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Author n_TOF Collaboration (Karadimos, D. et al); Domingo-Pardo, C.; Tain, J.L.
Title Neutron-induced fission cross section of U-234 measured at the CERN n_TOF facility Type Journal Article
Year 2014 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 89 Issue (down) 4 Pages 044606 - 11pp
Keywords
Abstract The neutron-induced fission cross section of U-234 has been measured at the CERN nTOF facility relative to the standard fission cross section of U-235 from 20 keV to 1.4 MeV and of U-238 from 1.4 to 200 MeV. A fast ionization chamber (FIC) was used as a fission fragment detector with a detection efficiency of no less than 97%. The high instantaneous flux and the low background characterizing the nTOF facility resulted in wide-energy-range data (0.02 to 200 MeV), with high energy resolution, high statistics, and systematic uncertainties bellow 3%. Previous investigations around the energy of the fission threshold revealed structures attributed to beta-vibrational levels, which have been confirmed by the present measurements. Theoretical calculations have been performed, employing the TALYS code with model parameters tuned to fairly reproduce the experimental data.
Address [Karadimos, D.; Vlastou, R.; Diakaki, M.; Papadopoulos, C.; Tsinganis, A.] Natl Tech Univ Athens, GR-10682 Athens, Greece, Email: dkaradim@gmail.com
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:000341496900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1924
Permanent link to this record
 
 
Author n_TOF Collaboration (Zugec, P. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L.
Title Integral measurement of the C-12(n, p)B-12 reaction up to 10 GeV Type Journal Article
Year 2016 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 52 Issue (down) 4 Pages 101 - 13pp
Keywords
Abstract The integral measurement of the C-12(n, p)B-12 reaction was performed at the neutron time-of-flight facility nTOF at CERN. The total number of B-12 nuclei produced per neutron pulse of the nTOF beam was determined using the activation technique in combination with a time-of-flight technique. The cross section is integrated over the n_TOF neutron energy spectrum from reaction threshold at 13.6 MeV to 10 GeV. Having been measured up to 1 GeV on basis of the U-235(n, f) reaction, the neutron energy spectrum above 200 MeV has been re-evaluated due to the recent extension of the cross section reference for this particular reaction, which is otherwise considered a standard up to 200 MeV. The results from the dedicated GEANT4 simulations have been used to evaluate the neutron flux from 1 GeV up to 10 GeV. The experimental results related to the C-12(n, p)B-12 reaction are compared with the evaluated cross sections from major libraries and with the predictions of different GEANT4 models, which mostly underestimate the B-12 production. On the contrary, a good reproduction of the integral cross section derived from measurements is obtained with TALYS-1.6 calculations, with optimized parameters.
Address [Zugec, P.; Bosnar, D.] Univ Zagreb, Fac Sci, Dept Phys, Zagreb 41000, Croatia, Email: pzugec@phy.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:000376181400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2683
Permanent link to this record
 
 
Author n_TOF Collaboration (Damone, L. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Be-7 (n,p)Li-7 Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN Type Journal Article
Year 2018 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 121 Issue (down) 4 Pages 042701 - 7pp
Keywords
Abstract We report on the measurement of the Be-7(n,p)Li-7 cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a Be-7 ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal Li-7(p,n)Be-7 reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p + Li-7 reaction is also discussed.
Address [Damone, L.; Barbagallo, M.; Mastromarco, M.; Colonna, N.; Mazzone, A.; Tagliente, G.; Variale, V.] Ist Nazl Fis Nucl, Sez Bari, Bari, Italy, Email: alberto.mengoni@enea.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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000439547100004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3674
Permanent link to this record
 
 
Author n_TOF Collaboration (Gawlik, A. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Measurement of the Ge-70(n, gamma) cross section up to 300 keV at the CERN n_TOF facility Type Journal Article
Year 2019 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 100 Issue (down) 4 Pages 045804 - 10pp
Keywords
Abstract Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The (n,gamma) cross section on Ge-70, which is mainly produced in the s process, was measured at the neutron time-of-flight facility n_TOF at CERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sections up to 300 keV. Stellar cross sections were calculated from kT = 5 keV to kT = 100 keV and are in very good agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average cross sections are in agreement with Walter and Beer (1985) over most of the neutron energy range covered, while they are systematically smaller for neutron energies above 150 keV. We have calculated isotopic abundances produced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close to solar model shows a good global match to solar system abundances in the range of mass numbers A = 60-80.
Address [Gawlik, A.; Andrzejewski, J.; Perkowski, J.; Marganiec, J.] Univ Lodz, Lodz, Poland, Email: claudia.lederer-woods@ed.ac.uk
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:000490751000004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4174
Permanent link to this record
 
