General Trend Of Variation Research Articles

Nuclear deformations from inelastic α-scattering on rare earth nuclei at energies near the Coulomb barrier

Alpha particles in the energy range of 10–20 MeV and scattered at various angles were used to excite the 0 +, 2 +, 4 + members in the ground state bands of 152Sm, 154Sm and 186W. The measured excitation probabilities for bombarding energies below the Coulomb barrier were analyzed in the framework of Coulomb excitation theory. The resulting matrix elements of the E2 and E4 multipole operators were interpreted in terms of charge deformation parameters β c λ = 2, 4. The cross sections for higher energies were analyzed in terms of the deformed optical potential and resulted in potential deformation parameters β p λ = 2, 4. The two sets of deformation parameters show the same general trend of variation with target mass number. Still, significant differences are observed in some particular cases.

Moments of inertia of asymmetric nuclei

It is known that the nuclear moments of inertia, calculated on the basis of the hydrodynamical model, yield values which are too small in comparison with the experimentalvalues. An expression for the moment of inertia of an asymmetric nucleus is derived in the framework of the cranking model and taking into account the residual interactions between nucleons. The result is a generalization of the Moszkowski formula, where the residual interaction parameter p is dependent on the axis of rotation. With suitable values of the parameters this model can reproduce the experimental moments of inertia obtained from the energy level data. Calculations show that the general trend of variation of the reduced width for electric quadrupole transitions with the energy ratio of the two 2 + states is also given satisfactorily in this model.