Improved global α-optical model potentials at low energies

Elastic α scattering onSn112andSn124at astrophysi

“…Therefore, the dead time was monitored using pulse generators in all spectra. Demetriou et al [23] Avrigeanu et al [24] Frohlich/Rauscher [25] Demetriou et al [23] Avrigeanu et al [24] Frohlich/Rauscher [25] 124 Sn( , ) 124 …”

“…In Fig. 4, which shows the ratio of the two cross sections (divided by the Rutherford cross section) as a function of angle, all global α-nucleus potentials of [22,23,24,25] fail to reproduce either the strength or the oscillation pattern for backward angles. Thus, the use of these potentials in the extrapolation to more proton-rich species (of interest in p process nucleosynthesis) should be questioned.…”

“…The data show a systematic smooth linear decrease at higher energies, in good agreement with the parameterization adopted for the 112 Sn and 124 Sn isotopes (solid line). The Gaussian parameterization, first suggested by [31] and modified in [20,23], is shown as a dotted line up to 50 MeV, which they proposed for astrophysical energies. The imaginary part of the nuclear potential has been chosen as a sum of volume and surface Woods-Saxon potentials.…”

“…Because of the scarce experimental data available on the 112 Sn(α,γ) 116 Te reaction, we can only perform a very limited comparison. Ozkan et al [16] McFadden/Satchler [22] Demetriou et al [23] Avrigeanu et al [24] Frohlich/Rauscher [25] This work The global parameterization from [25] provides a satisfactory description of the few experimental data, in contrast to its poor agreement with the elastic scattering data. The other potentials, with the exception of [24], reproduce the cross section data well.…”

“…For a comparison of the results provided by the different parameterizations of [22,23,24,25], the variation of the obtained reaction rates is shown in Table II, where the ratios of rates with respect to the rate obtained using [25] are presented. All other ingredients of the statistical model calculations have been kept fixed as in [37].…”