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We study the behavior of the fusion, break-up, reaction and elastic scattering of different projectiles on 64 Zn, at near and above barrier energies. We present fusion and elastic scattering data with the tightly bound 16 O and the stable weakly bound 6 Li, 7 Li and 9 Be projectiles. The data were analyzed by coupled channel calculations. The total fusion cross sections for these systems are not affected by the break-up process at energies above the barrier. The elastic (non-capture) break-up cross section is important at energies close and above the Coulomb barrier and increases the reaction cross sections. In addition we also show that the break-up process at near and sub-barrier energies is responsible for the vanishing of the usual threshold anomaly of the optical potential and give rise to a new type of anomaly.

Fusion cross sections have been measured for ' 0+ ' ' Sm at bombarding energies in the range 61 MeV~E&, . b(' 0)~75 MeV by o6'-line observation of x rays emitted in the radioactive decay of Yb isotopes and their daughters. The fusion excitation functions are similar to those of the adjacent even Sm isotopes. It appears, therefore, that the odd valence neutrons do not have any unusual inhuence on the subbarrier enhancement of o. f", in these systems. The x-n distributions of the evaporation residues were also determined. The nuclear deformation parameters P2 deduced for the odd and even Sm isotopes using Wong s model establish a smooth systematic behavior of P2 with target collectivity. Fusion cross sections for ' 0 with all the stable Sm isotopes are tabulated.

This paper discusses the role played by transfer reactions on the sub-barrier fusion enhancement. A semiclassical formalism is used to derive the transfer form factors, that are used in coupled-channel calculations. It is shown that transfer reactions that take place at small distances may be an important doorway to fusion. The relation between this formalism and the long-range absorptive fusion potential is also discussed. Results of calculations for the 16 O + A Sm, 32 S + 100 Mo and 16 O + 59 Co systems are presented.