Constraining the 22Ne(α,γ)26Mg and 22Ne(α,n)25Mg reaction rates using sub-Coulomb α-transfer reactions

The 22Ne(α,γ)26Mg and 22Ne(α,n)25Mg reactions play an important role in astrophysics because they have significant influence on the neutron flux during the weak branch of the s-process. We constrain the astrophysical rates for these reactions by measuring partial α-widths of resonances in 26Mg located in the Gamow window for the Ne22+α capture. These resonances were populated using 22Ne(6Li,d)26Mg and 22Ne(7Li,t)26Mg reactions at energies near the Coulomb barrier. At these low energies α-transfer reactions favor population of low spin states and the extracted partial α-widths for the observed resonances exhibit only minor dependence on the model parameters. The astrophysical rates for both the 22Ne(α,γ)26Mg and the 22Ne(α,n)25Mg reactions are shown to be significantly different than the previously suggested values. Keywords: s-Process, Reaction rate, 22Ne(α,γ)26Mg, 22Ne(α,n)25Mg, Sub-Coulomb α-transfer reaction