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Author n_TOF Collaboration (Guerrero, C. et al); Giubrone, G.; Tain, J.L.
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 (down) [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 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
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Author n_TOF Collaboration (Guerrero, C. et al); Domingo-Pardo, C.; Tain, J.L.
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 (down) [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 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
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Author Guardiola, R.; Navarro, J.
Title On the Lindemann Criterion for Quantum Clusters at Very Low Temperature Type Journal Article
Year 2011 Publication Journal of Physical Chemistry A Abbreviated Journal J. Phys. Chem. A
Volume 115 Issue 25 Pages 6843-6850
Keywords
Abstract The Lindemann criterion to discern the solid-like or liquid-like nature of a quantum cluster at T = 0 is discussed. A critical analysis of current Lindemann parameters is presented and a new parameter is proposed that is appropriate to study quantum clusters made of identical particles. A simple model wave function is introduced to fix the range of variation of these parameters. The model presents two extreme limits that correspond to either a liquid-like or a solid-like system; besides, it fulfills the Bose symmetry and also permits evaluations without symmetrization. Variational and diffusion Monte Carlo calculations are also performed for clusters of spinless bosons interacting through Lennard-Jones potentials. It is shown that the liquid-like or solid-like character of quantum clusters at zero temperature cannot be simply established in terms of a single parameter.
Address (down) [Guardiola, R.; Navarro, J.] Univ Valencia, CSIC, IFIC, Valencia 46071, Spain, Email: navarro@ific.uv.es
Corporate Author Thesis
Publisher Amer Chemical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1089-5639 ISBN Medium
Area Expedition Conference
Notes ISI:000291895500012 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 669
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Author Granero, D.; Vijande, J.; Ballester, F.; Rivard, M.J.
Title Dosimetry revisited for the HDR Ir-192 brachytherapy source model mHDR-v2 Type Journal Article
Year 2011 Publication Medical Physics Abbreviated Journal Med. Phys.
Volume 38 Issue 1 Pages 487-494
Keywords Ir-192; brachytherapy; dosimetry; TG-43; PSS model; MCNP5; PENELOPE2008; GEANT4
Abstract Purpose: Recently, the manufacturer of the HDR Ir-192 mHDR-v2 brachytherapy source reported small design changes (referred to herein as mHDR-v2r) that are within the manufacturing tolerances but may alter the existing dosimetric data for this source. This study aimed to (1) check whether these changes affect the existing dosimetric data published for this source; (2) obtain new dosimetric data in close proximity to the source, including the contributions from 192Ir electrons and considering the absence of electronic equilibrium; and (3) obtain scatter dose components for collapsed cone treatment planning system implementation. Methods: Three different Monte Carlo (MC) radiation transport codes were used: MCNP5, PENELOPE2008, and GEANT4. The source was centrally positioned in a 40 cm radius water phantom. Absorbed dose and collision kerma were obtained using 0.1 mm (0.5 mm) thick voxels to provide high-resolution dosimetry near (far from) the source. Dose-rate distributions obtained with the three MC codes were compared. Results: Simulations of mHDR-v2 and mHDR-v2r designs performed with three radiation transport codes showed agreement typically within 0.2% for r >= 0.25 cm. Dosimetric contributions from source electrons were significant for r<0.25 cm. The dose-rate constant and radial dose function were similar to those from previous MC studies of the mHDR-v2 design. The 2D anisotropy function also coincided with that of the mHDR-v2 design for r >= 0.25 cm. Detailed results of dose distributions and scatter components are presented for the modified source design. Conclusions: Comparison of these results to prior MC studies showed agreement typically within 0.5% for r >= 0.25 cm. If dosimetric data for r<0.25 cm are not needed, dosimetric results from the prior MC studies will be adequate. c 2011 American Association of Physicists in Medicine.
Address (down) [Granero, Domingo] Hosp Gen Univ, Dept Radiat Phys, ERESA, E-46014 Valencia, Spain, Email: dgranero@eresa.com
Corporate Author Thesis
Publisher Amer Assoc Physicists Medicine Amer 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 0094-2405 ISBN Medium
Area Expedition Conference
Notes ISI:000285769800050 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 557
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Author Gonzalez, P.; Mathieu, V.; Vento, V.
Title Heavy meson interquark potential Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 84 Issue 11 Pages 114008 - 7pp
Keywords
Abstract The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum dependence which is free from infrared divergences. We calculate the interquark static potential for heavy mesons by assuming that it is given by a massive One Gluon Exchange interaction and compare with phenomenologyical fits inspired by lattice QCD. We apply these potential forms to the description of quarkonia and conclude that, even though some aspects of the confinement mechanism are absent in the Dyson-Schwinger formalism, the spectrum can be reasonably reproduced. We discuss possible explanations for this outcome.
Address (down) [Gonzalez, P.; Mathieu, V.; Vento, V.] Univ Valencia, CSIC, IFIC, Dept Fis Teor, E-46100 Burjassot, Valencia, Spain, Email: p.gonzalez@uv.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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000297769700003 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 834
Permanent link to this record