Dynamical Synthesis of 4He in the Scission Phase of Nuclear Fission

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 240Pu, and show that the timescale of neck formation coincides with the assembly of two ??-like clusters. 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 ??-like clusters, which separate because of the Coulomb repulsion and are eventually absorbed by the two emerging fragments. The mechanism of light charged clusters formation at scission could also be linked to ternary fission.

Automated summary

This study examines the process of nuclear fission, focusing on the formation and scission mechanism of a neck between the nascent fragments. By using time-dependent density functional theory, it is found that the assembly of two α-like clusters coincides with the formation of the neck. During scission, the neck ruptures between the two α-like clusters, and light charged clusters are formed. The findings provide insights into the mechanism of nuclear fission and its potential connection to ternary fission.