Shell plus pairing effect arguments for cluster preformation at the nuclear surface in cold fission

TL;DR

This paper demonstrates that shell plus pairing corrections can support the preformation of a light fission fragment at the nuclear surface during cold fission, using a model where the fragment radius increases with separation.

Contribution

It introduces a novel argument based on shell plus pairing corrections for cluster preformation in cold fission, with a specific model of fragment radius evolution.

Findings

Shell plus pairing corrections support preformation near the nuclear surface.

Increasing fragment radius linearly with separation alters the potential barrier.

Constant fragment radius results in a two-hump potential barrier.

Abstract

In 1928 G. Gamow as well as Condon and Gurney gave the first explanation of alpha decay as a quantum tunnelling of a preformed particle at the nuclear surface. Soon after experimental discovery in 1984 by Rose and Jones of cluster radioactivity, confirming earlier (1980) predictions by Sandulescu, Poenaru and W. Greiner, a microscopic theory also explained the phenomenon in a similar way. Here we show for the first time that in a spontaneous cold fission process the shell plus pairing corrections calculated with Strutinsky's procedure may give a strong argument for preformation of a light fission fragment near the nuclear surface. It is obtained when the radius of the light fragment, $R_2$, is increased linearly with the separation distance, $R$, of the two fragments, while for $R_2=$~constant one gets the well known two hump potential barrier.