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264 results on '"Dahlfors, M"'

51. Neutron capture on Zr-94: Resonance parameters and Maxwellian-averaged cross sections

Author: Tagliente, G., Milazzo, P. M., Fujii, K., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Belloni, F., Berthoumieux, E., Bisterzo, S., Calvino, F., Calviani, M., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrari, A., Ferreira-Marques, R., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Jericha, E., Kappeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mengoni, A., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wiescher, M., and Wisshak, K.
Subjects: nuclear-data library, n-tof, elements, facility, evolution, nucleosynthesis, zirconium, giant branch stars, system, s-process
Abstract: The neutron capture cross sections of the Zr isotopes play an important role in nucleosynthesis studies. The s-process reaction flow between the Fe seed and the heavier isotopes passes through the neutron magic nucleus Zr-90 and through Zr-91,Zr-92,Zr-93,Zr-94, but only part of the flow extends to Zr-96 because of the branching point at Zr-95. Apart from their effect on the s-process flow, the comparably small isotopic (n, gamma) cross sections make Zr also an interesting structural material for nuclear reactors. The Zr-94 (n, gamma) cross section has been measured with high resolution at the spallation neutron source n_TOF at CERN and resonance parameters are reported up to 60 keV neutron energy. Physical Review C
Published: 2011

52. (237)Np(n,f) Cross Section: New Data and Present Status

Author: Paradela, C., Tassan-Got, L., Audouin, L., Berthier, B., Ferrant, L., Isaev, S., Le Naour, C., Stephan, C., Trubert, D., David, S., Duran, I., Tarrio, D., Alvarez, H., Abbondanno, U., Fujii, K., Milazzo, P. M., Moreau, C., Aerts, G., Alvarez-Velarde, F., Cano-Ott, D., Embid-Segura, M., Gonzalez-Romero, E., Guerrero, C., Martinez, T., Villamarin, D., Vicente, M. C., Andriamonje, S., Berthoumieux, E., Dridi, W., Gunsing, F., Pancin, J., Perrot, L., Plukis, A., Andrzejewski, J., Marganiec, J., Assimakopoulos, P., Karadimos, D., Karamanis, D., Papachristodoulou, C., Patronis, N., Badurek, G., Jericha, E., Leeb, H., Oberhummer, H., Pigni, M. T., Baumann, P., Kerveno, M., Lukic, S., Rudolf, G., Becvar, F., Krticka, M., Calvino, F., Cortes, G., Poch, A., Pretel, C., Calviani, M., Gramegna, F., Mastinu, P., Praena, J., Capote, R., Carrapico, C., Cennini, P., Chiaveri, E., Dahlfors, M., Ferrari, A., Herrera-Martinez, A., Kadi, Y., Sarchiapone, L., Vlachoudis, V., Chepel, V., Ferreira-Marques, R., Lindote, A., Lopes, I., Neves, F., Colonna, N., Tagliente, G., Terlizzi, R., Couture, A., Cox, J., Marrone, S., O'Brien, S., Wiescher, M., Dillmann, I., Heil, M., Kaeppeler, F., Mosconi, M., Voss, F., Walter, S., Wisshak, K., Domingo-Pardo, C., Plag, R., Plompen, A., Tain, J. L., Eleftheriadis, C., Savvidis, I., Furman, W., Goncalves, I., Salgado, J., Santos, C., Tavora, L., Vaz, P., Haas, B., Haight, R., Reifarth, R., Igashira, M., Koehler, P., Kossionides, E., Lampoudis, C., Lozano, M., Quesada, J., Massimi, C., Vannini, G., Mengoni, A., Oshima, M., Papadopoulos, C., Pavlix, A., Pavlopoulos, P., Vlastou, R., Rauscher, T., Rubbia, C., Rullhusen, P., Ventura, A., and n TOF Collaboration
Subjects: pu-239, u-233, neutron-induced fission reactions, n_tof experiment, nuclear data, np-237, energy
Abstract: In this document, we present the final result obtained at the n_TOF experiment; for the neutron-induced fission cross section of the (237)Np, from the fission threshold up to 1 GeV. The method applied to get tins result is briefly discussed. n_TOF data are compared to the last experimental measurements using other TOF facilities or the surrogate method, reported experiments performed with monoenergetic sources and the FISCAL systematic, including a discussion about the existing discrepancies. Journal of the Korean Physical Society
Published: 2011

