| Records |
| Author |
Ciemala, M. et al; Domingo-Pardo, C.; Perez-Vidal, R.M. |
| Title |
Testing ab initio nuclear structure in neutron-rich nuclei: Lifetime measurements of second 2(+) state in C-16 and O-20 |
Type |
Journal Article |
| Year |
2020 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
101 |
Issue |
2 |
Pages |
021303 - 7pp |
| Keywords |
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| Abstract |
To test the predictive power of ab initio nuclear structure theory, the lifetime of the second 2(+) state in neutron-rich O-20, tau(2(2)(+)) = 150(-30)(+80) fs, and an estimate for the lifetime of the second 2(+) state in C-16 have been obtained for the first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure nuclear state lifetimes in the tens-to-hundreds of femtoseconds range by analyzing the Doppler-shifted gamma-transition line shapes of products of low-energy transfer and deep-inelastic processes in the reaction O-18 (7.0 MeV/u) + Ta-181. The requested sensitivity could only be reached owing to the excellent performances of the Advanced gamma-Tracking Array AGATA, coupled to the PARIS scintillator array and to the VAMOS++ magnetic spectrometer. The experimental lifetimes agree with predictions of ab initio calculations using two- and three-nucleon interactions, obtained with the valence-space in-medium similarity renormalization group for O-20 and with the no-core shell model for C-16. The present measurement shows the power of electromagnetic observables, determined with high-precision gamma spectroscopy, to assess the quality of first-principles nuclear structure calculations, complementing common benchmarks based on nuclear energies. The proposed experimental approach will be essential for short lifetime measurements in unexplored regions of the nuclear chart, including r-process nuclei, when intense beams, produced by Isotope Separation On-Line (ISOL) techniques, become available. |
Address  |
[Ciemala, M.; Fornal, B.; Maj, A.; Bednarczyk, P.; Cieplicka-Orynczak, N.; Grebosz, J.; Iskra, L. W.; Kmiecik, M.; Mazurek, K.; Matejska-Minda, M.; Wasilewska, B.; Zieblinski, M.] Inst Nucl Phys, PAN, PL-31342 Krakow, Poland, Email: michal.ciemala@ifj.edu.pl; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2469-9985 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000517222700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4311 |
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| Author |
AGATA Collaboration (Clement, E. et al); Domingo-Pardo, C.; Gadea, A.; Perez-Vidal, R.M.; Civera, J.V. |
| Title |
Conceptual design of the AGATA 1 pi array at GANIL |
Type |
Journal Article |
| Year |
2017 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
855 |
Issue |
|
Pages |
1-12 |
| Keywords |
AGATA spectrometer; GANIL facility; gamma-ray tracking; Pulse shape analysis; VAMOS plus plus spectrometer; NEDA detector; DIAMANT detector; PARIS LaBr3 detector; FATIMA LaBr3 detector; Plunger device |
| Abstract |
The Advanced GAmma Tracking Array (AGATA) has been installed at the GANIL facility, Caen-France. This setup exploits the stable and radioactive heavy-ions beams delivered by the cyclotron accelerator complex of GANIL. Additionally, it benefits from a large palette of ancillary detectors and spectrometers to address in-beam gamma-ray spectroscopy of exotic nuclei. The set-up has been designed to couple AGATA with a magnetic spectrometer, charged-particle and neutron detectors, scintillators for the detection of high-energy gamma rays and other devices such as a plunger to measure nuclear lifetimes. In this paper, the design and the mechanical characteristics of the set-up are described. Based on simulations, expected performances of the AGATA l pi array are presented. |
| Address |
[Clement, E.; Michelagnoli, C.; de France, G.; Li, H. J.; Lemasson, A.; Dejeon, C. Barthe; Beuzard, M.; Bougault, P.; Cacitti, J.; Foucher, J. -L.; Fremont, G.; Gangnant, P.; Goupil, J.; Houarner, C.; Jean, M.; Lefevre, A.; Legeard, L.; Legruel, F.; Maugeais, C.; Menager, L.; Menard, N.; Munoz, H.; Ozille, M.; Raine, B.; Ropert, J. A.; Saillant, F.; Spitaels, C.; Tripon, M.; Vallerand, Ph.; Voltolini, G.; Lopez-Martens, A.] CEA, DRF, CNRS, IN2P3,GANIL, F-14076 Caen 05, France |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0168-9002 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000399846900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3091 |
| Permanent link to this record |
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| Author |
Delafosse, C. et al; Gadea, A.; Perez-Vidal, R.M.; Domingo-Pardo, C. |
| Title |
Pseudospin Symmetry and Microscopic Origin of Shape Coexistence in the Ni-78 Region: A Hint from Lifetime Measurements |
