Author: "Calviño Tavares, Francisco" - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Calviño Tavares, Francisco"' showing total 425 results

Start Over Author "Calviño Tavares, Francisco"

425 results on '"Calviño Tavares, Francisco"'

51. Nuclear astrophysics at n_TOF facility, CERN

Author: Tagliente, G., Aberle, O., Calviño Tavares, Francisco, Tarifeño Saldivia, Ariel Esteban, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Neutrons, Energies::Energia nuclear [Àrees temàtiques de la UPC], Física [Àrees temàtiques de la UPC], Nuclear Theory, Nuclear physics, Física nuclear, Nuclear Experiment
Abstract: CERN's neutron time-of-flight facility n_TOF has produced a considerable amount of experimental data since it has become fully operational with the start of its scientific measurement programme in 2001. The innovative features of the facility, in the two experimental areas, (flight paths 20 m and 185 m), allow for an accurate determination of the neutron cross section for radioactive samples or for isotopes with small neutron capture cross section, of interest for Nuclear Astrophysics. An outline of the experimental nuclear astrophysical data activities at n_TOF will be presented
Published: 2019

52. Measurement of the 235U(n,f) cross section relative to the 6Li(n,t) and 10B(n,a) standards from thermal to 170 keV neutron energy range at n_TOF

Author: Amaducci, Simone, Cosentino, Luigi, Barbagallo, Massimo, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Tarifeño Saldivia, Ariel Esteban, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Neutrons, Energies::Energia nuclear [Àrees temàtiques de la UPC], Cross section, Física [Àrees temàtiques de la UPC], Astrophysics::High Energy Astrophysical Phenomena, CERN, Nuclear physics, n_TOF, Física nuclear, Nuclear reactions
Abstract: The 235U(n,f) cross section was measured in a wide energy range at n_TOF relative to 6Li(n,t) and 10B(n,alpha), with high resolution and in a wide energy range, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the reaction yields under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10÷30 keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the evaluated cross section in the 9÷18 keV neutron energy range is indeed overestimated, both in the recent updates of ENDF/B-VIII.0 and of the IAEA reference data. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The new, high accuracy results here reported may lead to a reduction of the uncertainty in the 1÷100 keV neutron energy region. Finally, the present data provide additional confidence on the recently re-evaluated cross section integral between 7.8 and 11 eV.
Published: 2019

53. Commissioning of the BRIKEN detector for the measurement of very exotic ß-delayed neutron emitters

Author: Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Tolosa Delgado, Alvaro, Agramunt Ros, Jorge, Taín, J.L., Tarifeño Saldivia, Ariel Esteban, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Tolosa Delgado, Alvaro, Agramunt Ros, Jorge, Taín, J.L., Tarifeño Saldivia, Ariel Esteban, Calviño Tavares, Francisco, and Cortés Rossell, Guillem Pere
Abstract: A new detection system has been installed at the RIKEN Nishina Center (Japan) to investigate decay properties of very neutron-richnuclei. The setup consists of three main parts: a moderated neutron counter, a detection system sensitive to the implantation anddecay of radioactive ions, and γ-ray detectors. We describe here the setup, the commissioning experiment and some selected resultsdemonstrating its performance for the measurement of half-lives andβ-delayed neutron emission probabilities. The methodologyfollowed in the analysis of the data is described in detail. Particular emphasis is placed on the correction of the accidental neutronbackground., Postprint (author's final draft)
Published: 2019

54. Fission program at n_TOF

Author: International Workshop on Nuclear Data Evaluation for Reactor Applications (5. : 2018 : Aix-en-Provence), Tassan-Got, Laurent, Colonna, Nicola, Diakaki, Maria, Eleme, Zinovia, Manna, Alice, Sekhar, Adhitya, Stamatopoulos, Athanasios, Aberle, Oliver, Alcayne, Victor, Amaducci, Simone, Andrzejewski, Józef, Audouin, Laurent, Babiano Suarez, Victor, Bacak, Michael, Barbagallo, Massimo, Bennett, Samuel, Berthoumieux, Eric, Bosnar, Damir, Brown, Adam S., Busso, Maurizio, Caamaño, Manuel, Caballero Ontanaya, Luis, Calviani, Marco, Calviño Tavares, Francisco, Cano-Ott, Daniel, Casanovas Hoste, Adrià, Cerutti, Francesco, Chiaveri, Enrico, Cortés Rossell, Guillem Pere, Cortés-Giraldo, Miguel Antonio, Cosentino, Luigi, Cristallo, Sergio, Damone, Lucia Anna, Davies, Paul John, Dietz, Mirco, Domingo-Pardo, César, Dressler, Rugard, Ducasse, Quentin, Dupont, Emmeric, Durán, Ignacio, Fernández Domínguez, Beatriz, Ferrari, Alfredo, Gonçalves, Isabel Maria Ferro, Finocchiaro, Paolo, Furman, Valter, Garg, Ruchi, Gawlik, Aleksandra, Gilardoni, Simone, Göbel, Kathrin, González Romero, Enrique Miguel, Guerrero Sánchez, Carlos, Gunsing, Frank, Heinitz, Stephan, Heyse, Jan, Jenkins, David, Jiri, U., Junghans, Arnd Rudolf, Kadi, Yacine, Käppeler, Franz, Kimura, Atsushi, Knapová, Ingrid, Kokkoris, Michael, Kopatch, Yuri N., Krtička, Milan, Kurtulgil, Cem Deniz, Ladarescu, Ion, Lederer-Woods, Claudia, Lerendegui-Marco, Jorge, Lonsdale, Sarah-Jane, Macina, Daniela, Martinez, Trinitario, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Maugeri, Emilio Andrea, Mazzone, Annamaria, Mendoza Cembranos, Emilio, Mengoni, Alberto, Michalopoulou, Veatriki, Milazzo, Paolo Maria, Millán Callado, María de los Ángeles, Mingrone, Federica, Moreno-Soto, Javier, Musumarra, Agatino, Negret, Alexandru, Ogállar Ruiz, Francisco, Oprea, Andreea, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Petrone, Cristina, Piersanti, Luciano, Pirovano, Elisa, Porras Sánchez, José Ignacio, Praena, Javier, Quesada Molina, José Manuel, Ramos Doval, Diego, Reifarth, René, Rochman, Dimitri, Rubbia, Carlo, Sabaté-Gilarte, Marta, Saxena, Alok, Schillebeeckx, Peter, Schumann, Dorothea, Smith, Alastair Gavin, Sosnin, Nikolay V., Sprung, Peter, Tagliente, Giuseppe, Taı́n Enríquez, José Luis, Tarifeño-Saldivia, Ariel, Thomas, Benedikt, Torres-Sánchez, Pablo, Tsinganis, Andrea, Urlaß, Sebastian, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vescovi, Diego, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Woods, Philip John, Wright, Tobias J., Žugec, Petar, International Workshop on Nuclear Data Evaluation for Reactor Applications (5. : 2018 : Aix-en-Provence), Tassan-Got, Laurent, Colonna, Nicola, Diakaki, Maria, Eleme, Zinovia, Manna, Alice, Sekhar, Adhitya, Stamatopoulos, Athanasios, Aberle, Oliver, Alcayne, Victor, Amaducci, Simone, Andrzejewski, Józef, Audouin, Laurent, Babiano Suarez, Victor, Bacak, Michael, Barbagallo, Massimo, Bennett, Samuel, Berthoumieux, Eric, Bosnar, Damir, Brown, Adam S., Busso, Maurizio, Caamaño, Manuel, Caballero Ontanaya, Luis, Calviani, Marco, Calviño Tavares, Francisco, Cano-Ott, Daniel, Casanovas Hoste, Adrià, Cerutti, Francesco, Chiaveri, Enrico, Cortés Rossell, Guillem Pere, Cortés-Giraldo, Miguel Antonio, Cosentino, Luigi, Cristallo, Sergio, Damone, Lucia Anna, Davies, Paul John, Dietz, Mirco, Domingo-Pardo, César, Dressler, Rugard, Ducasse, Quentin, Dupont, Emmeric, Durán, Ignacio, Fernández Domínguez, Beatriz, Ferrari, Alfredo, Gonçalves, Isabel Maria Ferro, Finocchiaro, Paolo, Furman, Valter, Garg, Ruchi, Gawlik, Aleksandra, Gilardoni, Simone, Göbel, Kathrin, González Romero, Enrique Miguel, Guerrero Sánchez, Carlos, Gunsing, Frank, Heinitz, Stephan, Heyse, Jan, Jenkins, David, Jiri, U., Junghans, Arnd Rudolf, Kadi, Yacine, Käppeler, Franz, Kimura, Atsushi, Knapová, Ingrid, Kokkoris, Michael, Kopatch, Yuri N., Krtička, Milan, Kurtulgil, Cem Deniz, Ladarescu, Ion, Lederer-Woods, Claudia, Lerendegui-Marco, Jorge, Lonsdale, Sarah-Jane, Macina, Daniela, Martinez, Trinitario, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Maugeri, Emilio Andrea, Mazzone, Annamaria, Mendoza Cembranos, Emilio, Mengoni, Alberto, Michalopoulou, Veatriki, Milazzo, Paolo Maria, Millán Callado, María de los Ángeles, Mingrone, Federica, Moreno-Soto, Javier, Musumarra, Agatino, Negret, Alexandru, Ogállar Ruiz, Francisco, Oprea, Andreea, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Petrone, Cristina, Piersanti, Luciano, Pirovano, Elisa, Porras Sánchez, José Ignacio, Praena, Javier, Quesada Molina, José Manuel, Ramos Doval, Diego, Reifarth, René, Rochman, Dimitri, Rubbia, Carlo, Sabaté-Gilarte, Marta, Saxena, Alok, Schillebeeckx, Peter, Schumann, Dorothea, Smith, Alastair Gavin, Sosnin, Nikolay V., Sprung, Peter, Tagliente, Giuseppe, Taı́n Enríquez, José Luis, Tarifeño-Saldivia, Ariel, Thomas, Benedikt, Torres-Sánchez, Pablo, Tsinganis, Andrea, Urlaß, Sebastian, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vescovi, Diego, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Woods, Philip John, Wright, Tobias J., and Žugec, Petar
Abstract: Since its start in 2001 the n_TOF collaboration developed a measurement program on fission, in view of advanced fuels in new generation reactors. A special effort was made on measurement of cross sections of actinides, exploiting the peculiarity of the n_TOF neutron beam which spans a huge energy domain, from the thermal region up to GeV. Moreover fission fragment angular distributions have also been measured. An overview of the cross section results achieved with different detectors is presented, including a discussion of the 237Np case where discrepancies showed up between different detector systems. The results on the anisotropy of the fission fragments and its implication on the mechanism of neutron absorption, and in applications, are also shown.
Published: 2019

