Nuclear Astrophysics with Tagged Photons

For the modeling of the astrophysical s-process the knowledge of neutron capture cross sections is crucial. Where experimental data is not available for the (n,γ) cross-section like e.g. short-lived branching points, the observation of the inverse (γ ,n) reaction can provide useful information – in particular, if the cross section can be measured as a function of energy. The NEPTUN tagger setup at the S-DALINAC delivers a suited tagged photon beam (6–20MeV). In a first test run the resolution turned out to be 35 keV which is close to NEPTUN’s design specifications.