Quasi-elastic scattering measurements in the systems 6;7Li on 144Sm

O.A. CAPURRO; A. ARAZI; J.O. FERNÁNDEZ NIELLO; J.M. FIGUEIRA; G.V. MARTÍ; D. MARTÍNEZ HEIMANN; A. NEGRI; A.J. PACHECO; D.S. MONTEIRO; D.R. OTOMAR; P.R.S. GOMES; V. GUIMARÃES

São Sebastião, Brasil

Workshop; XXXI Reunião de Trabalho sobre Física Nuclear no Brasil,; 2008

Sociedade Brasileira de Física

Studies of nuclear reactions employing weakly bound nuclei as projectiles are being carried out at the Tandar Laboratory. The primal motivation is to investigate the influence of the breakup channel on other reaction channels, especially at energies near the Coulomb barrier. In the present work, the results of measurements of quasi-elastic scattering cross sections are given with the purpose of obtaining fusion barrier distributions, which can be deduced from the first derivative of the corresponding excitation function (-d(dSigmaqel/dSigmaRuth)/dE). qel/dSigmaRuth)/dE). We report data for the systems 6;7Li on 144Sm which are characterized by weakly bound projectiles onto a closed neutron shell target. The quasi{elastic scattering cross sections were obtained using a silicon telescope detector at backward angles. Precise measurements were performed at energies below and above the Coulomb barrier using an energy step of 1 MeV (0.5 MeV in speci¯c range of energies). The experimental excitation functions and the associated barrier distributions are compared for both systems, and although a theoretical analysis is still in progress, we discuss some qualitative aspects of the preliminary results.