|   | 
Details
   web
Records
Author (up) n_TOF Collaboration (Tagliente, G. et al.); Domingo-Pardo, C.; Tain, J.L.
Title Neutron capture on (94)Zr: Resonance parameters and Maxwellian-averaged cross sections Type Journal Article
Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 84 Issue 1 Pages 015801 - 9pp
Keywords
Abstract The neutron capture cross sections of the Zr isotopes play an important role in nucleosynthesis studies. The s-process reaction flow between the Fe seed and the heavier isotopes passes through the neutron magic nucleus (90)Zr and through (91,92,93,94)Zr, but only part of the flow extends to (96)Zr because of the branching point at (95)Zr. Apart from their effect on the s-process flow, the comparably small isotopic (n, gamma) cross sections make Zr also an interesting structural material for nuclear reactors. The (94)Zr (n, gamma) cross section has been measured with high resolution at the spallation neutron source n_TOF at CERN and resonance parameters are reported up to 60 keV neutron energy.
Address [Tagliente, G; Colonna, N; Marrone, S; Terlizzi, R] Ist Nazl Fis Nucl, I-70126 Bari, Italy, Email: giuseppe.tagliente@ba.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:000292767200010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 687
Permanent link to this record
 

 
Author (up) n_TOF Collaboration (Tagliente, G. et al.); Domingo-Pardo, C.; Tain, J.L.
Title (96)Zr(n,gamma) measurement at the n_TOF facility at CERN Type Journal Article
Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 84 Issue 5 Pages 055802 - 8pp
Keywords
Abstract The (n,gamma) cross section of (96)Zr has been investigated at the CERN n_TOF spallation neutron source. High-resolution time-of-flight measurements using an enriched ZrO(2) sample allowed us to analyze 15 resonances below 40 keV with improved accuracy. On average, the capture widths were found to be 25% smaller than reported in earlier experiments. If complemented with the contribution by direct radiative capture, the derived Maxwellian averaged cross sections are consistent with activation data at kT = 25 keV. The present results confirm the astrophysical implications for the s-process branching at (95)Zr.
Address [Tagliente, G; Colonna, N; Marrone, S; Terlizzi, R] Ist Nazl Fis Nucl, I-70126 Bari, Italy, Email: giuseppe.tagliente@ba.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:000297121100005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 812
Permanent link to this record
 

 
Author (up) n_TOF Collaboration (Tarrio D. et al.); Domingo-Pardo, C.; Tain, J.L.
Title Neutron-induced fission cross section of Pb-nat and Bi-209 from threshold to 1 GeV: An improved parametrization Type Journal Article
Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 83 Issue 4 Pages 044620 - 9pp
Keywords
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.
Address [Tarrio, D.; Duran, I.; Paradela, C.] Univ Santiago de Compostela, Santiago De Compostela, Spain, Email: diego.tarrio@usc.es
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 ISI:000290163300003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 617
Permanent link to this record
 

 
Author (up) n_TOF Collaboration (Tarrio, D. et al); Domingo-Pardo, C.; Plag, R.; Plompen, A.; Tain, J.L.
Title High-energy Neutron-induced Fission Cross Sections of Natural Lead and Bismuth-209 Type Journal Article
Year 2011 Publication Journal of the Korean Physical Society Abbreviated Journal J. Korean Phys. Soc.
Volume 59 Issue 2 Pages 1904-1907
Keywords Nuclear data; Neutron-induced fission reactions; Pb-nat(n,f); Bi-209(n,f); Spallation neutron source; n_TOF facility
Abstract The CERN Neutron Time-Of-Flight (n_TOF) facility is well suited to measure small neutron-induced fission cross sections, as those of subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors. The fragment coincidence method allows to unambiguously identify the fission events. The present experiment provides the first results for neutron-induced fission up to 1 GeV for (nat)Pb and (209)Bi. A good agreement with previous experimental data below 200 MeV is shown. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross section is close to 1 GeV.
Address [Tarrio, D] Univ Santiago de Compostela, Fac Fis, Santiago De Compostela 15782, Spain, Email: diego.tarrio@usc.es
Corporate Author Thesis
Publisher Korean 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 0374-4884 ISBN Medium
Area Expedition Conference
Notes WOS:000294080700109 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 739
Permanent link to this record
 

 
Author (up) n_TOF Collaboration; Kappeler, F.; Mengoni, A.; Mosconi, M.; Fujii, K.; Heil, M.; Domingo-Pardo, C.
Title Neutron Studies for Dating the Universe Type Journal Article
Year 2011 Publication Journal of the Korean Physical Society Abbreviated Journal J. Korean Phys. Soc.
Volume 59 Issue 2 Pages 2094-2099
Keywords Neutron capture and inelastic scattering cross sections; Re/Os cosmo-chronometer
Abstract The neutron capture cross sections of (186)Os and (187)Os are of key importance for defining the 8-process abundance of (187)Os at the formation of the solar system. This quantity can be used to determine the radiogenic abundance component of (187)Os from the decay of (187)Re (t(1/2) = 41.2 Gyr) and to infer the time-duration of the nucleosynthesis in our galaxy (Re/Os cosmochronometer). The neutron capture cross sections of (186)Os, (187)Os, and (188)Os have been measured at the CERN nTOF facility from 1 eV to 1 MeV, covering the entire energy range of astrophysical interest. From these data Maxwellian averaged capture cross sections have been calculated with uncertainties between 3.3 and 4.7%. Additional information was obtained by measuring the inelastic scattering cross section of (187)Os at the Karlsruhe 3.7 MV Van de Graaff accelerator and by neutron resonance analyses of the nTOF capture data to establish a comprehensive experimental basis for the Hauser-Feshbach statistical model. Consistent I-IF calculations for the capture and inelastic reaction channels were performed to determine the stellar enhancement factors, which are required to correct the Maxwellian averaged cross sections for the effect of thermally populated excited states. The consequences of this analysis for the s-process component of the (187)Os abundance and the related impact on the evaluation of the time-duration of Galactic nucleosynthesis via the Re/Os cosmo-chronometer are discussed.
Address [Kappeler, F] Karlsruhe Inst Technol, Inst Kernphys, Karlsruhe, Germany, Email: franz.kaeppeler@kit.edu
Corporate Author Thesis
Publisher Korean 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 0374-4884 ISBN Medium
Area Expedition Conference
Notes WOS:000294080700156 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 742
Permanent link to this record