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Author AGATA Collaboration (Avigo, R. et al); Domingo-Pardo, C.; Gadea, A.; Gonzalez, V.
Title Low-lying electric dipole gamma-continuum for the unstable Fe-62(,)64 nuclei: Strength evolution with neutron number Type Journal Article
Year (down) 2020 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 811 Issue Pages 135951 - 6pp
Keywords Fe-64; Fe-62; Nuclear structure; Dipole excitation around neutron threshold
Abstract The gamma-ray emission from the nuclei Fe-62,Fe-64 following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei Fe-62,Fe-64 were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The gamma decay was detected with AGATA. From the measured gamma-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1(-) states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy.
Address [Avigo, R.; Wieland, O.; Bracco, A.; Camera, F.; Benzoni, G.; Blasi, N.; Bottoni, S.; Brambilla, S.; Crespi, F. C. L.; Leoni, S.; Million, B.; Morales, A., I; Pullia, A.; Riboldi, S.] Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan, Italy, Email: oliver.wieland@mi.infn.it
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000612225400080 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4700
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Author AGATA Collaboration (Kaya, L. et al); Gadea, A.
Title Identification of high-spin proton configurations in Ba-136 and Ba-137 Type Journal Article
Year (down) 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 99 Issue 1 Pages 014301 - 19pp
Keywords
Abstract The high-spin structures of Ba-136 and Ba-137 are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Ba-136 is populated in a Xe-136 + U-238 MNT reaction employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and in two Be-9 + Te-130 fusion-evaporation reactions using the High-efficiency Observatory for gamma-Ray Unique Spectroscopy (HORUS) at the FN tandem accelerator of the University of Cologne, Germany. Furthermore, both isotopes are populated in an elusive reaction channel in the B-11 + Te-130 fusion-evaporation reaction utilizing the HORUS gamma-ray array. The level scheme above the J(pi) = 10(+) isomer in Ba-136 is revised and extended up to an excitation energy of approximately 5.5 MeV. From the results of angular-correlation measurements, the E-x = 3707- and E-x = 4920-keV states are identified as the bandheads of positive- and negative-parity cascades. While the high-spin regimes of both Te-132 and Xe-134 are characterized by high-energy 12(+) -> 10(+) transitions, the Ba-136 E2 ground-state band is interrupted by negative-parity states only a few hundred keV above the J(pi) = 10(+) isomer. Furthermore, spins are established for several hitherto unassigned high-spin states in Ba-137. The new results close a gap along the high-spin structure of N < 82 Ba isotopes. Experimental results are compared to large-scale shell-model calculations employing the GCN50:82, Realistic SM, PQM130, and SN100PN interactions. The calculations suggest that the bandheads of the positive-parity bands in both isotopes are predominantly of proton character.
Address [Kaya, L.; Vogt, A.; Reiter, P.; Mueller-Gatermann, C.; Blazhev, A.; Arnswald, K.; Birkenbach, B.; Droste, M.; Eberth, J.; Fransen, C.; Hess, H.; Hetzenegger, R.; Hirsch, R.; Jolie, J.; Lewandowski, L.; Rosiak, D.; Saed-Samii, N.; Seidlitz, M.; Weinert, M.; Wolf, K.; Zell, K. O.] Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany, Email: levent.kaya@ikp.uni-koeln.de
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000454768000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3859
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Author Soderstrom, P.A. et al; Agramunt, J.; Egea, J.; Gadea, A.; Huyuk, T.
Title Neutron detection and gamma-ray suppression using artificial neural networks with the liquid scintillators BC-501A and BC-537 Type Journal Article
Year (down) 2019 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 916 Issue Pages 238-245
Keywords BC-501A; BC-537; Digital pulse-shape discrimination; Fast-neutron detection; Liquid scintillator; Neural networks
Abstract In this work we present a comparison between the two liquid scintillators BC-501A and BC-537 in terms of their performance regarding the pulse-shape discrimination between neutrons and gamma rays. Special emphasis is put on the application of artificial neural networks. The results show a systematically higher gamma-ray rejection ratio for BC-501A compared to BC-537 applying the commonly used charge comparison method. Using the artificial neural network approach the discrimination quality was improved to more than 95% rejection efficiency of gamma rays over the energy range 150 to 1000 keV for both BC-501A and BC-537. However, due to the larger light output of BC-501A compared to BC-537, neutrons could be identified in BC-501A using artificial neural networks down to a recoil proton energy of 800 keV compared to a recoil deuteron energy of 1200 keV for BC-537. We conclude that using artificial neural networks it is possible to obtain the same gamma-ray rejection quality from both BC-501A and BC-537 for neutrons above a low-energy threshold. This threshold is, however, lower for BC-501A, which is important for nuclear structure spectroscopy experiments of rare reaction channels where low-energy interactions dominates.
Address [Soderstrom, P-A] ELI NP, Bucharest 077125, Romania, Email: par.anders@eli-np.ro
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000455016800033 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3869
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Author Valiente-Dobon, J.J. et al; Egea, J.; Huyuk, T.; Gadea, A.; Aliaga, R.; Jurado-Gomez, M.L.; Perez-Vidal, R.M.
Title NEDA-NEutron Detector Array Type Journal Article
Year (down) 2019 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 927 Issue Pages 81-86
Keywords NEDA; Nuclear structure; Gamma-ray spectroscopy; Neutron detector; Liquid scintillator; Digital electronics; Neutron-gamma discrimination
Abstract The NEutron Detector Array, NEDA, will form the next generation neutron detection system that has been designed to be operated in conjunction with gamma-ray arrays, such as the tracking-array AGATA, to aid nuclear spectroscopy studies. NEDA has been designed to be a versatile device, with high-detection efficiency, excellent neutron-gamma discrimination, and high rate capabilities. It will be employed in physics campaigns in order to maximise the scientific output, making use of the different stable and radioactive ion beams available in Europe. The first implementation of the neutron detector array NEDA with AGATA 1 pi was realised at GANIL. This manuscript reviews the various aspects of NEDA.
Address [Valiente-Dobon, J. J.; Jaworski, G.; Goasduff, A.; Egea, J.; Modamio, V; de Angelis, G.; Bissiato, E.; Carturan, S.; Cocconi, P.; Conventi, D.; Deltoro, J. M.; Hadynska-Klekn, K.; Illan, A.; Raggio, A.; Siciliano, M.; Zanon, I] Ist Nazl Fis Nucl, Lab Nazl Legnaro, Legnaro, Italy, Email: valiente@lnl.infn.it
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000462142700010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3956
Permanent link to this record
 

