Records |
Author |
n_TOF Collaboration (Mastromarco, M. et al); Domingo-Pardo, C.; Tain, J.L. |
Title |
High accuracy, high resolution U-235(n,f) cross section from n_TOF (CERN) from 18 meV to 10 keV |
Type |
Journal Article |
Year |
2022 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
Volume |
58 |
Issue |
8 |
Pages |
147 - 13pp |
Keywords |
|
Abstract |
The U-235(n,f) cross section was measured in a wide energy range (18 meV-170 keV) at the nTOF facility at CERN, relative to Li-6(n,t) and B-10(n,alpha) standard reactions, with high resolution and accuracy, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. In this paper we report on the results in the region between 18 meV and 10 keV neutron energy. A resonance analysis has been performed up to 200 eV, with the code SAMMY. The resulting fission kernels are compared with the ones extracted on the basis of the resonance parameters of the most recent major evaluated data libraries. A comparison of the nTOF data with the evaluated cross sections is also performed from thermal to 10 keV neutron energy for the energy-averaged cross section in energy groups of suitably chosen width. A good agreement, within 0.5%, is found on average between the new results and the latest evaluated data files ENDF/B-VIII.0 and JEFF-3.3, as well as with respect to the broad group average fission cross section established in the framework of the standard working group of IAEA (the so-called reference file). However, some discrepancies, of up to 4%, are still present in some specific energy regions. The new dataset here presented, characterized by a unique combination of high resolution and accuracy, low background and wide energy range, can help to improve the evaluations from the Resolved Resonance Region up to 10 keV, also reducing the uncertainties that affect this region. |
Address |
[Mastromarco, M.; Colonna, N.; Diacono, D.] Ist Nazl Fis Nucl, Sez Bari, Bari, Italy, Email: amaducci@lns.infn.it |
Corporate Author |
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Thesis |
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Publisher |
Springer |
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 |
1434-6001 |
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:000840312100002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5328 |
Permanent link to this record |
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Author |
n_TOF Collaboration (Lederer-Woods, C. et al.); Domingo-Pardo, C.; Tain, J.L. |
Title |
Destruction of the cosmic gamma-ray emitter Al-26 in massive stars: Study of the key Al-26(n, p) reaction |
Type |
Journal Article |
Year |
2021 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
104 |
Issue |
2 |
Pages |
L022803 - 7pp |
Keywords |
|
Abstract |
The Al-26(n, p) Mg-26 reaction is the key reaction impacting on the abundances of the cosmic gamma-ray emitter Al-26 produced in massive stars and impacts on the potential pollution of the early solar system with Al-26 by asymptotic giant branch stars. We performed a measurement of the Al-26(n, p) Mg-26 cross section at the high-flux beam line EAR-2 at the n_TOF facility (CERN). We report resonance strengths for eleven resonances, nine being measured for the first time, while there is only one previous measurement for the other two. Our resonance strengths are significantly lower than the only previous values available. Our cross-section data range to 150 keV neutron energy, which is sufficient for a reliable determination of astrophysical reactivities up to 0.5 GK stellar temperature. |
Address |
[Lederer-Woods, C.; Woods, P. J.; Davinson, T.; Kahl, D.; Lonsdale, S. J.] Univ Edinburgh, Sch Phys & Astron, Peter Guthrie Tait Rd, Edinburgh EH9 3FD, Midlothian, Scotland, Email: claudia.lederer-woods@ed.ac.uk |
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:000691442700005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4949 |
Permanent link to this record |
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Author |
n_TOF Collaboration (Lederer-Woods, C. et al.); Domingo-Pardo, C.; Tain, J.L. |
Title |
Destruction of the cosmic gamma-ray emitter Al-26 in massive stars: Study of the key Al-26(n, alpha) reaction |
Type |
Journal Article |
Year |
2021 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
104 |
Issue |
3 |
Pages |
L032803 - 6pp |
Keywords |
|
Abstract |
Neutron destruction reactions of the cosmic gamma-ray emitter Al-26 are of importance to determine the amount of Al-26 ejected into our galaxy by supernova explosions and for Al-26 production in asymptotic giant branch stars. We performed a new measurement of the Al-26(n, alpha) reaction up to 160-keV neutron energy at the neutron time-of-flight facilities n_TOF at CERN and GELINA at EC-JRC. We provide strengths for ten resonances, six of them for the first time. We use our data to calculate astrophysical reactivities for stellar temperatures up to 0.7 GK. Our results resolve a discrepancy between the two previous direct measurements of this reaction, and indicate higher stellar destruction rates than the most recently recommended reactivity. |
Address |
[Lederer-Woods, C.; Woods, P. J.; Davinson, T.; Estrade, A.; Kahl, D.; Lonsdale, S. J.] Univ Edinburgh, Sch Phys & Astron, Peter Guthrie Tait Rd, Edinburgh EH9 3FD, Midlothian, Scotland, Email: claudia.lederer-woods@ed.ac.uk |
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:000704560300002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4988 |
Permanent link to this record |
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Author |
n_TOF Collaboration (Lederer-Woods, C. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. |
Title |
Measurement of Ge-73(n, gamma) cross sections and implications for stellar nucleosynthesis |
Type |
Journal Article |
Year |
2019 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
790 |
Issue |
|
Pages |
458-465 |
Keywords |
Nucleosynthesis; Neutron capture; s process; Germanium; n_TOF |
Abstract |
Ge-73(n, gamma) cross sections were measured at the neutron time-of-flight facility n_TOF at CERN up to neutron energies of 300 keV, providing for the first time experimental data above 8 keV. Results indicate that the stellar cross section at kT = 30 keV is 1.5 to 1.7 times higher than most theoretical predictions. The new cross sections result in a substantial decrease of Ge-73 produced in stars, which would explain the low isotopic abundance of Ge-73 in the solar system. |
Address |
[Lederer-Woods, C.; Battino, U.; Tattersalla, A.; Dietz, M.] Univ Edinburgh, Sch Phys & Astron, Edinburgh, Midlothian, Scotland, Email: claudia.lederer-woods@ed.ac.uk |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
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 |
0370-2693 |
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:000460118200058 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3936 |
Permanent link to this record |
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Author |
n_TOF Collaboration (Lederer-Woods, C. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. |
Title |
Ge-74(n, gamma) cross section below 70 keV measured at n_TOF CERN |
Type |
Journal Article |
Year |
2022 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
Volume |
58 |
Issue |
12 |
Pages |
239 - 9pp |
Keywords |
|
Abstract |
Neutron capture reaction cross sections on Ge-74 are of importance to determine Ge-74 production during the astrophysical slow neutron capture process. We present new resonance data on Ge-74(n, gamma ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment. |
Address |
[Lederer-Woods, C.; Lonsdale, S. J.; Woods, P. J.] Univ Edinburgh, Sch Phys & Astron, Edinburgh, Midlothian, Scotland, Email: claudia.lederer-woods@ed.ac.uk |
Corporate Author |
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Thesis |
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Publisher |
Springer |
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 |
1434-6001 |
ISBN |
|
Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000913761400001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5472 |
Permanent link to this record |