Elastic Scattering and Total Reaction Cross Section for the 6He + 27Al System

The elastic scattering of the radioactive halo nucleus 6He on 27Al target was measured at four energies close to the Coulomb barrier using the RIBRAS (Radioactive Ion Beams in Brazil) facility. The Sao Paulo Potential(SPP) was used and its diffuseness and imaginary strength were adjusted to fit the elastic scattering angular distributions. Reaction cross-sections were extracted from the optical model fits. The reduced reaction cross-sections of 6He on 27Al are similar to those for stable, weakly bound projectiles as {6,7}Li, 9Be and larger than stable, tightly bound projectile as 16O on 27Al.Comment: 7 pages, 1 table, 3 figure

Experiments with a double solenoid system: Measurements of the

A recent experiment has been performed in the double solenoid system Radioactive Ion Beams in Brasil (RIBRAS) by impinging a pure 6He secondary beam on a thick CH2 target to measure the 6He + p excitation function. Results of this experiment will be presented

Role of direct mechanism in two-nucleon T=0 transfer reactions in light nuclei using the (Li 6,α) probe

Background: Two-nucleon transfer reactions provide a unique tool to understand the correlation between nucleon pairs. Two-nucleon (pp, nn, and np) transfer reactions can occur via isoscalar (T=0, S=1) or isovector (T=1, S=0) processes. In particular, the isoscalar pair transfer can be induced by the (α,d) or (Li6,α) probes. In the past, most of the isoscalar np-transfer studies were performed with the (α,d) reaction, but this probe is strongly momentum mismatched with respect to other two-nucleon transfer reactions. Purpose: We aim to investigate the interplay between direct and sequential reaction mechanisms from the analysis of experimental (Li6,α) angular distributions in light targets. Method: Differential cross sections of (Li6,α) reactions at a beam energy of 20 MeV were measured with C12 and F19 targets. The interplay between direct and sequential transfer mechanisms in the experimental angular distributions was investigated with coupled-reaction-channels calculations. Results: The experimental angular distributions of isoscalar np transfer were compared with theoretical calculations assuming a direct or a sequential reaction mechanism. Direct np-transfer calculations describe successfully most of the angular distributions. The sequential transfer mechanism is about two orders of magnitude smaller than the direct process. Conclusions: The present results suggest a significant np correlation in the C12(Li6,α)N∗14 and F19(Li6,α)Ne∗21 reactions. Despite the relatively low cross section for the reactions with the asymmetric F19 target, the direct transfer mechanism remains dominant over the sequential process. Further studies including measurements with other asymmetric sd-shell nuclei will be required to fully understand the isoscalar and isovector np-transfer mechanism in this nuclear region.Fil: Zamora, J.C.. Universidade de Sao Paulo; BrasilFil: Ferreira, J.L.. Universidade Federal Fluminense; BrasilFil: Barioni, A.. Universidade Federal de Sao Paulo; BrasilFil: Cardozo, E.N.. Universidade Federal Fluminense; BrasilFil: Abriola, Daniel Hugo. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Arazi, Andres. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Assunção, M.. Universidade Federal de Sao Paulo; BrasilFil: de Barbará, Ezequiel. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Cardona, Maria Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Guimarães, V.. Universidade de Sao Paulo; BrasilFil: Hojman, Daniel Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Martí, Guillermo Virginio. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Mendes, D.R.. Universidade Federal Fluminense; BrasilFil: Pacheco, Alberto Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Pires, K.C.C.. Universidade de Sao Paulo; BrasilFil: Ramos, D.. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Santos, O.C.B.. Universidade de Sao Paulo; BrasilFil: Lubian, J.. Universidade Federal Fluminense; Brasi

Four-body effects in the He6+Ni58 scattering

AbstractWe present angular distributions of the He6+Ni58 scattering measured at three bombarding energies above the Coulomb barrier: Elab=12.2 MeV,16.5 MeV,and 21.7 MeV. The angular distributions have been analysed in terms of three- and four-body Continuum-Discretized Coupled-Channels calculations considering the effect of the 6He breakup. A behaviour in the cross section at large angles has been observed which was reproduced only by the four-body Continuum-Discretized Coupled-Channels calculation

Study of reactions induced by

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

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 São 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.SCOPUS: cp.jinfo:eu-repo/semantics/publishe

Study of reactions induced by 6

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

Experiments with a double solenoid system: Measurements of the 6He + p Resonant Scattering

A recent experiment has been performed in the double solenoid system Radioactive Ion Beams in Brasil (RIBRAS) by impinging a pure 6He secondary beam on a thick CH2 target to measure the 6He + p excitation function. Results of this experiment will be presented