Records |
Author |
Cederwall, B. et al; Algora, A.; Gadea, A. |
Title |
Evidence for a spin-aligned neutron-proton paired phase from the level structure of Pd-92 |
Type |
Journal Article |
Year |
2011 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
469 |
Issue |
7328 |
Pages |
68-71 |
Keywords |
|
Abstract |
Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Cederwall, B.; Moradi, F. Ghazi; Back, T.; Johnson, A.; Blomqvist, J.; Andgren, K.; Lagergren, K.; Liotta, R.; Qi, C.; Hadinia, B.; Khaplanov, A.; Persson, A.; Sandzelius, M.] Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden, Email: cederwall@nuclear.kth.se |
Corporate Author |
|
Thesis |
|
Publisher |
Nature Publishing Group |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0028-0836 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
ISI:000285921600032 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
588 |
Permanent link to this record |
|
|
|
Author |
Clement, E. et al; Domingo-Pardo, C.; Gadea, A. |
Title |
Spectroscopic quadrupole moments in 124Xe |
Type |
Journal Article |
Year |
2023 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
107 |
Issue |
1 |
Pages |
014324 - 8pp |
Keywords |
|
Abstract |
Background: The Xe isotopic chain with four valence protons above the Z = 50 shell closure is an ideal laboratory for the study of the evolution of nuclear deformation. At the N = 82 shell closure, 136Xe presents all characteristics of a doubly closed shell nucleus with a spherical shape. In the very neutron-deficient isotopes close to N = 50, the alpha-decay chain of Xe was investigated to probe the radioactive decay properties near the drip-line and the magicity of 100Sn. Additionally, the Xe isotopes present higher order symmetries in the nuclear deformation such as the octupole degree of freedom near N = 60 and N = 90 or O(6) symmetry in stable isotopes.Purpose: The relevance of the O(6) symmetry has been investigated by measuring the spectroscopic quadrupole moment of the first excited states in 124Xe. In the O(6) symmetry limit, the spectroscopic quadrupole moment of collective states is expected to be null.Method: A stable 124Xe beam with energies of 4.03A MeV and 4.11A MeV was used to bombard a natW target at the GANIL facility. Excited states were populated via the safe Coulomb excitation reaction. The collision of the heavy ions with a large Z at low energy make this reaction sensitive to the diagonal E2 matrix element of the excited states. The recoils were detected in the VAMOS++ magnetic spectrometer and the gamma rays in the AGATA tracking array. The least squares fitting code GOSIA was used for the analysis to extract both E2 and M1 transitional and E2 diagonal matrix elements.Results: The rotational ground state band was populated up to the 8+1 state as well as the 2+2 and 4+2 states. Using high precision spectroscopic data to constrain the GOSIA fit, the spectroscopic quadrupole moments of the 2+1 , 4+1 , and 6+1 states were determined for the first time. Conclusions: The spectroscopic quadrupole moments were found to be negative, large, and constant in the ground state band underlining the prolate axially deformed ground state band of 124Xe. The present experimental data confirm that the is broken in 124Xe. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Clement, E.; Lemasson, A.; Rejmund, M.; Jacquot, B.; Ralet, D.; Michelagnoli, C.; de France, G.] CEA DRF CNRS IN2P3, GANIL, Bd Henri Becquerel,BP 55027, F-14076 Caen, France |
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:000941893100005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5493 |
Permanent link to this record |
|
|
|
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 ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[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 |
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:000399846900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3091 |
Permanent link to this record |
|
|
|
Author |
AGATA Collaboration (Korten, W. et al); Gadea, A. |
Title |
Physics opportunities with the Advanced Gamma Tracking Array: AGATA |
Type |
Journal Article |
Year |
2020 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
Volume |
56 |
Issue |
5 |
Pages |
137 - 33pp |
Keywords |
|
Abstract |
New physics opportunities are opening up by the Advanced Gamma Tracking Array, AGATA, as it evolves to the full 4 pi instrument. AGATA is a high-resolution gamma -ray spectrometer, solely built from highly segmented high-purity Ge detectors, capable of measuring gamma rays from a few tens of keV to beyond 10 MeV, with unprecedented efficiency, excellent position resolution for individual gamma -ray interactions, and very high count-rate capability. As a travelling detector AGATA will be employed at all major current and near-future European research facilities delivering stable and radioactive ion beams. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Clement, E.] CEA DRF CNRS IN2P3, GANIL, Bd Henri Becquerel,BP 55027, F-14076 Caen 05, France, Email: w.korten@cea.fr |