53. Neutron-induced fission cross sections of 233U and 243Am in the energy range 0.5 Mev En 20 MeV @ n_TOF

Author: Belloni, F, Milazzo, P M, Calviani, M, Colonna, N, Mastinu, P, Abbondanno, U, Aerts, G, Álvarez, H, Álvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Assimakopoulos, P, Audouin, L, Badurek, G, Baumann, P, Becvár, F, Berthoumieux, E, Calviño, F, Cano-Ott, D, Capote, R, Carrapiço, C, Cennini, P, Chepel, V, Chiaveri, E, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillmann, I, Domingo-Pardo, C, Dridi, W, Duran, I, Eleftheriadis, C, Embid-Segura, M, Ferrant, L, Ferrari, A, Ferreira-Marques, R, Fujii, K, Furman, W, Goncalves, I, González-Romero, E, Gramegna, F, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Jericha, E, Käppeler, F, Kadi, Y, Karadimos, D, Karamanis, D, Kerveno, M, Koehler, P, Kossionides, E, Krticka, M, Lampoudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marrone, S, Martínez, T, Massimi, C, Mengoni, A, Moreau, C, Mosconi, M, Neves, F, Oberhummer, H, O'Brien, S, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, N, Pavlik, A, Pavlopoulos, P, Perrot, L, Pigni, M T, Plag, R, Plompen, A, Plukis, A, Poch, A, Praena, J, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rubbia, C, Rudolf, G, Rullhusen, P, Salgado, J, Santos, C, Sarchiapone, L, Savvidis, I, Stephan, C, Tagliente, G, Tain, J L, Tassan-Got, L, Tavora, L, Terlizzi, R, Vannini, G, Vazl, P, Ventura, A, Villamarin, D, Vincente, M C, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wiescher, M, and Wisshak, K
Subjects: inorganic chemicals, biological sciences, Nuclear Theory, technology, industry, and agriculture, lipids (amino acids, peptides, and proteins), Nuclear Physics - Experiment, Nuclear Experiment
Abstract: Neutron-induced fission cross-sections of actinides have been recently measured at the neutron time of flight facility n_TOF at CERN in the frame of a research project involving isotopes relevant for nuclear astrophysics and nuclear technologies. Fission fragments are detected by a gas counter with good discrimination between nuclear fission products and background events. Neutron-induced fission cross-sections of 233U and 243Am were determined relative to 235U. The present paper reports the results obtained at neutron energies between 0.5 and 20 MeV.
Published: 2011

54. Study of Photon Strength Function of Actinides: the Case of (235)U, (238)Np and (241)Pu

Author: Guerrero, C., Alvarez-Velarde, F., Ano-Ott, D. C., Martinez, T., Mendoza, E., Villamarin, D., Colonna, N., Meaze, M. H., Marrone, S., Tagliente, G., Terlizzi, R., Belloni, F., Abbondanno, U., Fujii, K., Milazzo, P. M., Moreau, C., Aerts, G., Berthoumieux, E., Dridi, W., Gunsing, F., Pancin, J., Perrot, L., Plukis, A., Alvarez, H., Duran, I., Paradela, C., Andriamonje, S., Calviani, M., Chiaveri, E., Gonzalez-Romero, E., Kadi, Y., Vicente, M. C., Vlachoudis, V., Andrzejewski, J., Marganiec, J., Assimakopoulos, P., Karadimos, D., Karamanis, D., Papachristodoulou, C., Patronis, N., Audouin, L., David, S., Ferrant, L., Isaev, S., Stephan, C., Tassan-Got, L., Badurek, G., Jericha, E., Leeb, H., Oberhummer, H., Pigni, M. T., Baumann, P., Kerveno, M., Lukic, S., Rudolf, G., Becvar, F., Krticka, M., Calvino, F., Capote, R., De Albornoz, A. C., Marques, L., Salgado, J., Tavora, L., Vaz, P., Cennini, P., Dahlfors, M., Ferrari, A., Gramegna, F., Herrera-Martinez, A., Mastinu, P., Praena, J., Sarchiapone, L., Wendler, H., Chepel, V., Ferreira-Marques, R., Goncalves, I., Lindote, A., Lopes, I., Neves, F., Cortes, G., Poch, A., Pretel, C., Couture, A., Cox, J., O'Brien, S., Wiescher, M., Dillman, I., Kappeler, F., Mosconi, M., Plag, R., Voss, F., Walter, S., Wisshak, K., Dolfini, R., Rubbia, C., Domingo-Pardo, C., Tain, J. L., Eleftheriadis, C., Savvidis, I., Frais-Koelbl, H., Griesmayer, E., Furman, W., Konovalov, V., Goverdovski, A., Ketlerov, V., Haas, B., Haight, R., Reifarth, R., Heil, M., Igashira, M., Koehler, P., Kossionides, E., Lampoudis, C., Lozano, M., Quesada, J., Massimi, C., Vannini, G., Mengoni, A., Oshima, M., Papadopoulos, C., Vlastou, R., Pavlik, A., Pavlopoulos, P., Plompen, A., Rullhusen, P., Rauscher, T., Rosetti, M., Ventura, A., and N TOF Collaboration
Subjects: pygmy, parameter, resonance, photon/gamma strength functions, spectra, nuclei, scissor mode, n_tof, tac, total absorption calorimeter, systematics, neutron capture
Abstract: The decay from excited levels in medium and heavy nuclei can be described in a statistical approach by means of Photon Strength Functions and Level Density distributions. The study of electromagnetic cascades following neutron capture based on the use of high efficiency detectors has been shown to be well suited for probing the properties of the Photon Strength Function of heavy (high level density) and/or radioactive (high background) nuclei. In this work we have investigated for the first time the validity of the recommended PSF of actinides, in particular (235)U, (238)Np and (241)Pu. Our study includes the search for resonance structures in the PSF below S(n) and draws conclusions regarding their existence and their characteristics in terms of energy, width and electromagnetic nature. Journal of the Korean Physical Society
Published: 2011

55. Neutron physics of the Re/Os clock. I. Measurement of the (n,γ) cross sections of 186,187,188Os at the CERN n_TOF facility

