| Records |
| Author |
n_TOF Collaboration (Guerrero, C. et al); Domingo-Pardo, C.; Tain, J.L. |
| Title |
Neutron Capture on the s-Process Branching Point Tm-171 via Time-of-Flight and Activation |
Type |
Journal Article |
| Year |
2020 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
125 |
Issue |
14 |
Pages |
142701 - 8pp |
| Keywords |
|
| Abstract |
The neutron capture cross sections of several unstable nuclides acting as branching points in the s process are crucial for stellar nucleosynthesis studies. The unstable Tm-171 (t(1/2) = 1.92 yr) is part of the branching around mass A similar to 170 but its neutron capture cross section as a function of the neutron energy is not known to date. In this work, following the production for the first time of more than 5 mg of Tm-171 at the high-flux reactor Institut Laue-Langevin in France, a sample was produced at the Paul Scherrer Institute in Switzerland. Two complementary experiments were carried out at the neutron time-of-flight facility (nTOF) at CERN in Switzerland and at the SARAF liquid lithium target facility at Soreq Nuclear Research Center in Israel by time of flight and activation, respectively. The result of the time -of-flight experiment consists of the first ever set of resonance parameters and the corresponding average resonance parameters, allowing us to make an estimation of the Maxwellian-averaged cross sections (MACS) by extrapolation. The activation measurement provides a direct and more precise measurement of the MACS at 30 keV: 384 (40) mb, with which the estimation from the nTOF data agree at the limit of 1 standard deviation. This value is 2.6 times lower than the JEFF-3.3 and ENDF/B-VIII evaluations, 25% lower than that of the Bao et al. compilation, and 1.6 times larger than the value recommended in the KAlloNiS (v1) database, based on the only previous experiment. Our result affects the nucleosynthesis at the A similar to 170 branching, namely, the Yb-171 abundance increases in the material lost by asymptotic giant branch stars, providing a better match to the available pre-solar SiC grain measurements compared to the calculations based on the current JEFF-3.3 model-based evaluation. |
| Address |
[Guerrero, C.; Lerendegui-Marco, J.; Quesada, J. M.; Cortes-Giraldo, M. A.; Millan-Callado, M. A.; Praena, J.; Rodriguez-Gonzalez, T.; Sabate-Gilarte, M.] Univ Seville, Seville, Spain, Email: cguerrero4@us.es |
| 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  |
0031-9007 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000574781200004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4551 |
| Permanent link to this record |
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| Author |
Guerrero, C.; Cano-Ott, D.; Mendoza, E.; Tain, J.L.; Algora, A.; Berthoumieux, E.; Colonna, N.; Domingo-Pardo, C.; Gonzalez-Romero, E.; Heil, M.; Jordan, D.; Kappeler, F.; Lampoudis, C.; Martinez, T.; Massimi, C.; Plag, R. |
| Title |
Monte Carlo simulation of the n_TOF Total Absorption Calorimeter |
Type |
Journal Article |
| Year |
2012 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
671 |
Issue |
|
Pages |
108-117 |
| Keywords |
Monte Carlo simulation; Geant4; Neutron cross-sections; Time-of-flight; Neutron capture |
| Abstract |
The n_TOF Total Absorption Calorimeter (TAC) is a 4 pi BaF2 segmented detector used at CERN for measuring neutron capture cross-sections of importance for the design of advanced nuclear reactors. This work presents the simulation code that has been developed in GEANT4 for the accurate determination of the detection efficiency of the TAC for neutron capture events. The code allows to calculate the efficiency of the TAC for every neutron capture state, as a function of energy, crystal multiplicity, and counting rate. The code includes all instrumental effects such as the single crystal detection threshold and energy resolution, finite size of the coincidence time window, and signal pile-up. The results from the simulation have been validated with experimental data for a large set of electromagnetic de-excitation patterns: beta-decay of well known calibration sources, neutron capture reactions in light nuclei with well known level schemes like Ti-nat, reference samples used in (n,gamma) measurements like Au-197 and experimental data from an actinide sample like Pu-240. The systematic uncertainty in the determination of the detection efficiency has been estimated for all the cases. As a representative example, the accuracy reached for the case of Au-197(n,gamma) ranges between 0.5% and 2%, depending on the experimental and analysis conditions. Such a value matches the high accuracy required for the nuclear cross-section data needed in advanced reactor design. |
| Address |
[Guerrero, C.; Cano-Ott, D.; Mendoza, E.; Gonzalez-Romero, E.; Martinez, T.] CIEMAT, Ctr Invest Energet Medioambientales & Tecnol, E-28040 Madrid, Spain, Email: carlos.guerrero@cern.ch |
| 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 |
|
| Notes |
WOS:000301474600013 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
973 |
| Permanent link to this record |
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| Author |
Tain, J.L.; Agramunt, J.; Algora, A.; Aprahamian, A.; Cano-Ott, D.; Fraile, L.M.; Guerrero, C.; Jordan, M.D.; Mach, H.; Martinez, T.; Mendoza, E.; Mosconi, M.; Nolte, R. |
| Title |
The sensitivity of LaBr3:Ce scintillation detectors to low energy neutrons: Measurement and Monte Carlo simulation |
Type |
Journal Article |
| Year |
2015 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
774 |
Issue |
|
Pages |
17-24 |
| Keywords |
Neutron sensitivity; Scintillation detectors; Lanthanum bromide; Geant4 simulations; Nuclear data libraries |
| Abstract |