 
Author Testov, D. et al; Gadea, A.
Title The 4pi highly-efficient light-charged-particle detector EUCLIDES, installed at the GALILEO array for in-beam gamma-ray spectroscopy Type Journal Article
Year (down) 2019 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 55 Issue 4 Pages 47 - 8pp
Keywords
Abstract .In a fusion-evaporation reaction, nuclei are produced by evaporating light-charged particles and neutrons from the compound nucleus. Typically, a nucleus of interest is produced as a result of a part of the total cross-section and, in order to guarantee a good channel discrimination, a particle detector, like the EUCLIDES 4 Si-ball array, is necessary. EUCLIDES has been quoted in more than a hundred publications resulting from many experiments performed in combination with the EUROBALL and GASP -ray spectrometers. The present paper reports on the upgraded version of EUCLIDES, that is presently coupled to the new GALILEO -ray spectrometer, installed at the Laboratori Nazionali di Legnaro, INFN. The design, characteristics and performance of the EUCLIDES array are presented and discussed.
Address [Testov, D.; Mengoni, D.; Goasduff, A.; John, P. R.; Boso, A.; Canet, F. J. Egea; Grassi, L.; Lunardi, S.; Recchia, F.] Univ Padua, Dipartimento Fis & Astron, Padua, Italy, Email: testov@lnl.infn.it
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000462944600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3965
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Author Gottardo, A. et al; Gadea, A.; Algora, A.
Title New spectroscopic information on Tl-211,Tl-213: A changing structure beyond the N=126 shell closure Type Journal Article
Year (down) 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 99 Issue 5 Pages 054326 - 7pp
Keywords
Abstract The neutron-rich isotopes Tl-211,Tl-213, beyond the N = 126 shell closure, have been studied for the first time in isomer gamma-ray decay, exploiting the fragmentation of a primary uranium beam at the Fragment Separator-Rare Isotopes Investigation at GSI setup. The observed isomeric states in Tl-211,Tl-213 show a deviation from the seniority-like scheme of Tl-209. The possible interpretation of the data is discussed on the basis of energy-level systematics and shell-model calculations.
Address [Gottardo, A.; Valiente-Dobon, J. J.; de Angelis, G.; Napoli, D. R.; Sahin, E.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: andrea.gottardo@lnl.infn.it
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000469018900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4025
Permanent link to this record
 

 
Author Capra, S.; Mengoni, D.; Dueñas, J.A.; John, P.R.; Gadea, A.; Aliaga, R.J.; Dormard, J.J.; Assie, M.; Pullia, A.
Title Performance of the new integrated front-end electronics of the TRACE array commissioned with an early silicon detector prototype Type Journal Article
Year (down) 2019 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 935 Issue Pages 178-184
Keywords ASIC; Charge-sensitive preamplifier; Low-noise applications; Particle spectrometry; Dead time; Silicon detector
Abstract The spectroscopic performances of the new integrated ASIC (Application-Specific Integrated Circuit) preamplifiers for highly segmented silicon detectors have been evaluated with an early silicon detector prototype of the TRacking Array for light Charged Ejectiles (TRACE). The ASICS were mounted on a custom-designed PCB (Printed Circuit Board) and the detector plugged on it. Energy resolution tests, performed on the same detector before and after irradiation, yielded a resolution of 21 keV and 33 keV FWHM respectively. The output signals were acquired with an array of commercial 100-MHz 14-bit digitizers. The preamplifier chip is equipped with an innovative Fast-Reset device that has two functions: it reduces dramatically the dead time of the preamplifier in case of saturation (from milliseconds to microseconds) and extends the spectroscopic dynamic range of the preamplifier by more than one order of magnitude. Other key points of the device are the low noise and the wide bandwidth.
Address [Capra, S.; Pullia, A.] Univ Milan, Dipartimento Fis, Via Celoria 16, IT-20133 Milan, Italy, Email: stefano.capra@unimi.it
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000470063800026 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4042
Permanent link to this record
 

