The detection of cosmic radioactivity in the last decade has an immense impact on our understanding of stellar nucleosynthesis. The 1.809MeV gamma-ray radiation due to the decay of 26Al was observed in the interstellar medium in 1980s. Since the half-life of 26Al is much shorter than the time-scale of the galactic evolution, the detection of 1.809MeV gamma-ray demonstrates that nucleosynthesis is still active in our Galaxy. Many models have been used to explain the origin of the 1.809MeV g-ray, the origin of the1.809MeV g-ray radiation is still a mystery in astrophysics. There is one opinion that the reaction of 14N(16O,a)26Al may be one of the sources of the 1.809MeV gamma rays in the interstellar medium during the supernova explosion, such as SNIa. In present work, the cross sections of these reactions were measured in the sub-barrier energy region by using AMS technique. The cross-section measurement method involved three steps: first, the irradiation of a set of TiN targets with 16O beam of different energies; second, a chemical extraction of 26Al recoil nuclei implanted in catcher foil with a stable carrier (27Al), preparation of samples suitable for AMS analysis; third, the measurement of 26Al/27Al ration using AMS. The total number of 26Al atoms is determined by the 26Al/27Al ration and the known amount of 27Al carrier. The detail procedures is described and the results are present in this paper.
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