55. Observation of a us isomer in 134-In: Proton-neutron coupling “southeast” of 132-Sn

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Phong, V.H., Lorusso, G., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Phong, V.H., Lorusso, G., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: We report on the observation of a microsecond isomeric state in the single-proton-hole, three-neutron-particlenucleus134In. The nuclei of interest were produced by in-flight fission of a238U beam at the Radioactive IsotopeBeam Factory at RIKEN. The isomer depopulates through a¿ray of energy 56.7(1) keV and with a half-life ofT1/2=3.5(4)µs. Based on the comparison with shell-model calculations, we interpret the isomer as theIp=5-member of thep0g-19/2¿¿1f37/2multiplet, decaying to theIp=7-ground state with a reduced-transitionprobability ofB(E2; 5-¿7-)=0.53(6) W.u.Observation of this isomer, and lack of evidence in the currentwork for aIp=5-isomer decay in132In, provides a benchmark of the proton-neutron interaction in the regionof the nuclear chart “southeast” of132Sn, where experimental information on excited states is sparse., Postprint (author's final draft)
Published: 2019

56. Measurement of the 235U(n, f) cross section relative to the 6Li(n, t) and 10B(n, a) standards from thermal to 170 keV neutron energy range at n_TOF

Author: Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Amaducci, Simone, Cosentino, Luigi, Barbagallo, Massimo, Casanovas Hoste, Adrià, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Amaducci, Simone, Cosentino, Luigi, Barbagallo, Massimo, Casanovas Hoste, Adrià, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: The 235U(n, f ) cross section was measured at n_TOF relative to 6Li(n, t) and 10B(n,a) , with high resolution ( L=183.49(2) m) and in a wide energy range (25meV-170keV) with 1.5% systematic uncertainty, making use of a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the yields of the 235U(n, f ) and of the two reference reactions under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10-30keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the cross section in the 9-18keV neutron energy range is indeed overestimated by almost 5% in the recently released evaluated data files ENDF/B-VIII.0 and JEFF3.3, as a consequence of a 7% overestimate in a single GMA node in the IAEA reference file. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The results here reported may lead to a reduction of the uncertainty in the 1-100keV neutron energy region. Finally, from the present data, a value of 249.7±1.4(stat)±0.94(syst) b·eV has been extracted for the cross section integral between 7.8 and 11eV, confirming the value of 247.5±3 b·eV recently established as a standard., Postprint (published version)
Published: 2019

57. Preliminary results on the 233U capture cross section and alpha ratio measured at n_TOF (CERN) with the fission tagging technique

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Bacak, M., Aiche, Mourad, Bélier, Gilbert, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Bacak, M., Aiche, Mourad, Bélier, Gilbert, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: 233U is of key importance among the fissile nuclei in the Th-U fuel cycle. A particularity of 233U is its small neutron capture cross-section, which is on average about one order of magnitude lower than the fission cross-section.The accuracy in the measurement of the 233U capture cross-section depends crucially onan efficient capture-fission discrimination, thus a combined set-up of fission and ¿-detectors is needed. A measurement of the 233U capture cross-section and capture-to-fissionratio was performed at the CERN n_TOF facility. The Total Absorption Calorimeter (TAC) of n_TOF was employed as ¿-detector coupled with a novel compact ionization chamber as fission detector. A brief description of the experimental set-up will be given, and essential parts of the analysis procedure as well as the preliminary response of the set-up to capture are presented and discussed, Postprint (published version)
Published: 2019

58. (n,cp) reactions study at the n_TOF facilitty at CERN: results for the cosmological lithium problem

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Barbagallo, Massimo, Aberle, O., Alcayne, V., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Barbagallo, Massimo, Aberle, O., Alcayne, V., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: The Big Bang Nucleosynthesis describes the production of the lightest nuclides from deuterium to Li at the early stages of the Universe. While a general good agreement is found for most of the isotopes involved in the synthesis, a serious discrepancy between the predicted abundance of 7Li and the related experimental observations is still present. This discrepancy has been referred since several decades as Cosmological Lithium Problem. In one last attempt to find nuclear solutions to this longstanding conundrum, the 7Be(n,alpha)4He and 7Be(n,p)7Li reactions, that affect predominantly the production of 7Li via the destruction of his parent nucleus 7Be, have been studied. Here we present the 7Be(n,a)4He and 7Be(n,p)7Li reaction crosssection measurements performed at the high-resolution n_TOF facility using the time-of-flight technique and high purity samples. The result of the experiments definitely rules out neutron induced reactions as a solution to the puzzle, thus indicating that explanations have to be sought out in other Physics scenarios., Postprint (published version)
Published: 2019

59. Nuclear astrophysics at n_TOF facility, CERN

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Tagliente, G., Aberle, O., Calviño Tavares, Francisco, Tarifeño Saldivia, Ariel Esteban, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Tagliente, G., Aberle, O., Calviño Tavares, Francisco, Tarifeño Saldivia, Ariel Esteban, Casanovas Hoste, Adrià, and Cortés Rossell, Guillem Pere
Abstract: CERN's neutron time-of-flight facility n_TOF has produced a considerable amount of experimental data since it has become fully operational with the start of its scientific measurement programme in 2001. The innovative features of the facility, in the two experimental areas, (flight paths 20 m and 185 m), allow for an accurate determination of the neutron cross section for radioactive samples or for isotopes with small neutron capture cross section, of interest for Nuclear Astrophysics. An outline of the experimental nuclear astrophysical data activities at n_TOF will be presented, Postprint (published version)
Published: 2019

60. Cross section measurements of 155,157Gd(n,gamma) induced by thermal and epithermal neutrons

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Mastromarco, M., Aberle, O., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Mastromarco, M., Aberle, O., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: Neutron capture cross section measurements on 155Gd and 157Gd were performed using the time-of-flight technique at the n_TOF facility at CERN on isotopically enriched samples. The measurements were carried out in the n_TOF experimental area EAR1, at 185 m from the neutron source, with an array of 4 C6D6 liquid scintillation detectors. At a neutron kinetic energy of 0.0253 eV, capture cross sections of 62.2(2.2) and 239.8(8.4) kilobarn have been derived for 155Gd and 157Gd, respectively, with up to 6% deviation relative to values presently reported in nuclear data libraries, but consistent with those values within 1.6 standard deviations. A resonance shape analysis has been performed in the resolved resonance region up to 181 eV and 307 eV, respectively for 155Gd and 157Gd, where on average, resonance parameters have been found in good agreement with evaluations. Above these energies and up to 1 keV, the observed resonance-like structure of the cross section has been analysed and characterised. From a statistical analysis of the observed neutron resonances we deduced: neutron strength function of 2.01(28)×10-4 and 2.17(41)×10-4; average total radiative width of 106.8(14) meV and 101.1(20) meV and s-wave resonance spacing 1.6(2) eV and 4.8(5) eV for n + 155Gd and n + 157Gd systems, respectively., Postprint (author's final draft)
Published: 2019

61. Measurement of 73Ge(n,gamma) cross sections and implications for stellar nucleosynthesis

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Lederer-Woods, C., Battino, U., Ferreira, P.A., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Riego Pérez, Albert, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Lederer-Woods, C., Battino, U., Ferreira, P.A., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Riego Pérez, Albert
Abstract: 73Ge(n,gamma) cross sections were measured at the neutron time-of-flight facility n_TOF at CERN up to neutron energies of 300 keV, providing for the first time experimental data above 8 keV. Results indicate that the stellar cross section at keV is 1.5 to 1.7 times higher than most theoretical predictions. The new cross sections result in a substantial decrease of 73Ge produced in stars, which would explain the low isotopic abundance of 73Ge in the solar system., Postprint (published version)
Published: 2019

