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n_TOF Collaboration (Fujii, K. et al); Domingo-Pardo, C.; Tain, J.L. |
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Title  |
Neutron physics of the Re/Os clock. III. Resonance analyses and stellar (n, gamma) cross sections of Os-186,Os-187,Os-188 |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
82 |
Issue |
1 |
Pages |
015804 - 18pp |
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Keywords |
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Abstract |
Neutron resonance analyses have been performed for the capture cross sections of Os-186, Os-187, and Os-188 measured at the n_TOF facility at CERN. Resonance parameters have been extracted up to 5, 3, and 8 keV, respectively, using the SAMMY code for a full R-matrix fit of the capture yields. From these results average resonance parameters were derived by a statistical analysis to provide a comprehensive experimental basis for modeling of the stellar neutron capture rates of these isotopes in terms of the Hauser-Feshbach statistical model. Consistent calculations for the capture and inelastic reaction channels are crucial for the evaluation of stellar enhancement factors to correct the Maxwellian averaged cross sections obtained from experimental data for the effect of thermally populated excited states. These factors have been calculated for the full temperature range of current scenarios of s-process nucleosynthesis using the combined information of the experimental data in the region of resolved resonances and in the continuum. The consequences of this analysis for the s-process component of the Os-187 abundance and the related impact on the evaluation of the time duration of galactic nucleosynthesis via the Re/Os cosmochronometer are discussed. |
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Address |
[Fujii, K.; Abbondanno, U.; Belloni, F.; Milazzo, P. M.; Moreau, C.] Ist Nazl Fis Nucl, I-34149 Trieste, Italy, Email: Kaori.Fujii@ts.infn.it |
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Amer Physical Soc |
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Language |
English |
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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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Conference |
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Notes |
ISI:000279940200009 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
410 |
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Author |
n_TOF Collaboration (Massimi, C. et al.); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. |
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Title |
Neutron spectroscopy of Mg-26 states: Constraining the stellar neutron source Ne-22(alpha, n)Mg-25 |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
768 |
Issue |
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Pages |
1-6 |
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Keywords |
s Process; alpha+Ne-22; Neutron spectroscopy |
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Abstract |
This work reports on accurate, high-resolution measurements of the Mg-25(n, gamma)Mg-26 and Mg-25(n, tot) cross sections in the neutron energy range from thermal to about 300 keV, leading to a significantly improved Mg-25(n, gamma)Mg-26 parametrization. The relevant resonances for n+Mg-25 were characterized from a combined R-matrix analysis of the experimental data. This resulted in an unambiguous spin/parity assignment of the corresponding excited states in Mg-26. With this information experimental upper limits of the reaction rates for Ne-22(alpha, n)Mg-25 and Ne-22(alpha, gamma)Mg-26 were established, potentially leading to a significantly higher (alpha, n)/(alpha, gamma) ratio than previously evaluated. The impact of these results has been studied for stellar models in the mass range 2 to 25 M-circle dot. (C) 2017 The Author(s). Published by Elsevier B.V. |
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Address |
[Massimi, C.; Barbagallo, M.; Becvar, F.; Bisterzok, S.; Castelluccio, D. M.; Eleftheriadis, C.; Finocchiaro, P.; Kokkoris, M.; Marganiec, J.; Plompen, A.; Praena, J.; Rubbia, C.; Weiss, C.] Ist Nazl Fis Nucl, Bologna, Italy, Email: cristian.massimi@bo.infn.it |
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Publisher |
Elsevier Science Bv |
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English |
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Edition |
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ISSN |
0370-2693 |
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Conference |
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Notes |
WOS:000400677700001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3112 |
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Author |
n_TOF Collaboration (Belloni, F. et al); Domingo-Pardo, C.; Tain, J.L. |
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Title |
Neutron-induced fission cross section measurement of U-233, Am-241 and Am-243 in the energy range 0.5 MeV <= E-n <= 20 MeV at n_TOF at CERN |
Type |
Journal Article |
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Year |
2012 |
Publication |
Physica Scripta |
Abbreviated Journal |
Phys. Scr. |
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Volume |
T150 |
Issue |
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Pages |
014005 - 4pp |
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Keywords |
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Abstract |
Neutron-induced fission cross section measurements of U-233, Am-243 and Am-241 relative to U-235 have been carried out at the neutron time-of-flight facility n_TOF at CERN. A fast ionization chamber has been employed. All samples were located in the same detector; therefore the studied elements and the reference U-235 target are subject to the same neutron beam. |
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Address |
[Belloni, F.; Milazzo, P. M.; Abbondanno, U.; Fujii, K.; Moreau, C.] Ist Nazl Fis Nucl, Trieste, Italy, Email: francesca.belloni@cea.fr |
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Publisher |
Iop Publishing Ltd |
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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 |
0031-8949 |
ISBN |
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Conference |
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Notes |
WOS:000309605500006 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1184 |
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Author |
n_TOF Collaboration (Calviani, M. et al); Giubrone, G.; Tain, J.L. |
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Title |
Neutron-induced fission cross section of Cm-245: New results from data taken at the time-of-flight facility n_TOF |
Type |
Journal Article |
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Year |
2012 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
85 |
Issue |
3 |
Pages |
034616 - 10pp |
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Keywords |
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Abstract |
The neutron-induced fission cross section of Cm-245 was measured at n_TOF in a wide energy range and with high resolution. The energy dependence, measured in a single measurement from 30 meV to 1 MeV neutron energy, has been determined with 5% accuracy relative to the U-235(n,f) cross section. In order to reduce the uncertainty on the absolute value, the data have been normalized at thermal energy to recent measurements performed at ILL and BR1. In the energy range of overlap, the results are in fair agreement with some previous measurements and confirm, on average, the evaluated cross section in the ENDF/B-VII.0 database, although sizable differences are observed for some important resonances below 20 eV. A similar behavior is observed relative to JENDL/AC-2008, a reactor-oriented database for actinides. The new results contribute to the overall improvement of the databases needed for the design of advanced reactor systems and may lead to refinements of fission models for the actinides. |
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Address |
[Calviani, M.; Gramegna, F.; Mastinu, P.; Sarchiapone, L.] Univ Padua, Ist Nazl Fis Nucl, Lab Nazl Legnaro, Padua, Italy, Email: marco.calviani@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 |
0556-2813 |
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:000302105100004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
956 |
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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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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: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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| Permanent link to this record |