Author: Mosconi, M., Fujii, K., Mengoni, A., Domingo-Pardo, C., Käppeler, F., Abbondanno, U., Aerts, G., Álvarez-Pol, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Bečvář, F., Belloni, F., Berthoumieux, E., Bisterzo, S., Calviani, M., Calviño, F., Cano-Ott, D., Capote, R., Carrillo De Albornoz, A., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dolfini, R., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, Anthony, Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kadi, Y., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krtička, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Massimi, C., Mastinu, P., M. Milazzo, P., Moreau, C., Neves, F., Oberhummer, H., Oshima, M., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., L. Tain, J., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., C. Vincente, M., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., Département d'Electronique, des Détecteurs et d'Informatique pour la Physique (ex SEDI) (DEDIP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Pôle Universitaire Léonard de Vinci, Pôle Universitaire Léonard de Vinci (PULV), TOF, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract: The precise determination of the neutron capture cross sections of 186Os and 187Os is important to define the s-process abundance of 187Os at the formation of the solar system. This quantity can be used to evaluate the radiogenic component of the abundance of 187Os due to the decay of the unstable 187Re (t1/2=41.2 Gyr) and from this to infer the time duration of the nucleosynthesis in our galaxy (Re/Os cosmochronometer). The neutron capture cross sections of 186Os, 187Os, and 188Os have been measured at the CERN n_TOF facility from 1 eV to 1 MeV, covering the entire energy range of astrophysical interest. The measurement has been performed by time-of-flight technique using isotopically enriched samples and two C6D6 scintillation detectors for recording the prompt γ rays emitted in the capture events. Maxwellian averaged capture cross sections have been determined for thermal energies between kT=5 and 100 keV corresponding to all possible s-process scenarios. The estimated uncertainties for the values at 30 keV are 4.1, 3.3, and 4.7% for 186Os, 187Os, and 188Os, respectively.
Published: 2010

56. 197Au(n,γ ) cross section in the resonance region

Author: Massimi, C., Domingo-Pardo, C., Vannini, G., Audouin, L., Guerrero, C., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., G. Badurek, †, Baumann, P., Becvar, F., Belloni, F., Berthoumieux, E., Calvino, F., Calviani, M., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dridi, W., Duran, I., Eleftheriadis, C., Ferrant, L., Ferrari, Anthony, Ferreira-Marques, R., Fujii, K., Furman, W., Galanopoulos, S., F. Gonc¸alves, I., Gonz'Alez-Romero, E., Gramegna, F., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Jericha, E., Kappeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Koehler, P., Kossionides, E., Krticka, M., Lampoudis, C., Lederer, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martinez, T., Mastinu, P., Mendoza, E., Mengoni, A., M. Milazzo, P., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papadopoulos, C., Paradela, C., Pavlik, A., Pavlopoulos, P., Perdikakis, G., Perrot, L., T. Pigni, M., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Sarchiapone, L., Sarmento, R., Savvidis, I., Stephan, C., Tagliente, G., L. Tain, J., Tassan-Got, L., Tavora, L., Terlizzi, R., Vaz, P., Ventura, A., Villamarin, D., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wiescher, M., Wisshak, K., Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Pôle Universitaire Léonard de Vinci, Pôle Universitaire Léonard de Vinci (PULV), nTOF, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 25.40.Ny, 25.40.Lw, 29.30.Hs, 27.80.+w
Abstract: The (n,γ ) cross section of 197Au has been measured at n TOF in the resolved resonance region, up to 5 keV,with the aim of improving the accuracy in an energy range where it is not yet considered standard. The measurements were performed with two different experimental setup and detection techniques, the total energy method based on C6D6 detectors, and the total absorption calorimetry based on a 4π BaF2 array. By comparing the data collected with the two techniques, two accurate sets of neutron-capture yields have been obtained, which could be the basis for a new evaluation leading to an extended cross-section standard. Overall good agreement is found between the n TOF results and evaluated cross sections, with some significant exceptions for small resonances. A few resonances not included in the existing databases have also been observed.
Published: 2010

57. Neutron physics of the Re/Os clock. 1. Measurement of the (n, gamma) cross sections of Os-186, Os-187, Os-188 at the CERN n_TOF facility

Author: Mosconi, M, Fujii, K, Mengoni, A, Domingo-Pardo, C, Kappeler, F, Abbondanno, U, Aerts, G, Alvarez-Pol, H, Alvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Assimakopoulos, P, Audouin, L, Badurek, G, Baumann, P, Becvar, F, Belloni, F, Berthoumieux, E, Bisterzo, S, Calviani, M, Calvino, F, Cano-Ott, D, Capote, R, Carrillo de Albornoz, A, Cennini, P, Chepel, V, Chiaveri, E, Colonna, N, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillmann, I, Dolfini, R, Dridi, W, Duran, I, Eleftheriadis, C, Embid-Segura, M, Ferrant, L, Ferrari, A, Ferreira-Marques, R, Fitzpatrick, L, Frais-Koelbl, H, Furman, W, Gallino, R, Goncalves, I, Gonzalez-Romero, E, Goverdovski, A, Gramegna, F, Griesmayer, E, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Isaev, S, Jericha, E, Kadi, Y, Karamanis, D, Karadimos, D, Kerveno, M, Ketlerov, V, Koehler, P, Konovalov, V, Kossionides, E, Krticka, M, Lamboudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marques, L, Marrone, S, Massimi, C, Mastinu, P, Milazzo, P M, Moreau, C, Neves, F, Oberhummer, H, Oshima, M, O'Brien, S, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, N, Pavlik, A, Pavlopoulos, P, Perrot, L, Plag, R, Plompen, A, Plukis, A, Poch, A, Praena, J, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rosetti, M, Rubbia, C, Rudolf, G, Rullhusen, P, Salgado, J, Sarchiapone, L, Savvidis, I, Stephan, C, Tagliente, G, Tain, J L, Tassan-Got, L, Tavora, L, Terlizzi, R, Vannini, G, Vaz, P, Ventura, Alberto, Villamarin, D, Vincente, M C, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wendler, H, Wiescher, M, and Wisshak, K
Subjects: Nuclear Physics - Experiment
Published: 2010

