Speaker
Description
The production of heavy elements in the universe is mainly dominated by neutron capture processes. However, some of the nuclei cannot be produced via this path. It is believed that one of the processes that produces heavy p-nuclei is governed by photodisintegration of s-process seed nuclei via ($\gamma$,n), ($\gamma$,p) and ($\gamma$,$\alpha$) reactions. Systematic studies have shown that one of the main sources of uncertainty for this process is the $\alpha$-nuclear potential in exotic nuclei [1,2], which can be studied through the measurement of elastic scattering differential cross-sections at energies around the Coulomb Barrier. I will present the first ever measured differential cross-sections of elastic scattered $\alpha$ particles off exotic nuclei. The experiment was performed at the HIE-ISOLDE facility at CERN profiting from the use of newly developed Si films with high $^4$He concentrations [3] to scatter exotic beams of $^{108,109,110}$Sn and the stable $^{112}$Sn beam produced at ISOLDE. Following the astrophysical motivation for the measurement, I will present details on the performed experiment and a proof-of-concept comparison with the previous measurement on the stable isotope $^{112}$Sn [4], concluding with the current status of the analysis of the $\alpha$-scattering of exotic nuclei. This measurement opens the possibility to measure $\alpha$-nuclear potentials in exotic proton-rich nuclei, contributing to the reduction of uncertainties in nuclear network calculation studies.
References:
[1] A. Simon, et al. J. Phys. G 44, 064006 (2017)
[2] W. Rapp, et al. Astrophys. J. 653, 474 (2006).
[3] V. Godinho, et al. ACS Omega 1(6), 1229 (2016).
[4] D.Galaviz, et. al. Phys.Rev.C 71 065802 (2005)