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Author (down) 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 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 (down) 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 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 (down) n_TOF Collaboration (Domingo-Pardo, C. et al); Babiano-Suarez, V.; Balibrea-Correa, J.; Caballero, L.; Ladarescu, I.; Lerendegui-Marco, J.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF Type Journal Article
Year 2023 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 59 Issue 1 Pages 8 - 11pp
Keywords
Abstract This article presents a few selected developments and future ideas related to the measurement of (n, gamma ) data of astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for the use of low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with particular emphasis on the systematic accuracy. Several recent instrumental advances are also presented, such as the development of total-energy detectors with gamma- ray imaging capability for background suppression, and the development of an array of small-volume organic scintilla tors aimed at exploiting the high instantaneous neutron-flux of EAR2. Finally, astrophysics prospects related to the intermediate i neutron-capture process of nucleosynthesis are discussed in the context of the new NEAR activation area.
Address [Domingo-Pardo, C.; Babiano-Suarez, V.; Balibrea-Correa, J.; Caballero, L.; Ladarescu, I.; Lerendegui-Marco, J.; Tain, J. L.; Tarifeno-Saldivia, A.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: domingo@ific.uv.es
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:000926364900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5479
Permanent link to this record
 
 
Author (down) 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 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 (down) 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 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 (down) 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 Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000427814400005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3528
Permanent link to this record
 
 
Author (down) 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 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 (down) n_TOF Collaboration (Bacak, M. et al); Domingo-Pardo, C.; Tain, J.L.
Title A compact fission detector for fission-tagging neutron capture experiments with radioactive fissile isotopes Type Journal Article
Year 2020 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 969 Issue Pages 163981 - 10pp
Keywords Fission detector; U-233; n_TOF; Time-of-flight
Abstract In the measurement of neutron capture cross-sections of fissile isotopes, the fission channel is a source of background which can be removed efficiently using the so-called fission-tagging or fission-veto technique. For this purpose a new compact and fast fission chamber has been developed. The design criteria and technical description of the chamber are given within the context of a measurement of the U-233(n, gamma) cross-section at the nTOF facility at CERN, where it was coupled to the nTOF Total Absorption Calorimeter. For this measurement the fission detector was optimized for time resolution, minimization of material in the neutron beam and for alpha-fission discrimination. The performance of the fission chamber and its application as a fission tagging detector are discussed.
Address [Bacak, M.; Gunsing, F.; Vlachoudis, V.; Aberle, O.; Calviani, M.; Cardella, R.; Cerutti, F.; Chiaveri, E.; Ferrari, A.; Gilardoni, S.; Kadi, Y.; Macina, D.; Masi, A.; Mingrone, F.; Rubbia, C.; Sabate-Gilarte, M.; Zugec, P.] CERN, European Org Nucl Res, Geneva, Switzerland, Email: michael.bacak@cern.ch
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000536792400015 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4413
Permanent link to this record
 
 
Author (down) n_TOF Collaboration (Amaducci, S. et al); Domingo-Pardo, C.; Tain, J.L.
Title Measurement of the U-235(n, f) cross section relative to the Li-6(n, t) and B-10(n,alpha) standards from thermal to 170 keV neutron energy range at n_TOF Type Journal Article
Year 2019 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 55 Issue 7 Pages 120 - 19pp
Keywords
Abstract .The U-235(n, f ) cross section was measured at n_TOF relative to Li-6(n, t) and B-10(n,alpha) , with high resolution ( L=183.49(2) m) and in a wide energy range (25meV-170keV) with 1.5% systematic uncertainty, making use of a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the yields of the U-235(n, f ) and of the two reference reactions under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10-30keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the cross section in the 9-18keV neutron energy range is indeed overestimated by almost 5% in the recently released evaluated data files ENDF/B-VIII.0 and JEFF3.3, as a consequence of a 7% overestimate in a single GMA node in the IAEA reference file. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The results here reported may lead to a reduction of the uncertainty in the 1-100keV neutron energy region. Finally, from the present data, a value of 249.7 +/- 1.4( stat )+/- 0.94( syst ) b<bold>eV has been extracted for the cross section integral between </bold>7.8 and 11eV, confirming the value of 247.5 +/- 3 b<bold>eV recently established as a standard</bold>.
Address [Amaducci, S.; Cosentino, L.; Finocchiaro, P.; Musumarra, A.] INFN, Lab Nazl Sud, Catania, Italy, Email: finocchiaro@lns.infn.it
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:000477050900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4083
Permanent link to this record
 
 
Author (down) n_TOF Collaboration (Amaducci, S. et al); Babiano-Suarez, V.; Caballero-Ontanaya, L.; Domingo-Pardo, C.; Ladarescu, I.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Measurement of the 140Ceðn;γþ Cross Section at n_TOF and Its Astrophysical Implications for the Chemical Evolution of the Universe Type Journal Article
Year 2024 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 132 Issue 12 Pages 122701 - 8pp
Keywords
Abstract 140Ce(n, gamma) is a key reaction for slow neutron -capture (s -process) nucleosynthesis due to being a bottleneck in the reaction flow. For this reason, it was measured with high accuracy (uncertainty approximate to 5%) at the n_TOF facility, with an unprecedented combination of a high purity sample and low neutron -sensitivity detectors. The measured Maxwellian averaged cross section is up to 40% higher than previously accepted values. Stellar model calculations indicate a reduction around 20% of the s -process contribution to the Galactic cerium abundance and smaller sizeable differences for most of the heavier elements. No variations are found in the nucleosynthesis from massive stars.
Address [Amaducci, S.; Cosentino, L.; Finocchiaro, P.; Brown, A.] INFN, Lab Nazl Sud, Catania, Italy
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:001202102900011 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6074
Permanent link to this record