Dynamical synthesis of 4He in the scission phase of nuclear fission

Abstract

In the exothermic process of fission decay, an atomic nucleus splits into two or more independent fragments. Several aspects of nuclear fission are not properly understood, in particular the formation of the neck between the nascent fragments, and the subsequent mechanism of scission into two or more independent fragments. Using an implementation of time-dependent density functional theory, based on a relativistic energy density functional and including pairing correlations, we analyze the final phase of the process of induced fission of ${}^{240}$Pu, and show that the time-scale of neck formation coincides with the assembly of two $\alpha$-like clusters (less than 1 zs = 10${}^{-21}$ s). Because of its much larger binding energy, the dynamical synthesis of 4He in the neck predominates over other light clusters, e.g., ${}^3$H and ${}^6$He. At the instant of scission the neck ruptures exactly between the two $\alpha$-like clusters, which separate because of the Coulomb repulsion and are eventually absorbed by the two emerging fragments. The newly proposed mechanism of light charged clusters formation at scission provides a natural explanation of ternary fission.

5 pages, 4 figures, Final version for publication

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Cited by in corpus (21)

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• Fission dynamics, dissipation and clustering at finite temperature
• Generalized time-dependent generator coordinate method for small and large amplitude collective motion
• Ternary quasifission in collisions of actinide nuclei
• Microscopic description of the torque acting on fission fragments
• Nuclear Quantum Many-Body Dynamics: From Collective Vibrations to Heavy-Ion Collisions (2nd edition)
• Entanglement in multinucleon transfer reactions
• Effects of the tensor force on low-energy heavy-ion fusion reactions: A mini review
• Visualization of nuclear many-body correlations with the most probable configuration of nucleons
• Local alpha-removal strength in the mean-field approximation
• Time-dependent density functional theory study of induced-fission dynamics of ${}^{226}$Th
• Non-Markovian character and irreversibility of real-time quantum many-body dynamics
• Ternary fission with the emission of long-range $\alpha$ particles in fission of the heaviest nuclei
• Time-Dependent Density Functional Theory Description of ${}^{238}$U(n,f), ${}^{240,242}$Pu(n,f) and ${}^{237}$Np(n,f) Reactions
• Examining the justification for the introduction of a fermion localization function
• Exact-exchange relativistic density functional theory in three-dimensional coordinate space
• Non-local orbital-free density functional theory incorporating nuclear shell effects
• Characteristics of the fission fragments in the three-body model of binary fission