Filetype
Negative-parity excited states of doubly even nuclei have earlier been attributed to vibrational excitations. This paper shows that an interpretation starting from a reflection asymmetric intrinsic state is more appropriate for certain nuclei in the radium region. Theoretical evidence for stable octupole deformation comes from a deformed shell-model calculation in which we use a single-particle po
The very high spin behaviour of nuclei with ∼ 10 particles outside the 146Gd core are studied. Our method of calculation, which is based on the cranked Nilsson-Strutinsky formalism, makes possible to follow individual configurations as functions of spin. We concentrate on 158Er and 154Dy which nuclei become oblate with rotation around the symmetry axes for I = 40-50. It is found that most such obl
First, nuclear shapes are considered with focus on the γ degree of freedom and the unexplored high-spin regions of negative γ. Next, the role of approximate quantum numbers for very high-spin spectroscopy is examined, using as an example a calculation for 160Er which is related to available quasicontinuum data. The trend from regular to chaotic behavior is discussed in the broader context of theor
The reactions 78Kr( alpha ,n) and 80Kr( alpha ,3n) were used to populate excited states in 81Sr. The de-excitation of these states was studied by in-beam gamma -ray spectroscopy. A number of new high-spin states forming band structures have been observed. Lifetime measurements have also been performed. Theoretical calculations using a particle-rotor approach based on the Nilsson model have been ma
High spin states in 127,129,131La have been investigated using the 100Mo(32S,p4n), E= 160 MeV, 100Mo(34S,p4n), E=155 MeV, and 100Mo(36S,p4n), E=160 MeV reactions, respectively. γ rays were detected using the EUROBALL IV (127,131La) and EUROGAM II (129La) arrays. The results have enabled the negative parity yrast band, built on the πh 11/2 orbital at low spin, and the lowest lying (π, α) = (+, ± 1/
High-spin states in 72Br were studied with the EUROBALL III spectrometer using the 40Ca(40Ca,α3p1n) reaction. The negative-parity band observed in this experiment displays a signature inversion around spin I = 16. The interpretation within the cranked Nilsson-Strutinsky approach shows that this signature pattern is a signal of a substantial triaxial shape change with increasing spin where the nucl
The highest-spin discrete states (I ∼ 60ℏ and Ex ∼ 30MeV) in normal deformed nuclei have been observed in the rare-earth isotope 156Dy using the GAMMASPHERE spectrometer. The quadrupole moments for a variety of configurations, including the 9/2+[404] (g9/2) proton, 1/2+[660] (i13/2) and 1/2-[541] (f7/2, h9/2) neutron orbitals, were measured in a wide range of ∼ 130 nuclei.
The level scheme of 103Pd has been reconstructed using high-fold γ-ray coincidence data obtained with the EUROGAM-2 spectrometer in the 70Zn(36S,3n) reaction at E = 130 MeV. New spins and excitation energies are given for levels in the strongly coupled positive parity bands. Four high-spin bands are discussed in terms of terminating configurations using Nilsson-Strutinsky cranking calculations. On
High spin states of 101Rh have been populated using the reaction 70Zn+36S at 130 MeV. γ-rays were detected with the EUROGAM2 array. New high-spin bands have been observed in this nucleus up to 45/2-, 57/2- and 65/2+ states. They have been interpreted using the Nilsson-Strutinsky cranking formalism as terminating configurations. Two of the bands were observed up to the predicted terminating states
High-spin states have been populated in [Formula Presented] via the [Formula Presented] reaction at 150 MeV, using the EUROGAM II [Formula Presented]-ray spectrometer to record high-fold [Formula Presented]-ray coincidences. A quadruples [Formula Presented]-ray analysis [Formula Presented] has been used to extend the known level scheme. In addition to several aligned noncollective states, a new hi
Very high spin (50-60(Latin small letter h with stroke)) states in transitional 156Dy, 159Er and 160Er nuclei have been studied using the GAMMASPHERE and EUROGAM γ-ray spectrometers. The lowest energy positive-parity bands in 156Dy are found to evolve smoothly towards an oblate shape in contrast to the sudden change observed in the neighbouring 158Er nucleus. In 159Er, the decay path of the positi
The Unified Glare Rating (UGR) method defined by the International Commission on Illumination is practically the only one used for evaluation of discomfort glare in the lighting design process. However, it is unclear if this method aligns with subjective discomfort glare measures using subjective glare indexes (SGIs). We compared calculated UGR values with commonly used subjective discomfort glare
One of the most interesting features of nuclei is the process by which specific configurations, manifest as collective rotational bands at intermediate spin values, gradually lose their collectivity and terminate in a non-collective state at the maximum spin which can be built within the configuration. Recent advances in both experiment and theory allow the study of this nuclear structure feature
High-spin states have been populated in 11954Xe via the 96Mo(27Al,p3n) reaction at 133 MeV, using the JUROSPHERE γ-ray spectrometer to record triple γ-ray coincidences. The known level scheme has been significantly extended and several band crossings identified. In particular, the νh11/2 yrast band has been extended to Iπ = (83/2-) and shows features which are consistent with those of smooth band
The level structure of 102Rh has been investigated using the EUROGAM Phase2 array. Bands observed up to high spins are discussed in terms of band terminations. 102Rh is the first doubly odd nucleus below Z = 50 in which band terminations are established.
The highest-spin discrete states (I ∼ 60 ℏ and Ex ∼ 30 MeV) in normal deformed nuclei have been observed in the rare-earth isotope 156Dy using the 124Sn(36S,4n) reaction in conjunction with the GAMMASPHERE spectrometer. The positive parity yrast sequence appears to evolve smoothly from a prolate (collective) towards an oblate (non-collective) shape, in contrast to the sudden shape change observed
Four new superdeformed bands have been found in the nucleus 86Zr. The good agreement between experiment and configuration-dependent shell correction calculations suggests that three of the bands have triaxial superdeformed shapes. Such unique features in mass A ∼ 80 superdeformed bands have been predicted, but not observed experimentally until now. A fourth band in 86Zr is interesting due to a fai
Excited states in [Formula Presented] have been observed with the Stony Brook array of six Compton-suppressed HPGe detectors and the [Formula Presented] reaction at 60 MeV using a thick target. New excited states which decay solely towards the [Formula Presented] ns, [Formula Presented] isomer have been identified using time-correlated spectroscopy. The previously known level scheme has also been
The relative properties of smooth terminating bands observed in the A ∼ 110 mass region are studied within the effective alignment approach. Theoretical values of ieff are calculated using the configuration-dependent shell-correction model with the cranked Nilsson potential. Reasonable agreement with experiment shows that previous interpretations of these bands are consistent with the present stud
Six rotational bands in the odd-odd nucleus 174Ta have been populated with the 160Gd(19F,5n) reaction. High-spin states were identified using the NORDBALL array. Both signatures of the doubly decoupled π1/2- [541 ] ⊗ v1/2- [521] band and semi-decoupled π1/2- [541] ⊗ v7/2+ [633] band are observed, in addition to the high-K couplings of the π9/2- [514] ⊗ v7/2+ [633], π9/2- [514] ⊗ v5/2- [512], π7/2+
