High precision angular distribution data of (α,α) A systematic fitting procedure was applied to the presented experimental scattering data to obtain comprehensive local potential parameter sets which are composed of a real folding potential and an imaginary potential of Woods-Saxon surface type. The obtained potential parameters were used in turn to construct a new systematic α-nucleus potential with very few parameters.Although this new potential cannot reproduce the angular distributions with the same small deviations as the local potential, the new potential is able to predict the total reaction cross sections for all cases under study.

The cross sections for the elastic scattering reactions 112,124 Sn(α,α) 112,124 Sn at energies above and below the Coulomb barrier are presented and compared to predictions for global α-nucleus potentials. The high precision of the new data allows a study of the global α-nucleus potentials at both the proton and neutron-rich sides of an isotopic chain. In addition, local α-nucleus potentials have been extracted for both nuclei, and used to reproduce elastic scattering data at higher energies. Predictions from the capture cross section of the reaction 112 Sn(α,γ) 116 Te at astrophysically relevant energies are presented and compared to experimental data.

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The proton-capture reaction 26 Si(p,γ ) 27 P was studied via Coulomb dissociation (CD) of 27 P at an incident energy of about 500 MeV/u. The three lowest-lying resonances in 27 P have been populated and their resonance strengths have been measured. In addition, a nonresonant direct-capture component was clearly identified and its astrophysical S factor measured. The experimental results are compared to Monte Carlo simulations of the CD process using a semiclassical model. Our thermonuclear reaction rates show good agreement with the rates from a recent compilation. With respect to the nuclear structure of 27 P we have found evidence for a negative-parity intruder state at 2.88-MeV excitation energy.

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