Neutron spectroscopy of 26Mg states: Constraining the stellar neutron source 22Ne(α,n)25Mg

• Published in: Physics letters. B Vol. 768; no. C; pp. 1 - 6
• Main Authors: Massimi, C., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Bisterzo, S., Bosnar, D., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Castelluccio, D.M., Cerutti, F., Chiaveri, E., Cosentino, L., Chin, M., Clai, G., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Cristallo, S., Diakaki, M., Duran, I., Dressler, R., Eleftheriadis, C., Ferrari, A., Finocchiaro, P., Fraval, K., Ganesan, S., García, A.R., Giubrone, G., Gonçalves, I.F., Griesmayer, E., Gunsing, F., Hernández-Prieto, A., Jenkins, D.G., Kadi, Y., Käppeler, F., Karadimos, D., Kivel, N., Koehler, P., Kokkoris, M., Kopecky, S., Krtička, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Leong, L.S., Lo Meo, S., Losito, R., Mallick, A., Manousos, A., Marganiec, J., Martínez, T., Mastromarco, M., Mendoza, E., Mengoni, A., Milazzo, P.M., Mingrone, F., Mirea, M., Mondelaers, W., Paradela, C., Pavlik, A., Perkowski, J., Piersanti, L., Plompen, A., Praena, J., Quesada, J.M., Rauscher, T., Reifarth, R., Riego, A., Sabaté-Gilarte, M., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J.L., Tarrío, D., Tsinganis, A., Valenta, S., Variale, V., Vaz, P., Ventura, A., Vermeulen, M.J., Vlastou, R., Wallner, A., Ware, T., Weiß, C., Wynants, R., Wright, T., Žugec, P.
• Format: Journal Article Publication
• Language: English
• Published: Netherlands Elsevier B.V 01-05-2017; Elsevier
• Subjects: [formula omitted]Ne; Atomic spectroscopy; Capture; CERN; Cross section; Energia nuclear; Energies; Espectroscòpia atòmica; Experimental; Física; Neutron; Neutron spectroscopy; Neutrons; nTOF; s Process; Stellar nucleosynthesis; Àrees temàtiques de la UPC; α+22Ne; α+22Ne; Neutron spectroscopy; s Process
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2017.02.025

This 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⊙.