Magic radioactivity of 252Cf

TL;DR

This paper reveals that the sharp maximum in 252Cf cold fission fragment distribution is due to Sn-like radioactivity involving magic nuclei, analyzed through a theoretical model considering multiple degrees of freedom.

Contribution

It introduces a theoretical framework using the two-center shell model and semiclassical approach to explain Sn-like radioactivity in 252Cf fission.

Findings

Identification of Sn-like radioactivity as the cause of the maximum

Connection of the inner cold valley to the double magic 132Sn

Existence of an isomeric minimum between barriers

Abstract

We show that the sharp maximum corresponding to 107Mo in the fragment distribution of the 252Cf cold fission is actually a Sn-like radioactivity, similar to other decay processes in which magic nuclei are involved, namely alpha-decay and heavy cluster emission, also called Pb-like radioactivity. It turns out that the mass asymmetry degree of freedom has a key role in connecting initial Sn with the final Mo isotopes along the fission path. We suppose the cold rearrangement of nucleons within the framework of the two center shell model, in order to compute the cold valleys in the charge equilibrated fragmentation potential. The fission yields are estimated by using the semiclassical penetration approach. We consider five degrees of freedom, namely the inter-fragment distance, the shapes of fragments, the neck parameter and mass asymmetry. We found an isomeric minimum between the internal and external barriers. It turns out that the inner cold valley of the total potential energy is connected to the double magic isotope 132Sn