Elastic scattering and total reaction cross sections for the 10B + 58Ni system

N. N. DESHMUKH; V. GUIMARÃES; D. ABRIOLA; A. ARAZI; E. DE BARBARÁ; O. A. CAPURRO; M.A. CARDONA; A. N. DESHMUKH; J. FERNÁNDEZ NIELLO; J. GALLARDO; D. HOJMAN; G. V. MARTÍ ; D.R. MENDES JR; D.S. MONTEIRO; V. MORCELLE; A. J. PACHECO; D. RODRÍGUES; V. SCARDUELLI

Maresias

Workshop; XXXVII Reunião de Trabalho sobre Física Nuclear no Brasil; 2014

Sociedade Brasileira de Fisica

From the last several decades simple elastic scattering experiments in the nuclear reactions have proved to be a successful means to provide information about the nuclear properties. It is a known fact that the near Coulomb barrier elastic scattering of tightly bound heavy ions such as 12C, 16O and 32S shows a behaviour of the energy dependence of the interacting optical potential (OP) known as Threshold Anomaly (TA) [1,2], where the interacting potentials shows a rapid variation and is consistent with the dispersion relation [3,4]. The name ?anomaly? comes from the expectation that the real and imaginary parts of the OP are energy independent at higher energies, but not at near barrier energies. In continuation it is also found that the net polarization potential in the scattering of weakly bound nuclei such as 6,7Li and 9Be has two components: one attractive, due to the couplings of the elastic channel with inelastic excitations and other direct reactions, and one repulsive, due to the breakup. Thus if the component is attractive the usual TA is observed and if it is repulsive it is termed as Breakup Threshold Anomaly (BTA) [4,5]. In any situation, the real and imaginary parts of the OP should satisfy the dispersion relation.Thus to check the dependence of the interacting potentials with respect to energy we have performed an experiment using the stable beams 10,11B for which not much study has been pursued. The elastic scattering angular distribution experiment was performed at TANDAR laboratory in Buenos Aires, Argentina where beams of 10,11B were bombarded from the 20 UD tandem accelerator on a 58Ni target, 110 µg/cm2 thick, evaporated on 40 µg/cm2 carbon foil at energies ranging from below to much above the Coulomb barrier: 19 ≤ Elab ≤ 35 MeV. The detection system used for the measurements consisted of an array of ten surface-barrier detectors with an angular separation of 5º between adjacent detectors. Two monitor detectors were also used for absolute normalization purpose apart from gold foil. The whole set-up was mounted into 70 cm diameter scattering chamber.Currently Optical model analysis is being done to extract the optical potential parameters and reaction cross sections using the potential model, namely, the Sao Paulo double folding potential (SPP) [6,7], which has been successfully used to describe a large variety of systems in a wide energy range, including fusion excitation functions and barrier distributions of stable and weakly bound nuclei. The detailed aspects will be presented in the Conference.References:[1] G. R. Satchler, Phys. Rep. 199, 147 (1997).[2] M. A. Nagarajan, C. C. Mahaux, and G. R. Satchler, Phys. Rev. Lett 54, 1136 (1985)[3] M. S. Hussein et al., Phys. Rev. C 76, 019902(E) (2007).[4] M. S. Hussein et al., Phys. Rev. C 73, 044610 (2006).[5] P.R.S. Gomes et al., J. Phys. G 31, S1669 (2005)[6] L.C. Chamon et al., Phys. Rev. Lett. 79, 5218(1997)[7] L.C. Chamon et al., Phys. Rev. C 66, 014610 (2002)