62. Measurement of the 244Cm and 246Cm neutron-induced capture cross sections at the n_TOF facility

Author: International Workshop on Nuclear Data Evaluation for Reactor Applications (5. : 2018 : Aix-en-Provence), Alcayne, Victor, Kimura, Atsushi, Mendoza Cembranos, Emilio, Cano-Ott, Daniel, Martı́nez, Trinitario, Aberle, Oliver, Andrzejewski, Józef, Audouin, Laurent, Bécares, Vicente, Bacak, Michael, Barbagallo, Massimo, Bečvář, František, Bellia, Giorgio, Berthoumieux, Eric, Billowes, Jonathan, Bosnar, Damir, Brown, Adam, Busso, Maurizio, Caamaño, Manuel, Caballero Ontanaya, Luis, Calviño Tavares, Francisco, Calviani, Marco, Casanovas Hoste, Adrià, Cerutti, Francesco, Chen, Yonghao, Chiaveri, Enrico, Colonna, Nicola, Cortés Rossell, Guillem Pere, Cortés-Giraldo, Miguel Antonio, Cosentino, Luigi, Cristallo, Sergio, Damone, Lucia Anna, Diakaki, Maria, Dietz, Mirco, Domingo-Pardo, César, Dressler, Rugard, Dupont, Emmeric, Durán, Ignacio, Eleme, Zinovia, Fernández Domínguez, Beatriz, Ferrari, Alfredo, Finocchiaro, Paolo, Furman, Valter, Göbel, Kathrin, Gawlik, Aleksandra, Gilardoni, Simone, Glodariu, Tudor, Gonçalves, Isabel Maria Ferro, González Romero, Enrique Miguel, Guerrero Sánchez, Carlos, Gunsing, Frank, Harada, Hideo, Heinitz, Stephan, Heyse, Jan, Jenkins, David, Käppeler, Franz, Kadi, Yacine, Katabuchi, Tatsuya, Kivel, Nikolay, Knapová, Ingrid, Kokkoris, Michael, Kopatch, Yuri N., Krtička, Milan, Kurtulgil, Cem Deniz, Ladarescu, Ion, Lederer-Woods, Claudia, Lerendegui-Marco, Jorge, Lo Meo, Sergio, Lonsdale, Sarah Jane, Macina, Daniela, Manna, Alice, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Matteucci, Francesca, Maugeri, Emilio Andrea, Mazzone, Annamaria, Mengoni, Alberto, Michalopoulou, Veatriki, Milazzo, Paolo Maria, Mingrone, Federica, Musumarra, Agatino, Negret, Alexandru, Nolte, Ralf, Ogállar Ruiz, Francisco, Oprea, Andreea, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Piersanti, Luciano, Porras Sánchez, José Ignacio, Praena, Javier, Quesada Molina, José Manuel, Radeck, Désirée, Ramos Doval, Diego, Rauscher, Thomas, Reifarth, René, Rochman, Dimitri, Sabaté-Gilarte, Marta, Saxena, Alok, Schillebeeckx, Peter, Schumann, Dorothea, Simone, S., Smith, Alastair Gavin, Sosnin, Nikolay V., Stamatopoulos, Athanasios, Tagliente, Giuseppe, Taı́n Enríquez, José Luis, Talip, T., Tarifeño-Saldivia, Ariel, Tassan-Got, Laurent, Tsinganis, Andrea, Ulrich, Jiri, Urlaß, Sebastian, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vescovi, Diego, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Woods, Philip John, Wright, Tobias, Žugec, Petar, International Workshop on Nuclear Data Evaluation for Reactor Applications (5. : 2018 : Aix-en-Provence), Alcayne, Victor, Kimura, Atsushi, Mendoza Cembranos, Emilio, Cano-Ott, Daniel, Martı́nez, Trinitario, Aberle, Oliver, Andrzejewski, Józef, Audouin, Laurent, Bécares, Vicente, Bacak, Michael, Barbagallo, Massimo, Bečvář, František, Bellia, Giorgio, Berthoumieux, Eric, Billowes, Jonathan, Bosnar, Damir, Brown, Adam, Busso, Maurizio, Caamaño, Manuel, Caballero Ontanaya, Luis, Calviño Tavares, Francisco, Calviani, Marco, Casanovas Hoste, Adrià, Cerutti, Francesco, Chen, Yonghao, Chiaveri, Enrico, Colonna, Nicola, Cortés Rossell, Guillem Pere, Cortés-Giraldo, Miguel Antonio, Cosentino, Luigi, Cristallo, Sergio, Damone, Lucia Anna, Diakaki, Maria, Dietz, Mirco, Domingo-Pardo, César, Dressler, Rugard, Dupont, Emmeric, Durán, Ignacio, Eleme, Zinovia, Fernández Domínguez, Beatriz, Ferrari, Alfredo, Finocchiaro, Paolo, Furman, Valter, Göbel, Kathrin, Gawlik, Aleksandra, Gilardoni, Simone, Glodariu, Tudor, Gonçalves, Isabel Maria Ferro, González Romero, Enrique Miguel, Guerrero Sánchez, Carlos, Gunsing, Frank, Harada, Hideo, Heinitz, Stephan, Heyse, Jan, Jenkins, David, Käppeler, Franz, Kadi, Yacine, Katabuchi, Tatsuya, Kivel, Nikolay, Knapová, Ingrid, Kokkoris, Michael, Kopatch, Yuri N., Krtička, Milan, Kurtulgil, Cem Deniz, Ladarescu, Ion, Lederer-Woods, Claudia, Lerendegui-Marco, Jorge, Lo Meo, Sergio, Lonsdale, Sarah Jane, Macina, Daniela, Manna, Alice, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Matteucci, Francesca, Maugeri, Emilio Andrea, Mazzone, Annamaria, Mengoni, Alberto, Michalopoulou, Veatriki, Milazzo, Paolo Maria, Mingrone, Federica, Musumarra, Agatino, Negret, Alexandru, Nolte, Ralf, Ogállar Ruiz, Francisco, Oprea, Andreea, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Piersanti, Luciano, Porras Sánchez, José Ignacio, Praena, Javier, Quesada Molina, José Manuel, Radeck, Désirée, Ramos Doval, Diego, Rauscher, Thomas, Reifarth, René, Rochman, Dimitri, Sabaté-Gilarte, Marta, Saxena, Alok, Schillebeeckx, Peter, Schumann, Dorothea, Simone, S., Smith, Alastair Gavin, Sosnin, Nikolay V., Stamatopoulos, Athanasios, Tagliente, Giuseppe, Taı́n Enríquez, José Luis, Talip, T., Tarifeño-Saldivia, Ariel, Tassan-Got, Laurent, Tsinganis, Andrea, Ulrich, Jiri, Urlaß, Sebastian, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vescovi, Diego, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Woods, Philip John, Wright, Tobias, and Žugec, Petar
Abstract: The neutron capture reactions of the 244Cm and 246Cm isotopes open the path for the formation of heavier Cm isotopes and heavier elements such as Bk and Cf in a nuclear reactor. In addition, both isotopes belong to the minor actinides with a large contribution to the decay heat and to the neutron emission in irradiated fuels. There are only two previous 244Cm and 246Cm capture cross section measurements: one in 1969 using a nuclear explosion [1] and the most recent data measured at J-PARC in 2010 [2]. The data for both isotopes are very scarce due to the difficulties in performing the measurements: high intrinsic activity of the samples and limited facilities capable of providing isotopically enriched samples. We have measured both neutron capture cross sections at the n_TOF Experimental Area 2 (EAR-2) with three C6 D6 detectors and also at Area 1 (EAR-1) with the TAC. Preliminary results assessing the quality and limitations (back-ground subtraction, measurement technique and counting statistics) of this new experimental datasets are presented and discussed.
Published: 2019

63. Master in Nuclear Energy UPC-Endesa. Preparing students for a challenging world.

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. DRM - Dosimetria i Radiofísica Mèdica, Batet Miracle, Lluís, Calviño Tavares, Francisco, Duch Guillen, María Amor, León, Pablo, Serra, Eduardo, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. DRM - Dosimetria i Radiofísica Mèdica, Batet Miracle, Lluís, Calviño Tavares, Francisco, Duch Guillen, María Amor, León, Pablo, and Serra, Eduardo
Abstract: The Master's programme in Nuclear Engineering (MNE) from UPC is starting its 9th edition. The programme is fruit of the alliance of the university and Endesa with other players within the Spanish nuclear sector: from the industry, the regulatory authority, and research institutions. MNE is embedded in the European Master in Nuclear Energy (EMINE), offered by InnoEnergy under the auspices of the European Institute of Innovation and Technology (EIT).Both MNE and EMINE programmes are subject to a continuous review process, which includes the EIT LABEL review process in the case of EMINE and accreditation by the domestic quality agency in the case of MNE. Self-criticism and students’ feedback are important improvement drivers as well. Recent changes have resulted from internal reviews. For instance, a change in the conception of the second semester projects has resulted from the need to restructure the teaching of a number of engineering skills, the aim to maintain the high level of synergy with industry, and the students’ interest in new generation reactors and in nuclear fusion, Postprint (published version)
Published: 2019

64. Measurement of the 70Ge(n,¿) cross section up to 300 keV at the CERN n_TOF facility

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Lederer-Woods, C., Andrzejewski, Józef, Battino, U., Gunsing, Frank, Krticka, M., Massimi, Cristian, Mingrone, Federica, Aberle, O., Audouin, Ludmila, Bacak, M., Barbagallo, Massimo, Beinrucker, C., Berthoumieux, Eric, Bosnar, Damir, Brugger, Matthias, Calviño Tavares, Francisco, Chen, Yu-Hsiang, Colonna, Nicola, Cortés Rossell, Guillem Pere, Cosentino, Luigi, Diakaki, M., Domingo Pardo, César, Dressler, Rugard, Dupont, E., Gonzalez Romero, E., Goverdovski, A., Griesmayer, E., Jericha, E., Kaeppeler, F., Kadi, Y, Ketlerov, V., Kimura, Atsushi, Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., Losito, R., Marganiec, J., Mastromarco, M., Musumarra, A., Patronis, N., Pavlik, A., Rauscher, Thomas, Rubbia, C., Sabaté-Gilarte, M., Saxena, Avadh, Schmidt, Samuel, Stamatopoulos, A., Tassan-Got, L., Vannini, Gianni, Vlachoudis, V., Wallner, A., Wright, T., Žugec, Petar, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Lederer-Woods, C., Andrzejewski, Józef, Battino, U., Gunsing, Frank, Krticka, M., Massimi, Cristian, Mingrone, Federica, Aberle, O., Audouin, Ludmila, Bacak, M., Barbagallo, Massimo, Beinrucker, C., Berthoumieux, Eric, Bosnar, Damir, Brugger, Matthias, Calviño Tavares, Francisco, Chen, Yu-Hsiang, Colonna, Nicola, Cortés Rossell, Guillem Pere, Cosentino, Luigi, Diakaki, M., Domingo Pardo, César, Dressler, Rugard, Dupont, E., Gonzalez Romero, E., Goverdovski, A., Griesmayer, E., Jericha, E., Kaeppeler, F., Kadi, Y, Ketlerov, V., Kimura, Atsushi, Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., Losito, R., Marganiec, J., Mastromarco, M., Musumarra, A., Patronis, N., Pavlik, A., Rauscher, Thomas, Rubbia, C., Sabaté-Gilarte, M., Saxena, Avadh, Schmidt, Samuel, Stamatopoulos, A., Tassan-Got, L., Vannini, Gianni, Vlachoudis, V., Wallner, A., Wright, T., and Žugec, Petar
Abstract: Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weakcomponent of the slow neutron capture processes, which occurs in massive stars. The (n,¿) cross section on70Ge, which is mainly produced in thesprocess, was measured at the neutron time-of-flight facility n_TOF atCERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sectionsup to 300 keV. Stellar cross sections were calculated fromkT=5keVtokT=100 keV and are in verygood agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average crosssections are in agreement with Walter and Beer (1985) over most of the neutron energy range covered, while theyare systematically smaller for neutron energies above 150 keV. We have calculated isotopic abundances producedins-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar).While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close tosolar model shows a good global match to solar system abundances in the range of mass numbersA=60–80, Postprint (published version)
Published: 2019

