The elastic scattering of the radioactive halo nucleus 6He on 27Al target was measured at four energies close to the Coulomb barrier using the RIBRAS (Radioactive Ion Beams in Brazil) facility. The São Paulo Potential (SPP) was used and its diffuseness and imaginary strength were adjusted to fit the elastic scattering angular distributions. Reaction cross-sections were extracted from the optical model fits. The reduced reaction cross-sections of 6He on 27Al are similar to those for stable, weakly bound projectiles as 6,7Li, 9Be and larger than stable, tightly bound projectile as 16O on 27Al

The elastic scattering of 6 He on 120 Sn has been measured at four energies above the Coulomb barrier using the 6 He beam produced at the RIBRAS (Radioactive Ion Beams in Brasil) facility. The elastic angular distributions have been analyzed with the optical model and three-and four-body continuum-discretized coupled-channels calculations. The total reaction cross sections have been derived and compared with other systems of similar masses.

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The collision 6 He + 120 Sn has been investigated at four energies near the Coulomb barrier. A large yield of α particles has been detected, with energies around the energy of the scattered 6 He beam. The energy and angular distributions of the α particles have been analyzed and compared with breakup and neutron transfer calculations.

The delayed x-ray detection technique was used to measure complete and incomplete fusion cross sections for the 9 Be + 144 Sm reaction at sub-and near-barrier energies. Elastic and inelastic scattering for this system were also measured. Reaction cross sections were derived and the transfer cross sections of one neutron were calculated. The suppression of complete fusion above the barrier, of the order of 10%, is attributed to 9 Be breakup and is considerably smaller than the value of 30% found for the 9 Be + 208 Pb system.

The strengths of resonances located at center-of-mass energies of E c.m. = 189, 304, 374, and 418 keV for the 25 Mg(p,γ ) reaction have been measured for the first time with an off-line method: Mg targets were firstly activated with protons at the resonance energies and the produced 26 Al g nuclei were counted by means of highly sensitive accelerator mass spectrometry (AMS). Thus, the production of 26 Al in its ground state is determined independently from the γ -decay branching ratio. While the 304, 374, and 418 keV resonances show fair agreement with previous measurements, the 189 keV resonance yield a significantly less strength. In addition, an experimental upper limit for the E c.m. = 92 keV resonance was determined.

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.

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