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Author (up) n_TOF Collaboration (Alcayne, V. et al); Balibrea-Correa, J.; Domingo-Pardo, C.; Lerendegui-Marco, J.; Babiano-Suarez, V.; Ladarescu, I.
Title A Segmented Total Energy Detector (sTED) optimized for (n,γ) cross-section measurements at n_TOF EAR2 Type Journal Article
Year 2024 Publication Radiation Physics and Chemistry Abbreviated Journal Radiat. Phys. Chem.
Volume 217 Issue Pages 111525 - 11pp
Keywords Neutron capture; PHWT; Scintillation detectors; Monte Carlo simulation
Abstract The neutron time-of-flight facility nTOF at CERN is a spallation source dedicated to measurements of neutroninduced reaction cross-sections of interest in nuclear technologies, astrophysics, and other applications. Since 2014, Experimental ARea 2 (EAR2) is operational and delivers a neutron fluence of similar to 4 center dot 10(7) neutrons per nominal proton pulse, which is similar to 50 times higher than the one of Experimental ARea 1 (EAR1) of similar to 8 center dot 10(5) neutrons per pulse. The high neutron flux at EAR2 results in high counting rates in the detectors that challenged the previously existing capture detection systems. For this reason, a Segmented Total Energy Detector (sTED) has been developed to overcome the limitations in the detector's response, by reducing the active volume per module and by using a photo-multiplier (PMT) optimized for high counting rates. This paper presents the main characteristics of the sTED, including energy and time resolution, response to gamma-rays, and provides as well details of the use of the Pulse Height Weighting Technique (PHWT) with this detector. The sTED has been validated to perform neutron-capture cross-section measurements in EAR2 in the neutron energy range from thermal up to at least 400 keV. The detector has already been successfully used in several measurements at nTOF EAR2.
Address [Alcayne, V.; Cano-Ott, D.; Garcia, J.; Gonzalez-Romero, E.; Martinez, T.; de Rada, A. Perez; Plaza, J.; Sanchez-Caballero, A.; Mendoza, E.] Ctr Invest Energet Medioambient & Tecnol CIEMAT, Madrid, Spain, Email: victor.alcayne@ciemat.es
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0969-806x ISBN Medium
Area Expedition Conference
Notes WOS:001185584800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5999
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Author (up) n_TOF Collaboration (Amaducci, S. et al); Babiano-Suarez, V.; Caballero-Ontanaya, L.; Domingo-Pardo, C.; Ladarescu, I.; Tain, J.L.
Title First Results of the Ce-140(n,gamma)Ce-141 Cross-Section Measurement at n_TOF Type Journal Article
Year 2021 Publication Universe Abbreviated Journal Universe
Volume 7 Issue 6 Pages 200 - 11pp
Keywords
Abstract An accurate measurement of the Ce-140(n,gamma) energy-dependent cross-section was performed at the n_TOF facility at CERN. This cross-section is of great importance because it represents a bottleneck for the s-process nucleosynthesis and determines to a large extent the cerium abundance in stars. The measurement was motivated by the significant difference between the cerium abundance measured in globular clusters and the value predicted by theoretical stellar models. This discrepancy can be ascribed to an overestimation of the Ce-140 capture cross-section due to a lack of accurate nuclear data. For this measurement, we used a sample of cerium oxide enriched in Ce-140 to 99.4%. The experimental apparatus consisted of four deuterated benzene liquid scintillator detectors, which allowed us to overcome the difficulties present in the previous measurements, thanks to their very low neutron sensitivity. The accurate analysis of the p-wave resonances and the calculation of their average parameters are fundamental to improve the evaluation of the Ce-140 Maxwellian-averaged cross-section.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes WOS:000665969800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4877
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Author (up) 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 140Ce(n,γ) 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
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Author (up) 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
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Author (up) n_TOF Collaboration (Garcia-Infantes, F. et al); Babiano-Suarez, V.; Balibrea-Correa, J.; Casanovas-Hoste, A.; Domingo-Pardo, C.; Ladarescu, I.; Lerendegui-Marco, J.
Title Measurement of the 176Yb(n,γ) cross section at the n_TOF facility at CERN Type Journal Article
Year 2024 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 110 Issue 6 Pages 064619 - 16pp
Keywords
Abstract Background: The Yb-176(n, gamma)Yb-177 -> 177Lu reaction is of interest in nuclear medicine as it is the preferred production route for 177Lu. This radioisotope has seen a very fast growth of usage in nuclear medicine in recent years due to its outstanding properties. New data on this reaction could provide useful information for production at new facilities. Purpose: We aim to resolve resonances in the Yb-176(n, gamma)Yb-177 reaction for the first time. Previous capture measurement provided data at thermal point and encompassed integral measurements in the range from 3 keV to 1 MeV, where three time-of-flight measurements are available, but with low resolution to resolve the resonances. Transmission measurements from the 1970s resolved and analyzed some resonances. Method: We measure the neutron capture cross section of Yb-176(n, gamma)Yb-177 by means of the time-of-flight technique at the Experimental Area 1 of the n_TOF facility at CERN using an enriched (Yb2O3)-Yb-176 sample and an array of four C6D6 liquid scintillation detectors. Results: We have resolved 164 resonances up to 21 keV, including 96 new ones. We also provide new capture experimental data from 90 eV to 3 keV, and we extend the resolved resonance region up to 21 keV. In addition, resonance decay widths, Gamma(gamma) and Gamma(n), are provided for all resonances together with resonance energies. Conclusions: The Yb-176(n, gamma) Yb-177 reaction has been measured, providing resonance parameters for the first time from a few eV to 21 keV. The analysis of the resonances has been carried out and compared with previous works and existing libraries, revealing discrepancies due to the new information on Gamma(gamma) parameters. Our results are consistent with the Gamma(n) parameters obtained in transmission measurements.