65. Strong one-neutron emission from two-neutron unbound states in Beta decays of the r-process nuclei 86,87 Ga

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Yokoyama, R., Grzywacz, Robert, Rasco, B. Charles, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Yokoyama, R., Grzywacz, Robert, Rasco, B. Charles, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: Aquesta és una còpia de la versió author’s final draft d'un article publicat a la revista [Physical Review C ]. URL d'aquest document a UPCommons E-prints: http://hdl.handle.net/2117/174873, Beta-delayed one-neutron and two-neutron branching ratios (P1n and P2n) have been measured in the decay of A = 84 to 87 Ga isotopes at the Radioactive-Isotope Beam Factory (RIBF) at the RIKEN Nishina Center using a high-efficiency array of 3He neutron counters (BRIKEN). Two-neutron emission was observed in the decay of 84,85,87Ga for the first time and the branching ratios were measured to be P2n = 1.6(2)%, 1.3(2)%, and 10.2(28)stat(5)sys%, respectively. One-neutron branching ratio of 87Ga (P1n = 81(9)stat(8)sys%) and half-life of 29(4) ms were measured for the first time. The branching ratios of 86Ga were also measured to be P1n = 74(2)stat(8)sys% and 16.2(9)stat(6)sys% with better precision than a previous study. The observation that P1n > P2n for both 86,87Ga was unexpected and is interpreted as a signature of dominating one-neutron emission from the two-neutron unbound excited states in 86,87Ge. In order to interpret the experimental results, shell-model and Hauser-Feshbach statistical model calculations of delayed particle and ¿ -ray emission probabilities were performed. This model framework reproduces the experimental results. The shell model alone predicts P2n significantly larger than P1n for the 87Ga decay, and it is necessary to invoke a statistical description to successfully explain the observation that P1n > P2n. Our new results demonstrate the relevance and importance of a statistical description of neutron emission for the prediction of the decay properties of multineutron emitters and that it must be included in the r-process modeling., Postprint (author's final draft)
Published: 2019

66. Measurement of the 235U(n,f) cross section relative to the 6Li(n,t) and 10B(n,a) standards from thermal to 170 keV neutron energy range at n_TOF

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Amaducci, Simone, Cosentino, Luigi, Barbagallo, Massimo, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Tarifeño Saldivia, Ariel Esteban, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Amaducci, Simone, Cosentino, Luigi, Barbagallo, Massimo, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Tarifeño Saldivia, Ariel Esteban, and Cortés Rossell, Guillem Pere
Abstract: The 235U(n,f) cross section was measured in a wide energy range at n_TOF relative to 6Li(n,t) and 10B(n,alpha), with high resolution and in a wide energy range, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the reaction yields under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10÷30 keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the evaluated cross section in the 9÷18 keV neutron energy range is indeed overestimated, both in the recent updates of ENDF/B-VIII.0 and of the IAEA reference data. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The new, high accuracy results here reported may lead to a reduction of the uncertainty in the 1÷100 keV neutron energy region. Finally, the present data provide additional confidence on the recently re-evaluated cross section integral between 7.8 and 11 eV., Preprint
Published: 2019

67. Fission program at n_TOF

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Tassan Got, Laurence, Colonna, Nicola, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Tarifeño Saldivia, Ariel Esteban, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Tassan Got, Laurence, Colonna, Nicola, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Tarifeño Saldivia, Ariel Esteban, and Cortés Rossell, Guillem Pere
Abstract: Since its start in 2001 the n_TOF collaboration developed a measurement program on fission, in view of advanced fuels in new generation reactors. A special effort was made on measurement of cross sections of actinides, exploiting the peculiarity of the n_TOF neutron beam which spans a huge energy domain, from the thermal region up to GeV. Moreover fission fragment angular distributions have also been measured. An overview of the cross section results achieved with different detectors is presented, including a discussion of the 237Np case where discrepancies showed up between different detector systems. The results on the anisotropy of the fission fragments and its implication on the mechanism of neutron absorption, and in applications, are also shown., Postprint (published version)
Published: 2019

68. Measurement of the 244Cm and 246Cm neutron-induced capture cross sections at the n_TOF facility

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Alcayne Aicua, Víctor, Mendoza Cembranos, Emilio, Kimura, Atsushi, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Alcayne Aicua, Víctor, Mendoza Cembranos, Emilio, Kimura, Atsushi, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: The neutron capture reactions of the 244Cm and 246Cm isotopes open the path for the formation of heavier Cm isotopes and heavier elements such asThe neutron capture reactions of the 244Cm and 246Cm isotopes open the path for the formation of heavier Cm isotopes and heavier elements such as Bk and Cf in a nuclear reactor. In addition, both isotopes belong to the minor actinides with a large contribution to the decay heat and to the neutron emission in irradiated fuels. There are only two previous 244Cm and 246Cm capture cross section measurements: one in 1969 using a nuclear explosion and the most recent data measured at J-PARC in 2010. The data for both isotopes are very scarce due to the difficulties in performing the measurements: high intrinsic activity of the samples and limited facilities capable of providing isotopically enriched samples. We have measured both neutron capture cross sections at the n_TOF Experimental Area 2 (EAR-2) with three C6D6 detectors and also at Area 1 (EAR-1) with the TAC. Preliminary results assessing the quality and limitations (background subtraction, measurement technique and counting statistics) of this new experimental datasets are presented and discussed. Bk and Cf in a nuclear reactor. In addition, both isotopes belong to the minor actinides with a large contribution to the decay heat and to the neutron emission in irradiated fuels. There are only two previous 244Cm and 246Cm capture cross section measurements: one in 1969 using a nuclear explosion and the most recent data measured at J-PARC in 2010. The data for both isotopes are very scarce due to the difficulties in performing the measurements: high intrinsic activity of the samples and limited facilities capable of providing isotopically enriched samples. We have measured both neutron capture cross sections at the n_TOF Experimental Area 2 (EAR-2) with three C6D6 detectors and also at Area 1 (EAR-1) with the TAC. Preliminary results assessing the quality and limitations (bac, Postprint (published version)
Published: 2019

69. First determination of ß -delayed multiple neutron emission beyond A=100 through direct neutron measurement: the P2n value of Sb 136

Author: Caballero-Folch, R., Dillmann, Iris, Agramunt Ros, Jorge, Calviño Tavares, Francisco|||0000-0002-7198-4639, Cortés Rossell, Guillem Pere|||0000-0002-3648-5826, Riego Pérez, Albert|||0000-0001-8571-1546, Salvador Castiñeira, Paula Genoveva, Tarifeño Saldivia, Ariel Esteban|||0000-0001-8552-5030, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Nuclear engineering, Física [Àrees temàtiques de la UPC], Safety imputs for nuclear reactors, Enginyeria nuclear, Nuclear Theory, Nuclear physics, Física nuclear, Nuclear Experiment
Abstract: Background: ß-delayed multiple neutron emission has been observed for some nuclei with A=100, being the 100Rb the heaviest ß2n emitter measured to date. So far, only 25P2n values have been determined for the ˜300 nuclei that may decay in this way. Accordingly, it is of interest to measure P2n values for the other possible multiple neutron emitters throughout the chart of the nuclides. It is of particular interest to make such a measurement for nuclei with A>100 to test the predictions of theoretical models and simulation tools for the decays of heavy nuclei in the region of very neutron-rich nuclei. In addition, the decay properties of these nuclei are fundamental for the understanding of astrophysical nucleosynthesis processes, such as the r-process, and safety inputs for nuclear reactors.
Published: 2018

70. Measurement and resonance analysis of the 33S (n, alpha) 30Si cross section at the CERN n_TOF facility in the energy region from 10 to 300 keV

Author: Praena, J., Sabaté-Gilarte, M., Porras, I., Calviño Tavares, Francisco|||0000-0002-7198-4639, Cortés Rossell, Guillem Pere|||0000-0002-3648-5826, Gómez Hornillos, María Belén, Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Cross section, nTOF, CERN, Física::Física de partícules [Àrees temàtiques de la UPC], Nuclear physics, Física nuclear, Neutron, Nuclear reaction, Neutrons--Captura, Neutron-capture therapy, Neutrons--Capture
Abstract: The 33S(n,a)30Si cross section has been measured at the neutron time-of-flight (n_TOF) facility at CERN in the neutron energy range from 10 to 300 keV relative to the 10B(n,a)7Li cross-section standard. Both reactions were measured simultaneously with a set of micromegas detectors. The flight path of 185 m has allowed us to obtain the cross section with high-energy resolution. An accurate description of the resonances has been performed by means of the multilevel multichannel R-matrix code SAMMY. The results show a significantly higher area of the biggest resonance (13.45 keV) than the unique high-resolution (n,a) measurement. The new parametrization of the 13.45-keV resonance is similar to that of the unique transmission measurement. This resonance is a matter of research in neutron-capture therapy. The 33S(n,a)30Si cross section has been studied in previous works because of its role in the production of 36S in stars, which is currently overproduced in stellar models compared to observations.
Published: 2018

71. Preparation and characterization of 33-S samples for 33-S(n,alpha)30-Si cross-section measurements at the n_TOF facility at CERN

Author: Praena, J., Ferrer, F. Javier, Vollenberg, Will, Calviño Tavares, Francisco|||0000-0002-7198-4639, Cortés Rossell, Guillem Pere|||0000-0002-3648-5826, Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Anàlisi espectral, Cross section, nTOF, Energies [Àrees temàtiques de la UPC], CERN, Neutron, Neutron reactions, Spectrum analysis
Abstract: Thin 33S samples for the study of the 33S(n,a)30Si cross-section at the n_TOF facility at CERN were made by thermal evaporation of 33S powder onto a dedicated substrate made of kapton covered with thin layers of copper, chromium and titanium. This method has provided for the first time bare sulfur samples a few centimeters in diameter. The samples have shown an excellent adherence with no mass loss after few years and no sublimation in vacuum at room temperature. The determination of the mass thickness of 33S has been performed by means of Rutherford backscattering spectrometry. The samples have been successfully tested under neutron irradiation.
Published: 2018

72. First Measurement of 72Ge(n,γ) at n_TOF

Author: Dietz, M., Lederer Woods, Claudia, Aberle, O., Andrzejewski, J., Audouin, Laurent, Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, František, Brow, A., Calviño Tavares, Francisco, Calviani, M., Casanovas, A., Cerutti, F., Cortés Giraldo, Miguel Antonio, Ventura, A., Žugec, P., and Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Astrophysics::Solar and Stellar Astrophysics, Nuclear Experiment
Abstract: 9th European Summer School on Experimental Nuclear Astrophysics The slow neutron capture process (s-process) is responsible for producing about half of the elemental abundances heavier than iron in the universo.
Published: 2018

