Y. Eisen

Total fusion cross sections for 18, 17, 16O + 27Al at energies near the Coulomb barrier☆

Abstract Total fusion cross sections have been measured for 18, 17, 16O + 27Al systems at bombarding energies 27–42 MeV. The evaporation residues were detected in the angular range 4°–25° (lab) using a †E−E counter telescope. Barrier radii extracted from total fusion and elastic scattering cross sections are found to increase with the projectile mass. The effect of the yrast levels on the isotopic yields in the evaporation cascade is investigated.

The elastic scattering of 16O from even Ca isotopes near the Coulomb barrier

Abstract The elastic scattering of 16O from 40, 44, 48 Ca was studied at incident energies in the neighborhood of the Coulomb barrier. An optical model analysis established that only two independent parameters are determined. These are most appropriately chosen as rR, the radius of the maximum of the total potential, V(r) (Coulomb plus nuclear), and ƒ, defined by ƒ = 1−r R V(r R ) Z 1 Z 2 e 2 . The significance of these parameters is examined in detail. Unlike the mean radius of the charge distribution which is roughly constant for the three Ca isotopes, the Rutherford radius, rR, is found to increase approximately as A 1 3 .

The incoming wave boundary condition for elastic scattering of heavy particles at incident energies near the coulomb barrier

Abstract An incoming wave boundary condition (IWB) approach is used to calculate differential cross sections for 16O + Ca and α + Pb elastic scattering, at incident energies near the Coulomb barrier. A comparison is made to optical model (OM) calculations and it is shown that the present method is competitive with the OM method in the energy region mentioned above.

Elastic scattering of 16O and 18O by even Ca isotopes, 52Cr and 62Ni at incident energies near the Coulomb barrier

Abstract The excitation functions measured in this experiment show marked differences between 16O and 18O. The experimental data are analysed and discussed by means of an incoming-wave boundary-condition method (IWB).

Measurement of nuclear deformation parameters from elastic and inelastic scattering of α and 3He ions on Te isotopes

Abstract Cross sections for the elastic scattering of 4He by 122, 124, 126, 128Te and 3He by 128Te and for inelastic transitions to the lowest 2+ states of Te isotopes were measured for several scattering angles at bombarding energies in the vicinity of the Coulomb barrier. The data were analyzed in the framework of the optical model and the DWBA from which optical potential and deformation parameters were extracted. A detailed study of the fit procedure is presented with emphasis on the significance of the extracted parameters and the correlations among them.

Elastic scattering of 3He and 4He at incident energies near the coulomb barrier

Abstract The elastic scattering of 3 He and 4 He from Zr, Mo, Cd, and Te isotopes is studied at incident energies near the Coulomb barrier. Marked differences are observed between the excitation curves of 3 He and 4 He. These differences are shown to be due to a large surface absorption in the 3 He scattering. A systematic study of the size parameters deduced from the present and other 4 He experiments shows deviations from the A 1 3 law for nuclei near closed neutron shells.

Fusion of /sup 16/O+/sup 148,150,152,154/Sm at sub-barrier energies

Measurements of the cross section for fusion of /sup 16/O with /sup 148,150,152,154/Sm have been made in the range 60< or =EO< or =75 MeV. Evaporation residues trapped in a carbon catcher foil were observed off line by means of the K x rays emitted by radioactive Yb nuclei and their daughters. Absolute cross sections varying in magnitude from 0.1 to 400 mb were determined with an uncertainty of +- 10%. The cross sections for individual x-n channels were also determined. At high energies, the fusion cross sections for all isotopes are similar, whereas at lower bombarding energies the cross sections for the more deformed targets are larger than those for the spherical targets.

Fusion of O-16 + Sm-148, Sm-150, Sm-152, Sm-154 at sub-barrier energies

Measurements of the cross section for fusion of /sup 16/O with /sup 148,150,152,154/Sm have been made in the range 60< or =EO< or =75 MeV. Evaporation residues trapped in a carbon catcher foil were observed off line by means of the K x rays emitted by radioactive Yb nuclei and their daughters. Absolute cross sections varying in magnitude from 0.1 to 400 mb were determined with an uncertainty of +- 10%. The cross sections for individual x-n channels were also determined. At high energies, the fusion cross sections for all isotopes are similar, whereas at lower bombarding energies the cross sections for the more deformed targets are larger than those for the spherical targets.