58. Neutron-induced fission cross section of (234)U and (237)Np measured at the CERN Neutron Time-of-Flight (n_TOF) facility

Author: Paradela, C., Tassan-Got, L., Audouin, L., Berthier, B., Duran, I., Ferrant, L., Isaev, S., Le Naour, C., Stephan, C., Tarrio, D., Trubert, D., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calvino, F., Calviani, M., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Domingo-Pardo, C., Dridi, W., Eleftheriadis, C., Embid-Segura, M., Ferrari, A., Ferreira-Marques, R., Fujii, K., Furman, W., Goncalves, I., Gonzalez-Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Jericha, E., Kadi, Y., Kappeler, F., Karadimos, D., Karamanis, D., Kerveno, M., Koehler, P., Kossionides, E., Krticka, M., Lampoudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mengoni, A., Milazzo, P. M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Oshima, M., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Tagliente, G., Tain, J. L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wiescher, M., Wisshak, K., and n TOF Collaboration
Subjects: nuclear-data library, angular-distribution, pu-239, fragments, dependence, anisotropy, energy-range
Abstract: A high-resolution measurement of the neutron-induced fission cross section of (234)U and (237)Np has been performed at the CERN Neutron Time-of-Flight facility. The cross sections have been determined in a wide energy range from 1 eV to 1 GeV using the evaluated (235)U cross section as reference. In these measurements the energy determination for the (234)U resonances could be improved, whereas previous discrepancies for the (237)Np resonances were confirmed. New cross-section data are provided for high neutron energies that go beyond the limits of prior evaluations, obtaining important differences in the case of (237)Np. Physical Review C
Published: 2010

59. Neutron physics of the Re/Os clock. III. Resonance analyses and stellar (n, gamma) cross sections of (186,187,188)Os

Author: Fujii, K., Mosconi, M., Mengoni, A., Domingo-Pardo, C., Kappeler, F., Abbondanno, U., Aerts, G., Alvarez-Pol, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Belloni, F., Berthoumieux, E., Bisterzo, S., Calviani, M., Calvino, F., Cano-Ott, D., Capote, R., de Albornoz, A. C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dolfini, R., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kadi, Y., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Massimi, C., Mastinu, P., Milazzo, P. M., Moreau, C., Neves, F., Oberhummer, H., Oshima, M., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.
Subjects: osmium isotopes, re-187-os-187 systematics, statistical-model, age, cosmochronology, nucleosynthesis, giant branch stars, chemical evolution, capture, metal-poor
Abstract: Neutron resonance analyses have been performed for the capture cross sections of (186)Os, (187)Os, and (188)Os measured at the n_TOF facility at CERN. Resonance parameters have been extracted up to 5, 3, and 8 keV, respectively, using the SAMMY code for a full R-matrix fit of the capture yields. From these results average resonance parameters were derived by a statistical analysis to provide a comprehensive experimental basis for modeling of the stellar neutron capture rates of these isotopes in terms of the Hauser-Feshbach statistical model. Consistent calculations for the capture and inelastic reaction channels are crucial for the evaluation of stellar enhancement factors to correct the Maxwellian averaged cross sections obtained from experimental data for the effect of thermally populated excited states. These factors have been calculated for the full temperature range of current scenarios of s-process nucleosynthesis using the combined information of the experimental data in the region of resolved resonances and in the continuum. The consequences of this analysis for the s-process component of the (187)Os abundance and the related impact on the evaluation of the time duration of galactic nucleosynthesis via the Re/Os cosmochronometer are discussed. Physical Review C
Published: 2010

60. Neutron-induced fission cross section of U-234 and Np-237 measured at the CERN Neutron Time-of-Flight (n_TOF) facility

Author: Paradela, C, Tassan-Got, L, Audouin, L, Berthier, B, Duran, I, Ferrant, L, Isaev, S, Le Naour, C, Stephan, C, Tarrio, D, Trubert, D, Abbondanno, U, Aerts, G, Alvarez, H, Alvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Assimakopoulos, P, Badurek, G, Baumann, P, Becvar, F, Berthoumieux, E, Calvino, F, Calviani, M, Cano-Ott, D, Capote, R, Carrapico, C, Cennini, P, Chepel, V, Chiaveri, E, Colonna, N, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillmann, I, Domingo-Pardo, C, Dridi, W, Eleftheriadis, C, Embid-Segura, M, Ferrari, A, Ferreira-Marques, R, Fujii, K, Furman, W, Goncalves, I, Gonzalez-Romero, E, Gramegna, F, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Jericha, E, Kadi, Y, Kappeler, F, Karadimos, D, Karamanis, D, Kerveno, M, Koehler, P, Kossionides, E, Krticka, M, Lampoudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marrone, S, Martinez, T, Massimi, C, Mastinu, P, Mengoni, A, Milazzo, P M, Moreau, C, Mosconi, M, Neves, F, Oberhummer, H, O'Brien, S, Oshima, M, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Patronis, N, Pavlik, A, Pavlopoulos, P, Perrot, L, Pigni, M T, Plag, R, Plompen, A, Plukis, A, Poch, A, Praena, J, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rubbia, C, Rudolf, G, Rullhusen, P, Salgado, J, Santos, C, Sarchiapone, L, Savvidis, I, Tagliente, G, Tain, J L, Tavora, L, Terlizzi, R, Vannini, G, Vaz, P, Ventura, Alberto, Villamarin, D, Vincente, M C, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wiescher, M, and Wisshak, K
Subjects: Nuclear Physics - Experiment
Published: 2010

