Low Energy States of 3181Ga50^{81}_{31} Ga_{50} : Elements on the Doubly-Magic Nature of 78^{78}Ni

Excited levels were attributed to $^{81}_{31}$Ga$_{50}$ for the first time which were fed in the $\beta$-decay of its mother nucleus $^{81}$Zn produced in the fission of $^{nat}$U using the ISOL technique. We show that the structure of this nucleus is consistent with that of the less exotic proton-deficient N=50 isotones within the assumption of strong proton Z=28 and neutron N=50 effective shell effects.Comment: 4 pages, REVTeX 4, 5 figures (eps format

Cohesive and mixed sediment in the Regional Ocean Modeling System (ROMS v3.6) implemented in the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System (COAWST r1234)

We describe and demonstrate algorithms for treating cohesive and mixed sediment that have been added to the Regional Ocean Modeling System (ROMS version 3.6), as implemented in the Coupled Ocean-Atmosphere-Wave- Sediment Transport Modeling System (COAWST Subversion repository revision 1234). These include the following: floc dynamics (aggregation and disaggregation in the water column); changes in floc characteristics in the seabed; erosion and deposition of cohesive and mixed (combination of cohesive and non-cohesive) sediment; and biodiffusive mixing of bed sediment. These routines supplement existing noncohesive sediment modules, thereby increasing our ability to model fine-grained and mixed-sediment environments. Additionally, we describe changes to the sediment bed layering scheme that improve the fidelity of the modeled stratigraphic record. Finally, we provide examples of these modules implemented in idealized test cases and a realistic application

High-spin states with seniority v=4,4,6 in 119-126Sn

The 119-126Sn nuclei have been produced as fission fragments in two reactions induced by heavy ions: 12C+238U at 90 MeV bombarding energy, 18O+208Pb at 85 MeV. Their level schemes have been built from gamma rays detected using the Euroball array. High-spin states located above the long-lived isomeric states of the even- and odd-A 120-126Sn nuclei have been identified. Moreover isomeric states lying around 4.5 MeV have been established in 120,122,124,126Sn from the delayed coincidences between the fission fragment detector SAPhIR and the Euroball array. The states located above 3-MeV excitation energy are ascribed to several broken pairs of neutrons occupying the nu h11/2 orbit. The maximum value of angular momentum available in such a high-j shell, i.e. for mid-occupation and the breaking of the three neutron pairs, has been identified. This process is observed for the first time in spherical nuclei.Comment: 20 pages, 22 figures, 12 tables, accepted for publication in Physical Review

Study of the N=50 major shell effect close to 78^{78}Ni : First evidence of a weak coupling structure in 83_32^{83}\_{32}Ge_51\_{51} and three-proton configuration states in 81_31^{81}\_{31}Ga_50\_{50}

New levels were attributed to $^{81}\_{31}$Ga$\_{50}$ and $^{83}\_{32}$Ge$\_{51}$ which were fed by the $\beta$-decay of their respective mother nuclei $^{81}\_{30}$Zn$\_{51}$ and $^{83}\_{31}$Ga$\_{52}$ produced by fission at the "PARRNe" ISOL set-up installed at the Tandem accelerator of the Institut de Physique Nucl\'eaire, Orsay. We show that the low energy structure of $^{81}\_{31}$Ga$\_{50}$ and $^{83}\_{32}$Ge$\_{51}$ can easily be explained within the natural hypothesis of a strong energy gap at N=50 and a doubly-magic character for $^{78}$Ni.Comment: 2 pages, pdf file, To be published in the Proceedings of "International Symposium on Structure of Exotic Nuclei and Nuclear Forces (SENUF 06)", March 2006, Tokyo, Japa

Search for Fingerprints of Tetrahedral Symmetry in 156Gd^{156}Gd

Theoretical predictions suggest the presence of tetrahedral symmetry as an explanation for the vanishing intra-band E2-transitions at the bottom of the odd-spin negative parity band in $^{156}Gd$. The present study reports on experiment performed to address this phenomenon. It allowed to determine the intra-band E2 transitions and branching ratios B(E2)/B(E1) of two of the negative-parity bands in $^{156}Gd$.Comment: presented by Q.T. Doan at XLII Zakopane School of Physics: Breaking Frontiers: Submicron Structures in Physics and Biology, May 2008. 5 pages, minor corrections. To be published in the proceeding

