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[en] The elastic and inelastic cross sections for the scattering of ¹⁶,¹⁸O ions from targets of ⁷²,⁷⁴,⁷⁶Ge and of ¹⁶O from ⁶⁴Ni have been measured at a laboratory energy of 56 MeV. The angular distributions for the ground and first-excited (2⁺) levels have been analyzed simultaneously by a coupled-equations search routine, and optical potentials determined. It is shown that this method reduces the ambiguity in the potentials

[en] The excitation function for the fission isomer sup(240m) Pu produced in the reaction of ²³⁸U with α particles, has been measured at laboratory incident energies ranging from 20.1 to 27.3 MeV. A value of 3.8 sup(+0.6) sub(-0.4) nsec was obtained for the half-life of sup(240m) Pu. The results are compared with other measurements performed using different experimental methods. (Author)

[en] The elastic and inelastic cross-sections of ¹⁶¹⁸O and ¹²C scattered from targets of even-even Ge and Ni isotopes have been measured over an angular range 12.5⁰-100⁰ (laboratory angle) at Esub(¹⁶¹⁸O) = 56 MeV and Esub(¹²C) = 48 MeV. By simultaneously fitting the angular distributions for the ground state (0⁺) and first-excited level (2⁺) using a coupled-equations search routine, it has been possible to determine the optical potential parameters almost uniquely. The optical potentials so obtained exhibit two characteristic features: (1) the well depth of the imaginary part of the potential is larger than the well depth of the real part and (2) the radius and diffuseness of the imaginary part are respectively smaller than those of the real part. In addition, the deflection function corresponding to such surface transparent potentials displays a significant minimum at the grazing angular momentum. (Auth.)

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[en] Elastic and inelastic scatterings of ¹⁶O and ¹⁸O projectiles have been studied on ²⁸Si nucleus at 56 MeV incident energy. Optical model and coupled-channel analyses have been performed in order to define the nature of the optical potential. It has turned out that the enhanced backward angle oscillations appeared in the angular distribution for the ¹⁶O scattering are mainly due to refractive phenomena namely orbiting rather than diffractive phenomena. The potential necessary to reproduce the experimental data has to be surface transparent for ¹⁶O projectile, with a pocket in the effective potential in the grazing wave region and with a sharp diffusivity in the imaginary part in order to produce a mirror effect due to strong and abrupt volume absorption. On the other hand the potential necessary to fit the ¹⁸O scattering angular distributions is just a normal strong absorptive potential. The absence of any surface transparency in the case of ¹⁸O scattering can be attributed to the fact that many direct reaction channels are well Q matched

[en] The ⁶⁴Ni(¹⁶O, ¹⁴C)⁶⁶Zn and ¹⁰⁰Mo(¹²C, ¹⁰Be)¹⁰²Ru angular distributions have been measured between 13degree and 70degree lab respectively at 56 and 48 MeV incident energies. Distorted-wave Born approximation and coupled-channel Born approximation analyses have been performed using exact finite range codes. The marked difference in the angular distributions between the ¹⁰²Ru ground state and 2⁺ state can be well described using coupled-channel Born approximation calculations that take into account the important indirect processes. Furthermore, the relative intensities among various states are better reproduced by coupled-channel Born approximation calculations than by distorted-wave Born approximation calculations

[en] The neutron stripping and proton pickup reactions induced by a 44 MeV ¹⁵N beam on a ²⁸Si target have been studied. The data were analyzed in terms of the distorted-wave Born approximation. The coupled channel effects were also examined. The calculations reproduce well the shape of the observed angular distributions and the relative intensities. It is also found that the two-step processes involving core excitation of the target and residual nucleus play an important role in populating some excited states in the residual nucleus. However, the absolute magnitudes of the cross sections of the proton pickup reaction are not given by these approaches