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:000537289700004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4422 |
Permanent link to this record |
|
|
|
Author |
Clement, E.; Bracco, A.; Gadea, A.; Simpson, J. |
Title |
Organisation of the AGATA collaboration and physics campaigns |
Type |
Journal Article |
Year |
2023 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
Volume |
59 |
Issue |
7 |
Pages |
152 - 5pp |
Keywords |
|
Abstract |
The AGATA spectrometer has a well-established organisational and management structure for its construction and operation. The roles and responsibilities of each of the management committees and their interaction, as well as the scientific organisation is described in this contribution. The organisation of the present campaign, which aims to realise the 4p spectrometer, is presented. General comments on the previous physics campaigns at LNL (2010-2011), GSI (2012-2014) and GANIL (2015-2021) are made. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Clement, E.] GANIL, IN2P3, CNRS, CEA,DRF, BP 55027,Bd Henri Becquerel, F-14076 Caen, France, Email: angela.bracco@unimi.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:001032187000002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5603 |
Permanent link to this record |
|
|
|
Author |
AGATA collaboration (Collado, J. et al); Civera, J.V.; Gadea, A. |
Title |
AGATA phase 2 advancements in front-end electronics |
Type |
Journal Article |
Year |
2023 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
Volume |
59 |
Issue |
6 |
Pages |
133 - 20pp |
Keywords |
|
Abstract |
The AGATA collaboration has a long-standing leadership in the development of front-end electronics for high resolution ?-ray spectroscopy using large volume high purity germanium detectors. For two decades, the AGATA collaboration has been developing state-of-the-art digital electronics processing with high resolution sampling ADC, high-speed signal transfer and fast readout to a high throughput computing (HTC) farm for on-line pulse shape analysis. The collaboration is presently addressing the next challenge of equipping a 4p array with more than 6000 channels in high resolution mode, generating approximately 10 MHz of total trigger requests, coupled to a large variety of complementary instruments. A next generation of front-end electronics, presently under design, is based on industrial products (System on Module FPGA's), has higher integration and lower power consumption. In this contribution, the conceptual design of the new electronics is presented. The results of the very first tests of the pre-production electronics are presented as well as future perspectives. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Collado, J.; Gonzalez, V.] Univ Valencia, Dept Ingn Elect, Valencia 46100, Spain, Email: gadea@ific.uv.es |
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:001015065300001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5567 |
Permanent link to this record |
|
|
|
Author |
Colovic, P. et al; Gadea, A. |
Title |
Stretched configuration of states as inferred from gamma-ray angular distributions in Ar-40+Pb-208 neutron transfer reactions |
Type |
Journal Article |
Year |
2017 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
Volume |
53 |
Issue |
8 |
Pages |
166 - 6pp |
Keywords |
|
Abstract |
Angular distributions of.-rays for selected transitions in Ar-40,Ar-41,Ar-42 isotopes have been studied with the PRISMA magnetic spectrometer coupled to the CLARA gamma array. These transitions were populated in Ar isotopes reached via neutron transfer in the Ar-40 + Pb-208 reaction. By comparison with the shape of the experimental angular distribution of the known E2 transitions we established more firmly the spin and parity of excited states. In particular, in Ar-41 for the (11/2(-)) state through the (11/2(-)) -> 7/2(-) transition whose structure was discussed in terms of a phonon-fermion coupled state. The comparison with the expected fully aligned spin indicated that a high level of spin alignment has been reached. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Colovic, P.; Szilner, S.; Mijatovic, T.; Malenica, D. Jelavic; Soic, N.] Rudjer Boskovic Inst, Zagreb, Croatia, Email: petra.colovic@irb.hr |
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:000408433900002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3251 |
Permanent link to this record |
|
|
|
Author |
Corradi, L.; Szilner, S.; Pollarolo, G.; Colo, G.; Mason, P.; Farnea, E.; Fioretto, E.; Gadea, A.; Haas, F.; Jelavic-Malenica, D.; Marginean, N.; Michelagnoli, C.; Montagnoli, G.; Montanari, D.; Scarlassara, F.; Soic, N.; Stefanini, A.M.; Ur, C.A.; Valiente-Dobon, J.J. |
Title |
Single and pair neutron transfers at sub-barrier energies |
Type |
Journal Article |
Year |
2011 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
84 |
Issue |
3 |
Pages |
034603 - 10pp |
Keywords |
|
Abstract |
