Orateur
Description
A study of reaction mechanisms involved in the production of alpha particles in reactions induced by a 6He radioactive beam on a 9Be target nuclei is presented. Experimental data [1] was obtained using the RIBRAS (Radioactive Ion Beams in Brasil) facility of the Institute of Physics of the University of São Paulo, Brazil [2-4]. It is the first RIB facility in the southern hemisphere and is presently the only experimental equipment in South America capable of producing secondary beams of rare isotopes. The RIBRAS system consists of two superconducting solenoids used to select and focus light secondary beams of nuclei out of the stability valley. 6He+9Be angular distributions were measured at Elab=16.2MeV and Elab=21.3 MeV bombarding energies. A large yield of alpha particles was observed, that is absent with gold target measurements, indicating that they come from reactions with the 9Be target. The 6He secondary beam had many kind of particles (cocktail beam) like 7Li and light particles such as α, p and t. In particular, these 7Li and α-particles can also contribute to the production of the observed alpha particles, in addition to the breakup of the 9Be target, since the 9Be nucleus has (α+α+n) cluster configuration with binding energy of 1.564 MeV. Energy and angular distributions of those events were obtained taking into account these alpha particle production possibilities. The results were compared with theoretical calculations performed using the Continuum Discretized Coupled Channel (CDCC), the Ichimura-Austern-Vincent (IAV) formalisms [5,6], in addition to the fusion-evaporation calculations.
References
[1] K. C. C. Pires et al. Phys. Rev. C83, 064603, (2011).
[2] R. Lichtenthäler Filho, et al. Eur. Jour. of Phys., 25, 733, (2005).
[3] A. Lépine-Szily, et al. Nuclear Physics News, v. 23, p. 5-11, (2013).
[4] R. Lichtenthäler, et al. Eur. Phys. J. A57, 92 (2021).
[5] Jin Lei, A. M. Moro. Phys. Rev. C92, 044616 (2015).
[6] O. C. B. Santos et al. Phys. Rev. C103, 064601 (2021).
