Study of reactions induced by 6He on 9Be

We present the results of experiments using a 6He beam on a 9Be target at\ud energies 7 − 9 times the Coulomb barrier. Angular distributions of the elastic, inelastic\ud scattering (target breakup) and the -particle production in the 6He+9Be collision have\ud been analysed. Total reaction cross sections were obtained from the elastic scattering\ud analyses and a considerable enhancement has been observed by comparing to stable systems.FAPESPFundação Araucári

Deformation and cluster effects in the elastic scattering study of 10B and 10C nuclei in 58Ni target

Esse trabalho consistiu na medida e análise de distribuições angulares do espalhamento elástico e inelástico para núcleos de massa A=10 em alvos de 58Ni e no desenvolvimento de novos feixes secundários radioativos para o sistema RIBRAS. As distribuições angulares do sistema 10B+58Ni foram medidas nas energias E(lab)= 19, 20, 21, 23, 24, 25 e 35 MeV, no laboratório Tandar na Argentina, enquanto a distribuição angular do sistema 10C+58Ni foi medida na energia E(lab)= 35.3 MeV, utilizando o sistema TWINSOL, da Universidade de Notre Dame, Estados Unidos. O formalismo de canais acoplados foi utilizado para estudar a influência da estrutura deformada do núcleo 10B e da estrutura Bruniana do núcleo 10C. Os resultados indicaram a importância desses efeitos, bem como a possível influência dos canais de transferências e breakup.This work consisted in the analysis and measurement of angular distributions for elastic and inelastic scattering of mass A=10 projectiles in 58Ni target, as well as in the development of new secondaries radioactive ion beams for the RIBRAS system. Angular distributions for the 10B+58Ni system were measured at E(lab)= 19, 20, 21, 23, 24, 25 and 35 MeV, at Tandar Laboratory in Argentina, while an angular distribution at E(lab)= 35.3 MeV for the 10C+58Ni was measured at the University of Notre Dame, USA, using the Twinsol system. The coupled channel formalism was used to investigate the influence deformed structure of the 10B and Brunian structure for 10C nucleus. The results indicated the importance of these effect as well as the possible influence of transfer and breakup channels. In this work the development of 10C, 14C and 12B beams were investigated for future use in the RIBRAS system

Transfer reactions in the investigation of light-nuclei nucleosynthesis

Cross sections for the (6)Li(p,gamma)(7)Be, (7)Li(n,gamma)(8)Li (8)Li(n,gamma)(9)Li and (8)Li(p,gamma)(9)Be capture reactions have been investigated in the framework of the potential model. The main ingredients of the potential model are the potentials used to generate the continuum and bound-state wave functions and spectroscopic factors of the corresponding bound systems. The spectroscopic factors for the (7)Li circle times n=(8)Li(gs), (8)Li circle times n=(9)Li(gs) bound systems were obtained from a FR-DWBA analysis of neutron transfer reactions induced by (8)Li radioactive beam on a (9)Be target, while spetroscopic factor for the (8)Li circle times n=(9)Be(gs) bound system were obained from a proton transfer reaction. From the obtained capture reaction cross section, reaction rate for the (8)Li(n,gamma)(9)Li and (8)Li(p,gamma)(9)Be direct neutron and proton capture were determined and compared with other experimental and calculated values

The (9)Be((8)Li, (9)Be)(8)Li elastic-transfer reaction

Angular distributions for the (9)Be((8)Li, (9)Be) (8)Li elastic-transfer reaction have been measured with a 27-MeV (8)Li radioactive nuclear beam. Spectroscopic factors for the <(9)Be vertical bar(8)Li + p > bound system were obtained from the comparison between the experimental differential cross sections and finite-range distorted-wave Born approximation calculations made with the code FRESCO. The spectroscopic factors so obtained are compared with shell-model calculations and other experimental values. Using the present value for the spectroscopic factors, cross sections and reaction rates for the (8)Li(p,gamma) (9)Be direct proton-capture reaction of astrophysical interest were calculated in the framework of the potential model.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo[FAPESP 2001/06676-9]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[2006/00629-2]U. S. NSF National Science Foundation[PHY0354828]U. S. NSF National Science Foundation[INT03-05347]U. S. Department of Energy (DOE)[DE-FG02-08ER41533]U. S. Department of Energy (DOE)[DE-FC02-07ER41457]CONACY

First Experiment with the Double Solenoid RIBRAS System.

A description of the double solenoid system (RIBRAS) operating since 2004 in one of the beam lines of the Pelletron Laboratory of the Institute of Physics of the University of São Paulo is presented. The recent installation of the secondary scattering chamber after the second solenoid is reported and the first experiment in RIBRAS using both solenoids is described.FAPESPCNP

(7,9,10)Be elastic scattering and total reaction cross sections on a (12)C target

Elastic scattering angular distributions for (7)Be, (9)Be, and (10)Be isotopes on (12)C target were measured at laboratory energies of 18.8, 26.0, and 23.2 MeV, respectively. The analysis was performed in terms of optical model potentials using Woods-Saxon and double-folding form factors. Also, continuum discretized coupled-channels calculations were performed for (7)Be and (9)Be + (12)C systems to infer the role of breakup in the elastic scattering. For the (10)Be + (12)C system, bound states coupled-channels calculations were considered. Moreover, total reaction cross sections were deduced from the elastic scattering analysis and compared with published data on other weakly and tightly bound projectiles elastically scattered on the (12)C target, as a function of energy.Conselho Nacional de Pesquisa e Desenvolvimento (CNPq)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP