Edilson Crema - Academia.edu (original) (raw)
Papers by Edilson Crema
Nuclear Physics A, 2007
We analyze fusion cross sections induced by the 6 He halo projectile in the framework of the doub... more We analyze fusion cross sections induced by the 6 He halo projectile in the framework of the double folding São Paulo potential, which has been shown to be a reliable potential for the analysis of fusion cross sections induced by stable weakly bound nuclei. The results show that the fusion cross sections of 6 He + 209 Bi, 238 U are suppressed at energies above the barrier, when compared with coupled channel calculations that do not take into account the projectile breakup, whereas they are in agreement with the calculations at sub-barrier energies.
[
Estudo do espalhamento elástico do ANTPOT.16O pelo ANTPOT.27 ALStudy of elastic scattering of \&#... more Estudo do espalhamento elástico do ANTPOT.16O pelo ANTPOT.27 ALStudy of elastic scattering of \'ANTPOT.16O\' by \'ANTPOT.27 AL\
AIP Conference Proceedings, 2008
We present the recent experimental data of the quasielastic excitation function that was measured... more We present the recent experimental data of the quasielastic excitation function that was measured at &ptheta;lab = 161 ° for the 18O+64Zn system and its correspondent quasielastic barrier distributions has been derived. These data were taken at energies near and below of the Coulomb barrier. We compared the data with coupled channel calculations, and the results show a strong coupling effect of the quadrupole and octupole states of the 64Zn and the state 211+ of the 18O.
Nuclear Physics A, 1992
International audienc
The European Physical Journal A, 2010
We have measured the elastic scattering cross-section for 8 Li + 9 Be and 8 Li + 51 Vs y s t e m ... more We have measured the elastic scattering cross-section for 8 Li + 9 Be and 8 Li + 51 Vs y s t e m sa t 19.6 MeV and 18.5 MeV, respectively. We have also extracted total reaction cross sections from the elastic scattering analysis for several light weakly bound systems using the optical model with Woods-Saxon and double-folding-type potentials. Different reduction methods for the total reaction cross-sections have been applied to analyze and compare simultaneously all the systems.
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt età la diffusion de documents scientifiques de niveau recherche, publiés ou non, emanant desétablissements d'enseignement et de recherche français ouétrangers, des laboratoires publics ou privés.
Physical Review C, 2019
The precise quasielastic excitation function for the 18 O + 64 Zn system was measured at energies... more The precise quasielastic excitation function for the 18 O + 64 Zn system was measured at energies near and below the Coulomb barrier at θ lab = 161 • , from which its correlated quasielastic barrier distribution was derived. The excitation functions for the two-neutron, α, and tritium transfer reactions have also been measured at the same conditions. These data were well described by the coupled channel and coupled reaction channel calculations. The comparison of the data with theoretical calculations shows the strong influence of three inelastic channels in the coupling process: the quadrupole and octupole vibrational states of 64 Zn, 2 + 1 and 3 − 1 , and the quadrupole vibrational state of 18 O, 2 + 1. In addition, theoretical calculations indicate that the two-neutron stripping is mostly due to a one-step process, which has a striking effect on the reaction mechanism of this system.
Physical Review C, 2017
Full angular distributions of the B-10 elastically and inelastically scattered by Ni-58 have been... more Full angular distributions of the B-10 elastically and inelastically scattered by Ni-58 have been measured at different energies around the Coulomb barrier. The elastic and inelastic scattering of B-10 on a medium mass target has been measured for the first time. The obtained angular distributions have been analyzed in terms of large-scale coupled reaction channel calculations, where several inelastic transitions of the projectile and the target, as well as the most relevant one-and two-step transfer reactions have been included in the coupling matrix. The roles of the spin reorientation, the spin-orbit interaction, and the large ground-state deformation of the B-10, in the reaction mechanism, were also investigated. The real part of the interaction potential between projectile and target was represented by a parameter-free double-folding potential, whereas no imaginary potential at the surface was considered. In this sense, the theoretical calculations were parameter free and their results were compared to experimental data to investigate the relative importance of the different reaction channels. A striking influence of the ground-state spin reorientation of the B-10 nucleus was found, while all transfer reactions investigated had a minimum contribution to the dynamics of the system. Finally, the large static deformation of the B-10 and the spin-orbit coupling can also play an important role in the system studied. (AU) FAPESP's process: 14/02116-9-Investigation of direct nuclear reactions induced by light neutron rich nuclei.
International Journal of Modern Physics E, 2011
We show that halo effects enhance fusion cross sections of weakly bound systems, comparing with t... more We show that halo effects enhance fusion cross sections of weakly bound systems, comparing with the situation when there is no-halo. We introduce dimensionless fusion functions and energy variable quantity to investigate systematical trends in the fusion cross sections of weakly bound nuclei at near-barrier energies. We observe very clearly complete fusion suppression at energies above the barrier due to dynamic effects of the breakup on fusion. We explain this suppression in terms of the repulsive polarization potential produced by the breakup.
