Speaker
Description
The light ($30 < Z < 45$) neutron-rich isotopes are thought to be synthesized in the neutrino-driven ejecta of core-collapse supernova via the weak r-process [1]. Recent nucleosynthesis studies have shown that $(\alpha,n)$ reactions play an important role in their production. The rates of these reactions have been calculated using statistical models, and their main uncertainty at the energies relevant to the weak r-process comes from the $\alpha+\mathrm{nucleus}$ optical potential. Several sets of parameters are available for the calculation of the $\alpha+\mathrm{nucleus}$ optical potential, leading to large deviations of reaction rates, exceeding even one order of magnitude.
To constrain the parameters of the $\alpha+\mathrm{nucleus}$ optical potential and to provide high precision reaction rates for astrophysical simulations, recently the cross sections of the $^{96}\mathrm{Zr}(\alpha,\mathrm{n}){}^{99}\mathrm{Mo}$, ${}^{100}\mathrm{Mo}(\alpha,\mathrm{n}){}^{103}\mathrm{Ru}$ and ${}^{86}\mathrm{Kr}(\alpha,\mathrm{n}){}^{89}\mathrm{Sr}$ reactions were measured at the Gamow-window for the first time [2,3]. Details on the experimental approach, on the new ATOMKI-V2 potential [4] will be presented and an outlook into the astrophysical application of the data will be provided.
[1] A. Arcones and F. Montes, Astrophys. J. 731 5 (2011).
[2] G.G. Kiss et al., Astrophys. J. 908 202 (2021).
[3] T.N. Szegedi et al., PRC 104 035804 (2021).
[4] P. Mohr et al., PRL 124 252701 (2020).
