P. Holan

The study of the188Re nucleus by the189Os(t, α)188Re reaction atEt=15·1 MeV

The energy levels in the188Re nucleus were studied using the189Os(t, α)188Re reaction at triton energy Et=15·1 MeV. The energy of the excited states and the corresponding relative cross-sections were determined. The experimental relative intensities were compared with the theoretical DWBA predictions, calculated with the Nilsson model. The pairing effect and the Coriolis interaction in the residual as well as in the target nucleus were considered. Assignment of low-lying observed states was suggested. In contradiction with the DWBA predictions low intensity was found for excitation of the ground state rotational band and the ground state in the188 Re nucleus was not observed at all.

The study of the angular distributions of protons from the reaction162Dy(d,p)163Dy at 12·1 MeV

The angular distributions of protons from the reaction162Dy(d,p)163Dy were measured. The experimental results were analysed in a Distorted Waves Born Approximation theory and the transferred angular momentum and spectroscopic factors were determined for the stronger transitions. The experimental spectroscopic factors were compared with the Nilsson model including the pairing effect.

The study of the angular distributions of tritons from the reaction162Dy (d, t)161Dy at 12·1 mev

The angular distributions of tritons from the reaction162Dy (d, t)161Dy were measured. The experimental results were analysed by a Distorted Waves Born Approximation method and the transferred angular momenta were determined for the stronger transitions. The experimental relative intensities of transitions at 90° were compared with those obtained from the Nilssons model calculations including Coriolis and pairing effects. Eight rotational bands, built on the 5/2+[642], 5/2−[523], 3/2−[521], 1/2−[521], 11/2−[505], 3/2−[532], 1/2−[530] and 7/2+[404] Nilsson states were established. Some new information about the strongly mixed even parity 1/2+[400], 1/2+[660], 3/2+[402] and 3/2+[651] Nilsson states is presented.

Properties of the lowest states in the odd-odd160Tm and160Tm nuclei

Detailed study of the lowest states in the odd-odd160Tm and162Tm deformed nuclei and of corresponding electromagnetic transitions has been performed. In the theoretical analysis, performed within the framework of the “two-quasiparticle + rotor” model, the nondiagonal matrix elements of the residual p-n interaction have been included. Comparison of calculated energies and reduced transition probabilitiesB(XL) with experimental ones have proved importance of these matrix elements in the model calculations. More complex interpretation of the lowest states in both Tm nuclei has been achieved although some ambiguity has not been removed.

The structure of the states in the161Dy and163Dy isotopes excited by the one-neutron transfer reactions

The performed analysis fully supports the importance of the different residual interactions in the deformed nucleus for understanding the behaviour of the nuclear excited states. It was shown that the description of the nucleus, which considers simultaneously the pairing, multipole-multipole, Coriolis and δN=2 interactions, is able in the framework of the DWB A theory to explain the excitation of the states in the161Dy and163Dy nuclei in the one-neutron transfer reactions. The theory is not able to explain the behaviour and excitation of the states with the predominantly phonon character.

Influence of Coriolis coupling on inelastic scattering of deuterons

Influence of Coriolis coupling on excitation of some Nilsson states in155Gd,157Gd and167Er by inelastic scattering of 12·1 MeV deuterons is analysed. Expanded Nilsson potential with hexadecapolar deformation is used for the model calculations. Theoretical values of reduced transition probability,B(E2) are compared with experimental ones.

TheΔN=2 mixing of the 1/2+[660], 1/2+[400] and 3/2+[651], 3/2+[402] Nilsson states in161Dy and163Dy

The influence of theΔN=2 interaction simultaneously with the Coriolis coupling on the structure of the Kπ = 1/2+ and 3/2+ rotational bands built on the mixed states originating mainly from the 1/2+[660], 1/2+[400], 3/2+[651] and 3/2+[402] Nilsson states is analysed. The pairing interaction is also considered. The cross section for the (d, p) reaction on162Dy and160Dy and for the (d, t) reaction on164Dy and162Dy nuclei are calculated and compared with experimental values. Many members of four strongly mixed rotational bands in161Dy and163Dy are identified in experimental proton and triton spectra.

Non-adiabatic effects and coriolis interactions in odd deformed nuclei

The alignment of the intrinsic angular momentum of a rotating nucleus into the rotational axis is studied in terms of a simple quasi-adiabatic approach. In the framework of this approach using the “quasi-particle + phonon” model with Harris non-adiabatic corrections it is possible to describe the rotational bands up to relatively high spins. In the case of235U it is demonstrated that this simple approach enables the qualitative description of the process of alignment of the intrinsic angular momentum with respect to the rotational axis.