Sub-barrier capture with quantum diffusion approach

¹ Joint Institute for Nuclear Research, 141980 Dubna, Russia
² Institut für Theoretische Physik der Justus–Liebig–Universität, D–35392 Giessen, Germany
³ China Institute of Atomic Energy, Post Office Box 275, Beijing 102413, China

^a e-mail: adamian@theor.jinr.ru

Abstract

With the quantum diffusion approach the behavior of capture cross sections and mean-square angular momenta of captured systems are revealed in the reactions with deformed and spherical nuclei at sub-barrier energies. With decreasing bombarding energy under the barrier the external turning point of the nucleus-nucleus potential leaves the region of short-range nuclear interaction and action of friction. Because of this change of the regime of interaction, an unexpected enhancement of the capture cross section is found at bombarding energies far below the Coulomb barrier. This effect is shown its worth in the dependence of mean-square angular momentum on the bombarding energy. From the comparison of calculated capture cross sections and experimental capture or fusion cross sections the importance of quasifission near the entrance channel is demonstrated for the actinidebased reactions and reactions with medium-heavy nuclei at extreme sub-barrier energies.