Near-barrier fusion and total reaction of a proton-rich projectile:3He+58Ni

Abstract

Evaporation protons from the fusion of the 3 He + 58 Ni system were measured at three energies near but above the Coulomb barrier. The respective elastic scattering angular distribution was also determined for one of these energies. The fusion data, after being properly reduced to eliminate size and charge effects, are compared to the recently-measured fusion excitation function for the proton-halo system 8 B + 58 Ni. As a reference, fusion data for the 16 O + 58 Ni system are also presented. With respect to this reference, the fusion cross sections for the proton-rich systems show an enhancement likely related to static effects. An excitation function for the respective total reaction cross section was extracted from the measured elastic data along with additional data from the literature. Surprisingly, this excitation function follows the trend expected for weakly-bound systems. 25.60.Dz, 25.60.Pj

Determination of the $^{60}$Zn level density from neutron evaporation spectra

“…We note that these data are consistent with the lower statistics measurement of Ref. [34]. The benefit of including the proton spectrum in the present analysis is that these data are sensitive to the formation cross section of the 61 Zn compound nucleus, but not the neutron-decay daughter 60 Zn.…”

“…The increased absorption implied by Mod-2 is consistent with the 3 He + 58 Ni fusion cross section enhancement found by Ref. [34], where near 10 MeV Mod-2 results in σ fus. = 250 mb, as compared to 220 mb in Ref.…”

“…= 250 mb, as compared to 220 mb in Ref. [34]. Therefore, we use the Mod-2 3 He OMP and pre-equilibrium combination for the remainder of the analysis.…”