Excitation function studies of α induced reactions for niobium and preequilibrium effects -: art. no. 034605

Excitation functions of the reaction (alpha, n), (alpha, 2n), (alpha, 3n), and (alpha, alphan) for Nb-93 were measured up to 37 MeV using the stacked foil activation technique and high-purity Ge gamma-ray spectroscopy method. The measured experimental values were compared with the geometry-dependent hybrid model in which the emission of particles prior to the equilibrium decay is taken into account whenever the interaction of projectile with the target nucleus is considered. It was found that the compound nucleus decay mechanism alone is unable to explain the experimental trend of our data. The isomeric cross-section ratios (sigma(m)/sigma(g)) for the (alpha, 2n) reaction were also calculated as a function of alpha-particle energy. A definite trend was observed in the variation of the ratio with alpha-particle energy.