Emission of intermediate mass fragments from hot ${}^{116}$Ba${}^{\ast }$ formed in low-energy ${}^{58}$Ni+${}^{58}$Ni reaction

Abstract

The complex fragments (or intermediate mass fragments) observed in the low-energy ${}^{58}$Ni+${}^{58}$Ni${\to }^{116}$Ba${}^{\ast }$ reaction, are studied within the dynamical cluster decay model for s-wave with the use of the temperature-dependent liquid drop, Coulomb and proximity energies. The important result is that, due to the temperature effects in liquid drop energy, the explicit preference for $\alpha$-like fragments is washed out, though the ${}^{12}$C (or the complementary ${}^{104}$Sn) decay is still predicted to be one of the most probable $\alpha$-nucleus decay for this reaction. The production rates for non-$\alpha$ like intermediate mass fragments (IMFs) are now higher and the light particle production is shown to accompany the IMFs at all incident energies, without involving any statistical evaporation process in the model. The comparisons between the experimental data and the (s-wave) calculations for IMFs production cross sections are rather satisfactory and the contributions from other $\ell$-waves need to be added for a further improvement of these comparisons and for calculations of the total kinetic energies of fragments.

Comments: 22 pages, 15 figures