Theoretical Investigation of α-decay Chains of Fm-isotopes

Abstract

Background: The theoretical and experimental investigations of decay properties of heavy and superheavy nuclei are crucial to explore the nuclear structure and reaction dynamics.
 Purpose: The aim of this study is to probe the α-decay properties of 243Fm and 245Fm isotopic chains using relativistic mean-field (RMF) approach within the framework of preformed cluster-decay model (PCM).
 Methods: The RMF densities are folded with the relativistic R3Y NN potential to deduce the nuclear interaction potential between the α particle and daughter nucleus. The penetration probability is calculated within the WKB approximation.
 Results: The α-decay half-lives of even-odd 243Fm and 245Fm isotopes and their daughter nuclei are obtained from the preformed cluster-decay model. These theoretically calculated half-lives are found to be in good agreement with the recent experimental measurements.
 Conclusions: The novel result here is the applicability of the scaling factor within the PCM as a signature for shell/sub-shell closures in α-decay studies. As such, we have also demonstrated that N=137, 139 and Z=94 corresponding to 231,233Pu could be shell/sub-shell closures. The least T1/2 is found at 243,245Fm which indicate their individual stability and α-decay as their most probable decay mode.

Preformation probability and kinematics of cluster emission yielding Pb-daughters*

“…The barrier lowering parameter is an inherent feature of the pre-formed cluster decay model (PCM) that encapsulates various modifications in the barrier region, especially those caused by the neck length values [50]. Figure 3 illustrates the profile of with respect to the neutron number N of the U isotopes at different values of the neck length parameter ΔR that lie within the proximity potential limit [51][52][53]. Considering the predictions from the M3Y (open symbols) and R3Y (solid symbols) potentials separately, it is clear that the barrier lowering parameter is largely influenced by the neck configuration; therefore, its modification increases with ΔR.…”