The stellar (n,γ) cross sections of unstable s-process nuclei

Abstract

When the s‐process nucleosynthesis path encounters an unstable isotope with a half‐life comparable to the neutron capture time, the resulting branching of the reaction flow leads to an abundance pattern that carries information on the physical parameters of the stellar plasma. The (n,γ) cross section of these isotopes are important clues for the interpretation of these abundance patterns. While the neutron capture cross sections of the stable isotopes are known with good accuracy, there is a complete lack of experimental data for the radioactive branch point isotopes. This contribution describes a method for measurements on unstable targets, and presents the results on 155Eu and 163Ho.