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A double superconducting solenoid system is installed at the Pelletron Laboratory of the Uni- versity of Sao Paulo, Brazil. This system allows the production of secondary beams of 8 Li, 6 He, 7 Be and others light exotic nuclei. The first results using this facility are presented.

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 Sao 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 {6,7}Li, 9Be and larger than stable, tightly bound projectile as 16O on 27Al., 7 pages, 1 table, 3 figures

A double superconducting solenoid system is being installed at the Pelletron Laboratory of the University of S ao Paulo, Brazil. This system allows the production of secondary beams of light exotic nuclei like 8Li, 6He and others. The first results using this facility are presented.

The cluster structure of 7Li and 7Be has been investigated by the elastic‐transfer 4He(7Li,4He)7Li and 3He(7Be,3He)7Be reactions, respectively. Angular distribution for the elastic‐transfer of 7Li+4He has been measured in Sao Paulo at ECM = 9.67 MeV. Together with available elastic‐transfer angular distributions measured at other energies ranging from ECM = 2.29 to 32.13 MeV, a global optical model analysis has been performed. The measurement of the elastic‐transfer angular distribution at ELAB = 48.2 MeV for the 7Be+3He system is also described.

The RIBRAS (Radioactive Ion Beams Brazil) facility recently installed at the Pelletron Laboratory of the University of Sao Paulo consists of two superconducting solenoids used to produce and focalize beams of light radioactive nuclei, as 6He, 7Be,8Li etc. The low energy, light, radioactive beams available are used to study reactions close to the Coulomb barrier. The elastic scattering of the radioactive halo nucleus 6He on 27Al target was measured at four energies close to the Coulomb barrier. Reaction cross sections were extracted from the optical model fits, using the Sao Paulo Potential (SPP). The reduced reaction cross sections of 6He on 27Al were compared to reduced reaction cross sections for other projectiles as 6,7Li, 9Be and 16O on 27Al and they are larger than those for stable projectiles by an amount similar to the calculated nuclear break‐up cross section for this system.

We discuss evidences of strong cluster structures observed in nuclear reactions even at quite high excitation energies. The oscillatory angular distributions of the elastic scattering of the 12C+28Si system measured at 13 energies close to the Coulomb barrier were reproduced introducing in the scattering S-matrix additional Regge-pole form terms. These poles were interpreted as describing doorway states with 12C+28Si cluster structure in the composite nucleus 40Ca. The excitation energies of these states indicate that they can be part of a rotational band in 40Ca, together with similar states observed in the elastic scattering and α-transfer reactions of the 16O+24Mg system. We propose that the presently observed, largely deformed molecular band corresponds to the hyper-deformed band in 40Ca, which has been found in a new Nilsson-model-calculation, which predicts preference of the 12C + 28Si and 16O + 24Mg molecular structures, in accordance with our present results.