Type |
Journal Article |
| Year |
2018 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
121 |
Issue |
19 |
Pages |
192502 - 7pp |
| Keywords |
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| Abstract |
Lifetime measurements of excited states of the light N = 52 isotones Kr-88, Se-86, and Ge-84 have been performed, using the recoil distance Doppler shift method and VAMOS and AGATA spectrometers for particle identification and gamma spectroscopy, respectively. The reduced electric quadrupole transition probabilities B(E2; 2(+)-> 0(+)) and B(E2; 4(+)-> 2(+)) were obtained for the first time for the hard-to-reach 84Ge. While the B(E2; 2(+)-> 0(+) ) values of Kr-88, Se-86 saturate the maximum quadrupole collectivity offered by the natural valence (3s, 2d, 1g(7/2), 1h(11/2)) space of an inert Ni-78 core, the value obtained for Ge-84 largely exceeds it, suggesting that shape coexistence phenomena, previously reported at N less than or similar to 49, extend beyond N = 50. The onset of collectivity at Z = 32 is understood as due to a pseudo-SU(3) organization of the proton single-particle sequence reflecting a clear manifestation of pseudospin symmetry. It is realized that the latter provides actually reliable guidance for understanding the observed proton and neutron single particle structure in the whole medium-mass region, from Ni to Sn, pointing towards the important role of the isovector-vector rho field in shell-structure evolution. |
| Address |
[Delafosse, C.; Verney, D.; Marevic, P.; Gottardo, A.; Babo, M.; Franchoo, S.; Ibrahim, F.; Matea, I; Olivier, L.; Portail, C.; Stefan, I] Univ Paris Saclay, Univ Paris Sud, CNRS IN2P3, Inst Phys Nucl, F-91406 Orsay, France, Email: verney@ipno.in2p3.fr |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0031-9007 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000449791600008 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3800 |
| Permanent link to this record |
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| 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 |
2019 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
| Volume |
100 |
Issue |
1 |
Pages |
011301 - 6pp |
| Keywords |
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| 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 |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2469-9985 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000475500200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4095 |
| Permanent link to this record |
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| Author |
Dudouet, J. et al; Domingo-Pardo, C.; Gadea, A.; Perez-Vidal, R.M. |
| Title |
Kr-96(36)60-Low-Z Boundary of the Island of Deformation at N=60 |
Type |
Journal Article |
| Year |
2017 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
118 |
Issue |
16 |
Pages |
162501 - 6pp |
| Keywords |
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| Abstract |
Prompt.-ray spectroscopy of the neutron-rich Kr-96, produced in transfer-and fusion-induced fission reactions, has been performed using the combination of the Advanced Gamma Tracking Array and the VAMOS + +spectrometer. A second excited state, assigned to J pi = 4(+), is observed for the first time, and a previously reported level energy of the first 2+ excited state is confirmed. The measured energy ratio R-4/2 = E(4(+))/E(2(+)) = 2.12(1) indicates that this nucleus does not show a well-developed collectivity contrary to that seen in heavier N = 60 isotones. This new measurement highlights an abrupt transition of the degree of collectivity as a function of the proton number at Z = 36, of similar amplitude to that observed at N = 60 at higher Z values. A possible reason for this abrupt transition could be related to the insufficient proton excitations in the g(9/2), d(5/2), and s(1/2) orbitals to generate strong quadrupole correlations or to the coexistence of competing different shapes. An unexpected continuous decrease of R-4/2 as a function of the neutron number up to N = 60 is also evidenced. This measurement establishes the Kr isotopic chain as the low-Z boundary of the island of deformation for N = 60 isotones. A comparison with available theoretical predictions using different beyond mean-field approaches shows that these models fail to reproduce the abrupt transitions at N = 60 and Z = 36. |
| Address |
[Dudouet, J.; Maquart, G.; Stezowski, O.; Redon, N.] Univ Lyon 1, CNRS IN2P3, IPN Lyon, F-69622 Villeurbanne, France, Email: j.dudouet@ipnl.in2p3.fr |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0031-9007 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000399816500006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3098 |
| Permanent link to this record |
