| Records |
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 (Cosentino, L. et al); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A. |
| Title |
Experimental setup and procedure for the measurement of the Be-7(n,alpha)alpha reaction at n_TOF |
Type |
Journal Article |
| Year |
2016 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
830 |
Issue |
|
Pages |
197-205 |
| Keywords |
Cosmological lithium problem; Big bang nucleosynthesis; Be-7(n,alpha)alpha reaction; n_TOF spallation neutron source |
| Abstract |
The newly built second experimental area EAR2 of then n_ToF spallation neutron source at CERN allows to perform (n, charged particles) experiments on short-lived highly radioactive targets. This paper describes a detection apparatus and the experimental procedure for the determination of the cross-section of the Be-7(n,alpha)alpha reaction, which represents one of the focal points toward the solution of the cosmological Lithium abundance problem, and whose only measurement, at thermal energy, dates back to 1963. The apparently unsurmountable experimental difficulties stemming from the huge Be-7 gamma-activity, along with the lack of a suitable neutron beam facility, had so far prevented further measurements. The detection system is subject to considerable radiation damage, but is capable of disentangling the rare reaction signals from the very high background. This newly developed setup could likely be useful also to study other challenging reactions requiring the detectors to be installed directly in the neutron beam. |
| Address |
[Cosentino, L.; Musumarra, A.; Pappalardo, A.; Piscopo, M.; Finocchiaro, P.; Cardella, R.; Heyse, J.; Jenkins, D. G.; Kaeppeler, F.; Katabuchi, T.; Kokkoris, M.; Lederer, C.; Lonsdale, S.; Massimi, C.; Mastinu, P.; Matteucci, F.; Mazzone, A.; Milazzo, P. M.; Nolte, R.; Patronis, N.; Pavlik, A.; Rauscher, T.; Schillebeeckx, P.; Stamatopoulos, A.; Tsinganis, A.; Vannini, G.; Vlastou, R.; Wallner, A.; Woods, P. J.] INFN Lab Nazl Sud, Catania, Italy, Email: FINOCCHIARO@LNS.INFN.IT |
| 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 |
0168-9002 |
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:000381530300027 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2792 |
| Permanent link to this record |
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| Author |
n_TOF Collaboration (Barbagallo, M. et al); Domingo-Pardo, C.; Tain, J.L. |
| Title |
Experimental setup and procedure for the measurement of the Be-7(n,p)Li-7 reaction at n_TOF |
Type |
Journal Article |
| Year |
2018 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
887 |
Issue |
|
Pages |
27-33 |
| Keywords |
Cosmological Lithium problem; Big bang nucleosynthesis; Be-7(n,p)Li-7 reaction; n_TOF spallation neutron source |
| Abstract |
Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows to investigate neutron induced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the Be-7(n,alpha)alpha cross section, the Be-7(n,p)Li-7 reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization. |
| Address |
[Barbagallo, M.; Mastromarco, M.; Damone, L. A.; Mazzone, A.; Colonna, N.; Tagliente, G.; Variale, V.] Ist Nazl Fis Nucl, Sez Bari, Bari, Italy, Email: finocchiaro@lns.infn.ir |
| 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 |
0168-9002 |
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:000427814400005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3528 |
| Permanent link to this record |
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| Author |
Mangano, G.; Miele, G.; Pastor, S.; Pisanti, O.; Sarikas, S. |
| Title |
Constraining the cosmic radiation density due to lepton number with Big Bang Nucleosynthesis |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
03 |
Issue |
3 |
Pages |
035 - 18pp |
| Keywords |
big bang nucleosynthesis; neutrino properties; cosmological neutrinos; physics of the early universe |
| Abstract |
The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis (BBN) is typically parameterized in terms of the effective number of neutrinos N-eff. This quantity, in case of no extra degrees of freedom, depends upon the chemical potential and the temperature characterizing the three active neutrino distributions, as well as by their possible non-thermal features. In the present analysis we determine the upper bounds that BBN places on N-eff from primordial neutrino-antineutrino asymmetries, with a careful treatment of the dynamics of neutrino oscillations. We consider quite a wide range for the total lepton number in the neutrino sector, eta(nu) = eta(nu e) + eta(nu mu) + eta(nu tau) and the initial electron neutrino asymmetry eta(in)(nu e), solving the corresponding kinetic equations which rule the dynamics of neutrino (antineutrino) distributions in phase space due to collisions, pair processes and flavor oscillations. New bounds on both the total lepton number in the neutrino sector and the nu(e)-(nu) over bar (e) asymmetry at the onset of BBN are obtained fully exploiting the time evolution of neutrino distributions, as well as the most recent determinations of primordial H-2/H density ratio and He-4 mass fraction. Note that taking the baryon fraction as measured by WMAP, the H-2/H abundance plays a relevant role in constraining the allowed regions in the eta(nu)-eta(in)(nu e) plane. These bounds fix the maximum contribution of neutrinos with primordial asymmetries to N-eff as a function of the mixing parameter theta(13), and point out the upper bound N-eff less than or similar to 3.4. Comparing these results with the forthcoming measurement of N-eff by the Planck satellite will likely provide insight on the nature of the radiation content of the universe. |
| Address |
[Mangano, Gianpiero; Miele, Gennaro; Pisanti, Ofelia; Sarikas, Srdjan] Ist Nazl Fis Nucl, Sez Napoli, I-80126 Naples, Italy, Email: mangano@na.infn.it |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
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 |
1475-7516 |
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:000291258300035 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
642 |
| Permanent link to this record |
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| Author |
Guerrero, C.; Tessler, M.; Paul, M.; Lerendegui-Marco, J.; Heinitz, S.; Maugeri, E.A.; Domingo-Pardo, C.; Dressler, R.; Halfon, S.; Kivel, N.; Koster, U.; Palchan-Hazan, T.; Quesada, J.M.; Schumann, D.; Weissman, L. |
| Title |
The s-process in the Nd-Pm-Sm region: Neutron activation of Pm-147 |
Type |
Journal Article |
| Year |
2019 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
797 |
Issue |
|
Pages |
134809 - 6pp |
| Keywords |
Nucleosynthesis; Neutron capture; Nuclear reactions; s-process; MACS; Neutron activation |
| Abstract |
The Nd-Pm-Sm branching is of interest for the study of the s-process, related to the production of heavy elements in stars. As Sm-148 and Sm-150 are s-only isotopes, the understanding of the branching allows constraining the s-process neutron density. In this context the key physics input needed is the cross section of the three unstable nuclides in the region: Nd-147 (10.98 d half-life), Pm-147 (2.62 yr) and Pm-148 (5.37 d). This paper reports on the activation measurement of Pm-147, the longest-lived of the three nuclides. The cross section measurement has been carried out by activation at the SARAF LiLiT facility using a 56(2) μg target. Compared to the single previous measurement of Pm-147, the measurement presented herein benefits from a target 2000 times more massive. The resulting Maxwellian Averaged Cross Section (MACS) to the ground and metastable states in Pm-148 are 469(50) mb and 357(27) mb. These values are 41% higher (to the ground state) and 15% lower (to the metastable state) than the values reported so far, leading however to a total cross section of 826(107) mb consistent within uncertainties with the previous result and hence leaving unchanged the previous calculation of the s-process neutron density. |
| Address |
[Guerrero, C.; Lerendegui-Marco, J.; Quesada, J. M.] Univ Seville, Seville, Spain, Email: cguerrero4@us.es |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier |
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:000488071200026 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4161 |
| Permanent link to this record |
