Determining the ⁹⁵Zr(n, γ) and ⁹³Zr(n, γ) cross sections via ⁹⁶Zr(p, p’) and ⁹⁴Zr(p, p’)surrogate reactions

The surrogate-reaction method was used to obtain the (n, γ) cross section for the short-lived s-process branching point ⁹⁵Zr, which constrains crucial parameters in stellar-nucleosynthesis models. Inelastic proton scattering from the stable isotope ⁹⁶Zr served as the surrogate. The measurement was carried out at the Texas A&M University K150 Cyclotron. An enriched ⁹⁶Zr foil was bombarded with 21-MeV protons. Scattered protons and coincident γ rays were measured with the LLNL Hyperion array, which consists of three segmented annular silicon detectors in a dE-E1-E2 configuration surrounded by an array of BGO Compton-suppressed HPGe Clover detectors. A benchmark was also performed using ⁹⁴Zr(p, p’) to determine the ⁹³Zr(n, γ) cross section, which has been previously measured via direct methods. Results of the experiment will be discussed.