Y. Patin

Semi‐microscopic interpretation of fast neutron scattering from 208Pb

Angular distributions for elastic and inelastic neutron scattering on 208Pb have been measured for the ground state and for excited states at 2.164 MeV (3−), 3.198 MeV (5−), 4.076 MeV (2+) and 4.323 MeV (4+) +4.425 MeV (6+), at incident energies between 7.5 and 15.5 MeV. Semi‐microscopic folding‐model calculations of the cross sections have been performed with the microscopic optical model of Jeukenne, Lejeune and Mahaux together with a Hartree‐Fock‐Bogoluybov ground state nucleon density and RPA transition densities. The nucleon excitation strenghts deduced in this study will be compared to values obtained at higher energies and with other projectiles.

Etude de la Deformation des Noyaux de la Couche S-D a L’aide de la Diffusion de Neutrons Rapides

Nuclear deformation of 24Mg, 28Si and 32S has been investigated by means of fast neutron scattering. These nuclei lie in a mass region of the s-d shell where nuclear shape changes very rapidly from one nucleus to the other. Differential cross sections were measured at 9.76 and 14.83 MeV incident neutron energies over the angular range from 15 to 160 deg. Angular distributions were obtained for the elastic scattering and the inelastic scattering to levels of up to 6 MeV excitation energy. An analysis of the data using the deformed and the statistical models is presented and discussed. Quadrupole and hexadecapole deformations of the nuclear potential, deduced from the analysis of the 0+, 2+, 4+ states of the ground state rotational band, are compared to those obtained by other excitation processes.