Address [Garcia-Infantes, F.; Praena, J.; Es-Sghir, H. Amar; Martinez-Canada, M.; Porras, I.; Torres-Sanchez, P.] Univ Granada, Granada, Spain
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:001389562300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6514
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Author (up) n_TOF Collaboration (Lerendegui-Marco, J. et al); Babiano-Suarez, V.; Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Radiative neutron capture cross section of 242Pu measured at n_TOF-EAR1 in the unresolved resonance region up to 600 keV Type Journal Article
Year 2026 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 62 Issue 2 Pages 33 - 20pp
Keywords
Abstract Accurate neutron capture cross sections are essential for the design and operation of fast reactors using MOX fuels. For Pu-242, the Nuclear Energy Agency (NEA) recommends 8-12% accuracy in the fast energy region (2-500 keV), compared to the current uncertainty of 35%. Moreover, integral experiments and previous measurements suggest the evaluated Pu-242(n,gamma) cross section is overestimated, particularly in the JEFF-3.3 library, which shows a 14% overestimation between 1 keV and 1 MeV. Recent measurements from LANSCE reported a 20-30% reduction in the 1-40 keV range relative to evaluations. To solve these discrepancies, the Pu-242(n,gamma) cross section was measured from 1 to 600 keV at CERN n_TOF-EAR1 facility using a 95(4) mg Pu-242 target, enriched to 99.959%. Gamma rays from neutron capture were detected with an array of C6D6 scintillators and a novel application of the Pulse Height Weighting Technique was employed. The resulting cross section presents a systematic uncertainty between 8 and 12%, reducing the current uncertainties of 35% and achieving the accuracy requested by the NEA. Analysis using FITACS produced average resonance parameters, consistent with the analysis of the resolved resonance region. Our data align well with Wisshak and Kaeppeler, and are 10-14% lower than JEFF-3.3 in the 1-250 keV range, helping to achieve consistency with integral benchmarks. At higher energies, our results are in reasonable agreement with ENDF/B-VIII.1 and JEFF-3.3. In contrast, DANCE results appear to underestimate the cross section by a factor of 2-3 above a few keV.
Address [Lerendegui-Marco, J.; Guerrero, C.; Quesada, J. M.; Cortes-Giraldo, M. A.; Praena, J.; Sabate-Gilarte, M.] Univ Seville, Dept Fis Atom Mol & Nucl, Seville, Spain, Email: jorge.lerendegui@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:001695708900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 7109
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Author (up) n_TOF Collaboration (Manna, A. et al); Babiano-Suarez, V.; Caballero-Ontanaya, L.; Domingo-Pardo, C.; Ladarescu, I.; Tain, J.L.
Title New insights on fission of 235U induced by high energy neutrons from a new measurement at n_TOF Type Journal Article
Year 2025 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 860 Issue Pages 139213 - 8pp
Keywords Nuclear reaction; Neutron-induced reaction; n_TOF; High energy; Fission process; Cross section measurement; Uranium-235
Abstract The U-235(n, f) reaction cross section was measured relative to neutron-proton elastic scattering for the first time in the energy region from 10 MeV to 440 MeV at the CERN n_TOF facility, extending the upper limit of the only previous measurement in the literature by more than 200 MeV. For neutron energies below 200 MeV, our results agree within one standard deviation with data in literature. Above 200 MeV, the comparison of model calculations to our data indicates the need to introduce a transient time in neutron-induced fission to allow the simultaneous description of (n, f) and (p, f) reactions.
Address [Manna, A.; Camprini, P. Console; Massimi, C.; Mengoni, A.; Vannini, G.; Ventura, A.; Castelluccio, D. M.; Junghans, A.] Ist Nazl Fis Nucl, Sez Bologna, Bologna, Italy, Email: alice.manna@bo.infn.it;
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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:001399996800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6468
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Author (up) n_TOF Collaboration (Michalopoulou, V. et al); Babiano-Suarez, V.; Caballero, L.; Domingo-Pardo, C.; Ladarescu, I.; Tain, J.L.
