Suchergebnisse

R. Chapman et al. ; 8 págs.; 6 figs.; 1 tab. ; The neutron-rich S39 nucleus has been studied using binary grazing reactions produced by the interaction of a 215-MeV beam of S36 ions with a thin Pb208 target. The magnetic spectrometer, PRISMA, and the γ-ray array, CLARA, were used in the measurements. Gamma-ray transitions of the following energies were observed: 339, 398, 466, 705, 1517, 1656, and 1724 keV. Five of the observed transitions have been tentatively assigned to the decay of excited states with spins up to (11/2-). The results of a state-of-the-art shell-model calculation of the level scheme of S39 using the SDPF-U effective interaction are also presented. The systematic behavior of the excitation energy of the first 11/2- states in the odd-A isotopes of sulfur and argon is discussed in relation to the excitation energy of the first excited 2+ states of the adjacent even-A isotopes. The states of S39 that have the components in their wave functions corresponding to three neutrons in the 1f7/2 orbital outside the N=20 core have also been discussed within the context of the 0 ω shell-model calculations presented here. ©2016 American Physical Society ; This work was supported in part by the EPSRC (UK) and by the European Union under Contract No. RII3-CT- 2004-506065. Five of us (D.O., M.B., A.H., K.K., and A.P.) acknowledge financial support from the EPSRC. Z.M.W. acknowledges support from ORSAS and from the University of the West of Scotland. A.N.D. acknowledges support from the STFC. A.J. acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación under Contracts No. FPA2007-66069 and No. FPA2009-13377-C02-02. Zs.D. acknowledges financial support from OTKA under Project No. K100835. S.S. acknowledges support from the Croatian Science Foundation under Project No. 7194. The contribution of the accelerator and target-fabrication staff at the INFN Legnaro National Laboratory is gratefully acknowledged. ; Peer Reviewed

E. Sahin et al.; 9 pags.; 8 figs.; 2 tabs.; PACS number(s): 21.10.Tg, 21.60.Cs, 23.20.Lv ; © 2015 American Physical Society. The level structure of the neutron-rich 69Cu,71Cu, and Cu73 isotopes has been investigated by means of multinucleon transfer reactions. The experiment was performed at Laboratori Nazionali di Legnaro using the AGATA Demonstrator array coupled to the PRISMA magnetic spectrometer. Lifetimes of excited states in Cu nuclei were measured with the recoil-distance Doppler-shift method. The resulting electromagnetic matrix elements for transitions from excited states in Cu69,71,73 nuclei are used to assess the collective or single-particle character of these states. The results are compared with predictions of large-scale shell-model calculations, giving further insight into the evolution of the proton pf shell as neutrons fill the 1g9/2 orbital. ; This work has been partially supported by the European Union Seventh Framework Program FP7/2007-2013 under Grant Agreement No. 262010, ENSAR and MINECO, Spain, under Grants No. FPA2011-29854-C03 and No. FPA2011- 29854-C04, Generalitat Valenciana, Spain, under Grant No. PROMETEOII/2014/019, and MINECO, Spain, under Grant Consolider-Ingenio 2010 CSD2007-00042. ; Peer Reviewed

Yrast states in the neutron-rich 1433Si19 nucleus have been studied using binary grazing reactions produced by the interaction of a 215-MeV beam of S36 ions with a thin Pb208 target. An experimental setup that combines the large-acceptance magnetic spectrometer PRISMA and the high-efficiency γ-ray detection array CLARA was used in the experiment. Four new γ-ray photopeaks at energies of 971, 1724, 1772, and 2655 keV were observed and assigned to the Si33 level scheme. The experimental level scheme is compared with the results of 1ω p-sd-pf large-scale shell-model calculations using the recently developed PSDPFB effective interaction; good agreement is obtained. The structure of the populated states of Si33 is discussed within the context of an odd neutron coupled to states of the Si32 core. © 2010 The American Physical Society. ; This work was supported in part by the EPSRC (UK) and by the European Union under Contract No. RII3-CT-2004-506065. Five of us (D.O., M.B., A.H., K.K., and A.P.)acknowledge financial support from the EPSRC. Z.M.W acknowledges support from ORSAS and from the University of the West of Scotland. A.J. acknowledges financial supportfrom the Spanish Ministerio de Ciencia e Innovación under Contract Nos. FPA2007-66069 and FPA2009-13377-C02-02. Zs.D. acknowledges the financial support from OTKA Project No. K68801. ; Peer Reviewed

The nuclear structure of neutron-rich nuclei close to the double-magic nucleus 78Ni has been investigated by measuring the lifetime of excited states. In this contribution, it will be presented the lifetime of the Jπ = 7=2 excited state at 981 keV of the 71Cu isotope, measured using the AGATA Demonstrator coupled to the PRISMA spectrometer and the Köln plunger setup. This is the first time this combined setup has been used for a lifetime measurement. ; This work has been partially supported by the grants FPA2008-06419, FPA2008-03774, AIC10-D-000605, AIC-D-2011-0764 and Consolider CSD2007-00042 from the Spanish Government and by INFN Italy. ; Peer Reviewed

