Indirect measurements of neutron capture cross-sections on heavy elements

Most of the heavy elements beyond iron are synthesized by different types of neutron capture processes that occur in various astrophysical sites throughout the universe. The abundances of the elements produced depend sensitively on the neutron-capture reaction rates. Experimental determination of neutron-capture cross sections for unstable isotopes is challenging due to the difficulties in producing high-flux neutron beams and radioactive targets with the desired characteristics. As a result, several indirect experimental techniques including the Surrogate Reaction Method (SRM) and the Oslo method have been developed to indirectly constrain neutron capture rates. At a high level, these indirect approaches use charged particle reactions to mimic the neutron-induced reaction of interest and then utilize these data to constrain nuclear statistical models which describe the neutron-induced reaction rate of interest. The present work investigates the extension of the SRM and Oslo methods to the use of a (t, p-g) reaction channel for the first time by leveraging the newly developed tritium beam capability at Florida State University. I will present on the feasibility of these experimental methods and the anticipated challenges for the first planned experiment with 180 Hf. A simulation tool which has been developed for this task will be described.