61. Neutron physics of the Re/Os clock. I. Measurement of the (n, gamma) cross sections of (186,187,188)Os at the CERN n_TOF facility

Author: Mosconi, M., Fujii, K., Mengoni, A., Domingo-Pardo, C., Kappeler, F., Abbondanno, U., Aerts, G., Alvarez-Pol, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Belloni, F., Berthoumieux, E., Bisterzo, S., Calviani, M., Calvino, F., Cano-Ott, D., Capote, R., de Albornoz, A. C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dolfini, R., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kadi, Y., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Massimi, C., Mastinu, P., Milazzo, P. M., Moreau, C., Neves, F., Oberhummer, H., Oshima, M., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.
Subjects: stellar nucleosynthesis, age, os-187, giant branch stars, capture, metal-poor, inelastic-scattering, isotopes, s-process, w-185
Abstract: The precise determination of the neutron capture cross sections of (186)Os and (187)Os is important to define the s-process abundance of (187)Os at the formation of the solar system. This quantity can be used to evaluate the radiogenic component of the abundance of (187)Os due to the decay of the unstable (187)Re (t(1/2) = 41.2 Gyr) and from this to infer the time duration of the nucleosynthesis in our galaxy (Re/Os cosmochronometer). The neutron capture cross sections of (186)Os, (187)Os, and (188)Os have been measured at the CERN n_TOF facility from 1 eV to 1 MeV, covering the entire energy range of astrophysical interest. The measurement has been performed by time-of-flight technique using isotopically enriched samples and two C(6)D(6) scintillation detectors for recording the prompt. rays emitted in the capture events. Maxwellian averaged capture cross sections have been determined for thermal energies between kT = 5 and 100 keV corresponding to all possible s-process scenarios. The estimated uncertainties for the values at 30 keV are 4.1, 3.3, and 4.7% for (186)Os, (187)Os, and (188)Os, respectively. Physical Review C
Published: 2010

62. Study of Neutron-Induced Fission Cross Sections of U, Am, and Cm at n[underaccent underbar [below] TOF

Author: Milazzo, P. M., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Beccvar, F., Belloni, F., Berthoumieux, E., Calvino, F., Calviani, M., Cano Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillman, I., Domingo Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid Segura, M., Ferrant, L., Ferrari, Attilio, Ferreira Marques, R., Fujii, K., Furman, W., Goncalves, I., Gonzalez Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Heil, M., Herrera Martinez, A., Jericha, E., Kappeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Koehler, P., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mengoni, A., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Plag, R., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Reifarth, R., Rubbia, C., Rudolf, G., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wiescher, M., and nTOF collaboration, K. W.
Subjects: isotope effects, radioactive sources, fission, ionisation chambers, Monte Carlo methods
Published: 2010

63. The Zr-92 (n, gamma) reaction and its implications for stellar nucleosynthesis

Author: Tagliente, G, Milazzo, P M, Fujii, K, Abbondanno, U, Aerts, G, Alvarez, H, Alvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Audouin, L, Badurek, G, Baumann, P, Becvar, F, Belloni, F, Berthoumieux, E, Bisterzo, S, Calvino, F, Calviani, M, Cano-Ott, D, Capote, R, Carrapico, C, Cennini, P, Chepel, V, Chiaveri, E, Colonna, N, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillmann, I, Domingo-Pardo, C, Dridi, W, Duran, I, Eleftheriadis, C, Embid-Segura, M, Ferrari, A, Ferreira-Marques, R, Furman, W, Gallino, R, Goncalves, I, Gonzalez-Romero, E, Gramegna, F, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Jericha, E, Kappeler, F, Kadi, Y, Karadimos, D, Karamanis, D, Kerveno, M, Kossionides, E, Krticka, M, Lamboudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marrone, S, Martinez, T, Massimi, C, Mastinu, P, Mengoni, A, Moreau, C, Mosconi, M, Neves, F, Oberhummer, H, O'Brien, S, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, N, Pavlik, A, Pavlopoulos, P, Perrot, L, Pigni, M T, Plag, R, Plompen, A, Plukis, A, Poch, A, Praena, J, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rosetti, M, Rubbia, C, Rudolf, G, Rullhusen, P, Salgado, J, Santos, C, Sarchiapone, L, Savvidis, I, Stephan, C, Tain, J L, Tassan-Got, L, Tavora, L, Terlizzi, R, Vannini, G, Vaz, P, Ventura, A, Villamarin, D, Vincente, M C, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wendler, H, Wiescher, M, and Wisshak, K
Subjects: Nuclear Physics - Experiment
Published: 2010

