Non-equilibrium reaction mechanism in alpha-particle induced excitation function for 209Bi up to 60 MeV

Abstract

Excitation functions (α, 3n) and (α, 4n) for 209Bi have been measured up to 60 MeV α-particle energy. The excitation functions are measured at 15α-particle energies by a stack foil technique in two steps. Excitation functions for the above two reactions have been reported for the first time in the energy range from 40 to 60 MeV. The measured experimental values are compared with the geometry-dependent hybrid (GDH) 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 is found that the compound nucleus decay mechanism alone is unable to explain the experimental trend of our data. The initial exciton number 4 with different configurations has been tested and it is concluded that the configuration (2n + 2p + 0h) gives the best fit to the experimental data.