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Author |
Molina, F. et al; Rubio, B.; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Gadea, A.; Tain, J.L. |
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Title |
T-z =-1 -> 0 beta decays of Ni-54, Fe-50, Cr-46, and Ti-42 and comparison with mirror (He-3,t) measurements |
Type |
Journal Article |
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Year |
2015 |
Publication |
Physical Review C |
Abbreviated Journal  |
Phys. Rev. C |
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Volume |
91 |
Issue |
1 |
Pages |
014301 - 19pp |
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Keywords |
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Abstract |
We have studied the beta decay of the T-z = -1, f(7/2) shell nuclei Ni-54, Fe-50, Cr-46, and Ti-42 produced in fragmentation reactions. The proton separation energies in the daughter T-z = 0 nuclei are relatively large (approximate to 4-5 MeV) so studies of the. rays are essential. The experiments were performed at GSI as part of the Stopped-beam campaign with the RISING setup consisting of 15 Euroball Cluster Ge detectors. From the newly obtained high precision beta-decay half-lives, excitation energies, and beta branching ratios, we were able to extract Fermi and Gamow-Teller transition strengths in these beta decays. With these improved results it was possible to compare in detail the Gamow-Teller (GT) transition strengths observed in beta decay including a sensitivity limit with the strengths of the T-z = +1 to T-z = 0 transitions derived from high resolution (He-3,t) reactions on the mirror target nuclei at RCNP, Osaka. The accumulated B(GT) strength obtained from both experiments looks very similar although the charge exchange reaction provides information on a broader energy range. Using the “merged analysis” one can obtain a full picture of the B(GT) over the full Q(beta) range. Looking at the individual transitions some differences are observed, especially for the weak transitions. Their possible origins are discussed. |
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Address |
[Molina, F.; Rubio, B.; Agramunt, J.; Algora, A.; Domingo-Pardo, C.; Gadea, A.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: berta.rubio@ific.uv.es |
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Publisher |
Amer Physical Soc |
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English |
Summary Language |
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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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ISSN |
0556-2813 |
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Conference |
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Notes |
WOS:000347924300002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2087 |
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Author |
n_TOF Collaboration (Paradela, C. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. |
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Title |
High-accuracy determination of the U-238/U-235 fission cross section ratio up to approximate to 1 GeV at n_TOF at CERN |
Type |
Journal Article |
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Year |
2015 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
91 |
Issue |
2 |
Pages |
024602 - 11pp |
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Keywords |
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Abstract |
The U-238 to U-235 fission cross section ratio has been determined at nTOF up to approximate to 1 GeV, with two different detection systems, in different geometrical configurations. A total of four datasets has been collected and compared. They are all consistent to each other within the relative systematic uncertainty of 3-4%. The data collected at nTOF have been suitably combined to yield a unique fission cross section ratio as a function of neutron energy. The result confirms current evaluations up to 200 MeV. Good agreement is also observed with theoretical calculations based on the INCL++ /Gemini++ combination up to the highest measured energy. The n_TOF results may help solve a long-standing discrepancy between the two most important experimental datasets available so far above 20 MeV, while extending the neutron energy range for the first time up to approximate to 1 GeV. |
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Address |
[Paradela, C.; Tarrio, D.; Leal-Cidoncha, E.; Duran, I.; Alvarez, H.] Univ Santiago de Compostela, Santiago De Compostela, Spain, Email: nicola.colonna@ba.infn.it |
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Publisher |
Amer Physical Soc |
Place of Publication |
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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 |
0556-2813 |
ISBN |
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Expedition |
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Conference |
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Notes |
WOS:000350174000004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2139 |
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Author |
n_TOF Collaboration (Diakaki, M. et al); Domingo-Pardo, C.; Tain, J.L. |
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Title |
Neutron-induced fission cross section of Np-237 in the keV to MeV range at the CERN n_TOF facility |
Type |
Journal Article |
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Year |
2016 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
93 |
Issue |
3 |
Pages |
034614 - 12pp |
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Keywords |
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Abstract |
The neutron-induced fission cross section of Np-237 was experimentally determined at the high-resolution and high-intensity facility n_TOF, at CERN, in the energy range 100 keV to 9 MeV, using the U-235(n, f) and U-238(n, f) cross section standards below and above 2 MeV, respectively. A fast ionization chamber was used in order to detect the fission fragments from the reactions and the targets were characterized as far as their mass and homogeneity are concerned by means of a spectroscopy and Rutherford backscattering spectroscopy respectively. Theoretical calculations within the Hauser-Feshbach formalism have been performed, employing the EMPIRE code, and the model parameters were tuned in order to successfully reproduce the experimental fission cross-sectional data and simultaneously all the competing reaction channels. |