 
Author Dudouet, J. et al; Gadea, A.; Perez-Vidal, R.M.
Title Excitations of the magic N=50 neutron-core revealed in Ga-81 Type Journal Article
Year (down) 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 100 Issue 1 Pages 011301 - 6pp
Keywords
Abstract The high-spin states of the neutron-rich Ga-81, with three valence protons outside a Ni-78 core, were measured. The measurement involved prompt gamma-ray spectroscopy of fission fragments isotopically identified using the combination of the variable mode spectrometer (VAMOS++) and the advanced gamma tracking array (AGATA). The new gamma-ray transitions, observed in coincidence with Ga-81 ions, and the corresponding level scheme do not confirm the high-spin levels reported earlier. The newly observed high-spin states in Ga-81 are interpreted using the results of state-of-the-art large-scale shell model (LSSM) calculations. The lower excitation energy levels are understood as resulting from the recoupling of three valence protons to the closed doubly magic core, while the highest excitation energy levels correspond to excitations of the magic N = 50 neutron core. These results support the doubly magic character of Ni-78 and the persistence of the N = 50 shell closure but also highlight the presence of strong proton-neutron correlations associated with the promotion of neutrons across the magic N = 50 shell gap, only few nucleons away from Ni-78.
Address [Dudouet, J.; Maquart, G.; Stezowski, O.; Ducoin, C.; Guinet, D.; Redon, N.] Univ Lyon 1, CNRS IN2P3, IPN Lyon, F-69622 Villeurbanne, France, Email: jeremie.dudouet@csnsm.in2p3.fr
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000475500200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4095
Permanent link to this record
 

 
Author AGATA Collaboration (Kaya, L. et al); Gadea, A.
Title Isomer spectroscopy in Ba-133 and high-spin structure of Ba-134 Type Journal Article
Year (down) 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 100 Issue 2 Pages 024323 - 18pp
Keywords
Abstract 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.
Address [Kaya, L.; Vogt, A.; Reiter, P.; Arnswald, K.; Birkenbach, B.; Blazhev, A.; Droste, M.; Eberth, J.; Esmaylzadeh, A.; Fransen, C.; Hess, H.; Hirsch, R.; Jolie, J.; Karayonchev, V; Kornwebel, L.; Lewandowski, L.; Mueller-Gatermann, C.; Regis, J-M; Saed-Samii, N.; Schomacker, K.; Seidlitz, M.; Siebeck, B.; Wolf, K.; Zell, K. O.] Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany, Email: levent.kaya@ikp.uni-koeln.de
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000480688200004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4106
Permanent link to this record
 

 
Author Ralet, D. et al; Gadea, A.; Perez, R.M.
Title Evidence of octupole-phonons at high spin in Pb-207<bold> </bold> Type Journal Article
Year (down) 2019 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 797 Issue Pages 134797 - 6pp
Keywords AGATA spectrometer; gamma-Ray tracking; VAMOS plus plus spectrometer; Plunger device; Nuclear deformation; Octupole phonon
Abstract A lifetime measurement of the 19/2(-) state in Pb-207 has been performed using the Recoil Distance Doppler-Shift (RDDS) method. The nuclei of interest were produced in multi-nucleon transfer reactions induced by a Pb-208 beam impinging on a Mo-100 enriched target. The beam-like nuclei were detected<bold> </bold>and identified in terms of their atomic mass number in the VAMOS++ spectrometer while the prompt gamma rays were detected by the AGATA tracking array. The measured large reduced transition probability B(E3, 19/2(-) -> 13/2(+)) = 40(8) W.u. is the first indication of the octupole phonon at high spin in Pb-207. An analysis in terms of a particle-octupole-vibration coupling model indicates that the measured B(E3) value in Pb-207 is compatible with the contributions from single-phonon and single particle E3 as well as E3 strength arising from the double-octupole-phonon 6(+) state, all adding coherently. A crucial aspect of the coupling model, namely the strong mixing between single-hole and the phonon-hole states, is confirmed in a realistic shell-model calculation.
Address [Ralet, D.; Georgiev, G.; Ljungvall, J.; Dupont, E.; Konstantinopoulos, T.; Korichi, A.; Lozeva, R.] Univ Paris Saclay, Univ Paris Sud, CSNSM, CNRS IN2P3, F-91405 Orsay, France, Email: clement@ganil.fr
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000488071200015 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4163
Permanent link to this record