Nuclear Physics A, 2007
We analyze fusion cross sections induced by the 6 He halo projectile in the framework of the doub... more We analyze fusion cross sections induced by the 6 He halo projectile in the framework of the double folding São Paulo potential, which has been shown to be a reliable potential for the analysis of fusion cross sections induced by stable weakly bound nuclei. The results show that the fusion cross sections of 6 He + 209 Bi, 238 U are suppressed at energies above the barrier, when compared with coupled channel calculations that do not take into account the projectile breakup, whereas they are in agreement with the calculations at sub-barrier energies.
[
Estudo do espalhamento elástico do ANTPOT.16O pelo ANTPOT.27 ALStudy of elastic scattering of \&#... more Estudo do espalhamento elástico do ANTPOT.16O pelo ANTPOT.27 ALStudy of elastic scattering of \'ANTPOT.16O\' by \'ANTPOT.27 AL\
AIP Conference Proceedings, 2008
We present the recent experimental data of the quasielastic excitation function that was measured... more We present the recent experimental data of the quasielastic excitation function that was measured at &ptheta;lab = 161 ° for the 18O+64Zn system and its correspondent quasielastic barrier distributions has been derived. These data were taken at energies near and below of the Coulomb barrier. We compared the data with coupled channel calculations, and the results show a strong coupling effect of the quadrupole and octupole states of the 64Zn and the state 211+ of the 18O.
Nuclear Physics A, 1992
International audienc
The European Physical Journal A, 2010
We have measured the elastic scattering cross-section for 8 Li + 9 Be and 8 Li + 51 Vs y s t e m ... more We have measured the elastic scattering cross-section for 8 Li + 9 Be and 8 Li + 51 Vs y s t e m sa t 19.6 MeV and 18.5 MeV, respectively. We have also extracted total reaction cross sections from the elastic scattering analysis for several light weakly bound systems using the optical model with Woods-Saxon and double-folding-type potentials. Different reduction methods for the total reaction cross-sections have been applied to analyze and compare simultaneously all the systems.
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt età la diffusion de documents scientifiques de niveau recherche, publiés ou non, emanant desétablissements d'enseignement et de recherche français ouétrangers, des laboratoires publics ou privés.
Physical Review C, 2019
The precise quasielastic excitation function for the 18 O + 64 Zn system was measured at energies... more The precise quasielastic excitation function for the 18 O + 64 Zn system was measured at energies near and below the Coulomb barrier at θ lab = 161 • , from which its correlated quasielastic barrier distribution was derived. The excitation functions for the two-neutron, α, and tritium transfer reactions have also been measured at the same conditions. These data were well described by the coupled channel and coupled reaction channel calculations. The comparison of the data with theoretical calculations shows the strong influence of three inelastic channels in the coupling process: the quadrupole and octupole vibrational states of 64 Zn, 2 + 1 and 3 − 1 , and the quadrupole vibrational state of 18 O, 2 + 1. In addition, theoretical calculations indicate that the two-neutron stripping is mostly due to a one-step process, which has a striking effect on the reaction mechanism of this system.
Physical Review C, 2017
Full angular distributions of the B-10 elastically and inelastically scattered by Ni-58 have been... more Full angular distributions of the B-10 elastically and inelastically scattered by Ni-58 have been measured at different energies around the Coulomb barrier. The elastic and inelastic scattering of B-10 on a medium mass target has been measured for the first time. The obtained angular distributions have been analyzed in terms of large-scale coupled reaction channel calculations, where several inelastic transitions of the projectile and the target, as well as the most relevant one-and two-step transfer reactions have been included in the coupling matrix. The roles of the spin reorientation, the spin-orbit interaction, and the large ground-state deformation of the B-10, in the reaction mechanism, were also investigated. The real part of the interaction potential between projectile and target was represented by a parameter-free double-folding potential, whereas no imaginary potential at the surface was considered. In this sense, the theoretical calculations were parameter free and their results were compared to experimental data to investigate the relative importance of the different reaction channels. A striking influence of the ground-state spin reorientation of the B-10 nucleus was found, while all transfer reactions investigated had a minimum contribution to the dynamics of the system. Finally, the large static deformation of the B-10 and the spin-orbit coupling can also play an important role in the system studied. (AU) FAPESP's process: 14/02116-9-Investigation of direct nuclear reactions induced by light neutron rich nuclei.
International Journal of Modern Physics E, 2011
We show that halo effects enhance fusion cross sections of weakly bound systems, comparing with t... more We show that halo effects enhance fusion cross sections of weakly bound systems, comparing with the situation when there is no-halo. We introduce dimensionless fusion functions and energy variable quantity to investigate systematical trends in the fusion cross sections of weakly bound nuclei at near-barrier energies. We observe very clearly complete fusion suppression at energies above the barrier due to dynamic effects of the breakup on fusion. We explain this suppression in terms of the repulsive polarization potential produced by the breakup.