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Address |
[Diakaki, M.; Aerts, G.; Andriamonje, S.; Berthoumieux, E.] CEA Saclay, DSM, F-91191 Gif Sur Yvette, France, Email: maria.diakaki@cea.fr |
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Publisher |
Amer Physical Soc |
Place of Publication |
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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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Area |
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Expedition |
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Conference |
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Notes |
WOS:000372415600004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2591 |
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Author |
n_TOF Collaboration (Mingrone, F. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. |
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Title |
Neutron capture cross section measurement of U-238 at the CERN n_TOF facility in the energy region from 1 eV to 700 keV |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
95 |
Issue |
3 |
Pages |
034604 - 14pp |
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Keywords |
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Abstract |
The aim of this work is to provide a precise and accurate measurement of the U-238(n,gamma) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behavior of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross section of U-238 should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the nTOF facility, were proposed and carried out within the 7th Framework Project ANDES of the European Commission. The results of one of these U-238(n, gamma) measurements performed at the nTOF CERN facility are presented in this work. The gamma-ray cascade following the radiative neutron capture has been detected exploiting a setup of two C6D6 liquid scintillators. Resonance parameters obtained from this work are on average in excellent agreement with the ones reported in evaluated libraries. In the unresolved resonance region, this work yields a cross section in agreement with evaluated libraries up to 80 keV, while for higher energies our results are significantly higher. |
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Address |
[Mingrone, F.; Berthoumieux, E.; Brugger, M.; Calviani, M.; Cerutti, F.; Chiaveri, E.; Chin, M.; Guerrero, C.; Hernandez-Prieto, A.; Kadi, Y.; Losito, R.; Rubbia, C.; Tsinganis, A.; Vlachoudis, V.] CERN, European Org Nucl Res, Geneva, Switzerland, Email: federica.mingrone@cern.ch |
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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:000396022500002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3030 |
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Author |
PreSPEC and AGATA Collaborations (Ralet, D. et al); Domingo-Pardo, C.; Gadea, A.; Huyuk, T. |
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Title |
Lifetime measurement of neutron-rich even-even molybdenum isotopes |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
95 |
Issue |
3 |
Pages |
034320 - 11pp |
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Keywords |
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Abstract |
Background: In the neutron-rich A approximate to 100 mass region, rapid shape changes as a function of nucleon number as well as coexistence of prolate, oblate, and triaxial shapes are predicted by various theoretical models. Lifetime measurements of excited levels in the molybdenum isotopes allow the determination of transitional quadrupole moments, which in turn provides structural information regarding the predicted shape change. Purpose: The present paper reports on the experimental setup, the method that allowed one to measure the lifetimes of excited states in even-even molybdenum isotopes from mass A = 100 up to mass A = 108, and the results that were obtained. Method: The isotopes of interest were populated by secondary knock-out reaction of neutron-rich nuclei separated and identified by the GSI fragment separator at relativistic beam energies and detected by the sensitive PreSPEC-AGATA experimental setup. The latter included the Lund-York-Cologne calorimeter for identification, tracking, and velocity measurement of ejectiles, and AGATA, an array of position sensitive segmented HPGe detectors, used to determine the interaction positions of the gamma ray enabling a precise Doppler correction. The lifetimes were determined with a relativistic version of the Doppler-shift-attenuation method using the systematic shift of the energy after Doppler correction of a gamma-ray transition with a known energy. This relativistic Doppler-shift-attenuation method allowed the determination of mean lifetimes from 2 to 250 ps. Results: Even-even molybdenum isotopes from mass A = 100 to A = 108 were studied. The decays of the low-lying states in the ground-state band were observed. In particular, two mean lifetimes were measured for the first time: tau = 29.7(-9.1)(+11.3) ps for the 4(+) state of Mo-108 and tau = 3.2(-0.7)(+ 0.7) ps for the 6(+) state of Mo-102. Conclusions: The reduced transition strengths B(E2), calculated from lifetimes measured in this experiment, compared to beyond-mean-field calculations, indicate a gradual shape transition in the chain of molybdenum isotopes when going from A = 100 to A = 108 with a maximum reached at N = 64. The transition probabilities decrease for Mo-108 which may be related to its well-pronounced triaxial shape indicated by the calculations. |
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Address |
[Ralet, D.; Cortes, M. L.; Gregor, E.; Guastalla, G.; Givechev, A.; Habermann, T.; Louchart-Henning, C.; Merchan, E.; Pietralla, N.; Reese, M.; Singh, P. P.; Stahl, C.] Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, Germany, Email: ralet@csnsm.in2p3.fr |
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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:000399143200002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3045 |
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| Permanent link to this record |
