The fission of high- K , two-quasiparticle isomers is considered, with specific reference to 250 No, 254 No and 256 Fm. The published experimental evidence is discussed in relation to configuration-constrained potential-energy-surface calculations, which suggest that the high- K isomers should be less susceptible to fission than their corresponding ground states.

Configuration-constrained potential energy surface calculations have been performed to investigate four-quasiparticle high- K configurations in neutron-deficient lead and polonium isotopes. A good agreement between the calculations and the experimental data has been found for the excitation energy of the observed K π = 19 − state in 188 Pb. Several lowly excited high- K states are predicted, and the large oblate deformation and low energy indicate high- K isomerism in these nuclei.

Full shell-model diagonalization has been performed to study the structure of neutron-rich nuclei around 20C. We investigate in detail the roles played by the different monopole components of the effective interaction in the evolution of the N = 14 shell in C, N and O isotopes. It is found that the relevant neutron–neutron monopole terms, V d 5 / 2 d 5 / 2 n n and V s 1 / 2 s 1 / 2 n n , contribute significantly to the reduction of the N = 14 shell gap in C and N isotopes in comparison with that in O isotopes. The origin of this unexpectedly large effect, which is comparable with (sometimes even larger than) that caused by the proton–neutron interaction, is related to the enhanced configuration mixing in those nuclei due to many-body correlations. Such a scheme is also supported by the large B ( E 2 ) value in the nucleus 20C which has been measured recently.

Energy-dependent phenomenological optical model potentials based on a single-folding model approach for the α- 12 C and deuteron- 12 C systems were obtained for incident energies between 10 and 100 MeV/nucleon. The Lane-consistent Bruyères Jeukenne–Lejeune–Mahaux model nucleon–nucleus potentials were used in these calculations. With only three free parameters, these potentials account satisfactorily for both angular distributions of elastic scattering cross sections and total reaction cross sections of both projectile–target systems within the energy range studied. Comparisons were made between the present potentials and other systematic phenomenological potentials.

Within the framework of the cluster-tunneling model, a folded ¶¡ -core potential that is based on the Woods®CSaxon potential is proposed to investigate ¶¡ -decays in the superheavy mass region. The calculated ¶¡ -decay half-lives of even®Ceven superheavy nuclei from Z = 100 to Z = 116 are in reasonable agreement with the experimental data.

Octupole correlation in near-proton-drip-line nuclei 106,108Te has been investigated using improved total Routhian surface calculations with the inclusion of reflection-asymmetric deformations. It is found that 106,108Te have reflection-symmetric shapes at low spins, then become octupole deformed at rotational frequencies ¶ÿ°÷0.50 - 0.60 MeV/\hbar. The onset of strong octupole correlation is consistent with the observation of octupole bands in 108Te. The octupole structure predicted for 106Te would be accessible in experiments.

Octupole properties in even®Ceven 220®C230 U isotopes have been investigated using improved total Routhian surface calculations with the inclusion of reflection-asymmetric deformations. We pay attention to the evolution of octupole properties with increasing nucleon and rotational frequency. 222 U is predicted to have static octupole deformation up to high spins. A shape transition from reflection-symmetry to reflection-asymmetry happens across 228 92 U 136 with decreasing neutron number in uranium isotopes or decreasing proton number in N = 136 isotones. Our calculations were compared with previous calculations and available experiments.