 
Author n_TOF Collaboration (Balibrea-Correa, J. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Measurement of the alpha ratio and (n, gamma) cross section of U-235 from 0.2 to 200 eV at n_TOF Type Journal Article
Year 2020 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 102 Issue (down) 4 Pages 044615 - 18pp
Keywords
Abstract We measured the neutron capture-to-fission cross-section ratio (alpha ratio) and the capture cross section of U-235 between 0.2 and 200 eV at the nTOF facility at CERN. The simultaneous measurement of neutron-induced capture and fission rates was performed by means of the nTOF BaF2 Total Absorption Calorimeter (TAC), used for detection of gamma rays, in combination with a set of micromegas detectors used as fission tagging detectors. The energy dependence of the capture cross section was obtained with help of the Li-6(n, t) standard reaction determining the n_TOF neutron fluence; the well-known integral of the U-235(n, f) cross section between 7.8 and 11 eV was then used for its absolute normalization. The alpha ratio, obtained with slightly higher statistical fluctuations, was determined directly, without need for any reference cross section. To perform the analysis of this measurement we developed a new methodology to correct the experimentally observed effect that the probabilities of detecting a fission reaction in the TAC and the micromegas detectors are not independent. The results of this work have been used in a new evaluation of U-235 performed within the scope of the Collaborative International Evaluated Library Organisation (CIELO) Project, and are consistent with the ENDF/B-VIII.0 and JEFF-3.3 capture cross sections below 4 eV and above 100 eV. However, the measured capture cross section is on average 10% larger between 4 and 100 eV.
Address [Balibrea-Correa, J.; Mendoza, E.; Cano-Ott, D.] Ctr Invest Energet Medioambientales & Tecnol, CIEMAT, Madrid, Spain, Email: emilio.mendoza@ciemat.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 WOS:000579839000003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4575
Permanent link to this record
 
 
Author n_TOF Collaboration (Dietz, M. et al); Domingo-Pardo, C.; Tain, J.L.
Title Measurement of the Ge-72(n, y) cross section over a wide neutron energy range at the CERN n_TOF facility Type Journal Article
Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 103 Issue (down) 4 Pages 045809 - 8pp
Keywords
Abstract The Ge-72(n, gamma) cross section was measured for neutron energies up to 300 keV at the neutron time-of-flight facility n_TOF (CERN), Geneva, for the first time covering energies relevant to heavy-element synthesis in stars. The measurement was performed at the high-resolution beamline EAR-1, using an isotopically enriched (GeO2)-Ge-72 sample. The prompt capture gamma rays were detected with four liquid scintillation detectors, optimized for low neutron sensitivity. We determined resonance capture kernels up to a neutron energy of 43 keV, and averaged cross sections from 43 to 300 keV. Maxwellian-averaged cross section values were calculated from kT = 5 to 100 keV, with uncertainties between 3.2% and 7.1%. The new results significantly reduce uncertainties of abundances produced in the slow neutron capture process in massive stars.
Address [Dietz, M.; Lederer-Woods, C.; Tattersall, A.; Battino, U.; Kahl, D.; Lonsdale, S. J.; Woods, P. J.] Univ Edinburgh, Sch Phys & Astron, Edinburgh, Midlothian, Scotland, Email: mirco.dietz@ptb.de
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:000647603800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4811
Permanent link to this record
 
