Proton-γ coincidences from (d,p) reactions between a 66Ni beam and a deuterated polyethylene target have been analyzed with the inverse-Oslo method to find the nuclear level density (NLD) and γ-ray strength function (γSF) of 67Ni. The 66Ni(n,γ) capture cross section has been calculated using the Hauser-Feshbach model in TALYS using the measured NLD and γSF as constraints. The results confirm that the 66Ni(n,γ) reaction acts as a bottleneck when relying on one-zone nucleosynthesis calculations. However, the impact of this reaction is strongly dampened in multi-zone models of low-metallicity AGB stars experiencing i-process nucleosynthesis.
@article{arxiv.2307.07153,
title = {Nuclear Level Density and $\gamma$-ray Strength Function of $^{67}\mathrm{Ni}$ and the impact on the i-process},
author = {V. W. Ingeberg and S. Siem and M. Wiedeking and A. Choplin and S. Goriely and L. Siess and K. J. Abrahams and K. Arnswald and F. Bello Garrote and D. L. Bleuel and J. Cederkäll and T. L. Christoffersen and D. M. Cox and H. De Witte and L. P. Gaffney and A. Görgen and C. Henrich and A. Illana and P. Jones and B. V. Kheswa and T. Kröll and S. N. T. Majola and K. L. Malatji and J. Ojala and J. Pakarinen and G. Rainovski and P. Reiter and M. von Schmid and M. Seidlitz and G. M. Tveten and N. Warr and F. Zeiser},
journal= {arXiv preprint arXiv:2307.07153},
year = {2025}
}