Deformation change in light iridium nuclei from laser spectroscopy

Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first transition of the ionization path 5d^{7}6s ^{2}^{4}F_{9/2} \to 5d^{7}6s6p ^{6}F_{11/2} at 351.5nm were measured for $^{182-189}$Ir, $^{186}Ir^{m}$ and the stable $^{191,193}$Ir. The nuclear magnetic moments μI and the spectroscopic quadrupole moments Qs were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of μI was experimentally determined for the first time for the masses 182≤A≤189 and the isomeric state $^{186}Ir^ m$ . The spectroscopic quadrupole moments of $^{182}$Ir and $^{183}$Ir were measured also for the first time. A large mean square charge radius change between $^{187}$Ir and $^{186}Ir^g$ and between $^{186}Ir^m$ and $^{186}Ir ^g$ was observed corresponding to a sudden increase in deformation: from β2 ≃ + 0.16 for the heavier group A = 193, 191, 189, 187 and 186m to β2 ≥ + 0.2 for the lighter group A = 186g, 185, 184, 183 and 182. These results were analyzed in the framework of a microscopic treatment of an axial rotor plus one or two quasiparticle(s). This sudden deformation change is associated with a change in the proton state that describes the odd-nuclei ground state or that participates in the coupling with the neutron in the odd-odd nuclei. This state is identified with the π3/2+[402] orbital for the heavier group and with the π1/2-[541] orbital stemming from the 1h _9/2 spherical subshell for the lighter group. That last state seems to affect strongly the observed values of the nuclear moments

Medium-spin states in neutron-rich 83As and 81As

The 83,81 As nuclei have been produced as fission fragments in the fusion reaction 18O + 208Pb at 85 MeV bombarding energy and studied with the Euroball array. Medium-spin states of 83,81 As have been established up to ∼3.5 MeV excitation energy. From angular correlation analysis, spin values have been assigned to most of the 81 As excited states. The behaviors of the yrast structures identified in this work are discussed in comparison with the general features known in the mass region. Then they are compared to the results of two theoretical approaches: the "rotor + quasiparticle" for 81 As and the shell model using the effective interactions JUN45 for 83,81 As

Charge-radius change and nuclear moments in the heavy tin isotopes from laser spectroscopy: Charge radius of 132^{132}Sn

NESTER ACCLaser spectroscopy measurements have been carried out on the neutron-rich tin isotopes with the COMPLIS experimental setup. Using the $5s^25p^2$ $^3P_0 \rightarrow 5s^25_p6s$ $^3P_1$ optical transition, hyperfine spectra of $^{126-132}$Sn and $^{125,127,129-131}Sn^m$ were recorded for the first time. The nuclear moments and the mean square charge radius variation ($\delta) were extracted. From the quadrupole moment values, these nuclei appear to be spherical. The magnetic moments measured are thus compared with those predicted by spherical basis approaches. From the measured$\delta, the absolute charge radii of these isotopes were deduced in particular that of the doubly magic $^{132}$Sn nucleus. The comparison of the results with several mean-field-type calculations have shown that dynamical effects play an important role in the tin isotopes

Toward a Romanian version of the Three Factor Eating Questionnaire–R21 for children and adolescents (CTFEQr21): Preliminary psychometric analysis and relation with body composition

YesPurpose. The aim of this study was to develop and validate a Romanian version of the three factor eating questionnaire-r21 for children and adolescents (ctfeqr21), and to assess its psychometric properties and factor structure. Associations between this version of the ctfeqr21 and anthropometric measures as well as body composition were also examined. Design and methods. 153 children and adolescents (68 boys and 95 girls; 10.8 ± 3.5 years) took part in this study (bmi of 17.7 ± 3.1 kg/m²). The participants were first interviewed to ascertain their understanding of the ctfeq-r21 and were then asked to self-complete the questionnaire. Height and weight were measured and body composition assessed using bio impedance analyzers (Tanita MC 780). Results. The CTFEQr21 showed satisfactory internal consistency (cronbach’s α=0.78). Cronbach’s alpha coefficients were 0.55 for CR, 0.75 for UE, and 0.76 for EE separately. UE and EE were found to be significantly correlated (r=0.54, p<0.05). The three factors explained 43% of the total variance. Correlation between CR, UE and EE with body weight, BMI and FFM were significant but low to moderate with coefficients ranging from 0.20 to 0.37. The higher the CR, UE and EE tertiles, the higher the weight, fat mass (kg) and fat-free mass values. Conclusions. According to the psychometric analysis of the questionnaire, the proposed version of the CTFEQr21 proposed here is a satisfactory tool to assess eating behaviors in Romanian child population that remains to be further developed