Cluster Structure of 209Bi

We present the results of analyses of the \(\alpha + {{\,}^{{209}}}{\text{Bi}}\) elastic scattering for projectile energies \({{E}_{\alpha }} = 19- 104\) MeV in terms of the single folded (SF) potential based on α-cluster and unclustered nucleonic configuration of ²⁰⁹Bi in the framework of the optical model (OM). The \(\alpha {{{\text{ - }}}^{{209}}}{\text{Bi}}\) potential is constructed by folding the α–α and α–N interactions using their density distributions. In a time-averaged picture, the number of nucleons making α-cluster has been found to be \(4{{A}_{\alpha }} = 180\) and the number of unclustered nucleons as \({{A}_{{\text{N}}}} = 29\), which gives the renormalization factor equal to unity.