Fission dynamics at low excitation energy. 2

Abstract

The mass asymmetry in the fission of U-236 at low excitation energy is clarified by the analysis of the trajectories obtained by solving the Langevin equations for the shape degrees of freedom. It is demonstrated that the position of the peaks in the mass distribution of fission fragments is determined mainly by the saddle point configuration originating from the shell correction energy. The width of the peaks, on the other hand, results from the shape fluctuations close to the scission point caused by the random force in the Langevin equation. We have found out that the fluctuations between elongated and compact shapes are essential for the fission process. According to our results the fission does not occur with continuous stretching in the prolate direction, similarly to that observed in starch syrup, but is accompanied by the fluctuations between elongated and compact shapes. This picture presents a new viewpoint of fission dynamics and the splitting mechanism.

9 pages, 12 figures, submitted to Phys. Rev. C. arXiv admin note: substantial text overlap with arXiv:1310.3156

References in corpus (1)

• Brownian shape motion on five-dimensional potential-energy surfaces: Nuclear fission-fragment mass distributions

Cited by in corpus (8)

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• Formation and distribution of fragments in the spontaneous fission of 240Pu
• Modes of massive nucleon transfer appearing in quasifission processes for collisions of superheavy nuclei
• Dynamical mechanism of fusion hindrance in heavy ion collisions
• Effects of neck and nuclear orientations on the mass drift in heavy ion collisions
• Three-dimensional potential energy surface for fission of ${}^{236}$U within covariant density functional theory
• Nuclear viscosity estimated by dynamics of neck formation in the early stage of nuclear collision
• Kinetic energy of fission fragments within a dynamical model