Neutron-capture cross sections from indirect measurements

Cross sections for direct, resonance, and compound reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods, such as the ANC (asymptotic normalization coefficient) and Trojan Horse methods, Coulomb dissociation, and the surrogate reactions method. Indirect approaches come with their own challenges, as experimental observables have to be related to the quantity of interest. The surrogate method, for instance, aims at determining cross sections for compound-nuclear reactions on unstable targets by producing the compound nucleus via an alternative (transfer or inelastic scattering) reaction and observing the subsequent decay via γ emission, particle evaporation, or fission. The decay probabilities that are extracted from the measurements depend on the reaction used to produce the compound nucleus. We present recent work that takes into account these differences between direct and surrogate reaction. Cross sections for (n, γ) reactions on both stable and unstable isotopes will be presented