Four-quasiparticle alignments in 66Ge

13 págs.; 7 figs.; 1 tab. ; PACS number(s): 23.20.Lv, 21.10.Re, 25.70.Hi, 27.50.1eThe neutron-deficient nucleus 66Ge was populated at high spin in two experiments using the reaction 40Ca(32S, α2p) at beam energies of 105 and 95 MeV. In the first experiment, a self-supporting 40Ca target was used, while a gold-backed target of similar thickness was used in the second experiment, γ rays were detected with the EUROBALL array, combined with the charged-particle detector array EUCLIDES and the Neutron Wall. The level scheme of 66Ge was extended up to E ≈ 18 MeV and Iπ = (23-). Above angular momentum 10+, we found two sequences, connected by energetically staggered ΔI = 1 M 1 transitions. The total Routhian surface calculations describe 66Ge at lower spins as a γ-soft nucleus having a moderate deformation of β2 ≈ 0.23, while a triaxial deformation is predicted for the band structures above Iπ = 10+. To our knowledge, this is the first observation of staggered Ml transitions in a deformed four-quasiparticle π(g9/2 2) ν(g9/2 2) structure. ©2003 American Physical SocietyThis work was supported by BMBF 06 GO¨ 951 and TMR/LSF Contract No. HPRI-CT-1999-00078. The authors are indebted to the crew of the VIVITRON accelerator and the EUROBALL facility at IReS for their dedicated efforts and cooperation.Peer Reviewe

Structure of high-spin states in 91Sr and 92Sr

The nuclei 91Sr and 92Sr were produced at high spin as fission fragments following the fusion reaction 36S+ 159Tb at 165 MeV. γ rays were detected with the Gammasphere array. The level schemes of 91Sr and 92Sr were extended up to E≈6 MeV and E≈8 MeV, respectively. Level structures in 91Sr and 92Sr were interpreted in shell-model calculations performed in the configuration space (0f5/2, 1p3/2, 1p1/2, 0g9/2) for the protons and (1p1/2, 0g9/2, 1d5/2) for the neutrons. Negative-parity states in the yrast sequences are described in these calculations by coupling 3- proton excitations to the unpaired 1d5/2 neutrons. A possible reduction of the gap between the proton 1p3/2 and 1p1/2 orbitals in 92Sr is discussed

Fast-timing measurements in neutron-rich odd-mass zirconium isotopes using LaBr3:Ce detectors coupled with Gammasphere

A fast-timing experiment was performed at the Argonne National Laboratory to measure the lifetimes of the lowest lying states of nuclei belonging to the deformed regions around mass number A 110 and A 150. These regions were populated via spontaneous fission of 252 Cf and the gamma radiation following the decay of excited states in the fission fragments was measured using 51 Gammasphere detectors coupled with 25 LaBr 3 :Ce detectors. A brief description of the acquisition system and some preliminary results from the fast-timing analysis of the fission fragment 100Zr are presented. The lifetime value of \u3c4 = 840(65) ps was found for the 2 + state in 100 Zr consistent within one standard deviation of the adopted value with 791 +26 -35 ps. This is associated with a quadrupole deformation parameter of 0.36(2) which is within one standard deviation of the literature value of 0.3556 +82 -57

Fast-timing measurements in the ground-state band of Pd114

Using a hybrid Gammasphere array coupled to 25 LaBr3(Ce) detectors, the lifetimes of the first three levels of the yrast band in Pd-114, populated via Cf-252 decay, have been measured. The measured lifetimes are tau(2+) = 103(10) ps, tau(4+) = 22(13) ps, and tau(6+) <= 10 ps for the 2(1)(+), 4(1)(+), and 6(1)(+) levels, respectively. Palladium-114 was predicted to be the most deformed isotope of its isotopic chain, and spectroscopic studies have suggested it might also be a candidate nucleus for low-spin stable triaxiality. From the lifetimes measured in this work, reduced transition probabilities B(E2; J -> J - 2) are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio R-B(E2) = B(E2; 4(1)(+) -> 2(1)(+))/B(E2; 2(1)(+) -> 0(1)(+)) = 0.80(42) is measured for the first time in Pd-114 and compared with the known values R-B(E2) in the palladium isotopic chain: the systematics suggest that, for N = 68, a transition from gamma-unstable to a more rigid gamma-deformed nuclear shape occurs

