Microscopic analysis of induced nuclear fission dynamics
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The dynamics of low-energy induced fission is explored using a consistent microscopic framework that combines the time-dependent generator coordinate method (TDGCM) and time-dependent nuclear density functional theory (TDDFT). While the former presents a fully quantum mechanical approach that describes the entire fission process as an adiabatic evolution of collective degrees of freedom, the latter models the dissipative dynamics of the final stage of fission by propagating nucleons independently toward scission and beyond. The two methods, based on the same nuclear energy density functional and pairing interaction, are employed in an illustrative study of the charge distribution of yields and total kinetic energy for induced fission [1]. The TDDFT is also used to study the formation of the neck between the nascent fragments, and the subsequent mechanism of scission into two or more independent fragments. In the final phase of the fission process, it is shown that the timescale of neck formation coincides with the assembly of two alpha-like clusters [2]. Because of its much larger binding energy, the dynamical synthesis of 4He in the neck predominates over other light clusters, e.g., 3H and 6He. At the instant of scission, the neck ruptures exactly between the two alpha-like clusters (Fig. 1), which separate because of the Coulomb repulsion and are eventually absorbed by the two emerging fragments.
[1] Z. X. Ren, J. Zhao, D. Vretenar, T. Nikšić, P. W. Zhao, and J. Meng, Phys. Rev. C 105, 044313 (2022).
[2] Z. X. Ren, D. Vretenar, T. Nikšić, P. W. Zhao, J. Zhao, and J. Meng, Phys. Rev. Lett. 128, 172501 (2022).