73. Application of Photon Strength Functions to (n,gamma) measurements with the n_TOF TAC

Author: Guerrero, Carlos, Abbondanno, U., Aerts, G., Calviño Tavares, Francisco|||0000-0002-7198-4639, Cortés Rossell, Guillem Pere|||0000-0002-3648-5826, Pretel Sánchez, Carme|||0000-0001-6199-3366, Poch, Agustí, Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Física::Física de partícules::Fotons [Àrees temàtiques de la UPC], Monte Carlo method, Photons, Física [Àrees temàtiques de la UPC], Montecarlo, Mètode de, Física::Física de partícules [Àrees temàtiques de la UPC], Nuclear physics, Física nuclear, Fotons
Abstract: The neutron capture cross section measurements at the CERN n_TOF facility are performed using a new detection system, the segmented Total Absorption Calorimeter (TAC). All measurements are performed in reference to the well known 197Au s(n,¿). The accuracy of the measurements depends on the accuracy of the TAC detection efficiency, which is calculated by means of Monte Carlo simulations. In this MC simulation photon strength functions and level densities play a major role as ingredients used for the generation of primary events, that is the electromagnetic cascades following the (n,¿) process. We have calculated the TAC detection efficiency for the case of 197Au(n,¿) by adjusting the photon strength functions of 198Au so that the simulation reproduces the experimental data. Both the MC method and the uncertainty of the results are discussed.
Published: 2018

74. 7Be(n , p)7Li reaction and the cosmological lithium problem: measurement of the cross section in a wide energy range at n_TOF at CERN

Author: Damone, L., Barbagallo, Massimo, Mastromarco, M., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Neutrons, Energies::Energia nuclear [Àrees temàtiques de la UPC], nTOF, Física [Àrees temàtiques de la UPC], CERN, Neutron, Nuclear reaction, Nuclear Experiment, Nucleosynthesis, Nucleosíntesi
Abstract: We report on the measurement of the 7Be(n,p)7Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a 7Be ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal 7Li(p,n)7Be reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p+7Li reaction is also discussed.
Published: 2018

75. Radiative neutron capture on 242Pu in the resonance region at the CERN n_TOF-EAR1 facility

Author: Lerendegui-Marco, J., Guerrero, C., Mendoza, E., Casanovas Hoste, Adrià, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Neutrons, Spent nuclear fuel, Energies::Energia nuclear [Àrees temàtiques de la UPC], Nuclear engineering, Cross section, nTOF, Física [Àrees temàtiques de la UPC], Enginyeria nuclear, Nuclear fuel, NEA, CERN, Neutron
Abstract: The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with uranium to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. However, an extensive use of MOX fuels, in particular in fast reactors, requires more accurate capture and fission cross sections for some Pu isotopes. In the case of 242Pu there are sizable discrepancies among the existing capture cross-section measurements included in the evaluations (all from the 1970s) resulting in an uncertainty as high as 35% in the fast energy region. Moreover, post-irradiation experiments evaluated with JEFF-3.1 indicate an overestimation of 14% in the capture cross section in the fast neutron energy region. In this context, the Nuclear Energy Agency (NEA) requested an accuracy of 8% in this cross section in the energy region between 500 meV and 500 keV. This paper presents a new time-of-flight capture measurement on 242Pu carried out at n_TOF-EAR1 (CERN), focusing on the analysis and statistical properties of the resonance region, below 4 keV. The 242Pu(n,gamma) reaction on a sample containing 95(4) mg enriched to 99.959% was measured with an array of four C6D6 detectors and applying the total energy detection technique. The high neutron energy resolution of n_TOF-EAR1 and the good statistics accumulated have allowed us to extend the resonance analysis up to 4 keV, obtaining new individual and average resonance parameters from a capture cross section featuring a systematic uncertainty of 5%, fulfilling the request of the NEA.
Published: 2018
Full Text: View/download PDF

76. This title is unavailable for guests, please login to see more information.

Author: Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Dietz, M., Lederer Woods, Claudia, Aberle, O., Andrzejewski, J., Audouin, Laurent, Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, František, Brow, A., Calviño Tavares, Francisco, Calviani, M., Casanovas, A., Cerutti, F., Cortés Giraldo, Miguel Antonio, Ventura, A., Žugec, P., Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Dietz, M., Lederer Woods, Claudia, Aberle, O., Andrzejewski, J., Audouin, Laurent, Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, František, Brow, A., Calviño Tavares, Francisco, Calviani, M., Casanovas, A., Cerutti, F., Cortés Giraldo, Miguel Antonio, Ventura, A., and Žugec, P.
Abstract: The slow neutron capture process (s-process) is responsible for producing about half of the elemental abundances heavier than iron in the universo.
Published: 2018

77. First Measurement of 72Ge(n,γ) at n_TOF

Author: Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Dietz, M., Lederer Woods, C., Aberle, O., Andrzejewski, J., Audouin, Laurent, Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, František, Brow, A., Calviño Tavares, Francisco, Calviani, M., Casanovas, A., Cerutti, F., Cortés Giraldo, Miguel Antonio, Ventura, A., Žugec, P., Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, Dietz, M., Lederer Woods, C., Aberle, O., Andrzejewski, J., Audouin, Laurent, Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, František, Brow, A., Calviño Tavares, Francisco, Calviani, M., Casanovas, A., Cerutti, F., Cortés Giraldo, Miguel Antonio, Ventura, A., and Žugec, P.
Abstract: The slow neutron capture process (s-process) is responsible for producing about half of the elemental abundances heavier than iron in the universo.
Published: 2018

78. Diseño preliminar de un sistema de detección de neutrones

Author: Universitat Politècnica de Catalunya. Departament de Física, Tarifeño Saldivia, Ariel Esteban, Calviño Tavares, Francisco, Montoliu Losada, Mariana, Universitat Politècnica de Catalunya. Departament de Física, Tarifeño Saldivia, Ariel Esteban, Calviño Tavares, Francisco, and Montoliu Losada, Mariana
Abstract: Estudio de las capacidades de caracterización de un campo neutrónico utilizando detectores de He-3 insertados en moderadores de polietileno. - Estudio de las caractarísticas básicas de los detectores de He-3 - Análisis, por técnicas montecarlo, de las capacidades de moderación del polietileno - Diseño conceptual del prototipo - Montaje del detector - Testeo experiemntal El dispositivo se optimizará para campos neutrónicos que se definirán en función de la evolución del trabajo.
Published: 2018

79. Melcor feasability analysis using containment heat removal systems and pars to prevent FCV opening in a PWR during an SBO

Author: Universitat Politècnica de Catalunya. Departament de Física, Robledo Sanz, Fernando, Calviño Tavares, Francisco, Pintos, Gaston, Universitat Politècnica de Catalunya. Departament de Física, Robledo Sanz, Fernando, Calviño Tavares, Francisco, and Pintos, Gaston
Published: 2018

80. Application of Photon Strength Functions to (n,gamma) measurements with the n_TOF TAC

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Guerrero, Carlos, Abbondanno, U., Aerts, G., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Pretel Sánchez, Carme, Poch, Agustí, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Guerrero, Carlos, Abbondanno, U., Aerts, G., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Pretel Sánchez, Carme, and Poch, Agustí
Abstract: The neutron capture cross section measurements at the CERN n_TOF facility are performed using a new detection system, the segmented Total Absorption Calorimeter (TAC). All measurements are performed in reference to the well known 197Au s(n,¿). The accuracy of the measurements depends on the accuracy of the TAC detection efficiency, which is calculated by means of Monte Carlo simulations. In this MC simulation photon strength functions and level densities play a major role as ingredients used for the generation of primary events, that is the electromagnetic cascades following the (n,¿) process. We have calculated the TAC detection efficiency for the case of 197Au(n,¿) by adjusting the photon strength functions of 198Au so that the simulation reproduces the experimental data. Both the MC method and the uncertainty of the results are discussed., Postprint (published version)
Published: 2018

81. 7Be(n , p)7Li reaction and the cosmological lithium problem: measurement of the cross section in a wide energy range at n_TOF at CERN

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Damone, L., Barbagallo, Massimo, Mastromarco, M., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Damone, L., Barbagallo, Massimo, Mastromarco, M., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: We report on the measurement of the 7Be(n,p)7Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n_TOF facility at CERN. This reaction plays a key role in the lithium yield of the big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and they showed a large discrepancy between each other. The measurement was performed with a Si telescope and a high-purity sample produced by implantation of a 7Be ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low energy, relative to current evaluations, in the region of BBN interest, the present results are consistent with the values inferred from the time-reversal 7Li(p,n)7Be reaction, thus yielding only a relatively minor improvement on the so-called cosmological lithium problem. The relevance of these results on the near-threshold neutron production in the p+7Li reaction is also discussed., Postprint (published version)
Published: 2018

82. Conceptual prototype of a new neutron dosimeter

Author: Universitat Politècnica de Catalunya. Departament de Física, Tarifeño Saldivia, Ariel Esteban, Calviño Tavares, Francisco, Lázaro López, Aarón, Universitat Politècnica de Catalunya. Departament de Física, Tarifeño Saldivia, Ariel Esteban, Calviño Tavares, Francisco, and Lázaro López, Aarón
Abstract: Identify the main commercial devices, and its response to high energy neutrons - Compile the nowadays, and future recommendations, on neutron dosimetry from international bodies - Study the behavior of actual dosimeters using Montecarlo simulation - Design a conceptual prototype of neutron dosimeter with a improved response to high energy neutrons
Published: 2018

83. Measurement and resonance analysis of the 33S (n, alpha) 30Si cross section at the CERN n_TOF facility in the energy region from 10 to 300 keV

