Dynamical approach to heavy ion-induced fission

Department of Nuclear Physics, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601, Australia

^a D. Y. Jeung: dongyun.jeung@anu.edu.au
^b Current address: Malmö University, Faculty of Technology and Society, 205 06 Malmö, Sweden
^c Current address: Institute of Functional Genomics, University of Regensburg, 93053, Germany
^d Current address: China Institute of Atomic Energy, Beijing 102413, China
^e Current address: National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA

Published online: 6 April 2015

Abstract

Deep inelastic collisions (DICs) can compete strongly with fusion in collisions of heavy nuclei. However, standard coupled-channels calculations do not take DIC processes into account. As a result, calculations have been shown to overestimate the fusion cross-sections, resulting in a discrepancy between experimental data and theoretical calculations, particularly at energies above the fusion barrier. To investigate this discrepancy, we conducted a series of experiments using the ANU 14UD tandem accelerator and the CUBE 2-body fission spectrometer to examine the competition between transfer/DIC and fusion. In particular, fusion-fission and 3-body fission yields have been extracted for ³⁴S + ²³²Th and ⁴⁰Ca + ²³²Th systems. This work shows that the transfer-fission probability is enhanced relative to fusion-fission for ⁴⁰Ca + ²³²Th, when compared to ³⁴S+ ²³²Th. It is suggested that the enhancement of this DIC process in ⁴⁰Ca + ²³²Th is linked to an increase in the density overlap of the colliding nuclei as a function of the charge product and contributes to fusion hindrance.