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Author Colonna, N.; Belloni, F.; Berthoumieux, E.; Calviani, M.; Domingo-Pardo, C.; Guerrero, C.; Karadimos, D.; Lederer, C.; Massimi, C.; Paradela, C.; Plag, R.; Praena, J.; Sarmento, R. doi  openurl
  Title Advanced nuclear energy systems and the need of accurate nuclear data: the n_TOF project at CERN Type Journal Article
  Year 2010 Publication Energy & Environmental Science Abbreviated Journal Energy Environ. Sci.  
  Volume 3 Issue 12 Pages 1910-1917  
  Keywords  
  Abstract To satisfy the world's constantly increasing demand for energy, a suitable mix of different energy sources has to be devised. In this scenario, an important role could be played by nuclear energy, provided that major safety, waste and proliferation issues affecting current nuclear reactors are satisfactorily addressed. To this purpose, a large effort has been under way for a few years towards the development of advanced nuclear systems with the aim of closing the fuel cycle. Generation IV reactors, with full or partial waste recycling capability, accelerator driven systems, as well as new fuel cycles are the main options being investigated. The design of advanced systems requires improvements in basic nuclear data, such as cross-sections for neutron-induced reactions on actinides. In this paper, the main concepts of advanced reactor systems are described, together with the related needs of new and accurate nuclear data. The present activity in this field at the neutron facility n_TOF at CERN is discussed.  
  Address [Colonna, N.] Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy, Email: nicola.colonna@ba.infn.it  
  Corporate Author Thesis  
  Publisher Royal Soc Chemistry Place of Publication Editor  
  Language (up) English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1754-5692 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000284590900007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 319  
Permanent link to this record
 

 
Author n_TOF Collaboration (Guerrero, C. et al); Domingo-Pardo, C.; Tain, J.L. doi  openurl
  Title Study of Photon Strength Function of Actinides: the Case of (235)U, (238)Np and (241)Pu Type Journal Article
  Year 2011 Publication Journal of the Korean Physical Society Abbreviated Journal J. Korean Phys. Soc.  
  Volume 59 Issue 2 Pages 1510-1513  
  Keywords Photon/Gamma strength functions; Pygmy; Scissor mode; n_TOF; Total absorption calorimeter; TAC; Neutron capture  
  Abstract The decay from excited levels in medium and heavy nuclei can be described in a statistical approach by means of Photon Strength Functions and Level Density distributions. The study of electromagnetic cascades following neutron capture based on the use of high efficiency detectors has been shown to be well suited for probing the properties of the Photon Strength Function of heavy (high level density) and/or radioactive (high background) nuclei. In this work we have investigated for the first time the validity of the recommended PSF of actinides, in particular (235)U, (238)Np and (241)Pu. Our study includes the search for resonance structures in the PSF below S(n) and draws conclusions regarding their existence and their characteristics in terms of energy, width and electromagnetic nature.  
  Address [Guerrero, C; Alvarez-Velarde, F; Ano-Ott, DC; Martinez, T; Mendoza, E; Villamarin, D] Ctr Invest Energet Medioambientales & Technol CIE, Madrid, Spain, Email: carlos.guerrero@ciemat.es  
  Corporate Author Thesis  
  Publisher Korean 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 0374-4884 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000294080700013 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 731  
Permanent link to this record
 

 
Author n_TOF Collaboration (Guerrero, C. et al); Giubrone, G.; Tain, J.L. doi  openurl
  Title Characterization of the New n_TOF Neutron Beam: Fluence, Profile and Resolution Type Journal Article
  Year 2011 Publication Journal of the Korean Physical Society Abbreviated Journal J. Korean Phys. Soc.  
  Volume 59 Issue 2 Pages 1624-1627  
  Keywords n_TOF; Time-of-flight; Neutron beam; Nuclear data; Cross sections  
  Abstract After a halt of four years, the nTOF spallation neutron facility at CERN has resumed operation in November 2008 with a new spallation target characterized by an improved safety and engineering design, resulting in a more robust overall performance and efficient cooling. The first measurement during the 2009 run has aimed at the full characterization of the neutron beam. Several detectors, such as calibrated fission chambers, the nTOF Silicon Monitor, a MicroMegas detector with (10)B and (235)U samples, as well as liquid and solid scintillators have been used in order to characterize the properties of the neutron fluence. The spatial profile of the beam has been studied with a specially designed “X-Y” MicroMegas which provided a 2D image of the beam as a function of neutron energy. Both properties have been compared with simulations performed. with the FLUKA code. The characterization of the resolution function is based on results from simulations which have been verified by the study of narrow capture resonances. of (56)Fe, which were measured as part of a new campaign of (n,gamma) measurements on Fe and Ni isotopes.  
  Address [Guerrero, C; Becares, V; Cano-Ott, D; Fernandez-Ordonez, M; Gonzalez-Romero, E; Martin-Fuertes, F; Martinez, T; Mendoza, E; Pina, G; Quinones, J; Vlachoudis, V] Ctr Invest Energet Medioambientales & Tecnol, Madrid 28040, Spain, Email: carlos.guerrero@ciemat.es  
  Corporate Author Thesis  
  Publisher Korean 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 0374-4884 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000294080700041 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 735  
Permanent link to this record
 

 
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. doi  openurl
  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  
Permanent link to this record
 

 
Author n_TOF Collaboration (Guerrero, C. et al); Domingo-Pardo, C.; Tain, J.L. doi  openurl
  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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