| 1. |
- Forsberg, Ulrika, et al.
(författare)
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Spectroscopic Tools Applied to Element Z = 115 Decay Chains
- 2014
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X .- 2101-6275. - 9782759811755 - 9782759811762 ; 66, s. 02036-02036
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Konferensbidrag (refereegranskat)abstract
- Nuclides that are considered to be isotopes of element Z = 115 were produced in the reaction 48Ca + 243Am at the GSI Helmholtzzentrum für Schwerionenforschung Darmstadt. The detector setup TASISpec was used. It was mounted behind the gas-filled separator TASCA. Thirty correlated α-decay chains were found, and the energies of the particles were determined with high precision. Two important spectroscopic aspects of the offline data analysis are discussed in detail: the handling of digitized preamplified signals from the silicon strip detectors, and the energy reconstruction of particles escaping to upstream detectors relying on pixel-by-pixel dead-layer thicknesses.
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| 2. |
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| 3. |
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| 4. |
- Atanasova, L., et al.
(författare)
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g-factor Measurements at RISING: The Cases of 127Sn and 128Sn
- 2010
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Ingår i: Europhysics Letters. - : IOP Publishing. - 0295-5075. ; 91:4
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Tidskriftsartikel (refereegranskat)abstract
- We report on g-factor measurements of the 19/2(+) T-1/2 = 4.5(3) mu s isomer in Sn-127 and the 10(+) T-1/2 = 2.69(23) mu s isomer in Sn-128. These isomers were produced and spin-aligned in relativistic heavy-ion fragmentation at GSI and were selected and separated by the GSI fragment separator ( FRS). The gamma-rays of the isomeric decay were detected by the RISING gamma-ray spectrometer. The method of time-differential perturbed angular distributions was utilized. The measured g-factors, g(19/2(+); Sn-127) =-0.17(2) and g(10(+); Sn-128)=-0.20(4), are compared with shell model calculations. The measured g-factors confirm the predominantly nu h(11/2)(-2) and nu(s(1/2)(-1) h(11/2)(-2)) character of the 10(+) and 19/2(-) isomers in Sn-128 and Sn-127, respectively. The results demonstrate the feasibility of the method for similar measurements in exotic neutron-rich nuclei. Copyright (C) EPLA, 2010
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| 5. |
- DiJulio, Douglas, et al.
(författare)
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Electromagnetic properties of vibrational bands in Er-170
- 2011
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 47:2, s. 25-
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Tidskriftsartikel (refereegranskat)abstract
- Excited states of the nucleus Er-170 have been studied by Coulomb excitation using the GASP gamma-ray detector system at the Laboratori Nazionali di Legnaro. The ground-state band along with a low-lying K-pi = 0(+) band and gamma-vibrational band were populated during the experiment. Based on the measured gamma-ray yields, a set of interband and intraband matrix elements has been extracted using the Coulomb excitation code GOSIA. The resulting E2 matrix elements are compared to collective model predictions.
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| 6. |
- Gellanki, Jnaneswari, et al.
(författare)
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Extensive Gamma-ray Spectroscopy of Band Structures in 62Zn
- 2012
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 86:3
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Tidskriftsartikel (refereegranskat)abstract
- An experimental study of the Zn-62 nucleus has been performed by combining the data sets from four fusion-evaporation reaction experiments. Apart from the previously published data, the present results include ten new rotational band structures and two more superdeformed bands. The Gammasphere Ge-detector array in conjunction with the 4 pi charged-particle detector array Microball allowed for the detection of gamma rays in coincidence with evaporated light particles. The deduced level scheme includes some 260 excited states, which are connected with more than 450 gamma-ray transitions. Spins and parities of the excited states have been determined via directional correlations of. rays emitted from oriented states. The experimental characteristics of the rotational bands are analyzed and compared with results from cranked Nilsson-Strutinsky calculations. The present analysis, combined with available experimental results in the A similar to 60 mass region, can be used to improve the current set of Nilsson parameters in the N = 3 and N = 4 oscillator shells.
