The (n, α) Reaction in the s-process Branching Point 59Ni

Abstract The (n, α ) reaction in the radioactive 59 Ni is of relevance in nuclear astrophysics as 59 Ni can be considered as the first branching point in the astrophysical s-process. Its relevance in nuclear technology is especially related to material embrittlement in stainless steel. However, there is a discrepancy between available experimental data and the evaluated nuclear data files for this reaction. At the n_TOF facility at CERN, a dedicated system based on sCVD diamond diodes was set up to measure the 59 Ni(n, α ) 56 Fe cross section. The results of this measurement, with special emphasis on the dominant resonance at 203 eV, are presented here.