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Alpha particle energy distributions in the 6He+120Sn collision have been measured at 7 bombarding energies above the Coulomb barrier. A phenomenological analysis of the centroids of the experimental distributions was performed and compared with the expected alpha-particle energies from breakup and neutron transfer reactions. Q-optimum conditions were determined using the Brinks formula for the di-neutron transfer reaction. A comparison of the measured alpha-particle production cross-sections with Continuum Discretized Coupled Channels (CDCC) calculations for breakup is presented.

We present new experimental angular distributions for the elastic scattering of Li6+Sn120 at three bombarding energies. We include these data in a wide systematic involving the elastic scattering of He4,6,Li7, Be9,B10, and O16,18 projectiles on the same target at energies around the respective Coulomb barriers. Considering this data set, we report on optical model analyses based on the double-folding São Paulo potential. Within this approach, we study the sensitivity of the data fit to different models for the nuclear matter densities and to variations in the optical potential strengths.

The (p, p), (p, α) and (p, d) reactions on 8Li were measured at low energies. The experiment was performed using a thick [CH2]n target and a radioactive 8Li beam available at the RIBRAS facility of São Paulo. This experiment represents an upgrade of a previous experiment, where only the 8Li(p, a)5He cross section was measured. High lying resonances of 9Be, which are still uncertain, could be studied in this way. The detection of several reaction channels allows a reliable determination of the resonance parameters, such as energy, width and spin-parity. In the deuteron channel we could observe the same resonance decaying to d+7Ligs and to d+7Li&z.ast; The properties of the resonances are determined by a R-matrix analysis, which provides evidence for a significant clustering as well in the (p, α) as in the (p, d) channels. The experimental data and the multi-channel R-matrix analysis will be presented., SCOPUS: cp.p, info:eu-repo/semantics/published

We present the results of the 8Li(p,α)5He and 8Li(p,p)8Li reactions measured at the RIBRAS (Radioactive Ion Beams in Brazil) system. The experiment was realized in inverse kinematics using a thick [CH2]n polyethylene target and an incident 8Li beam, produced by RIBRAS. Using the thick target method, the complete excitation function could be measured between Ecm = 0.2 - 2.1 MeV, which includes the Gamow peak energy region. The excitation function of the 8Li(p,α)5He reaction, populating resonances between 16.888 and 19.0 MeV in 9Be, was obtained[1] and the resonances were fitted using R-matrix calculations. This study shed light on spins, parities, partial widths and isospin values of high lying resonances in 9Be. The measurement of the resonant elastic scattering 8Li(p,p)8Li populating resonances in the same energy region can constrain the resonance parameters. Preliminary results of the elastic scattering are also presented. © Owned by the authors, published by EDP Sciences, 2014., SCOPUS: cp.p, info:eu-repo/semantics/published

We present the results of the 8Li(p, α) 5He reaction of astrophysical interest, measured at the RIBRAS system. It was realized in inverse kinematics and using a thick CH 2 polyethylene target. Using the thick target method the complete excitation function could be measured between E cm=0.2-2.5 MeV, which includes the Gamow peak energy region. The contribution of contaminating 12C( 8Li, 4He) 16N and 12C( 7Li, 4He) 15N reactions is still under analysis. However, if the cross section is expected to be somewhat reduced, the subtraction of the contamination will not change the general feature of the excitation function. © 2012 American Institute of Physics., SCOPUS: cp.p, info:eu-repo/semantics/published

We present a direct measurement of the low-energy 8Li(p ,α)5He cross section, using a radioactive 8Li beam impinging on a thick target. With four beam energies, we cover the energy range between Ec.m.=0.2 and 2.1 MeV. An R-matrix analysis of the data is performed and suggests the existence of two broad overlapping resonances (5/2+ at Ec.m.=1.69 MeV and 7/2+ at E c.m.=1.76 MeV). At low energies our data are sensitive to the properties of a subthreshold state (Ex=16.67 MeV) and of two resonances above threshold. These resonances were observed in previous experiments. The R-matrix fit confirms spin assignments, and provides partial widths. We propose a new 8Li(p,α)5He reaction rate and briefly discuss its influence in nuclear astrophysics. © 2012 American Physical Society., SCOPUS: ar.j, info:eu-repo/semantics/published

Nuclear astrophysics is a relatively young science; it is about half a century old. It is a multidisciplinary subject, since it combines nuclear physics with astrophysics and observations in astronomy. It also addresses fundamental issues in astrobiology through the formation of elements, in particular those required for a carbon-based life. In this paper, a rapid overview of nucleosynthesis is given, mainly from the point of view of nuclear physics. A short historical introduction is followed by the definition of the relevant nuclear parameters, such as nuclear reaction cross sections, astrophysical S-factors, the energy range defined by the Gamow peak and reaction rates. The different astrophysical scenarios that are the sites of nucleosynthesis, and different processes, cycles and chains that are responsible for the building of complex nuclei from the elementary hydrogen nuclei are then briefly described. Copyright © Cambridge University Press 2012., SCOPUS: ar.j, info:eu-repo/semantics/published

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 São 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. © 2012 American Institute of Physics., SCOPUS: cp.p, info:eu-repo/semantics/published

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 CH 2 polyethylene target. The complete excitation function was measured between E cm=0.4-2.7 2MeV, which includes the Gamow peak energy region. The excitation function was reproduced with the R-matrix theory. © 2011 American Institute of Physics., SCOPUS: cp.p, info:eu-repo/semantics/published

The RIBRAS facility (Radioactive Ion Beams in Brasil) is installed in connection with the 8MV Pelletron tandem of the University of São Paulo Physics Institute. It consists of two superconducting solenoids which focalize light radioactive secondary beams of low energy, produced by transfer reactions. Recent experimental results include the elastic scattering and transfer reactions of 6He halo nucleus on 9Be, 27Al, 51V and 120Sn targets. The elastic scattering and transfer of 8Li and 7Be on several targets is also being studied. The transfer reaction 8Li(p,α)5He of astrophysical interest was also studied in the Ec m = 0.2 - 2.5 MeV energy range. © 2010 Elsevier B.V. All rights reserved., SCOPUS: ar.j, info:eu-repo/semantics/published