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Synopsis

The s-process rates are greatly impacted by the competition between the 22Ne(α, γ)26Mg and the 22Ne(α, n)25Mg reaction. 26Mg resonances are key to the understanding of nucleosynthesis in AGB and massive stars. The α spectroscopic factors of 26Mg states in the Gamow window corresponding to a temperature from 0.15 GK to 0.3 GK were inferred by combining the measured yields of 22Ne(7Li, t)26Mg α-transfer reaction with FRESCO calculations. The experiment was performed in the ISAC-II facility at TRIUMF, where a stable 66 MeV 22Ne beam bombarded LiF targets. The Electro-Magnetic Mass Analyzer (EMMA) was used to select the 26Mg recoils, the γ-rays were detected by the TRIUMF-ISAC Gamma- Ray Escape Suppressed Spectrometer (TIGRESS) and the tritons were detected by a Micron S3 silicon detector. Geant4 simulations were developed in order to model the two-body reaction and fusion contaminants. The yields of 26Mg states were extracted via the Markov Chain Monte Carlo method. Upper limits on two spectroscopic factors within the astrophysical region were determined and confirmed to be consistent with previous measurements.

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