Ядерна фізика та енергетика Nuclear Physics and Atomic Energy   ISSN: 1818-331X (Print), 2074-0565 (Online)   Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine   Languages: Ukrainian, English   Periodicity: 4 times per year   Open access peer reviewed journal

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T. J. Abd Alhessien^*, F. A. Majeed

Department of Physics, College of Education for Pure Sciences, University of Babylon, Babylon, Iraq

^*Corresponding author. E-mail address: thaeir.alkawwaz@gmail.com

Abstract: Fusion of ^4,6,8He + ¹⁹⁷Au has been investigated near and below the Coulomb barrier. Three complementary approaches were employed: (i) a quantum coupled-channels (CC) framework (with continuum discretized coupled-channels when breakup was relevant), (ii) a semiclassical treatment of the relative motion, and (iii) the Wong single-parabolic-barrier formula. The fusion cross-section σ_fus, barrier distribution D_fus = d²(Eσ_fus)/dE², and fusion probability σ_fus were computed. Couplings to collective excitations and transfer/breakup channels were incorporated through the coupling matrix, while barrier transmission was evaluated via WKB penetrabilities. These couplings were shown to broaden the effective barrier distribution and to enhance sub-barrier tunneling relative to a one-barrier picture. Across all systems, the quantum CC description was found to reproduce the data most accurately, the semiclassical model was observed to capture the main systematics, and the Wong formula was used chiefly above the barrier as a baseline. In this way, the joint roles of nuclear structure and reaction dynamics in shaping fusion observables were delineated for light-on-heavy systems.

Keywords: fusion reaction, elastic and inelastic scattering, low and intermediate energy, heavy-ion reactions, nuclear reaction models and methods.

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