Observation of high-spin bands with large moments of inertia in Xe 124

High-spin states in Xe124 have been populated using the Se80(Ca48,4n) reaction at a beam energy of 207 MeV and high-multiplicity, γ-ray coincidence events were measured using the Gammasphere spectrometer. Six high-spin bands with large moments of inertia, similar to those observed in neighboring nuclei, have been observed. The experimental results are compared with calculations within the framework of the cranked Nilsson-Strutinsky model. It is suggested that the configurations of the bands involve excitations of protons across the Z=50 shell gap coupled to neutrons within the N=50-82 shell or excited across the N=82 shell closure

Feel4Diabetes healthy diet score: Development and evaluation of clinical validity

Background: The aim of this paper is to present the development of the Feel4Diabetes Healthy Diet Score and to evaluate its clinical validity. Methods: Study population consisted of 3268 adults (63% women) from high diabetes risk families living in 6 European countries. Participants filled in questionnaires at baseline and after 1 year, reflecting the dietary goals of the Feel4Diabetes intervention. Based on these questions the Healthy Diet Score was constructed, consisting of the following components: breakfast, vegetables, fruit and berries, sugary drinks, whole-grain cereals, nuts and seeds, low-fat dairy products, oils and fats, red meat, sweet snacks, salty snacks, and family meals. Maximum score for each component was set based on its estimated relative importance regarding T2DM risk, higher score indicating better quality of diet. Clinical measurements included height, weight, waist circumference, heart rate, blood pressure, and fasting blood sampling, with analyses of glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides. Analysis of (co) variance was used to compare the Healthy Diet Score and its components between countries and sexes using baseline data, and to test differences in clinical characteristics between score categories, adjusted for age, sex and country. Pearson''s correlations were used to study the association between changes from baseline to year 1 in the Healthy Diet Score and clinical markers. To estimate reproducibility, Pearson''s correlations were studied between baseline and 1 year score, within the control group only. Results: The mean total score was 52.8 ± 12.8 among women and 46.6 ± 12.8 among men (p < 0.001). The total score and its components differed between countries. The change in the Healthy Diet Score was significantly correlated with changes in BMI, waist circumference, and total and LDL cholesterol. The Healthy Diet Score as well as its components at baseline were significantly correlated with the values at year 1, in the control group participants. Conclusion: The Feel4Diabetes Healthy Diet Score is a reproducible method to capture the dietary information collected with the Feel4Diabetes questionnaire and measure the level of and changes in the adherence to the dietary goals of the intervention. It gives a simple parameter that associates with clinical risk factors in a meaningful manner

Fast-timing measurements in the ground-state band of Pd 114

Using a hybrid Gammasphere array coupled to 25 LaBr3(Ce) detectors, the lifetimes of the first three levels of the yrast band in Pd114, populated via Cf252 decay, have been measured. The measured lifetimes are τ2+=103(10)ps, τ4+=22(13)ps, and τ6+≤10ps for the 21+, 41+, and 61+ levels, respectively. Palladium-114 was predicted to be the most deformed isotope of its isotopic chain, and spectroscopic studies have suggested it might also be a candidate nucleus for low-spin stable triaxiality. From the lifetimes measured in this work, reduced transition probabilities B(E2;J→J-2) are calculated and compared with interacting boson model, projected shell model, and collective model calculations from the literature. The experimental ratio RB(E2)=B(E2;41+→21+)/B(E2;21+→01+)=0.80(42) is measured for the first time in Pd114 and compared with the known values RB(E2) in the palladium isotopic chain: the systematics suggest that, for N=68, a transition from γ-unstable to a more rigid γ-deformed nuclear shape occurs

Fast-Timing measurements in 100zr using labr3(ce) detectors coupled with gammasphere

In order to investigate the evolution of nuclear deformation in the region of the chart of nuclides around mass numbers A ' 110 and A ' 150, an experiment was performed at the Argonne National Laboratory where the gamma-decay radiation emitted from the fission fragments of 252Cf was measured using 51 Gammasphere detectors coupled with 25 LaBr3(Ce) detectors. In this work, a short description of the experimental setup is presented together with some preliminary results from the fast-Timing analysis of the 4+ state of the nucleus 100Zr. A lifetime value of τ = 50(28) ps was obtained using the Generalized Centroid Shift Method. This result agrees with the literature value of τ = 53(4) ps within one standard deviation