α-particles optical potential for medium and heavy-mass nuclei around the Coulomb barrier

“Horia Hulubei”National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, 76900 Bucharest, Romania

^a e-mail: vavrig@ifin.nipne.ro

Abstract

Recent high-precision measurements α-particle elastic scattering and (α,x) reaction cross sections has motivated the extension of a previous semi-microscopic analysis for the mass-region 50<A<120 and energies from 13 to 50 MeV to heavy nuclei up to 209Bi. The regional optical model potential for low-energy α-particles which has thus been obtained entirely on the basis of elastic-scattering data analysis, for the nuclei within the above-mentioned mass and energy ranges, is involved within the (α,γ), (α,n) and (α,p) reaction cross sections analysis at incident energies below the Coulomb barrier. The statistical-model parameters used for the cross section calculations were established by analyzing various independent experimental data for the involved nuclei, making possible the focus on the uncertainties of α-particle OMP. An optical potential which describe equally well both the low energy elastic-scattering and induced-reaction data of α-particles has finally been obtained for medium and heavy mass nuclei.