Results of total cross-section measurements of the 87Rb(p,γ)88Sr reaction

Abstract

The existence of a set of stable proton-rich nuclei - the p nuclei - cannot be explained via neutron-capture reactions. Therefore, another mechanism has to exist in order to explain their origin, the most probable, especially at high masses, being photodisintegration reactions. This gives rise to the γ process. Since most photodisintegration reactions involved in the process are not experimentally accessible, reliable statistical model calculations are needed to predict cross sections and reaction rates. To improve these calculations nuclear input parameters need to be constrained and a large experimental database is needed. Via comparison of experimental data to theoretical predictions different models can be tested and constrained. In order to study the 87Rb(p,γ)88Sr reaction, for which previously no experimental data have been available, an in-beam experiment at at the University of Cologne’s high-efficiency HPGe γ-ray spectrometer HORUS was performed. Proton beams with energies between Ep = 2000 to 5000 keV reaching deep into the Gamow window of the reaction were provided by the 10 MV FN Tandem accelerator. Cross-section values at six proton beam energies were determined. The experimental results are in good agreement with statistical model calculations. The obtained results are the first experimental cross-section values for the87Rb(p,γ)88Sr reaction and help to constrain the nuclear physics input for statistical model calculations.