Title Measurement of the neutron-induced fission cross section of Th-230 at the CERN n_TOF facility Type Journal Article
Year 2023 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 108 Issue 1 Pages 014616 - 15pp
Keywords
Abstract The neutron-induced fission cross section of Th-230 has been measured at the neutron time-of-flight facility n_TOF located at CERN. The experiment was performed at the experimental area EAR-1 with a neutron flight path of 185 m, using Micromegas detectors for the detection of the fission fragments. The Th-230(n, f ) cross section was determined relative to the U-235(n, f ) one, covering the energy range from the fission threshold up to 400 MeV. The results from the present work are compared with existing cross-section datasets and the observed discrepancies are discussed and analyzed. Finally, using the code EMPIRE 3.2.3 a theoretical study, based on the statistical model, was performed leading to a satisfactory reproduction of the experimental results with the proper tuning of the respective parameters, while for incident neutron energy beyond 200 MeV the fission of( 230)Th was described by Monte Carlo simulations.
Address [Michalopoulou, V; Stamatopoulos, A.; Diakaki, M.; Vlastou, R.; Kokkoris, M.; Tassan-Got, L.] Natl Tech Univ Athens, Dept Phys, Zografou Campus, Athens, Greece, Email: veatriki.michalopoulou@cern.ch
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:001063908000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5700
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Author (up) n_TOF Collaboration (Moreno-Soto, J. et al); Babiano-Suarez, V.; Caballero-Ontanaya, L.; Domingo-Pardo, C.; Ladarescu, I.; Tain, J.L.
Title Constraints on the dipole photon strength for the odd uranium isotopes Type Journal Article
Year 2022 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 105 Issue 2 Pages 024618 - 14pp
Keywords
Abstract Background: The photon strength functions (PSFs) and nuclear level density (NLD) are key ingredients for calculation of the photon interaction with nuclei, in particular the reaction cross sections. These cross sections are important especially in nuclear astrophysics and in the development of advanced nuclear technologies. Purpose: The role of the scissors mode in the M1 PSF of (well-deformed) actinides was investigated by several experimental techniques. The analyses of different experiments result in significant differences, especially on the strength of the mode. The shape of the low-energy tail of the giant electric dipole resonance is uncertain as well. In particular, some works proposed a presence of the E1 pygmy resonance just above 7 MeV. Because of these inconsistencies additional information on PSFs in this region is of great interest. Methods: The gamma-ray spectra from neutron-capture reactions on the U-234, U-236, and U-238 nuclei have been measured with the total absorption calorimeter of the n_TOF facility at CERN. The background-corrected sum-energy and multi-step-cascade spectra were extracted for several isolated s-wave resonances up to about 140 eV. Results: The experimental spectra were compared to statistical model predictions coming from a large selection of models of photon strength functions and nuclear level density. No combination of PSF and NLD models from literature is able to globally describe our spectra. After extensive search we were able to find model combinations with modified generalized Lorentzian (MGLO) E1 PSF, which match the experimental spectra as well as the total radiative widths. Conclusions: The constant temperature energy dependence is favored for a NLD. The tail of giant electric dipole resonance is well described by the MGLO model of the E1 PSF with no hint of pygmy resonance. The M1 PSF must contain a very strong, relatively wide, and likely double-resonance scissors mode. The mode is responsible for about a half of the total radiative width of neutron resonances and significantly affects the radiative cross section.
Address [Moreno-Soto, J.; Berthoumieux, E.; Dupont, E.; Gunsing, F.; Bacak, M.] Univ Paris Saclay, CEA Irfu, F-91191 Gif Sur Yvette, France, Email: jmoreno53@us.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 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000810791100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5278
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Author (up) n_TOF Collaboration (Patronis, N. et al); Babiano-Suarez, V.; Balibrea-Correa, J.; Domingo-Pardo, C.; Ladarescu, I.; Lerendegui-Marco, J.
Title Status report of the n_TOF facility after the 2nd CERN long shutdown period Type Journal Article
Year 2023 Publication EPJ Techniques and Instrumentation Abbreviated Journal EPJ Tech. Instrum.
Volume 10 Issue 1 Pages 13 - 10pp
Keywords Neutron time of flight; Spallation target; Nuclear astrophysics; Neutron physics; Neutron induced fission; Neutron reactions
Abstract During the second long shutdown period of the CERN accelerator complex (LS2, 2019-2021), several upgrade activities took place at the nTOF facility. The most important have been the replacement of the spallation target with a next generation nitrogen-cooled lead target. Additionally, a new experimental area, at a very short distance from the target assembly (the NEAR Station) was established. In this paper, the core commissioning actions of the new installations are described. The improvement in the nTOF infrastructure was accompanied by several detector development projects. All these upgrade actions are discussed, focusing mostly on the future perspectives of the n_TOF facility. Furthermore, some indicative current and future measurements are briefly reported.
Address [Patronis, N.; Goula, S.; Eleme, Z.; Stamati, M. E.; Vagena, E.] Univ Ioannina, Ioannina, Greece, Email: nikolaos.patronis@cern.ch
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 2195-7045 ISBN Medium
Area Expedition Conference
Notes WOS:001008786600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5591
Permanent link to this record