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| 7. |
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| 8. |
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| 9. |
- Rudolph, Dirk, et al.
(författare)
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Alpha-Photon Coincidence Spectroscopy Along Element 115 Decay Chains
- 2014
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 45, s. 263-272
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Tidskriftsartikel (refereegranskat)abstract
- Produced in the reaction 48Ca+243Am, thirty correlated α-decay chains were observed in an experiment conducted at the GSI Helmholzzentrum für Schwerionenforschung, Darmstadt, Germany. The decay chains are basically consistent with previous findings and are considered to originate from isotopes of element 115 with mass numbers 287, 288, and 289. A set-up aiming specifically for high-resolution charged particle and photon coincidence spectroscopy was placed behind the gas-filled separator TASCA. For the first time, γ rays as well as X-ray candidates were observed in prompt coincidence with the α-decay chains of element 115.
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| 10. |
- Rudolph, Dirk, et al.
(författare)
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Spectroscopy of Element 115 Decay Chains
- 2013
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Ingår i: Physical Review Letters. - 1079-7114. ; 111:11
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Tidskriftsartikel (refereegranskat)abstract
- A high-resolution , X-ray and gamma-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum für Schwerionenforschung. Thirty correlated alpha-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.
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| 11. |
- Söderström, Pär-Anders, et al.
(författare)
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Spectroscopy of neutron-rich Dy-168,Dy-170 : Yrast band evolution close to the NpNn valence maximum
- 2010
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 81:3, s. 034310-
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Tidskriftsartikel (refereegranskat)abstract
- The yrast sequence of the neutron-rich dysprosium isotope Dy-168 has been studied using multinucleon transfer reactions following collisions between a 460-MeV Se-82 beam and an Er-170 target. The reaction products were identified using the PRISMA magnetic spectrometer and the gamma rays detected using the CLARA HPGe-detector array. The 2(+) and 4(+) members of the previously measured ground-state rotational band of Dy-168 have been confirmed and the yrast band extended up to 10(+). A tentative candidate for the 4(+) -> 2(+) transition in Dy-170 was also identified. The data on these nuclei and on the lighter even-even dysprosium isotopes are interpreted in terms of total Routhian surface calculations and the evolution of collectivity in the vicinity of the proton-neutron valence product maximum is discussed.
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| 12. |
- Gellanki, Jnaneswari, et al.
(författare)
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High-spin Structure Studies in 62Zn
- 2012
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Ingår i: Physica Scripta. - 0031-8949. ; T150
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Tidskriftsartikel (refereegranskat)abstract
- A detailed experimental study of the Zn-62 nucleus was conducted by combining the data sets from four fusion-evaporation reaction experiments. Apart from the previous published data, the present results include ten new rotational band structures and two new superdeformed bands. The GAMMASPHERE Ge-detector array in conjunction with the 4 pi charged-particle detector array Microball allowed for detection of gamma-rays in coincidence with evaporated light particles. The deduced level scheme includes some 260 excited states, which are connected with 450 gamma-ray transitions. The multipolarities have been assigned via directional correlations of gamma-rays emitted from oriented states. The experimental characteristics of the rotational bands are analyzed and compared with the results from the cranked Nilsson-Strutinsky calculations.
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| 13. |
- Hoischen, Robert, et al.
(författare)
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Isomeric Mirror States as Probes for Effective Charges in the Lower pf Shell
- 2011
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Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 38:3
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Tidskriftsartikel (refereegranskat)abstract
- Following the fragmentation of a 550 MeV u(-1)primary beam of Ni-58, time-and energy-correlated gamma decays from isomeric states in neutron-deficient nuclei in the 1f(7/2) shell have been identified using the GSI fragment separator in combination with the RISING Ge-detector array. The results on isomers in the mirror pairs Ti-43(22)21-Sc-43(21)22 (I-pi = 3/2(+) and 19/2(-)), Cr-45(24)21-Sc-45(21)24 (I-pi = 3/2(+)) and V-45(23)22-Ti-45(22)23 (I-pi = 3/2(-)) are discussed in the framework of large scale pf and sdpf shell-model calculations, the former in conjunction with isospin symmetry breaking effects with emphasis on effective charges.