64. Au-197 (n, gamma) cross section in the resonance region

Author: Massimi, C, Domingo-Pardo, C, Vannini, G, Audouin, L, Guerrero, C, Abbondanno, U, Aerts, G, Alvarez, H, Alvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Assimakopoulos, P, Badurek, G, Baumann, P, Becvar, F, Belloni, F, Berthoumieux, E, Calvino, F, Calviani, M, Cano-Ott, D, Capote, R, Carrapico, C, Cennini, P, Chepel, V, Chiaveri, E, Colonna, N, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillmann, I, Dridi, W, Duran, I, Eleftheriadis, C, Ferrant, L, Ferrari, A, Ferreira-Marques, R, Fujii, K, Furman, W, Galanopoulos, S, Goncalves, I F, Gonzalez-Romero, E, Gramegna, F, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Jericha, E, Kappeler, F, Kadi, Y, Karadimos, D, Karamanis, D, Kerveno, M, Koehler, P, Kossionides, E, Krticka, M, Lampoudis, C, Lederer, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marrone, S, Martinez, T, Mastinu, P, Mendoza, E, Mengoni, A, Milazzo, P M, Moreau, C, Mosconi, M, Neves, F, Oberhummer, H, O'Brien, S, Pancin, J, Papadopoulos, C, Paradela, C, Pavlik, A, Pavlopoulos, P, Perdikakis, G, Perrot, L, Pigni, M T, Plag, R, Plompen, A, Plukis, A, Poch, A, Praena, J, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rosetti, M, Rubbia, C, Rudolf, G, Rullhusen, P, Sarchiapone, L, Sarmento, R, Savvidis, I, Stephan, C, Tagliente, G, Tain, J L, Tassan-Got, L, Tavora, L, Terlizzi, R, Vaz, P, Ventura, A, Villamarin, D, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wiescher, M, and Wisshak, K
Subjects: Nuclear Physics - Experiment
Published: 2010

65. The (92)Zr(n,gamma) reaction and its implications for stellar nucleosynthesis

Author: Tagliente, G., Milazzo, P. M., Fujii, K., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Belloni, F., Berthoumieux, E., Bisterzo, S., Calvino, F., Calviani, M., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrari, A., Ferreira-Marques, R., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Jericha, E., Kappeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mengoni, A., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., and N TOF Collaboration
Subjects: n-tof, elements, zr isotopes, facility, energy range, cern, capture cross-sections, giant branch stars, neutron-capture, s-process
Abstract: Because the relatively small neutron capture cross sections of the zirconium isotopes are difficult to measure, the results of previous measurements are often not adequate for a number of problems in astrophysics and nuclear technology. Therefore, the (92)Zr(n,gamma) cross section has been remeasured at the CERN n_TOF facility, providing a set of improved parameters for 44 resonances in the neutron energy range up to 40 keV. With this information the cross-section uncertainties in the keV region could be reduced to 5% as required for s-process nucleosynthesis studies and technological applications. Physical Review C
Published: 2010

66. Neutron physics of the Re/Os clock. 3. Resonance analyses and stellar (n, gamma) cross sections of Os-186, Os-187, Os-188

Author: Fujii, K, Mosconi, M, Mengoni, A, Domingo-Pardo, C, Kappeler, F, Abbondanno, U, Aerts, G, Alvarez-Pol, H, Alvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Assimakopoulos, P, Audouin, L, Badurek, G, Baumann, P, Becvar, F, Belloni, F, Berthoumieux, E, Bisterzo, S, Calviani, M, Calvino, F, Cano-Ott, D, Capote, R, Carrillo de Albornoz, A, Cennini, P, Chepel, V, Chiaveri, E, Colonna, N, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillmann, I, Dolfini, R, Dridi, W, Duran, I, Eleftheriadis, C, Embid-Segura, M, Ferrant, L, Ferrari, A, Ferreira-Marques, R, Fitzpatrick, L, Frais-Koelbl, H, Furman, W, Gallino, R, Goncalves, I, Gonzalez-Romero, E, Goverdovski, A, Gramegna, F, Griesmayer, E, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Isaev, S, Jericha, E, Kadi, Y, Karamanis, D, Karadimos, D, Kerveno, M, Ketlerov, V, Koehler, P, Konovalov, V, Kossionides, E, Krticka, M, Lamboudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marques, L, Marrone, S, Massimi, C, Mastinu, P, Milazzo, P M, Moreau, C, Neves, F, Oberhummer, H, Oshima, M, O'Brien, S, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, N, Pavlik, A, Pavlopoulos, P, Perrot, L, Plag, R, Plompen, A, Plukis, A, Poch, A, Praena, J, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rosetti, M, Rubbia, C, Rudolf, G, Rullhusen, P, Salgado, J, Sarchiapone, L, Savvidis, I, Stephan, C, Tagliente, G, Tain, J L, Tassan-Got, L, Tavora, L, Terlizzi, R, Vannini, G, Vaz, P, Ventura, Alberto, Villamarin, D, Vincente, M C, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wendler, H, Wiescher, M, and Wisshak, K
Subjects: Nuclear Physics - Experiment
Published: 2010

67. High-accuracy $^{233}$U(n,f) cross-section measurement at the white-neutron source n_TOF from near-thermal to 1 MeV neutron energy