 
Author n_TOF Collaboration (Gawlik, A. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Radiative Neutron Capture Cross-Section Measurement of Ge Isotopes at n_TOF CERN Facility and Its Importance for Stellar Nucleosynthesis Type Journal Article
Year 2021 Publication Acta Physica Polonica A Abbreviated Journal Acta Phys. Pol. A
Volume 139 Issue (down) 4 Pages 383-388
Keywords n_TOF; neutron time-of-flight; neutron capture cross-section; MACS
Abstract This manuscript summarizes the results of radiative neutron capture cross-section measurements on two stable germanium isotopes, Ge-70 and Ge-73. Experiments were performed at the n_TOF facility at CERN via the time-of-flight technique, over a wide neutron energy range, for all stable germanium isotopes (70,72,73,74, and 76). Results for Ge-70 [Phys. Rev. C 100, 045804 (2019)] and Ge-73 [Phys. Lett. B 790, 458 (2019)] are already published. In the field of nuclear structure, such measurements allow to study excited levels close to the neutron binding energy and to obtain information on nuclear properties. In stellar nucleosynthesis research, neutron induced reactions on germanium are of importance for nucleosynthesis in the weak component of the slow neutron capture processes.
Address [Gawlik, A.; Andrzejewski, J.; Perkowski, J.] Univ Lodz, Lodz, Poland, Email: aleksandra.gawlik@uni.lodz.pl
Corporate Author Thesis
Publisher Polish Acad Sciences Inst Physics Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0587-4246 ISBN Medium
Area Expedition Conference
Notes WOS:000653413700004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4840
Permanent link to this record
 
 
Author n_TOF Collaboration (Gawlik, A. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Measurement of the Ge-76(n, gamma) cross section at the n_TOF facility at CERN Type Journal Article
Year 2021 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 104 Issue (down) 4 Pages 044610 - 7pp
Keywords
Abstract The Ge-76(n, gamma) reaction has been measured at the n_TOF facility at CERN via the time-of-flight technique. Neutron capture cross sections on Ge-76 are of interest to a variety of low-background experiments, such as neutrinoless double beta decay searches, and to nuclear astrophysics. We have determined resonance capture kernels up to 52 keV neutron energy and used the new data to calculate Maxwellian-averaged neutron capture cross sections for k(B)T values of 5 to 100 keV.
Address [Gawlik-Ramiega, A.; Andrzejewski, J.; Perkowski, J.] Univ Lodz, Lodz, Poland, Email: aleksandra.gawlik@uni.lodz.pl
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:000707420400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5003
Permanent link to this record
 
 
Author n_TOF Collaboration (Tarrío, D. et al); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L.
Title Neutron-induced fission cross sections of Th-232 and U-233 up to 1 GeV using parallel plate avalanche counters at the CERN n_TOF facility Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 107 Issue (down) 4 Pages 044616 - 21pp
Keywords
Abstract The neutron-induced fission cross sections of Th-232 and U-233 were measured relative to U-235 in a wide neutron energy range up to 1 GeV (and from fission threshold in the case of Th-232, and from 0.7 eV in case of U-233), using the white-spectrum neutron source at the CERN Neutron Time-of-Flight (nTOF) facility. Parallel plate avalanche counters (PPACs) were used, installed at the Experimental Area 1 (EAR1), which is located at 185 m from the neutron spallation target. The anisotropic emission of fission fragments were taken into account in the detection efficiency by using, in the case of U-233, previous results available in EXFOR, whereas in the case of Th-232 these data were obtained from our measurement, using PPACs and targets tilted 45 degrees with respect to the neutron beam direction. Finally, the obtained results are compared with past measurements and major evaluated nuclear data libraries. Calculations using the high-energy reaction models INCL++ and ABLA07 were performed and some of their parameters were modified to reproduce the experimental results. At high energies, where no other neutron data exist, our results are compared with experimental data on proton-induced fission. Moreover, the dependence of the fission cross section at 1 GeV with the fissility parameter of the target nucleus is studied by combining those ( p, f) data with our (n, f) data on Th-232 and U-233 and on other isotopes studied earlier at nTOF using the same experimental setup.
Address [Tarrio, D.] Uppsala Univ, Dept Phys & Astron, Box 516, S-75120 Uppsala, Sweden, Email: diego.tarrio@physics.uu.se
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:001021341000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5618
Permanent link to this record
 
 
Author n_TOF Collaboration (Lederer, C. et al); Domingo-Pardo, C.; Tain, J.L.
Title Au-197(n,gamma) cross section in the unresolved resonance region Type Journal Article
Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 83 Issue (down) 3 Pages 034608 - 11pp
Keywords
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.
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
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:000288511800004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 550
Permanent link to this record