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We report for the first time two distinctive features in the odd–odd nucleus 120I: a pair of doublet bands and a high-spin isomer built on the π h 11 / 2 ν h 11 / 2 configuration. For producing the excited states of 120I, a fusion-evaporation reaction 118Sn(6Li, 4n) at E = l a b 48 MeV was employed. The beam was provided by the 14UD tandem accelerator of the Heavy Ion Accelerator Facility at the Australian National University. The observed doublet structure built on the positive-parity states is the first case and unique in isotopes with Z = 53 . The emerging properties are indicative of the known chiral characteristics, leading to a doubling of states for the π h 11 / 2 ν h 11 / 2 configuration. In contrast, the high-spin isomer with a half-life of 49(2) ns at spin-parity J π = 25 + can be explained in terms of a noncollective oblate structure with the full alignment of six valence nucleons outside the 114Sn core: three protons ( g 7 / 2 ) 1 ( d 5 / 2 ) 1 ( h 11 / 2 ) 1 and three neutrons ( h 11 / 2 ) 3 . This is an outstanding case that reveals a pure single-particle structure consisting of equal numbers of valence protons and neutrons outside the semi-double shell closure of 114Sn with Z = 50 and N = 64 .

A pair of rotational bands associated with the pi h(9/2) circle times nu i(13/2)(-1) configuration at lower spins and with the pi h(9/2) circle times nu i(13/2)(-3) configuration at higher spins is found in Tl-194. The two 4-quasiparticle bands show exceptionally close near-degeneracy in the excitation energies. Furthermore close similarity is also found in their alignments and B(M1)/B(E2) reduced transition probability ratios. Such close near-degeneracy probably indicates chiral geometry in the angular momentum space. (c) 2013 Elsevier B.V. All rights reserved.

The first 2+ states in 134Ce and 136Nd and the second 2+ state in 136Nd were populated by Coulomb excitation at relativistic energies, and γ-rays were measured using the RISING setup at GSI. For 134Ce an indication of the excitation to the second 2+ state was observed. This experiment performed for the first time Coulomb excitation to second 2+ states with rare isotope beams at relativistic energies. For 136Nd the B ( E 2 ; 2 1 + → 0 + ) , B ( E 2 ; 2 2 + → 0 + ) , and B ( E 2 ; 2 2 + → 2 1 + ) values relative to the previously known B ( E 2 ; 2 1 + → 0 + ) value for 134Ce are determined as 81(10), 11(3) and 180(92) W.u., respectively. The results are discussed in the framework of geometrical models that indicate pronounced γ-softness in these nuclei.

The average g factors of high-spin states in 180,182,184 Pt were measured by the transient-field technique. In all three isotopes the quasicontinuum g factor at an angular momentum of ∼20ℏ is 〈 g 〉∼0.37. This contrasts with similar measurements on other nuclei that have 70⩽ Z ⩽80, where typical values of 〈 g 〉∼0.22 have been attributed to the influence of quasineutron alignments. Evidently proton and neutron configurations are about equally important at high spin in the Pt isotopes near mid-shell. This inference is consistent with the discrete spectroscopy, including the contention, supported by g K − g R values, that h 9/2 proton pairs align along with the i 13/2 neutrons at rotational frequencies of ℏ ω ≈0.3 MeV in 184 Pt. Links between the quasicontinuum g factors and features in the discrete spectroscopy are explored by comparing and contrasting the behavior of 184 Pt and 166 Hf.

In a search for exotic structures in odd-odd 164 Lu, performed as one of the first Euroball experiments eight new, presumably triaxial, superdeformed bands were found. For the first time, evidence is presented for superdeformation in an odd-odd Lu isotope for which theory predicts large triaxiality. The data are compared to expectations from calculations with the code “Ultimate Cranker”. Two of the bands are connected to normal-deformed structures and the E1 strength of the decay-out appears to be enhanced over single particle expectations, possibly due to octupole correlations.

Excited states have been identified for the first time in very neutron deficient Pt-171.172 nuclei using the recoil-or-decay tagging technique. The ground-state band in Pt-172 has been established up to I-pi = 8+. A similar level sequence, presumably built on the I-pi = 13/2(+) state, is observed for Pt-171. The data are compared with theoretical calculations based on the mean field approach and the random phase approximation and are put into the context of the systematics of platinum isotopes. (C) 1998 Elsevier Science B.V. All rights reserved.

The lifetime of the unresolved transitions forming the rotational quasi-continuum spectra has been measured in 163 Tm using the Doppler shift attenuation technique. Spectra associated to different values of the coincidence folds, angular anisotropies and the dynamical moment of inertia were also obtained from the present experiment. The Doppler shift has been measured for discrete transitions, for the ridge structures in E γ 1 × E γ 2 spectra and for the rotational E2 bump in one dimensional spectra. The data were compared to the theory using a simulation model which makes use of microscopically calculated levels and transition probabilities. Above 1300 keV the results indicate collectivity with lifetime faster than 10 −14 s, while at lower E γ the results are well described by predictions with B (E2) = 400 WU.

Semi-decoupled bands based on the πh 9 2 ⊗ vi 13 2 configuration are observed in 162 Tm, 164 Tm and 174 Ta. Spins assigned to these bands imply an inversion of the expected signature splitting, which is interpreted as being the result of a residual proton-neutron interaction.

Deformations as function of spin, based on diabatic configurations, have been calculated for proton i132 and h92 bands in Re and Ir isotopes. Generally, constant deformations are predicted for the h92 bands while the i132 bands are predicted to increase in deformation until the alignment of i132 neutrons. The results are compared with recently measured Qt values. The alignment systematics are qualitatively explained in terms of the predicted deformations.