Author: Sarchiapone, L., Savvidis, I., Konovalov, V., Stephan, C., Tagliente, G., Krticka, M., Rudolf, G., Kossionides, E., Rullhusen, P., Leeb, H., Salgado, J., Capote, R., Cano-Ott, D., Mengoni, A., Calviño Tavares, Francisco|||0000-0002-7198-4639, Milazzo, P.M., Berthoumieux, E., Massimi, C., Berthier, B., Mastinu, P., Belloni, F., Lampoudis, C., Marrone, S., Becvár, F., Martínez, T., Baumann, P., Badurek, G., Audouin, L., Carrapiço, C., Marganiec, J., Lukic, S., Lozano, M., Santos, C., Lopes, I., Lindote, A., Taín Enríquez, José Luis|||0000-0002-3263-6965, Tassan-Got, L., Assimakopoulos, P.A., Kadi, Y., Calviani, M., Karadimos, D., Praena, J., Karamanis, D., Abbondanno, U., Ketlerov, V., Aerts, G., Kerveno, M., Álvarez, H., Koehler, P., Álvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Vlachoudis, V., Vlastou, R., Villamarin, D., Vincente, M.C., Käppeler, F., Vaz, P., Jericha, E., Ventura, A., Igashira, M., Terlizzi, R., Herrera-Martinez, A., Vannini, G., Voss, F., Guerrero, C., Tavora, L., Gunsing, F., Goverdovski, A., Gramegna, F., Heil, M., Haas, B., Haight, R., Furman, W., Gonzalez-Romero, E., Goncalves, I., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fujiii, K., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Domingo-Pardo, C., Dillmann, I., David, S., Cox, J., Dahlfors, M., Cortés Rossell, Guillem Pere|||0000-0002-3648-5826, Couture, A., Chiaveri, E., Colonna, N., Cennini, P., Chepel, V., Rubbia, C., Rosetti, M., Plukis, A., Poch Parés, Agustí, Plag, R., Plompen, A., Rauscher, T., Reifarth, R., Pretel Sánchez, Carme|||0000-0001-6199-3366, Quesada, J., Pigni, M.T., Perrot, L., Pavlopoulos, P., Papadopoulos, C., Paradela, C., Wisshak, K., Patronis, N., Pavlik, A., O'Brien, S., Pancin, J., Papachristodoulou, C., Mosconi, M., Moreau, C., Oberhummer, H., Walter, S., Neves, F., Wiescher, M., Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Pôle Universitaire Léonard de Vinci, Pôle Universitaire Léonard de Vinci (PULV), TOF, Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya. GREENER - Grup de recerca d'estudis energètics i de les radiacions, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Energies::Energia nuclear [Àrees temàtiques de la UPC], Física::Física de partícules [Àrees temàtiques de la UPC], Nuclear physics, Física nuclear, Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: The 233U(n,f ) cross section has been measured at the white neutron source n TOF in a wide energy range with a dedicated fission ionization chamber. We report here the results from ∼30 meV to 1 MeV neutron energy. The 233U(n,f ) cross section has been determined relative to a reference sample of 235U(n,f )measured simultaneously with the same detector. The very high instantaneous neutron flux and the intrinsically low background of the n TOF installation result in an accuracy around 3% in the whole energy range, while the energy resolution of the neutron beam allows for an accurate description of the fission cross section by means of R-matrix analysis over a wide energy range. The results are, in general, in good agreementwith the most recent high-accuracy measurement of this fission cross section, over the more limited range of the previous measurements, and indicated that even the latest evaluations underestimate the cross section in the epithermal region. The present high-quality data provide the basis for a more precise evaluation of the 233U fission cross section and for improving the reliability of databases needed for the design of new energy systems based on the Th/U cycle.
Published: 2009

68. High-accuracy (233)U(n, f) cross-section measurement at the white-neutron source n_TOF from near-thermal to 1 MeV neutron energy

Author: Calviani, M., Praena, J., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Belloni, F., Berthier, B., Berthoumieux, E., Calvino, F., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fujii, K., Furman, W., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Jericha, E., Kappeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Ketlerov, V., Kerveno, M., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lampoudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mengoni, A., Milazzo, P. M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wiescher, M., Wisshak, K., and N TOF Collaboration
Subjects: nuclear-data library, region, facility, cern, fission, targets, uranium-233
Abstract: The (233)U(n, f) cross section has been measured at the white neutron source n_TOF in a wide energy range with a dedicated fission ionization chamber. We report here the results from similar to 30 meV to 1 MeV neutron energy. The (233)U(n, f) cross section has been determined relative to a reference sample of (235)U(n, f) measured simultaneously with the same detector. The very high instantaneous neutron flux and the intrinsically low background of the n_TOF installation result in an accuracy around 3% in the whole energy range, while the energy resolution of the neutron beam allows for an accurate description of the fission cross section by means of R-matrix analysis over a wide energy range. The results are, in general, in good agreement with the most recent high-accuracy measurement of this fission cross section, over the more limited range of the previous measurements, and indicated that even the latest evaluations underestimate the cross section in the epithermal region. The present high-quality data provide the basis for a more precise evaluation of the (233)U fission cross section and for improving the reliability of databases needed for the design of new energy systems based on the Th/U cycle. Physical Review C
Published: 2009

