Speaker
Description
Among the proton-rich nuclei there are a few dozen which cannot be produced by the s- and r-process. These nuclei, called p-nuclei, are synthesized by the γ-process. This process involves a complex reaction network of about 20000 reactions, simulations are the only feasible method to determine the final isotopic abundances. The γ-process mainly occurs in explosive events such as Type Ia supernovae. Under these conditions, in the intermediate mass number range, the (γ,α) reaction destroys the waiting point nuclei. For this and other reasons the precise description of the interaction between the α particle and the nucleus is crucial for reliable simulations. This interaction is described with the α-optical model potential (AOMP). Recent experiments have shown that (α,n) reactions are useful to study the AOMP. By measuring the (α,n) cross section close to the threshold energy, the parameters of the AOMP can be constrained. The aim of the present work is thus to measure the cross section of the 89Y(α,n)92Nb and 109Ag(α,n)112In reactions and compare the results to the theoretical predictions based on different AOMPs.
The half-lives of the produced isotopes allow the use of the activation technique. In both cases targets with natural isotopic composition were used. The experiments were carried out at the HUN-REN ATOMKI facility. This poster presents details of the experimental procedure and preliminary results of the measurements.