Report on the development of R-matrix based formalisms for non-binary channels and corresponding application to specific reaction in 2021

Abstract

The focus of the task BB-S.05.02-T001 is the development of tools for the evaluation of reaction data of light nuclear systems. The treatment of reactions in light nuclear systems bears severe di culties. On the one hand fully microscopic calculations from rst principle are rather involved and do not yield quantitatively reliable results. On the other hand models based on mean- eld considerations are not applicable. Therefore R-matrix theory seems to be best suited for light nuclear systems. However, the standard theory is limited to two-particle channels and due to the occurrence of dominant three-and more-particle channels in light nuclear systems at low energies, e.g. in the fusion relevant neutron-9Be system, the available R-matrix methods are of limited use. In addition it will be di cult to perform an analysis of a complete scattering system because of lack of experimental data in some channels. Therefore the research activity of the nuclear data group at TU Wien has been focussed on the development and implementation of an R-matrix method for three-body channels. Especially, the idea of Gl ockle (1974) of an R-matrix inspired formalism for the solution of the Faddeev equations for three equal mass objects in s-states was followed (for basic idea see Appendix A.3).