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Praena, J., Sabaté-Gilarte, M., Porras, I., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Gómez Hornillos, María Belén, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Praena, J., Sabaté-Gilarte, M., Porras, I., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Gómez Hornillos, María Belén
Abstract: The 33S(n,a)30Si cross section has been measured at the neutron time-of-flight (n_TOF) facility at CERN in the neutron energy range from 10 to 300 keV relative to the 10B(n,a)7Li cross-section standard. Both reactions were measured simultaneously with a set of micromegas detectors. The flight path of 185 m has allowed us to obtain the cross section with high-energy resolution. An accurate description of the resonances has been performed by means of the multilevel multichannel R-matrix code SAMMY. The results show a significantly higher area of the biggest resonance (13.45 keV) than the unique high-resolution (n,a) measurement. The new parametrization of the 13.45-keV resonance is similar to that of the unique transmission measurement. This resonance is a matter of research in neutron-capture therapy. The 33S(n,a)30Si cross section has been studied in previous works because of its role in the production of 36S in stars, which is currently overproduced in stellar models compared to observations., Postprint (published version)
Published: 2018

84. Measurement and analysis of the 241-Am neutron capture cross section at the n_TOF facility at CERN

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Mendoza, E., Cano-Ott, D, Altstadt, Sebastian, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Riego Pérez, Albert, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Mendoza, E., Cano-Ott, D, Altstadt, Sebastian, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Riego Pérez, Albert
Abstract: The 241Am(n,¿ ) cross section has been measured at the n_TOF facility at CERN with the n_TOF BaF2 Total Absorption Calorimeter in the energy range between 0.2 eV and 10 keV. Our results are analyzed as resolved resonances up to 700 eV, allowing a more detailed description of the cross section than in the current evaluations, which contain resolved resonances only up to 150–160 eV. The cross section in the unresolved resonance region is perfectly consistent with the predictions based on the average resonance parameters deduced from the resolved resonances, thus obtaining a consistent description of the cross section in the full neutron energy range under study. Below 20 eV, our results are in reasonable agreement with JEFF-3.2 as well as with the most recent direct measurements of the resonance integral, and differ up to 20–30% with other experimental data. Between 20 eV and 1 keV, the disagreement with other experimental data and evaluations gradually decreases, in general, with the neutron energy. Above 1 keV, we find compatible results with previously existing values., Postprint (published version)
Published: 2018

85. The BRIKEN Project: extensive measurements of ß-delayed neutron emitters for the astrophysical r process

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Taín Enríquez, José Luis, Agramunt Ros, Jorge, Algora, A., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Taín Enríquez, José Luis, Agramunt Ros, Jorge, Algora, A., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: An ambitious program to measure decay properties, primarily ß-delayed neutron emission probabilities and half-lives, for a significant number of nuclei near or on the path of the rapid neutron capture process, has been launched at the RIKEN Nishina Center. We give here an overview of the status of the project., Postprint (published version)
Published: 2018

86. Preparation and characterization of 33-S samples for 33-S(n,alpha)30-Si cross-section measurements at the n_TOF facility at CERN

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Praena, J., Ferrer, F. Javier, Vollenberg, Will, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Praena, J., Ferrer, F. Javier, Vollenberg, Will, Calviño Tavares, Francisco, and Cortés Rossell, Guillem Pere
Abstract: Thin 33S samples for the study of the 33S(n,a)30Si cross-section at the n_TOF facility at CERN were made by thermal evaporation of 33S powder onto a dedicated substrate made of kapton covered with thin layers of copper, chromium and titanium. This method has provided for the first time bare sulfur samples a few centimeters in diameter. The samples have shown an excellent adherence with no mass loss after few years and no sublimation in vacuum at room temperature. The determination of the mass thickness of 33S has been performed by means of Rutherford backscattering spectrometry. The samples have been successfully tested under neutron irradiation., Postprint (published version)
Published: 2018

87. Radiative neutron capture on 242Pu in the resonance region at the CERN n_TOF-EAR1 facility

Author: Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Lerendegui-Marco, J., Guerrero, C., Mendoza, E., Casanovas Hoste, Adrià, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Lerendegui-Marco, J., Guerrero, C., Mendoza, E., Casanovas Hoste, Adrià, Calviño Tavares, Francisco, and Cortés Rossell, Guillem Pere
Abstract: The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with uranium to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. However, an extensive use of MOX fuels, in particular in fast reactors, requires more accurate capture and fission cross sections for some Pu isotopes. In the case of 242Pu there are sizable discrepancies among the existing capture cross-section measurements included in the evaluations (all from the 1970s) resulting in an uncertainty as high as 35% in the fast energy region. Moreover, post-irradiation experiments evaluated with JEFF-3.1 indicate an overestimation of 14% in the capture cross section in the fast neutron energy region. In this context, the Nuclear Energy Agency (NEA) requested an accuracy of 8% in this cross section in the energy region between 500 meV and 500 keV. This paper presents a new time-of-flight capture measurement on 242Pu carried out at n_TOF-EAR1 (CERN), focusing on the analysis and statistical properties of the resonance region, below 4 keV. The 242Pu(n,gamma) reaction on a sample containing 95(4) mg enriched to 99.959% was measured with an array of four C6D6 detectors and applying the total energy detection technique. The high neutron energy resolution of n_TOF-EAR1 and the good statistics accumulated have allowed us to extend the resonance analysis up to 4 keV, obtaining new individual and average resonance parameters from a capture cross section featuring a systematic uncertainty of 5%, fulfilling the request of the NEA., Postprint (published version)
Published: 2018

88. Estudio del haz de neutrones rápidos producidos por la fuente de neutrones Hispalis en el Centro Nacional de Aceleradores (CNA)

Author: Universitat Politècnica de Catalunya. Departament de Física, Tarifeño Saldivia, Ariel Esteban, Calviño Tavares, Francisco, Torres Escubos, Clara De Asis, Universitat Politècnica de Catalunya. Departament de Física, Tarifeño Saldivia, Ariel Esteban, Calviño Tavares, Francisco, and Torres Escubos, Clara De Asis
Abstract: El Centro Nacional de Aceleradores (CNA) es un centro mixto de la Universidad de Sevilla, la Junta de Andalucía y el Consejo Superior de Investigaciones Científicas, que tiene como misión el desarrollo de la investigación en aceleradores de partículas y sus múltiples aplicaciones. El CNA, reconocido como Instalación Científico-Técnica Singular (ICTS) es un centro abierto para que la comunidad científica y tecnológica nacional e internacional pueda desarrollar investigaciones utilizando sus instalaciones. Entre las seis grandes instalaciones que se hallan en el centro, se encuentra el acelerador Tándem de 3MV, una herramienta potente y versátil para la Instrumentación Nuclear. En este acelerador se instaló HISPANOS (HISPAlis NeutrOn Source), que será un referente en España como fuente de neutrones. Con tal de evaluar dicha instalación para la producción de neutrones, del 4 al 7 de julio del año 2016 se realizó una primera campaña de caracterización del haz de neutrones rápidos producidos por reacciones de fusión D(d,n)3He. En ésta, participaron diferentes grupos de investigación, entre ellos, el grupo de Física Nuclear experimental de la Universidad Politécnica de Cataluña (UPC). Con esta primera campaña de mediciones se buscaba que la comunidad de usuarios de HISPANOS se familiarizara con el uso de la instalación de neutrones, un paso necesario para la planificación y realización de futuros experimentos. En el presente trabajo se realiza un análisis de los datos de esas medidas de producción de neutrones, obtenidas usando detectores de 3He. Para ello, se han desarrollado rutinas para el procesamiento de dichos datos. También se hacen comparaciones con estimaciones teóricas de producción de neutrones en la instalación. Finalmente, se realizan recomendaciones para mediciones futuras.
Published: 2018

89. Commissioning of the BRIKEN beta-delayed neutron detector for the study of exotic neutron-rich nuclei

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Tolosa-Delgado, Alvaro, Agramunt Ros, Jorge, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Tolosa-Delgado, Alvaro, Agramunt Ros, Jorge, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: Beta-delayed neutron emission (Beta-n) is a form of radioactive decay in which an electron, an anti-neutrino and one or more neutrons are emitted. This process arises if the energy window of the decay Q_Beta is greater than the neutron separation energy S n of the daughter. The probability in each decay of emitting neutrons is called the Pn value. This form of decay plays a key role in the synthesis of chemical elements in the Universe via the rapid neutron capture process, or r-process. The r-process proceeds far from the valley of nuclear stability, and leads to very neutron-rich nuclei that then decay to the line of stability. Most of these nuclei are ßn emitters. The initial abundance distribution is shaped by the decay half-life T1/2, but the neutron emission affects the final abundances in two ways: on the one hand it shifts the decay path to lower masses and on the other hand it provides a source of neutrons for late captures that will shift it in the opposite way. Thus, a good knowledge of Pn and T1/2 values of the nuclei between the line of stability and the r-process path is needed for a correct understanding of the observed abundances. Besides the astrophysical interest, the measurement of new Pn values and half-lives is also useful for refining nuclear structure models, constraining parameters of the models and testing ß-strength functions [3]. Our current understanding of the process of ß-delayed multiple neutron emission, as well as the competition between different open channels (gamma, one-neutron, two-neutron, etc), is incomplete because of the scarcity of experimental data. With these ideas in mind, the BRIKEN (Beta-delayed-neutron-measurements at RIKEN) collaboration was established, with the aim of greatly improving the quantity and quality of data the decays of very neutron-rich nuclei close to the r-process path., Postprint (published version)
Published: 2018

90. First Measurement of 72Ge(n gamma) at n-TOF

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: The slow neutron capture process (s-process) is responsible for producing about half of the elemental abundances heavier than iron in the universe. Neutron capture cross sections on stable isotopes are a key nuclear physics input for s-process studies. The 72Ge(n,gamma) cross section has an important influence on production of isotopes between Ge and Zr during s-process in massive stars and therefore experimental data are urgently required. 72Ge(n,gamma) was measured at the neutron time-of-flight facility n_TOF (CERN) for the first time at stellar energies. The measurement was performed using an enriched 72GeO2 sample at a flight path of 185 m with a set of liquid scintillation detectors (C6D6). The motivation, experiment and current status of the data analysis are reported., Postprint (published version)
Published: 2018

