Study of preequilibrium decay in (α,xn) reactions in holmium up to 70 MeV

Alpha particle induced reactions on the target element holmium were investigated upto 70 MeV using stacked foil activation technique and Ge(Li) gamma ray spectroscopy methods. Excitation functions for the formation of reaction residues 168 Tm, 167 Tm, 166 Tm and 165 Tm from α-induced reactions on 165 Ho were investigated for the first time in the energy range from 50-70 MeV. The measured cross sections were compared with theoretical calculations considering equilibrium as well as preequilibrium hybrid models of Blann. The high energy tails of the excitation functions show a substantial contribution from preequilibrium emission. A general agreement is observed between the experimental results and theoretical predictions with an initial excition configuration of n 0 = 4(4p 0h).