The astrophysical p process, which is responsible for the origin of the proton rich stable nuclei heavier than iron, was investigated using a full nuclear reaction network for a type II supernova explosion when the shock front passes through the O/Ne layer. Calculations were performed with a multi-layer model adopting the seed of a pre-explosion evolution of a 25 solar mass star. The reaction flux was calculated to determine the main reaction path and branching points responsible for synthesizing the proton rich nuclei. In order to investigate the impact of nuclear reaction rates on the predicted pprocess abundances, extensive simulations with different sets of collectively and individually modified neutron-, proton-, α-capture and photodisintegration rates have been performed. These results are not only relevant to explore the nuclear physics related uncertainties in p-process calculations but are also important for identifying the strategy and planning of future experiments.

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The cross section of the reaction 112 Sn(α, γ ) 116 Te has been measured in the energy range of astrophysical interest for the p-process. Highly enriched self-supporting 112 Sn foils were bombarded with α beams in the effective center of mass energy range from 7.59 to 11.42 MeV at the Notre Dame FN Tandem Van de Graaff accelerator. The characteristic activity of 116 Te was counted with a pair of large volume Ge clover detectors in close geometry to maximize the detection efficiency. The cross section of the concurrent (α, p) reaction has also been measured. The results are compared with statistical model predictions for different global α-nucleus potentials.

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