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| 14. |
- Khuyagbaatar, J., et al.
(författare)
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48Ca+249Bk Fusion Reaction Leading to Element Z=117: Long-Lived α-Decaying 270Db and Discovery of 266Lr
- 2014
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Ingår i: Physical Review Letters. - 1079-7114. ; 112:17
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Tidskriftsartikel (refereegranskat)abstract
- The superheavy element with atomic number Z=117 was produced as an evaporation residue in the 48Ca+249Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allowed measuring decays of single atomic nuclei with half-lives between sub-μs and a few days. Two decay chains comprising seven α decays and a spontaneous fission each were identified and are assigned to the isotope 294-117 and its decay products. A hitherto unknown α-decay branch in 270Db (Z=105) was observed, which populated the new isotope 266Lr (Z=103). The identification of the long-lived (T1/2=1.0+1.9−0.4 h) α-emitter 270Db marks an important step towards the observation of even more long-lived nuclei of superheavy elements located on an “island of stability.”
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| 15. |
- Rudolph, Dirk, et al.
(författare)
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Isospin and Deformation Studies in the Odd-odd N = Z Nucleus 54Co
- 2010
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 82:5
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in the odd-odd N = Z nucleus Co-54 have been investigated by the fusion-evaporation reaction Si-28(S-32,1 alpha 1p1n)Co-54. Gamma-ray information gathered with the Ge detector array Gammasphere was correlated with evaporated particles detected in the charged particle detector system Microball and a 1 pi neutron detector array. A significantly extended excitation scheme of Co-54 is presented, which includes a candidate for the isospin T = 1, 6(+) state of the 1f(7/2)(-2) multiplet. The results are compared to large-scale shell-model calculations in the fp shell. Effective interactions with and without isospin-breaking terms have been used to probe isospin symmetry and isospin mixing. A quest for deformed high-spin rotational cascades proved negative. This feature is discussed by means of cranking calculations.
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| 16. |
- Zaidman-Remy, Anna, et al.
(författare)
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Drosophila Immunity : Analysis of PGRP-SB1 Expression, Enzymatic Activity and Function
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:2, s. e17231-
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Tidskriftsartikel (refereegranskat)abstract
- Peptidoglycan is an essential and specific component of the bacterial cell wall and therefore is an ideal recognition signature for the immune system. Peptidoglycan recognition proteins (PGRPs) are conserved from insects to mammals and able to bind PGN (non-catalytic PGRPs) and, in some cases, to efficiently degrade it (catalytic PGRPs). In Drosophila, several non-catalytic PGRPs function as selective peptidoglycan receptors upstream of the Toll and Imd pathways, the two major signalling cascades regulating the systemic production of antimicrobial peptides. Recognition PGRPs specifically activate the Toll pathway in response to Lys-type peptidoglycan found in most Gram-positive bacteria and the Imd pathway in response to DAP-type peptidoglycan encountered in Gram-positive bacilli-type bacteria and in Gram-negative bacteria. Catalytic PGRPs on the other hand can potentially reduce the level of immune activation by scavenging peptidoglycan. In accordance with this, PGRP-LB and PGRP-SC1A/B/2 have been shown to act as negative regulators of the Imd pathway. In this study, we report a biochemical and genetic analysis of PGRP-SB1, a catalytic PGRP. Our data show that PGRP-SB1 is abundantly secreted into the hemolymph following Imd pathway activation in the fat body, and exhibits an enzymatic activity towards DAP-type polymeric peptidoglycan. We have generated a PGRP-SB1/2 null mutant by homologous recombination, but its thorough phenotypic analysis did not reveal any immune function, suggesting a subtle role or redundancy of PGRP-SB1/2 with other molecules. Possible immune functions of PGRP-SB1 are discussed.
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