F. Štěrba

Energy levels of167Er populated by the (d,d′) reaction

Data on the inelastic deuteron scattering on low lying energy levels in167Er are presented as a supplement to an investigation of this nucleus by the (d,p) and (d,t) reactions.The deuterons with an energy of 12·1 MeV were scattered from an167Er target and were recorded in a high resolution magnetic spectrograph at angles of observation of 60°, 90°, 125° and 150°. Absolute inelastic cross sections for several excited states were determined and discussed in terms of collective excitations and Coriolis coupling of the single particle states.

The study of the233U and235U by the inelastic scattering of 13·1 MeV deuterons

Excited states in odd uranium isotopes233U and235U were studied by the inelastic scattering of 13·1 MeV deuterons. The multipolarities and reduced transition probabilities were extracted from experimental cross sections. The results are discussed within the framework of a unified model with Coriolis coupling and pairing effect included. Theγ-vibrational andβ-vibrational states were interpreted in both isotopes and the role of Coriolis coupling for excitation of some Nilsson states in235U was testified.

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.

Angular distributions of 12 MeV deuterons inelastically scattered by the162Dy

The inelastic scattering of 12·1 MeV deuterons from162Dy target has been investigated. Angular distributions of the inelastic groups were measured in the region from 30° to 150°. A magnetic spectrograph was used to record the deuteron spectra with an overall energy resolution of ∼15 keV. For the strongly populated collective levels the shape dependence of the angular distributions on transferred angular momentum was studied. The rather different shapes for the rotational and vibrational 2+ levels were observed. The tentative assignment of some other excited states populated by the (d,d′) process in162Dy was deduced.

Excitation functions for some output channels following the p +55Mn interaction atEp=1·3–2·0 MeV

Excitation functions for the55Mn(p, p′ γ)55Mn,55Mn(p, n γ)55Fe and55Mn(p, γ)56Fe reactions are studied for proton beam energyEp=1·3–2 MeV. The excitation functions are established from yield functions for γ-rays emitted from the first excited states of final nuclei. Many resonances are observed and competition of their decay into all three output channels is analysed. Spin-parity assignment for some resonant states in the56Fe compound nucleus is deduced.

The octupole states in odd uranium isotopes233U and235U

The behaviour of some excited states in odd uranium isotopes is compared with octupole vibrational states in even-even uranium isotopes. The possibility to interpret the states in odd isotopes as octupole vibrations is discussed.

The study of the ground state rotational bands in U 233 and U 235 by the inelastic scattering of deuterons

The ground state rotational bands in the odd isotopes of uranium U 233 and U 235, were studied by the inelastic scattering of 13.1 MeV deuterons. Seven members of these bands were seen in both nuclei. By fitting the experimental energies of the levels to the relation E(I)= =AI(I+1)+B[I(I+1)]2, the parametersA andB were determined. Their values and the upper limits of the quadrupole reduced transition probabilities determined from the cross sections were: U 233:A=(5.93±0.10)keV,B=(−0.002±0.001)keV,B(E2,5/2→7/2)= =(6.51±0.66)×10−48 e2 cm4,B(E2,5/2→9/2)=(2.80±0.37) X 10−48 e2 cm4. U 235:A=(5.36±0.04)keV,B=(−0.0017±0.0004) keV,B(E2,7/2→9/2)=(8.05±0.71) × × 10−48 e2 cm4,B(E2,7/2→11/2)=(2.17±0.39) X 10−48 e2 cm4.

Some properties of 1805 keV resonance in p +55Mn interaction

Rather special behaviour of the 1805 keV resonance in the p +55Mn interaction, especially an extremely strong decay into the inelastic channel is discussed.

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.