Study of the excitation functions of 27Al(n,α)24Na, 27Al(n,p)27Mg and 28Si(n,p)28Al reactions

Cross sections for the reactions 27Al(n, p)27Mg and 28Si(n, p)28Al were measured by activation method between 13.40 and 14.83 MeV neutron energy. An accuracy of about 4% was achieved using the 27Al(n, α)24Na reaction as a reference at 14.1 MeV where the relative excitation function has also been measured. Results obtained were compared to a recent compilation and that calculated by the Hauser-Feshbach model. Using the back-shifted level density formula and taking into account the contribution of the separated levels, the calculations were extended to the energy range from the threshold to 18 MeV. A structure was observed in the 27Al(n, α)24Na reaction cross section curve around 14 MeV neutron energy. (orig.)