Assessing the impact of valence sd neutrons and protons on fusion

Abstract

Experimental above-barrier fusion cross-sections for ${}^{17}$F + ${}^{12}$C are compared to the fusion excitation functions for ${}^{16,18}$O, ${}^{19}$F, and ${}^{20}$Ne ions on a carbon target. In comparing the different systems both the differing static size of the incident ions and changes in fusion barrier are accounted for by examining the reduced fusion cross-section. Remaining trends of the fusion cross-section above the barrier which reflect the sensitive interplay of the sd protons and neutrons are observed. The experimental data are also compared to both a widely-used analytical model of near-barrier fusion, as well as a time-dependent Hartree-Fock model. Both models fail to describe the trends observed.

Comments: 6 pages, 5 figures