18 pags., 11 figs., 4 tabs. ; The transitional nuclei Ba-134 and Ba-133 are investigated after multinucleon transfer employing the high-resolution Advanced GAmma Tracking Array coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and after fusion-evaporation reaction at the FN tandem accelerator of the University of Cologne, Germany. The J(pi) = 19/2(+) state at 1942 keV in Ba-133 is identified as an isomer with a half-life of 66.6(20) ns corresponding to a B(E1) value of 7.7(4) x 10(-6) e(2) fm(2) for the J(pi) = 19/2(+) to J(pi) = 19/2(-) transition. The level scheme of Ba-134 above the J(pi) = 10(+) isomer is extended to approximately 6 MeV. A pronounced backbending is observed at h omega = 0.38 MeV along the positive-parity yrast band. The results are compared to the high-spin systematics of the Z = 56 isotopes. Large-scale shell-model calculations employing the GCN50:82, SN100PN, SNV, PQM130, Realistic SM, and EPQQM interactions reproduce the experimental findings and elucidate the structure of the high-spin states. The shell-model calculations employing the GCN50:82 and PQM130 interactions reproduce alignment properties and provide detailed insight into the microscopic origin of this phenomenon in transitional Ba-134. ; The research leading to these results has received funding from the German BMBF under Contracts No. 05P15PKFN9 TP1 and No. 05P18PKFN9 TP1, from the European Union Seventh Framework Programme FP7/2007-2013 under Grant No. 262010-ENSAR, from the Spanish Ministerio de Ciencia e Innovación under Contract No. FPA2011-29854-C04, from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2014- 57196-C5, and from the U.K. Science and Technology Facilities Council (STFC). One of the authors (A. Gadea) has been supported by the Generalitat Valenciana, Spain, under Grant No. PROMETEOII/2014/019 and EU under the FEDER program.

18 pags., 11 figs., 4 tabs. ; The transitional nuclei Ba-134 and Ba-133 are investigated after multinucleon transfer employing the high-resolution Advanced GAmma Tracking Array coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and after fusion-evaporation reaction at the FN tandem accelerator of the University of Cologne, Germany. The J(pi) = 19/2(+) state at 1942 keV in Ba-133 is identified as an isomer with a half-life of 66.6(20) ns corresponding to a B(E1) value of 7.7(4) x 10(-6) e(2) fm(2) for the J(pi) = 19/2(+) to J(pi) = 19/2(-) transition. The level scheme of Ba-134 above the J(pi) = 10(+) isomer is extended to approximately 6 MeV. A pronounced backbending is observed at h omega = 0.38 MeV along the positive-parity yrast band. The results are compared to the high-spin systematics of the Z = 56 isotopes. Large-scale shell-model calculations employing the GCN50:82, SN100PN, SNV, PQM130, Realistic SM, and EPQQM interactions reproduce the experimental findings and elucidate the structure of the high-spin states. The shell-model calculations employing the GCN50:82 and PQM130 interactions reproduce alignment properties and provide detailed insight into the microscopic origin of this phenomenon in transitional Ba-134. ; The research leading to these results has received funding from the German BMBF under Contracts No. 05P15PKFN9 TP1 and No. 05P18PKFN9 TP1, from the European Union Seventh Framework Programme FP7/2007-2013 under Grant No. 262010-ENSAR, from the Spanish Ministerio de Ciencia e Innovación under Contract No. FPA2011-29854-C04, from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2014- 57196-C5, and from the U.K. Science and Technology Facilities Council (STFC). One of the authors (A. Gadea) has been supported by the Generalitat Valenciana, Spain, under Grant No. PROMETEOII/2014/019 and EU under the FEDER program.

WOS: 000350998600002 ; The level structure of the neutron-rich Cu-69, Cu-71, and Cu-73 isotopes has been investigated by means of multinucleon transfer reactions. The experiment was performed at Laboratori Nazionali di Legnaro using the AGATA Demonstrator array coupled to the PRISMA magnetic spectrometer. Lifetimes of excited states in Cu nuclei were measured with the recoil-distance Doppler-shift method. The resulting electromagnetic matrix elements for transitions from excited states in Cu-69,Cu-71,Cu-73 nuclei are used to assess the collective or single-particle character of these states. The results are compared with predictions of large-scale shell-model calculations, giving further insight into the evolution of the proton pf shell as neutrons fill the 1g(9/2) orbital. ; European Union Seventh Framework Program FP7 [262010]; ENSAR; MINECO, Spain [FPA2011-29854-C03, FPA2011-29854-C04, Consolider-Ingenio 2010 CSD2007-00042]; Generalitat Valenciana, Spain [PROMETEOII/2014/019] ; This work has been partially supported by the European Union Seventh Framework Program FP7/2007-2013 under Grant Agreement No. 262010, ENSAR and MINECO, Spain, under Grants No. FPA2011-29854-C03 and No. FPA2011-29854-C04, Generalitat Valenciana, Spain, under Grant No. PROMETEOII/2014/019, and MINECO, Spain, under Grant Consolider-Ingenio 2010 CSD2007-00042.