69. Nuclear physics for the Re/Os clock

Author: Mosconi, M., Heil, M., Kappeler, F., Plag, R., Mengoni, A., Fujii, K., Domingo-Pardo, C., Aerts, G., Terlizzi, R., Gallino, R., Abbondanno, U., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calvino, F., Calviani, M., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Furman, W., Goncalves, I., Gonzalez-Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Herrera-Martinez, A., Igashira, M., Jericha, E., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Koehler, P., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Massimi, C., Mastinu, P., Milazzo, P. M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wiescher, M., Wisshak, K., and n TOF Collaboration
Subjects: stars, age, neutron cross-sections, nucleosynthesis, os-187, inelastic-scattering, isotopes
Abstract: Dating the age of the universe by the beta-decay of (187)Re (t(1/2) = 41.2 Gyr) requires the accurate assessment of the s-process reaction flow. The daughter nucleus (187)Os as well as its immediate s-only neighbor (186)Os are shielded from the r-process. Therefore, the radiogenic contribution to (187)Os can be derived via the local approximation of the s-process, which is well justified in this mass region: ( N(s))(187) = ( N(s))(186). Accordingly, accurate Maxwellian-averaged (n,gamma) cross sections have to be known for (186)Os and (187)Os over the full range of s-process temperatures. Because (187)Os has low-lying excited states, which are significantly populated during the s-process, neutron captures on these excited states have to be properly taken into account. The input for the corresponding Hauser-Feshbach calculations can be constrained by deriving the strength functions from a detailed resonance analysis of the measured (n,gamma) cross sections as well as by an additional measurement of the inelastic scattering cross section for the first exited level, which dominates the competition between the capture and scattering channels. This contribution reports on measurements of the neutron capture cross sections of (186)Os, (187)Os and (188)Os from the eV region to 1MeV at the CERN/n_TOF facility and of the inelastic scattering cross section of (187)Os around 30 keV at the Karlsruhe 3.7 MV Van de Graaff accelerator. Based on these results and on a detailed resonance analysis, improved Maxwellian-averaged cross sections were obtained for thermal energies between 5 keV and 100 keV. The implications of these results for the Re/Os clock are discussed. Journal of Physics G-Nuclear and Particle Physics
Published: 2008

70. Experimental study of the 91Zr(n gamma) reaction up to 26 keV

Author: Tagliente, G, Milazzo, P M, Fujii, K, Aerts, G, Abbondanno, U, Alvarez, H, Alvarez-Velarde, F, Andriamonje, Samuel A, Andrzejewski, J, Assimakopoulos, Panayiotis, Audouin, L, Badurek, G, Baumann, P, Becvár, F, Belloni, F, Berthoumieux, E, Calviño, F, Calviani, M, Cano-Ott, D, Capote, R, Carrapiço, C, Cennini, P, Chepel, V, Colonna, N, Cortés, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillmann, I, Domingo-Pardo, C, Dridi, W, Durán, I, Eleftheriadis, C, Embid-Segura, M, Ferrant, L, Ferrari, A, Ferreira-Marques, R, Furman, W, Gonçalves, I, Gonzalez-Romero, E, Gramegna, F, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martínez, A, Igashira, M, Jericha, E, Kappeler, F, Kadi, Y, Karadimos, D, Karamanis, D, Kerveno, M, Köhler, P, Kossionides, E, Krticka, M, Lamboudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marrone, S, Martínez, T, Massimi, C, Mastinu, P, Mengoni, A, Moreau, C, Mosconi, M, Neves, F, Oberhummer, H, O'Brien, S, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, N, Pavlik, A, Pavlopoulos, P, Perrot, L, Pigni, M T, Plag, R, Plompen, A, Plukis, A, Poch, A, Praena-Rodriguez, J, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rubbia, C, Rudolf, G, Rullhusen, P, Salgado, J, Santos, C, Sarchiapone, L, Savvidis, I, Stéphan, C, Taín, J L, Tassan-Got, L, Tavora, L, Terlizzi, R, Vannini, G, Vaz, P, Ventura, A, Villamarín, D, Vincente, M C, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wiescher, M, Wisshak, K, Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Laboratori Nazionali di Legnaro (LNL), Istituto Nazionale di Fisica Nucleare (INFN), European Organization for Nuclear Research (CERN), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (INFN, Sezione di Bologna), nTOF, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and National Institute for Nuclear Physics (INFN)
Subjects: statistical-model, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, cern, transmission, nucleosynthesis, capture cross-sections, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 25.40.Lw, 25.70.Ef, 27.60.+j, 97.10.Cv, n-tof, evolution, Nuclear Physics - Experiment, giant branch stars, Nuclear Experiment, neutron-capture, s-process
Abstract: The neutron capture cross sections of the Zr isotopes are relevant to studies in nuclear structure, nuclear astrophysics, and nuclear technology. The valence neutron of (91)Zr with respect to the neutron magic nucleus (90)Zr has interesting implications for the statistical analysis in the proximity of shell closures. In stellar nucleosynthesis, the Zr isotopes are important for the s-process reaction flow between the Fe seeds and the heavier isotopes. Because of its relatively small (n, gamma) cross sections, Zr represents also an interesting structural material for nuclear reactors. For the same reason, these cross sections are difficult to measure and reliable data are sparse. Therefore, the (n, gamma) cross sections of the Zr isotopes have been remeasured at the CERN n_TOF facility. Thanks to its high instantaneous flux, good energy resolution, and low background, this facility is particularly suited for the determination of small, resonance-dominated cross sections. In this work, results for the (91)Zr(n, gamma) (92)Zr reaction are reported in the neutron energy range from thermal to 26 keV. In this region, accurate data of 157 resonances could be obtained, 33 of these resonances are not present in the main databases and/or were observed for the first time. Physical Review C
Published: 2008

71. The measurement of the (206)Pb(n,gamma) cross section and stellar implications

Author: Domingo-Pardo, C., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Bisterzo, S., Calvino, F., Calviani, M., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fujii, K., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Jericha, E., Kadi, