J. Theuerkauf

Superdeformed band in 146Gd. First observation of band crossing

Abstract A discrete superdeformed band is found in 146 Gd. Lifetime measurements yield an average quadrupole moment of 12±2 e b. A band crossing corresponding to an alignment of ≈2ħ is observed at a rotational frequency of 0.65 MeV. A theoretical analysis suggests that the band has a π6 2 v7 1 configuration with odd spins and odd parity. Arguments are given that the [651 1/2] and [642 5/2] single-particle states are involved in the band crossing.

Study of the high-spin structure of 144Gd

Abstract High-spin states in 144 Gd have been investigated through the 108 Pd( 40 Ar, 4n) reaction. An extended level scheme is proposed. A ridge structure has been observed in a γγ coincidence matrix, consistent with energy spacings in the superdeformed bands of neighbouring nuclei. Several discrete high-spin sequences have been observed. They are interpreted in the context of cranked-Strutinsky-type calculations in terms of different coexisting shapes.

High spin structure in127Xe and125Xe

Excited states of the nuclei127Xe and125Xe have been investigated in the inverse kinematic reactions48Ca(82Se,(3.5)n) at 275 MeV beam energy with the OSIRIS multidetector system at the VICKSI-accelerator of the HMI Berlin. The level scheme of127Xe was extended up to a level of tentative spin (51/2−). Two excited bands of 3QP-character were observed. For125Xe these structures were extended towards higher spins. Experimental Routhians of selected bands are presented.

Excited superdeformed band in146Gd

A non-yrast superdeformed band has been found in146Gd using the110Pd(40Ar, 4n)146Gd reaction. The nuclear assignment was made from the analysis of an experiment using a backed target. This band and the previously identified yrast SD band are probably not signature partners.A non-yrast superdeformed band has been found in146Gd using the110Pd(40Ar, 4n)146Gd reaction. The nuclear assignment was made from the analysis of an experiment using a backed target. This band and the previously identified yrast SD band are probably not signature partners.

High spin states in147Tb

The level scheme of147Tb has been extended to 116 levels and 198 transitions in two experiments with the OSIRIS Compton suppressed detector array at the HMI Berlin with the reactions122Sn(31P, 6n)147Tb at 160 MeV and120Sn(31P, 4n)147Tb at 152 MeV. Evidence for a new high spin isomer atE=7664.1 keV with a life-time of the order of 2 ns has been found.

High spin states in148Tb

The level scheme of148Tb has been extended to an excitation energyEx=14.0 MeV and a spinI≈ 38ħ in two experiments with the OSIRIS Comptom suppressed detector array at the HMI Berlin using the reactions122Sn(31P,5n)148Tb at 160 MeV and120Sn(31P,3n)148Tb at 152 MeV.

High spin states in145Gd

The data from two experiments with heavy ion induced reactions at the OSIRIS Compton suppressed Ge detector array has been analyzed to study high spin states in145Gd. The level scheme of145Gd has been extended up to an excitation energy of 12 MeV and an estimated spin of 25 ħ. No evidence for high spin isomers was found.

High spin states in127Ba

High spin states of127Ba have been investigated by means of the OSIRIS anti-comptonγ -spectrometer. Five new bands, 48levels and 77transitions were found. Spin suggestions for four bandheads could be given. On ground of these suggestions routhians and alignments were compiled for the observed bands, giving a first insight into the high spin structure of this nucleus.

High spin states in the doubly-closed shell nucleus146Gd

High spin states of146Gd, populated in heavyion induced reactions, have been investigated by means of in-beamγ-ray spectroscopy using the Compton-suppressed germanium detector arrays OSIRIS and ESSA30. 35 new levels and 47 new transitions could be placed in the level scheme. In addition to the extension to very high spins, a new cascade has been observed at intermediate spins.

High spin states in128Ba

High spin states of128Ba have been investigated via the96Zr (36S, 4n)reaction at 150Me V beam energy using the Osiris anti- compton spectrometer. 14new levels and 23new transitions up to a maximum spin of 34ħ could be placed in the levelscheme.