Relation between the 16O(α,γ)20Ne reaction and its reverse 20Ne(γ,α)16O reaction in stars and in the laboratory

Photo-induced nucleosynthesis: Current problems and experimental approaches

“…Nevertheless, a number of reactions has been measured in the last years at energies close or slightly above E (α,γ) eff including the following p-nuclei : 144 Sm(α,γ) 148 Gd [30], 112 Sn(α,γ) 116 Te [35,36], 106 Cd(α,γ) 110 Sn [34], 96 Ru(α,γ) 100 Pd [37]. Further data for heavy nuclei exist for 70 Ge(α,γ) 74 Se [38], 106 Cd(α,γ) 110 Sn [39], and 139 La(α,γ) 143 Pr [40,41], and extensive studies are in progress [42].…”

“…(2.2). The ground state cross section σ lab and rate λ lab are usually only small contributions to the stellar cross section σ * and rate λ * (see also [73,74]).…”

“…Stellar enhancement factors for heavy nuclei are listed in [15,68,80,81]. Because of the high level density the influence of electromagnetic selection rules is relatively small for heavy nuclei compared to their dom-inating role in the photodissociation of light nuclei as discussed in [74].…”

Elastic alpha scattering experiments and the alpha-nucleus optical potential at low energies

“…In addition, the uncertainties of (α,γ) cross sections translate into similar uncertainties for the prediction of (γ,α) cross sections and (γ,α) reaction rates under the stellar conditions of the astrophysical p-or γ-process [13][14][15]. The stellar reaction rates of these photon-induced (γ,α) reactions are usually determined from the inverse (α,γ) capture cross sections using detailed balance because thermally excited states contribute significantly to the stellar reaction rate of photon-induced reactions [1,16]; these thermally excited states are not accessible for (γ,α) experiments in the laboratory.…”

$ \alpha$ α -cluster states in 46,54Cr from double-folding potentials

“…Properties of 8 Be = 4 He ⊗ α and the 4 He(α,γ) 8 Be capture cross section were calculated in [13]. A detailed 16 O ⊗ α is given in [14] which was later extended to (α,γ) capture reactions [15,16,17]. 44 Ti = 40 Ca ⊗ α and 40 Ca(α,α) 40 Ca elastic scattering was studied in [18], and the mass region around A ≈ 40 was also reviewed in detail in [6].…”