Angular-Momentum Effect In The Fusion Reaction Of Pr-141 With Ar-40 Projectiles

Excitation functions for evaporation-residue formation and fission in the reaction of Pr-141 With Ar-40 ions were measured by a radiochemical method. The projectile energies ranged from 7 to 94 MeV/u. The excitation function for evaporation-residue formation showed a linear dependence on the reciprocal of center-of-mass energy around 10 MeV/u, which was in agreement with the prediction on the basis of sharp cut-off approximation. The fusion cross section data for energies less than 10 MeV/u were well reproduced by the model by Bass except for the data at the bombarding energy of 7.2 MeV/u. It was demonstrated that the critical angular momentum for fusion and that for evaporation residues play an important role in determining the respective cross sections.