2017-05-182017-05-182017Massimi, C., Altstadt, S.G., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V.,...,Sabaté Gilarte, M. (2017). Neutron spectroscopy of 26Mg states: Constraining the stellar neutron source 22Ne(α,n)25Mg. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 768, 1-6.0370-2693http://hdl.handle.net/11441/60050This work reports on accurate, high-resolution measurements of the 25Mg(n,γ)26Mg and 25Mg(n,tot) cross sections in the neutron energy range from thermal to about 300 keV, leading to a significantly improved 25Mg(n,γ)26Mg parametrization. The relevant resonances for n+25Mg were characterized from a combined R-matrix analysis of the experimental data. This resulted in an unambiguous spin/parity assignment of the corresponding excited states in 26Mg. With this information experimental upper limits of the reaction rates for 22Ne(α,n)25Mg and 22Ne(α,γ)26Mg were established, potentially leading to a significantly higher (α,n)/(α,γ) ratio than previously evaluated. The impact of these results has been studied for stellar models in the mass range 2 to 25 M⊙application/pdfengAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess10.1016/j.physletb.2017.02.025