Speaker
Description
Calculations of nuclear reactions for astrophysical reaction networks can be a large scale computational effort. While dedicated fine tuned models can reproduce cross-sections in specific regions with high precision, network calculations usually use a global approach that can reproduce a large fraction of the nuclear chart although with less precision. For this purpose, the reaction code TALYS is commonly used and it is known to work well for intermediate and heavy nuclei – for example nuclei involved in the s-process. One recent undertaking that has begun is the PANDORA project coordinated as a collaboration between ELI-NP in Romania, RCNP in Japan, and iThemba LABS in South Africa. In this collaboration, the goal is to measure the nuclear properties, with special focus on photo-disintegration, for the understanding of the propagation of ultra-high energy cosmic rays (UHECSs). The nuclei involved in this process are, however, in the light region of the nuclear chart, below 56Fe, where global TALYS calculations in the same manner as for the s-process is significantly more difficult. In this contribution we will show recent work comparing experimental data on photo-nuclear reactions with theoretical calculations in TALYS for light nuclei to understand what the limits of global calculations are, and how to reach beyond this limit. By using different nuclear structure inputs, in particular regarding level densities and gamma strength functions, we want to find the most important quantities and improve the predictability of the TALYS code in the region relevant to UHECRs.
