Review on the progress in nuclear fission

Abstract

An overview is given on some of the main advances in experimental methods, experimental results and theoretical models and ideas of the last years in the field of nuclear fission. New experimental approaches extended the availability of fissioning systems considerably and provided a full identification of all fission products in A and Z for the first time. In particular, the transition from symmetric to asymmetric fission around 226Th and some unexpected structure in the mass distributions in the fission of systems around Z = 80 to 84 as well as an extended systematics of the odd-even effect in fission fragment Z distributions have been measured [A. N. Andreyev et al., Rep. Progr. Phys. 81 (2018) 016301]. Three classes of theoretical descriptions of fission presently appear to be the most promising or the most successful ones: Self-consistent quantum-mechanical models fully consider the quantum-mechanical features of the fission process. Intense efforts are presently made to develop suitable theoretical tools [N. Schunck, L. M. Robledo, Rep. Prog. Phys. 79 (2016) 116301] for modeling the non-equilibrium, large-amplitude collective motion leading to fission. Stochastic, essentially classical models provide a fully developed technical framework. The main features of the fission-fragment mass distribution are well reproduced from mercury to fermium and beyond [P. Möller, J. Randrup, Phys. Rev. C 91 (2015) 044316]. In an alternative semi-empirical approach [K.-H. Schmidt et al., Nucl. Data Sheets 131 (2016) 107], considerable progress in describing the fission observables has been achieved by combining several general theoretical concepts. This new approach reveals a high degree of regularity and allows calculating high-quality data with a unique parameter set for a large number of systems and an extended excitation-energy range.

70 pages, 41 figures

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Cited by in corpus (54)

• Origin of the Heaviest Elements: the Rapid Neutron-Capture Process
• Bayesian Evaluation of Incomplete Fission Yields
• Theory of Nuclear Fission
• Effect of shell structure on the fission of sub-lead nuclei
• Fission Fragment Decay Simulations with the CGMF Code
• Nuclear Fission Dynamics: Past, Present, Needs, and Future
• From Asymmetric to Symmetric Fission in the Fermium Isotopes within the Time-Dependent GCM Formalism
• Primary fission fragment mass yields across the chart of nuclides
• Dynamical synthesis of 4He in the scission phase of nuclear fission
• Study of angular momentum effects in fission
• Microscopic analysis of induced nuclear fission dynamics
• Fission Dynamics of Compound Nuclei: Pairing versus Fluctuations
• Following nuclei through nucleosynthesis: a novel tracing technique
• Quasifission dynamics in microscopic theories
• Comparison of fission and quasi-fission modes
• Fission of ${}^{240}$Pu with symmetry-restored density functional theory
• Optimizing multilayer Bayesian neural networks for evaluation of fission yields
• First direct measurement of isotopic fission-fragment yields of ${}^{239}$U
• Efficient method for estimation of fission fragment yields of r-process nuclei
• Time-dependent Hartree-Fock study of quasifission trajectories in reactions forming ${}^{294}$Og
• Scission configuration of ${}^{239}$U from yields and kinetic information of fission fragments
• Fission dynamics, dissipation and clustering at finite temperature
• Improvements to the macroscopic-microscopic approach of nuclear fission
• The angular correlation between the fission fragment intrinsic spins
• Hartree-Fock-Bogoliubov study of quantum shell effects on the path to fission in ${}^{180}$Hg, ${}^{236}$U and ${}^{256}$Fm
• Coupled fission fragment angular momenta
• Mapping reactor neutrino spectra from TAO to JUNO
• A New Radioactive Decay Mode, True Ternary Fission, the Decay of Heavy Nuclei Into Three Comparable Fragments
• Benchmark of the GEF model for fission-fragment yields over an enlarged range
• ${}^{178}$Hg and asymmetric fission of neutron-deficient pre-actinides
• A schematic reaction-theory model for nuclear fission
• Experimental evidence of the effect of nuclear shells on fission dissipation and time
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• Fission of relativistic nuclei with fragment excitation and reorientation
• Nascent fragment shell effects on the nuclear fission processes in semiclassical periodic orbit theory
• Schematic model for induced fission in a configuration-interaction approach
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• Disentangling the influence of excitation energy and compound nucleus angular momentum on fission fragment angular momentum
• The fast neutron induced fission of ${}^{240}$Pu and ${}^{242}$Pu
• Three-dimensional potential energy surface for fission of ${}^{236}$U within covariant density functional theory
• Pairing in fission: Mean-field and collective inertias study
• Impact of choices for center-of-mass correction energy on the surface energy of Skyrme energy density functionals
• Hypothesis about Enrichment of Solar System
• Production of neptunium and plutonium nuclides from uranium carbide using 1.4-GeV protons
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• Transformations of mass/charges fission fragments spectra with consideration the postfission emission of nuclear particles: 232Th
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