A systematic study of the fission and evaporation residue excitation functions in complete fusion reactions with weakly bound stable nuclei

Abstract

We carry out a systematic study on the fusion fission and evaporation residue excitation functions for the reactions of (6,7)Li, (9)Be, (10,11)B + (209)Bi and (6,9)Li, (9)Be + (208)Pb, in which the projectiles are loosely bound and have low threshold energies against breakup. The fusion cross sections are calculated by the coupled-channel model. The compound nuclei decay are analyzed with the standard statistical model. The fission and evaporation residue excitation functions are well reproduced by our calculations, proving the validity of the standard statistical model in describing the compound nuclei decay in these characteristic reactions. For the compound nuclei with A = 215-220 and Z = 86-88, the liquid drop fission barriers need to be scaled by 0.80-1.02 to reproduce the experimental data. And a decreasing trend of the scaling factor with increasing fissionability parameter Z(2)/(50A) is found. (C) 2011 Elsevier B.V. All rights reserved.