R. Lichtenthäler

Radioactive ion beams in Brasil (RIBRAS)

The study of the so called exotic nuclei constitutes an important field of research in nuclear physics. The possibility of producing secondary beams of unstable nuclei(RIB) allows the investigation of nuclei at extreme conditions as low binding energies, high angular momentum and isospin. More laboratories are going through the process of re-direction of their experimental effort towards this activity. The nuclear physics community in Brazil has enthusiastically decided to join this endeavor to provide the Pelletron/LINAC complex with two superconducting solenoids which will permit the production of secondary beams of radioactive nuclei. A description of this facility and project RIBRAS follows.

Recent results on reactions with radioactive beams at RIBRAS (Radioactive Ion Beams in Brazil)

We present a quick description of RIBRAS (Radioactive Ion beams in Brazil), which is a superconducting double solenoid system, installed at the Pelletron Laboratory of the University of Sao Paulo and extends the capabilities of the original Pelletron Tandem Accelerator of 8MV terminal voltage (8UD) by producing secondary beams of unstable nuclei. The experimental program of the RIBRAS covers the study of elastic and inelastic scattering with the objective to study the interaction potential and the reaction mechanisms between weakly bound (RIB) and halo (6He and 8B) projectiles on light, medium and heavy mass targets. With highly purified beams, the study of resonant elastic scattering and resonant transfer reactions, using inverse kinematics and thick targets, have also been included in our recent experimental program.

Recent results with radioactive ion beams in Brasil (RIBRAS)

The RIBRAS facility (Radiactive Ion Beams in Brasil) is installed next to the 8 MV Pelletron Tandem of the Nuclear Physics Laboratory of the Institute of Physics of the University of Sao Paulo. It consists of two superconducting solenoids with maximum magnetic field of B=6.5T. Light radioactive ion beams are produced through transfer reactions, using solid or gaseous production targets of Be, LiF, 3He etc. The solenoids make a magnetic rigidity selection and the use of the two solenoids with a degrader between them allows the production of quite pure secondary beams. Beams of 6He, 8Li, 7Be, 10Be, 8B, 12B are currently produced and used to study elastic, inelastic, and transfer reactions on a variety of light, medium mass and heavy secondary targets. Some examples of reactions recently studied are presented below.The RIBRAS facility (Radiactive Ion Beams in Brasil) is installed next to the 8 MV Pelletron Tandem of the Nuclear Physics Laboratory of the Institute of Physics of the University of Sao Paulo. It consists of two superconducting solenoids with maximum magnetic field of B=6.5T. Light radioactive ion beams are produced through transfer reactions, using solid or gaseous production targets of Be, LiF, 3He etc. The solenoids make a magnetic rigidity selection and the use of the two solenoids with a degrader between them allows the production of quite pure secondary beams. Beams of 6He, 8Li, 7Be, 10Be, 8B, 12B are currently produced and used to study elastic, inelastic, and transfer reactions on a variety of light, medium mass and heavy secondary targets. Some examples of reactions recently studied are presented below.

The 8Li(p,α)5He Reaction Measured at Astrophysical Energies at RIBRAS

We present the results of the 8Li(p,α)5He transfer reaction, measured at the RIBRAS facility. It was performed in inverse kinematics using a thick CH2 polyethylene target. The complete excitation function was measured between Ecm = 0.4–2.7 MeV, which includes the Gamow peak energy region. The excitation function was reproduced with the R‐matrix theory.