91. Neutron capture on ^{205}Tl: depicting the abundance pattern of lead isotopes in s-process nucleosynthesis

Author: Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Casanovas Hoste, Adrià, Tarifeño Saldivia, Ariel Esteban, Domingo-Pardo, C, Calviño Tavares, Francisco, Universitat Politècnica de Catalunya. Doctorat en Enginyeria Nuclear i de les Radiacions Ionitzants, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Casanovas Hoste, Adrià, Tarifeño Saldivia, Ariel Esteban, Domingo-Pardo, C, and Calviño Tavares, Francisco
Abstract: Proposal: Neutron capture on 205Tl: depicting the abundance pattern of lead isotopes in s-process nucleosynthesis, We propose to use the TOF technique to measure the neutron capture cross section of 205Tl(n,gamma) over the full energy range of stellar interest. An accurate measurement of this cross section is needed for a complete and consistent understanding of the s-process nucleosynthesis of the heaviest nuclei which are produced in low-mass and low metallicity AGB-stars. The only previous TOF measurement has yield only a partial information, insufficient for a reliable analysis of the complex branching pattern around 205Pb and 205Tl. Furthermore, there is also a discrepancy of 40% between the two previous activation measurements made at kT=24 keV. The cross section of 205Tl(n,gamma) is particularly relevant because it affects the equilibrium that is established in some stellar conditions between the 205Tl -> 205Pb bound-state Beta-decay and the 205Pb -> 205Tl E.C. decay. This effect induces a complex interplay which influences the final s-process abundance of both nuclei. We propose to measure accurately and with high resolution the 205Tl(n,gamma) cross section by using a set of four C6D6 detectors in combination with the pulsed neutron-source of CERN n_TOF., Preprint
Published: 2018

92. Study of the photon strength function of 152SM in resonance neutron capture at n-TOF

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. CTTC - Centre Tecnològic de la Transferència de Calor, Marrone, S., Colonna, Nicola, Krticka, M., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Alvarez Pol, Héctor, Alvarez Velarde, Francisco, Andrzejewski, Józef, Audouin, Ludmila, Berthoumieux, Eric, Capdevila Paramio, Roser, Poch, Agustí, Pretel Sánchez, Carme, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Universitat Politècnica de Catalunya. CTTC - Centre Tecnològic de la Transferència de Calor, Marrone, S., Colonna, Nicola, Krticka, M., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Alvarez Pol, Héctor, Alvarez Velarde, Francisco, Andrzejewski, Józef, Audouin, Ludmila, Berthoumieux, Eric, Capdevila Paramio, Roser, Poch, Agustí, and Pretel Sánchez, Carme
Abstract: The Photon Strength Function of 152Sm has been investigated at nTOF by studying the ¿-ray spectra from resonance neutron capture of 151Sm. The experimental apparatus consisted of two C6D6 liquid scintillator detectors. The measured spectra were compared with the predictions of the DICEBOX code, for different assumptions on the Photon Stregth Functions and on the Nuclear Level Density. For a meaningful comparison, the model calculations were filtered through a detailed software replica of the experimental apparatus, performed by means of three different Monte Carlo simulations. Preliminary results indicate that a reasonable reproduction of the experimental ¿-ray spectrum is obtained by postulating the presence of a Scissors Resonance. Some hints on the most suitable models, developed in the most recent studies of the Photon Strength Functions and Nuclear Level Density, are also obtained. © 2007 Sissa Medialab Srl. All rights reserved., Postprint (published version)
Published: 2018

93. First determination of ß -delayed multiple neutron emission beyond A=100 through direct neutron measurement: the P2n value of Sb 136

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Caballero-Folch, R., Dillmann, Iris, Agramunt Ros, Jorge, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Riego Pérez, Albert, Salvador Castiñeira, Paula Genoveva, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Caballero-Folch, R., Dillmann, Iris, Agramunt Ros, Jorge, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Riego Pérez, Albert, Salvador Castiñeira, Paula Genoveva, and Tarifeño Saldivia, Ariel Esteban
Abstract: Background: ß-delayed multiple neutron emission has been observed for some nuclei with A=100, being the 100Rb the heaviest ß2n emitter measured to date. So far, only 25P2n values have been determined for the ˜300 nuclei that may decay in this way. Accordingly, it is of interest to measure P2n values for the other possible multiple neutron emitters throughout the chart of the nuclides. It is of particular interest to make such a measurement for nuclei with A>100 to test the predictions of theoretical models and simulation tools for the decays of heavy nuclei in the region of very neutron-rich nuclei. In addition, the decay properties of these nuclei are fundamental for the understanding of astrophysical nucleosynthesis processes, such as the r-process, and safety inputs for nuclear reactors., Postprint (published version)
Published: 2018

94. Experimental setup and procedure for the measurement of the 7Be(n,p)7Li reaction at n_TOF

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Barbagallo, Massimo, Andrzejewski, Józef, Mastromarco, M., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Barbagallo, Massimo, Andrzejewski, Józef, Mastromarco, M., Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows to investigate neutron induced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the 7Be(n,alpha)alpha cross section, the 7Be(n,p)7Li reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization., Postprint (published version)
Published: 2018

95. The Nuclear astrophysics program at n_TOF (CERN)

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Colonna, Nicola, Aberle, O., Andrzejewski, Józef, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, Tarifeño Saldivia, Ariel Esteban, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Colonna, Nicola, Aberle, O., Andrzejewski, Józef, Calviño Tavares, Francisco, Casanovas Hoste, Adrià, Cortés Rossell, Guillem Pere, and Tarifeño Saldivia, Ariel Esteban
Abstract: An important experimental program on Nuclear Astrophysics is being carried out at the n_TOF since several years, in order to address the still open issues in stellar and primordial nucleosynthesis. Several neutron capture reactions relevant to s-process nucleosynthesis have been measured so far, some of which on important branching point radioisotopes. Furthermore, the construction of a second experimental area has recently opened the way to challenging measurements of (n, charged particle) reactions on isotopes of short half-life. The Nuclear Astrophysics program of the n_TOF Collaboration is here described, with emphasis on recent results relevant for stellar nucleosynthesis, stellar neutron sources and primordial nucleosynthesis., Postprint (published version)
Published: 2018

96. Measurement of the radiative capture cross section of the s-process branching points 204Tl and 171Tm at the n_TOF facility (CERN)

Author: Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Casanovas Hoste, Adrià, Domingo-Pardo, C, Guerrero, C., Calviño Tavares, Francisco, Tarifeño Saldivia, Ariel Esteban, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Institut de Tècniques Energètiques, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Casanovas Hoste, Adrià, Domingo-Pardo, C, Guerrero, C., Calviño Tavares, Francisco, Tarifeño Saldivia, Ariel Esteban, and Cortés Rossell, Guillem Pere
Abstract: The neutron capture cross section of some unstable nuclei is especially relevant for s-process nucleosynthesis studies. This magnitude is crucial to determine the local abundance pattern, which can yield valuable information of the s-process stellar environment. In this work we describe the neutron capture (n,¿) measurement on two of these nuclei of interest, 204Tl and 171Tm, from target production to the final measurement, performed successfully at the n_TOF facility at CERN in 2014 and 2015. Preliminary results on the ongoing experimental data analysis will also be shown. These results include the first ever experimental observation of capture resonances for these two nuclei., Postprint (published version)
Published: 2018

97. Beta-decay half-lives and beta-delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N = 126

Author: Caballero-Folch, R., Domingo-Pardo, C, Agramunt Ros, Jorge, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Energies::Energia nuclear [Àrees temàtiques de la UPC], Neutrons, Astrofísica, Física [Àrees temàtiques de la UPC], Física::Astronomia i astrofísica [Àrees temàtiques de la UPC], Beta decay, Astrophysics, Delayed neutrons, Exotic nuclei
Abstract: Background: There have been measurements on roughly 230 nuclei that are beta-delayed neutron emitters. They range from 8He up to 150La. Apart from 210Tl, with a branching ratio of only 0.007%, no other neutron emitter has been measured beyond A = 150. Therefore, new data are needed, particularly in the region of heavy nuclei around N = 126, in order to guide theoretical models and help understand the formation of the third r-process peak at A ~ 195. Purpose: To measure both ß-decay half-lives and neutron branching ratios of several neutron-rich Au, Hg, Tl, Pb, and Bi isotopes beyond N = 126. Method: Ions of interest were produced by fragmentation of a 238U beam, selected and identified via the GSI-FRS fragment separator. A stack of segmented silicon detectors (SIMBA) was used to measure ion implants and Beta decays. An array of 30 3He tubes embedded in a polyethylene matrix (BELEN) was used to detect neutrons with high efficiency and selectivity. A self-triggered digital system is employed to acquire data and to enable time correlations. The latter were analyzed with an analytical model and results for the half-lives and neutron-branching ratios were derived by using the binned maximum-likelihood method. Results: Twenty new beta-decay half-lives are reported for 204-206Au, 208–211Hg,211–216Tl,215–218Pb, and 218–220Bi, nine of them for the first time. Neutron emission probabilities are reported for 210,211Hg and 211–216Tl.
Published: 2017

98. Neutron capture cross section measurement of 238U at the CERN n_TOF facility in the energy region from 1 eV to 700 keV

Author: Mingrone, Federica, Massimi, Cristian, Vannini, Gianni, Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group
Subjects: Neutrons, Energies::Energia nuclear [Àrees temàtiques de la UPC], nTOF, Cross section, Reaction, CERN, Energia nuclear, Nuclear energy, Nuclear, Neutron, Nuclear Experiment
Abstract: The aim of this work is to provide a precise and accurate measurement of the 238U(n, gamma) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behavior of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross section of 238U should be further reduced to 1–3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were proposed and carried out within the 7th Framework Project ANDES of the European Commission. The results of one of these 238U(n, gamma) measurements performed at the n_TOF CERN facility are presented in this work. The gamma-ray cascade following the radiative neutron capture has been detected exploiting a setup of two C6D6 liquid scintillators. Resonance parameters obtained from this work are on average in excellent agreement with the ones reported in evaluated libraries. In the unresolved resonance region, this work yields a cross section in agreement with evaluated libraries up to 80 keV, while for higher energies our results are significantly higher.
Published: 2017

