Effects of level density in the cross sections of (α, xn), (α, pxn), (α, 2pxn) and (α, αxn) reactions in 197Au, 181Ta, natIn and 93Nb and pre-equilibrium analysis

Abstract

Excitation functions are measured for α-particle-induced reactions on 197Au, 181Ta, natIn, and 93Nb in the energy region 18 to 60 MeV using the activation method and γ-ray spectrometry. The experimental results are compared with semiclassical model codes, STAPRE, ALICE-91, and COMPLET. These models take into account compound nuclei as well as pre-equilibrium emissions. The angular momentum removal effects have also been included in the COMPLET code. The Monte Carlo simulation code PACE4 is also employed for the calculations of equilibrium cross sections. In the case of neutron emission channels, both the model codes give fairly good agreement. The COMPLET code on the other hand, explains the α-particle emission channels in a more convincing manner.