The neutron sensitivity of a cylindrical circle minus 1.5 in x 1.5 in LaBr3:Ce scintillation detector was measured using quasi-monoenergetic neutron beams in the energy range from 40 keV to 2.5 MeV. In this energy range the detector is sensitive to gamma-rays generated in neutron inelastic and capture processes. The experimental energy response was compared with Monte Carlo simulations performed with the Geant4 simulation toolkit using the so-called High Precision Neutron Models. These models rely on relevant information stored in evaluated nuclear data libraries. The performance of the Geant4 Neutron Data Library as well as several standard nuclear data libraries was investigated. In the latter case this was made possible by the use of a conversion tool that allowed the direct use of the data from other libraries in Geant4. Overall it was found that there was good agreement with experiment for some of the neutron data bases like ENDF/B-VII.0 or JENDL-3.3 but not with the others such as ENDF/B-VI.8 or JEFF-3.1. |
| Address |
[Tain, J. L.; Agramunt, J.; Algora, A.; Jordan, M. D.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-28040 Valencia, Spain, Email: tain@ific.uv.es |
| 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:000347407800003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2076 |
| Permanent link to this record |
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| Author |
Magan, D.L.P.; Caballero, L.; Domingo-Pardo, C.; Agramunt-Ros, J.; Albiol, F.; Casanovas, A.; Gonzalez, A.; Guerrero, C.; Lerendegui-Marco, J.; Tarifeño-Saldivia, A. |
| Title |
First tests of the applicability of gamma-ray imaging for background discrimination in time-of-flight neutron capture measurements |
Type |
Journal Article |
| Year |
2016 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
823 |
Issue |
|
Pages |
107-119 |
| Keywords |
Neutron capture cross-sections; gamma-ray imaging; Total energy detectors; Pulse-height weighting technique; Time-of-flight method |
| Abstract |
In this work we explore for the first time the applicability of using gamma-ray imaging in neutron capture measurements to identify and suppress spatially localized background. For this aim, a pinhole gamma camera is assembled, tested and characterized in terms of energy and spatial performance. It consists of a monolithic CeBr3 scintillating crystal coupled to a position-sensitive photomultiplier and readout through an integrated circuit AMIC2GR. The pinhole collimator is a massive carven block of lead. A series of dedicated measurements with calibrated sources and with a neutron beam incident on a Au-197 sample have been carried out at n_TOF, achieving an enhancement of a factor of two in the signal-to-background ratio when selecting only those events coming from the direction of the sample. |
| Address |
[Perez Magan, D. L.; Caballero, L.; Domingo-Pardo, C.; Agramunt-Ros, J.; Albiol, F.; Tarifeno-Saldivia, A.] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: domingo@ific.uv.es |
| 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:000374661600015 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
2665 |
| Permanent link to this record |
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| Author |
Balibrea-Correa, J.; Lerendegui-Marco, J.; Calvo, D.; Caballero, L.; Babiano, V.; Ladarescu, I.; Redondo, M.L.; Tain, J.L.; Tolosa, A.; Domingo-Pardo, C.; Calvino, F.; Casanovas, A.; Tarifeño-Saldivia, A.; Alcayne, V.; Cano-Ott, D.; Martinez, T.; Guerrero, C.; Barbagallo, M.; Macina, D.; Bacak, M. |
| Title |
A first prototype of C6D6 total-energy detector with SiPM readout for neutron capture time-of-flight experiments |
Type |
Journal Article |
| Year |
2021 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
| Volume |
985 |
Issue |
|
Pages |
164709 - 8pp |
| Keywords |
Silicon photomultiplier; Radiation detectors; Time-of-flight; Radiative capture; Total energy detector; Pulse-height weighting technique |
| Abstract |
Low efficiency total-energy detectors (TEDs) are one of the main tools for neutron capture cross section measurements utilizing the time-of-flight (TOF) technique. State-of-the-art TEDs are based on a C6D6 liquid-scintillation cell optically coupled to a fast photomultiplier tube. The large photomultiplier tube represents yet a significant contribution to the so-called neutron sensitivity background, which is one of the most conspicuous sources of uncertainty in this type of experiments. Here we report on the development of a first prototype of a TED based on a silicon-photomultiplier (SiPM) readout, thus resulting in a lightweight and much more compact detector. Apart from the envisaged improvement in neutron sensitivity, the new system uses low voltage (+28 V) and low current supply (-50 mA), which is more practical than the-kV supply required by conventional photomultipliers. One important difficulty hindering the earlier implementation of SiPM readout for this type of detector was the large capacitance for the output signal when all pixels of a SiPM array are summed together. The latter leads to long pulse rise and decay times, which are not suitable for time-of-flight experiments. In this work we demonstrate the feasibility of a Schottky-diode multiplexing readout approach, that allows one to preserve the excellent timing properties of SiPMs, hereby paving the way for their implementation in future neutron TOF experiments. |
| Address |
[Balibrea-Correa, J.; Lerendegui-Marco, J.; Calvo, D.; Caballero, L.; Babiano, V; Ladarescu, I; Redondo, M. Lopez; Tain, J. L.; Tolosa, A.; Domingo-Pardo, C.] Univ Valencia, Inst Fis Corpuscular, CSIC, Valencia, Spain, Email: dacaldia@ific.uv.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 |
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:000592358200019 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4638 |
| Permanent link to this record |