Multinucleon transfer cross sections in the (96)Zr+(40)Ca system have been measured, in inverse kinematics, at bombarding energies ranging from the Coulomb barrier to similar to 25% below. Targetlike recoils have been identified in A, Z and velocity with the large solid angle magnetic spectrometer PRISMA. The experimental data for one- and two-neutron transfer channels have been compared with semiclassical microscopic calculations. For the two-neutron transfer channels the relevance of the transitions to the ground state and to the 0(+) excited states of (42)Ca are discussed by employing, for the reaction mechanism, the successive approximation. It is found that the transition to the 0(+) state at similar to 6 MeV, whose wave function is dominated by the two neutrons in the 2p(3/2) shell, is much larger than the ground state one. The comparison with the inclusive data reveals that transitions to states with high multipolarity and non-natural parity are important. This suggests that more complex two-particle correlations have to be incorporated in the treatment of the transfer process. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Corradi, L; Szilner, S; Fioretto, E; Michelagnoli, C; Stefanini, AM; Valiente-Dobon, JJ] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy |
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 |
0556-2813 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000294566900007 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
751 |
Permanent link to this record |
|
|
|
Author |
AGATA Collaboration (Crespi, F.C.L. et al); Gadea, A. |
Title |
Response of AGATA segmented HPGe detectors to gamma rays up to 15.1 MeV |
Type |
Journal Article |
Year |
2013 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
Volume |
705 |
Issue |
|
Pages |
47-54 |
Keywords |
AGATA; Gamma-ray spectroscopy; Gamma-ray tracking; HPGe detectors; Pulse-shape and gamma-ray tracking algorithms; Semiconductor detector performance and simulations |
Abstract |
The response of AGATA segmented HPGe detectors to gamma rays in the energy range 2-15 MeV was measured. The 15.1 MeV gamma rays were produced using the reaction d(B-11,n gamma)C-12 at E-beam=19.1 MeV, while gamma rays between 2 and 9 MeV were produced using an Am-Be-Fe radioactive source. The energy resolution and linearity were studied and the energy-to-pulse-height conversion resulted to be linear within 0.05%.Experimental interaction multiplicity distributions are discussed and compared with the results of Geant4 simulations. It is shown that the application of gamma-ray tracking allows a suppression of background radiation caused by n-capture in Ge nuclei. Finally the Doppler correction for the 15.1 MeV gamma line, performed using the position information extracted with Pulse-shape analysis is discussed. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Crespi, F. C. L.; Avigo, R.; Camera, F.; Bottoni, S.; Bracco, A.; Ceruti, S.; Giaz, A.; Leoni, S.; Nicolini, R.; Pellegri, L.; Riboldi, S.; Vandone, V.] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy, Email: fabio.crespi@mi.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:000314826000009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1329 |
Permanent link to this record |
|
|
|
Author |
AGATA Collaboration (Crespi, F.C.L. et al); Gadea, A. |
Title |
1(-) and 2(+) discrete states in Zr-90 populated via the (O-17, O-17 'gamma) reaction |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
91 |
Issue |
2 |
Pages |
024323 - 9pp |
Keywords |
|
Abstract |
2(+) and 1(-) states in Zr-90 were populated via the (O-17, O-17 'gamma) reaction at 340 MeV. The gamma decay was measured with high resolution using the AGATA (advanced gamma tracking array demonstrator array). Differential cross sections were obtained at few different angles for the scattered particle. The results of the elastic scattering and inelastic excitation of 2(+), 3(,)(-) and 1(-) states are compared with distorted-wave Born approximation (DWBA) calculations, using both the standard collective form factor and a form factor obtained by folding microscopically calculated transition densities. This allowed to extract the isoscalar component of the 1(-) state at 6.424 MeV. The comparison of the present (17O, 17O 'gamma) data with existing (gamma,gamma') and (p, p') data in the corresponding region of the gamma continuum (6-11 MeV), characterized by a large E1 component, shows completely different behaviors of the cross section as a function of the nuclear excitation energy. The comparison of the data with DWBA calculations suggests a decrease of the isoscalar strength in the cross section with increasing excitation energy. |
Address ![sorted by Address field, ascending order (up)](img/sort_asc.gif) |
[Crespi, F. C. L.; Bracco, A.; Nicolini, R.; Leoni, S.; Bottoni, S.; Camera, F.; Corsi, A.; Pellegri, L.; Vandone, V.; Pullia, A.] Univ Milan, Dipartimento Fis, I-20133 Milan, Italy, Email: angela.bracco@mi.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 |
0556-2813 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000350104800002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2147 |
Permanent link to this record |