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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 Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language (up) 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:000301474600013 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 973
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Author Domingo-Pardo, C.
Title A new technique for 3D gamma-ray imaging: Conceptual study of a 3D camera Type Journal Article
Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 675 Issue Pages 123-132
Keywords Gamma-ray detector; Three dimensional gamma-ray imaging; Compton camera; Gamma camera
Abstract A novel technique for 3D gamma-ray imaging is presented. This method combines the positron annihilation Compton scattering imaging technique with a supplementary position sensitive detector, which registers gamma-rays scattered in the object at angles of about 90 degrees. The 3D coordinates of the scattering location can be determined rather accurately by applying the Compton principle. This method requires access to the object from two orthogonal sides and allows one to achieve a position resolution of few mm in all three space coordinates. A feasibility study for a 3D camera is presented based on Monte Carlo calculations.
Address Univ Valencia, Inst Fis Corpuscular, CSIC, E-46071 Valencia, Spain, Email: domingo@ific.uv.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language (up) 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:000302973600019 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 989
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Author n_TOF Collaboration (Guerrero, C. et al); Domingo-Pardo, C.; Tain, J.L.
Title Measurement and resonance analysis of the Np-237 neutron capture cross section Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 85 Issue 4 Pages 044616 - 15pp
Keywords
Abstract The neutron capture cross section of Np-237 was measured between 0.7 and 500 eV at the CERN n_TOF facility using the 4 pi BaF2 Total Absorption Calorimeter. The experimental capture yield was extracted minimizing all the systematic uncertainties and was analyzed together with the most reliable transmission data available using the SAMMY code. The result is a complete set of individual as well as average resonance parameters [D-0 = 0.56(2) eV, <Gamma(gamma)> = 40.9(18) meV, 10(4)S(0) = 0.98(6), R' = 9.8(6) fm]. The capture cross section obtained in this work is in overall agreement with the evaluations and the data of Weston and Todd [Nucl. Sci. Eng. 79, 184 (1981)], thus showing sizable differences with respect to previous data from Scherbakov et al. [J. Nucl. Sci. Technol. 42, 135 (2005)] and large discrepancies with data Kobayashi et al. [J. Nucl. Sci. Technol. 39, 111 (2002)]. The results indicate that a new evaluation combining the present capture data with reliable transmission data would allow reaching an accuracy better than 4%, in line with the uncertainty requirements of the nuclear data community for the design and operation of current and future nuclear devices.
Address [Guerrero, C.; Cano-Ott, D.; Mendoza, E.; Alvarez-Velarde, F.; Embid-Segura, M.; Gonzalez-Romero, E.; Martinez, T.; Villamarin, D.; Vicente, M. C.] Ctr Invest Energet Medioambientales & Tecnol, CIEMAT, Madrid, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language (up) 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:000303069400004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 993
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Author n_TOF Collaboration (Massimi, C. et al); Domingo-Pardo, C.; Tain, J.L.
Title Resonance neutron-capture cross sections of stable magnesium isotopes and their astrophysical implications Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 85 Issue 4 Pages 044615 - 15pp
Keywords
Abstract We have measured the neutron capture cross sections of the stable magnesium isotopes Mg-24,Mg-25,Mg-26 in the energy range of interest to the s process using the neutron time-of-flight facility n_TOF at CERN. Capture events from a natural metal sample and from samples enriched in Mg-25 and Mg-26 were recorded using the total energy method based on (C6H6)-H-2 detectors. Neutron resonance parameters were extracted by a simultaneous resonance shape analysis of the present capture data and existing transmission data on a natural isotopic sample. Maxwellian-averaged capture cross sections for the three isotopes were calculated up to thermal energies of 100 keV and their impact on s-process analyses was investigated. At 30 keV the new values of the stellar cross section for Mg-24, Mg-25, and Mg-26 are 3.8 +/- 0.2 mb, 4.1 +/- 0.6 mb, and 0.14 +/- 0.01 mb, respectively.
Address [Massimi, C.; Vannini, G.] Univ Bologna, Dipartimento Fis, Bologna, Italy, Email: Cristian.Massimi@bo.infn.it
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language (up) 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:000303069400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 994
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Author n_TOF Collaboration (Gunsing, F. et al); Domingo-Pardo, C.; Tain, J.L.
Title Measurement of resolved resonances of Th-232(n, gamma) at the n_TOF facility at CERN Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 85 Issue 6 Pages 064601 - 17pp
Keywords
Abstract The yield of the neutron capture reaction Th-232(n, gamma) has been measured at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The reduction of the acquired data to the capture yield for resolved resonances from 1 eV to 4 keV is described and compared to a recent evaluated data set. The resonance parameters were used to assign an orbital momentum to each resonance. A missing level estimator was used to extract the s-wave level spacing of D-0 = 17.2 +/- 0.9 eV.
Address [Gunsing, F.; Berthoumieux, E.; Aerts, G.; Andriamonje, S.; Dridi, W.; Pancin, J.; Perrot, L.; Plukis, A.] CEA Saclay, DSM, Irfu, SPhN, F-91191 Gif Sur Yvette, France, Email: gunsing@cea.fr
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language (up) 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:000304693700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1048
Permanent link to this record