}$U from yields and kinetic information of fission fragments
• Time-dependent generator coordinate method study of fission: mass parameters
• Extended time-dependent generator coordinate method study of induced fission (II): total kinetic energy distribution
• Three-dimensional potential energy surface for fission of ${}^{236}$U within covariant density functional theory
• Semi-empirical model to determine pre- and post-neutron fission product yields and neutron multiplicity
• Microscopic self-consistent description of induced fission: dynamical pairing degree of freedom