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Author |
n_TOF Collaboration (Tarrio D. et al.); Domingo-Pardo, C.; Tain, J.L. |
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Title |
Neutron-induced fission cross section of Pb-nat and Bi-209 from threshold to 1 GeV: An improved parametrization |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
83 |
Issue |
4 |
Pages |
044620 - 9pp |
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Keywords |
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Abstract |
Neutron-induced fission cross sections for Pb-nat and Bi-209 were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n_TOF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides the first results for these nuclei above 200 MeV. The cross sections were measured relative to U-235 and U-238 in a dedicated fission chamber with parallel plate avalanche counter detectors. Results are compared with previous experimental data. Upgraded parametrizations of the cross sections are presented, from threshold energy up to 1 GeV. The proposed new sets of fitting parameters improve former results along the whole energy range. |
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Address |
[Tarrio, D.; Duran, I.; Paradela, C.] Univ Santiago de Compostela, Santiago De Compostela, Spain, Email: diego.tarrio@usc.es |
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Thesis |
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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 |
0556-2813 |
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Expedition |
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Conference |
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Notes |
ISI:000290163300003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
617 |
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Permanent link to this record |
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Author |
n_TOF Collaboration (Lederer, C. et al); Domingo-Pardo, C.; Tain, J.L. |
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Title |
Au-197(n,gamma) cross section in the unresolved resonance region |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
83 |
Issue |
3 |
Pages |
034608 - 11pp |
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Keywords |
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Abstract |
The cross section of the reaction Au-197(n,gamma) was measured with the time-of-flight technique at the n_TOF (neutron time-of-flight) facility in the unresolved resonance region between 5 and 400 keV using a pair of C6D6 (where D denotes H-2) liquid scintillators for the detection of prompt capture gamma rays. The results with a total uncertainty of 3.9%-6.7% for a resolution of 20 bins per energy decade show fair agreement with the Evaluated Nuclear Data File Version B-VII.0 (ENDF/B-VII.0), which contains the standard evaluation. The Maxwellian-averaged cross section (MACS) at 30 keV is in excellent agreement with the one according to the ENDF/B-VII.0 evaluation and 4.7% higher than the MACS measured independently by activation technique. Structures in the cross section, which had also been reported earlier, have been interpreted as being due to clusters of resonances. |
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Address |
[Colonna, N.; Barbagallo, M.; Marrone, S.; Tagliente, G.; Terlizzi, R.] Ist Nazl Fis Nucl, I-70126 Bari, Italy, Email: claudia.lederer@univie.ac.at |
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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 |
ISI:000288511800004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
550 |
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Permanent link to this record |
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Author |
n_TOF Collaboration (Paradela, C. et al); Domingo-Pardo, C.; Tain, J.L. |
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Title |
Neutron-induced fission cross section of U-234 and Np-237 measured at the CERN Neutron Time-of-Flight (n_TOF) facility |
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 |
3 |
Pages |
034601 - 11pp |
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Keywords |
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Abstract |
A high-resolution measurement of the neutron-induced fission cross section of U-234 and Np-237 has been performed at the CERN Neutron Time-of-Flight facility. The cross sections have been determined in a wide energy range from 1 eV to 1 GeV using the evaluated U-235 cross section as reference. In these measurements the energy determination for the U-234 resonances could be improved, whereas previous discrepancies for the Np-237 resonances were confirmed. New cross-section data are provided for high neutron energies that go beyond the limits of prior evaluations, obtaining important differences in the case of Np-237. |
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Address |
[Paradela, C.; Duran, I.; Tarrio, D.; Alvarez, H.] Univ Santiago de Compostela, Santiago De Compostela, Spain, Email: carlos.paradela@usc.es |
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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 |
ISI:000281651400002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
382 |
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Permanent link to this record |
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Author |
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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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 |
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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Permanent link to this record |
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Author |
n_TOF Collaboration (Mosconi, M. et al); Domingo-Pardo, C.; Tain, J.L. |
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Title |
Neutron physics of the Re/Os clock. I. Measurement of the (n, gamma) cross sections of Os-186,Os-187,Os-188 at the CERN n_TOF facility |
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 |
015802 - 10pp |
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Keywords |
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Abstract |
The precise determination of the neutron capture cross sections of Os-186 and Os-187 is important to define the s-process abundance of Os-187 at the formation of the solar system. This quantity can be used to evaluate the radiogenic component of the abundance of Os-187 due to the decay of the unstable Re-187 (t(1/2) = 41.2 Gyr) and from this to infer the time duration of the nucleosynthesis in our galaxy (Re/Os cosmochronometer). The neutron capture cross sections of Os-186, Os-187, and Os-188 have been measured at the CERN n_TOF facility from 1 eV to 1 MeV, covering the entire energy range of astrophysical interest. The measurement has been performed by time-of-flight technique using isotopically enriched samples and two C6D6 scintillation detectors for recording the prompt. rays emitted in the capture events. Maxwellian averaged capture cross sections have been determined for thermal energies between kT = 5 and 100 keV corresponding to all possible s-process scenarios. The estimated uncertainties for the values at 30 keV are 4.1, 3.3, and 4.7% for Os-186, Os-187, and Os-188, respectively. |
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Address |
[Mosconi, M.; Domingo-Pardo, C.; Kaeppeler, F.; Audouin, L.; Bisterzo, S.; Dillmann, I.; Heil, M.; Plag, R.; Voss, F.; Walter, S.; Wisshak, K.] KIT, Inst Kernphys, D-76021 Karlsruhe, Germany, Email: Marita.Mosconi@ptb.de |
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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 |
ISI:000279940200007 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
409 |
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Permanent link to this record |