99. The measurement programme at the neutron time-of-flight facility n_TOF at CERN

Author: International Conference on Nuclear Data for Science and Technology (2016 : Bruges), Gunsing, Frank, Aberle, Oliver, Andrzejewski, Józef, Audouin, Laurent, Bécares, Vicente, Bacak, Michael, Balibrea Correa, Javier, Barbagallo, Massimo, Barros, Susana C.C., Bečvář, František, Beinrucker, Clemens, Belloni, Fabio, Berthoumieux, Eric, Billowes, Jonathan, Bosnar, Damir, Brown, Adam, Brugger, Markus, Caamaño, Manuel, Calviño Tavares, Francisco, Calviani, Marco, Cano-Ott, Daniel, Cardella, Roberto, Casanovas Hoste, Adrià, Castelluccio, Donato Maurizio, Cerutti, Francesco, Chen, Yonghao, Chiaveri, Enrico, Colonna, Nicola, Cortés-Giraldo, Miguel Antonio, Cortés Rossell, Guillem Pere, Cosentino, Luigi, Damone, Lucia Anna, Deo, Kapil, Diakaki, Maria, Domingo-Pardo, César, Dressler, Rugard, Dupont, Emmeric, Durán, Ignacio, Fernández Domínguez, Beatriz, Ferrari, Alfredo, Ferreira, Pedro G., Finocchiaro, Paolo, Frost, Robert J. W., Furman, Valter, Ganesan, Srinivasan, García Ríos, Aczel Regino, Gawlik, Aleksandra, Gheorghe, Ioana, Gilardoni, Simone, Glodariu, Tudor, Gonçalves, Isabel Maria Ferro, González Romero, Enrique Miguel, Goverdovski, Andrey, Griesmayer, Erich, Guerrero Sánchez, Carlos, Göbel, Kathrin, Harada, Hideo, Heftrich, Tanja, Heinitz, Stephan, Hernández Prieto, Álvaro, Heyse, Jan, Jenkins, David, Jericha, Erwin, Käppeler, Franz, Kadi, Yacine, Kalamara, Antigoni, Katabuchi, Tatsuya, Kavrigin, Pavel, Ketlerov, Vladimir, Khryachkov, Vitaly, Kimura, Atsushi, Kivel, Nikolay, Kokkoris, Michael, Krtička, Milan, Kurtulgil, Cem Deniz, Leal Cidoncha, Esther, Lederer, Claudia, Leeb, Helmut, Lerendegui, Jorge, Licata, Mauro, Lo Meo, Sergio, Lonsdale, Sarah Jane, Losito, Roberto, Macina, Daniela, Marganiec, Justyna, Martı́nez, Trinitario, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Matteucci, Francesca, Maugeri, Emilio Andrea, Mazzone, Annamaria, Mendoza Cembranos, Emilio, Mengoni, Alberto, Milazzo, Paolo Maria, Mingrone, Federica, Mirea, Mihail, Montesano, Simone, Musumarra, Agatino, Nolte, Ralf, Negret, Alexandru, Oprea, Andreea, Palomo Pinto, Francisco Rogelio, Paradela Dobarro, Carlos, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Porras Sánchez, José Ignacio, Praena, Javier, Quesada Molina, José Manuel, Radeck, Désirée, Rajeev, K., Rauscher, Thomas, Reifarth, René, Riego Pérez, Albert, Robles Manzano, Maria Soledad, Rout, Prakash Chandra, Rubbia, Carlo, Ryan, James, Sabaté-Gilarte, Marta, Saxena, Alok, Schillebeeckx, Peter, Schmidt, Stefan, Schumann, Dorothea, Sedyshev, Pavel V., Smith, Alastair Gavin, Sosnin, Nikolay V., Stamatopoulos, Athanasios, Suryanarayana, Saraswatula Venkata, Tagliente, Giuseppe, Taı́n Enríquez, José Luis, Tarifeño-Saldivia, Ariel, Tarrío Vilas, Diego, Tassan-Got, Laurent, Tsinganis, Andrea, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Warren, Stephen J., Weigand, Mario, Weiß, Christina, Wolf, Clemens, Woods, Philip John, Wright, Tobias, Žugec, Petar, International Conference on Nuclear Data for Science and Technology (2016 : Bruges), Gunsing, Frank, Aberle, Oliver, Andrzejewski, Józef, Audouin, Laurent, Bécares, Vicente, Bacak, Michael, Balibrea Correa, Javier, Barbagallo, Massimo, Barros, Susana C.C., Bečvář, František, Beinrucker, Clemens, Belloni, Fabio, Berthoumieux, Eric, Billowes, Jonathan, Bosnar, Damir, Brown, Adam, Brugger, Markus, Caamaño, Manuel, Calviño Tavares, Francisco, Calviani, Marco, Cano-Ott, Daniel, Cardella, Roberto, Casanovas Hoste, Adrià, Castelluccio, Donato Maurizio, Cerutti, Francesco, Chen, Yonghao, Chiaveri, Enrico, Colonna, Nicola, Cortés-Giraldo, Miguel Antonio, Cortés Rossell, Guillem Pere, Cosentino, Luigi, Damone, Lucia Anna, Deo, Kapil, Diakaki, Maria, Domingo-Pardo, César, Dressler, Rugard, Dupont, Emmeric, Durán, Ignacio, Fernández Domínguez, Beatriz, Ferrari, Alfredo, Ferreira, Pedro G., Finocchiaro, Paolo, Frost, Robert J. W., Furman, Valter, Ganesan, Srinivasan, García Ríos, Aczel Regino, Gawlik, Aleksandra, Gheorghe, Ioana, Gilardoni, Simone, Glodariu, Tudor, Gonçalves, Isabel Maria Ferro, González Romero, Enrique Miguel, Goverdovski, Andrey, Griesmayer, Erich, Guerrero Sánchez, Carlos, Göbel, Kathrin, Harada, Hideo, Heftrich, Tanja, Heinitz, Stephan, Hernández Prieto, Álvaro, Heyse, Jan, Jenkins, David, Jericha, Erwin, Käppeler, Franz, Kadi, Yacine, Kalamara, Antigoni, Katabuchi, Tatsuya, Kavrigin, Pavel, Ketlerov, Vladimir, Khryachkov, Vitaly, Kimura, Atsushi, Kivel, Nikolay, Kokkoris, Michael, Krtička, Milan, Kurtulgil, Cem Deniz, Leal Cidoncha, Esther, Lederer, Claudia, Leeb, Helmut, Lerendegui, Jorge, Licata, Mauro, Lo Meo, Sergio, Lonsdale, Sarah Jane, Losito, Roberto, Macina, Daniela, Marganiec, Justyna, Martı́nez, Trinitario, Masi, Alessandro, Massimi, Cristian, Mastinu, Pierfrancesco, Mastromarco, Mario, Matteucci, Francesca, Maugeri, Emilio Andrea, Mazzone, Annamaria, Mendoza Cembranos, Emilio, Mengoni, Alberto, Milazzo, Paolo Maria, Mingrone, Federica, Mirea, Mihail, Montesano, Simone, Musumarra, Agatino, Nolte, Ralf, Negret, Alexandru, Oprea, Andreea, Palomo Pinto, Francisco Rogelio, Paradela Dobarro, Carlos, Patronis, Nikolas, Pavlik, Andreas, Perkowski, Jarosław, Porras Sánchez, José Ignacio, Praena, Javier, Quesada Molina, José Manuel, Radeck, Désirée, Rajeev, K., Rauscher, Thomas, Reifarth, René, Riego Pérez, Albert, Robles Manzano, Maria Soledad, Rout, Prakash Chandra, Rubbia, Carlo, Ryan, James, Sabaté-Gilarte, Marta, Saxena, Alok, Schillebeeckx, Peter, Schmidt, Stefan, Schumann, Dorothea, Sedyshev, Pavel V., Smith, Alastair Gavin, Sosnin, Nikolay V., Stamatopoulos, Athanasios, Suryanarayana, Saraswatula Venkata, Tagliente, Giuseppe, Taı́n Enríquez, José Luis, Tarifeño-Saldivia, Ariel, Tarrío Vilas, Diego, Tassan-Got, Laurent, Tsinganis, Andrea, Valenta, Stanislav, Vannini, Gianni, Variale, Vincenzo, Vaz, Pedro, Ventura, Alberto, Vlachoudis, Vasilis, Vlastou, Rosa, Wallner, Anton, Warren, Stephen J., Weigand, Mario, Weiß, Christina, Wolf, Clemens, Woods, Philip John, Wright, Tobias, and Žugec, Petar
Abstract: Neutron-induced reaction cross sections are important for a wide variety of research fields ranging from the study of nuclear level densities, nucleosynthesis to applications of nuclear technology like design, and criticality and safety assessment of existing and future nuclear reactors, radiation dosimetry, medical applications, nuclear waste transmutation, accelerator-driven systems and fuel cycle investigations. Simulations and calculations of nuclear technology applications largely rely on evaluated nuclear data libraries. The evaluations in these libraries are based both on experimental data and theoretical models. CERN’s neutron time-of-flight facility n_TOF has produced a considerable amount of experimental data since it has become fully operational with the start of its scientific measurement programme in 2001. While for a long period a single measurement station (EAR1) located at 185 m from the neutron production target was available, the construction of a second beam line at 20 m (EAR2) in 2014 has substantially increased the measurement capabilities of the facility. An outline of the experimental nuclear data activities at n_TOF will be presented.
Published: 2017

100. Measurement of the U-238(n,gamma) cross section up to 80 keV with the total absorption calorimeter at the CERN n_TOF facility

Author: Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Wright, T., Guerrero, C., Billowes, J., Calviño Tavares, Francisco, Cortés Rossell, Guillem Pere, Universitat Politècnica de Catalunya. Departament de Física, Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group, Wright, T., Guerrero, C., Billowes, J., Calviño Tavares, Francisco, and Cortés Rossell, Guillem Pere
Abstract: The radiative capture cross section of a highly pure (99.999%), 6.125(2) grams and 9.56(5)E-4 atoms/barn areal density 238U sample has been measured with the Total Absorption Calorimeter (TAC) in the 185 m flight path at the CERN neutron time-of-flight facility n_TOF. This measurement is in response to the NEA High Priority Request list, which demands an accuracy in this cross section of less than 3% below 25 keV. These data have undergone careful background subtraction, with special care being given to the background originating from neutrons scattered by the 238U sample. Pileup and dead-time effects have been corrected for. The measured cross section covers an energy range between 0.2 eV and 80 keV, with an accuracy that varies with neutron energy, being better than 4% below 25 keV and reaching at most 6% at higher energies., Postprint (published version)
Published: 2017

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Database

Publisher

425 results on '"Calviño Tavares, Francisco"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources