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.

arXiv comment10 pages, 8 figures. arXiv admin note: text overlap with arXiv:1809.06144

References in corpus (42)

• 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
• Microscopic Theory of Nuclear Fission: A Review
• Microscopic approach of fission dynamics applied to fragment kinetic energy and mass distributions in 238U
• Induced Fission of ${}^{240}$Pu within a Real-Time Microscopic Framework
• Global systematics of octupole excitations in even-even nuclei
• Beyond the relativistic mean-field approximation (III): collective Hamiltonian in five dimensions
• Potential Energy Surfaces of Actinide Nuclei from a Multi-dimensional Constraint Covariant Density Functional Theory: Barrier Heights and Saddle Point Shapes
• Multidimensionally-constrained relativistic mean field models and potential energy surfaces of actinide nuclei
• Formation and dynamics of fission fragments
• Fission barriers in covariant density functional theory: extrapolation to superheavy nuclei
• Systematics of Fission Barriers in Superheavy Elements
• Fission fragment charge and mass distributions in 239Pu(n,f) in the adiabatic nuclear energy density functional theory
• Octupole deformation in the ground states of even-even nuclei: a global analysis within the covariant density functional theory
• Microscopic description of octupole shape-phase transitions in light actinides and rare-earth nuclei
• Quadrupole collective states within the Bohr collective Hamiltonian
• Fission barriers in actinides in covariant density functional theory: the role of triaxiality
• Fission Barriers of Compound Superheavy Nuclei
• Multidimensionally-constrained covariant density functional theories --- nuclear shapes and potential energy surfaces
• Microscopic phase-space exploration modeling of ${}^{258}$Fm spontaneous fission
• Microscopic calculation of 240Pu scission with a finite-range effective force
• Multidimensionally-constrained relativistic mean-field study of spontaneous fission: coupling between shape and pairing degrees of freedom
• Microscopic study of induced fission dynamics of ${}^{226}$Th with covariant energy density functionals
• Microscopic analysis of the octupole phase transition in Th isotopes
• Simultaneous quadrupole and octupole shape phase transitions in Thorium
• Excitation energy dependence of fission in the mercury region
• Relativistic Energy Density Functional Description of Shape Transition in Superheavy Nuclei
• From Asymmetric to Symmetric Fission in the Fermium Isotopes within the Time-Dependent GCM Formalism
• Assessing theoretical uncertainties in fission barriers of superheavy nuclei
• Third minima in thorium and uranium isotopes in a self-consistent theory
• Microscopic self-consistent description of induced fission dynamics: finite temperature effects
• Multidimensionally-constrained relativistic mean-field study of triple-humped barriers in actinides
• Coexistence of nuclear shapes: self-consistent mean-field and beyond
• Spectroscopy of reflection-asymmetric nuclei with relativistic energy density functionals
• The temperature dependence of the shell corrections
• Description of Induced Nuclear Fission with Skyrme Energy Functionals: II. Finite Temperature Effects
• FELIX-2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation
• Fission dynamics of ${}^{252}$Cf
• Thermal fission rates with temperature dependent fission barriers
• FELIX-1.0: A finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation
• Microscopic analysis of octupole shape transitions in neutron-rich actinides with relativistic energy density functional

Cited by in corpus (30)

• Future of Nuclear Fission Theory
• Theory of Nuclear Fission
• Effect of shell structure on the fission of sub-lead nuclei
• The time-dependent generator coordinate method in nuclear physics
• Angular Momentum of Fission Fragments from Microscopic Theory
• Nucleosynthesis and observation of the heaviest elements
• Microscopic analysis of induced nuclear fission dynamics
• Ground state properties and potential energy surfaces of ${}^{270}$Hs from multidimensionally-constrained relativistic mean field model
• Microscopic Calculation of Fission Product Yields with Particle Number Projection
• Fission of ${}^{240}$Pu with symmetry-restored density functional theory
• Time-dependent generator coordinate method study of fission: dissipation effects
• Angular momentum and parity projected multidimensionally constrained relativistic Hartree-Bogoliubov model
• Efficient method for estimation of fission fragment yields of r-process nuclei
• Generalized time-dependent generator coordinate method for induced fission dynamics
• Scission configuration of ${}^{239}$U from yields and kinetic information of fission fragments
• Time-dependent generator coordinate method study of fission: mass parameters
• Microscopic description of the self-conjugate ${}^{108}$Xe and ${}^{104}$Te $\alpha$-decay chain
• Fission dynamics, dissipation and clustering at finite temperature
• Extended time-dependent generator coordinate method study of induced fission (II): total kinetic energy distribution
• Shape phase transitions in odd-A Zr isotopes
• Microscopic Calculation of Fission Product Yields for Odd-Mass Nuclei
• Microscopic model for the collective enhancement of nuclear level densities
• Time-dependent density functional theory study of induced-fission dynamics of ${}^{226}$Th
• Multi-body wave function of ground and low-lying excited states using unornamented deep neural networks
• Ground state and fission properties of even-$A$ uranium isotopes from multidimensionally-constrained relativistic mean field model
• Three-dimensional potential energy surface for fission of ${}^{236}$U within covariant density functional theory
• Microscopic theory of angular momentum distributions across the full range of fission fragments
• Semi-empirical model to determine pre- and post-neutron fission product yields and neutron multiplicity
• A Nonequilibrium Information Entropy Approach to Ternary Fission of Actinides
• Microscopic self-consistent description of induced fission: dynamical pairing degree of freedom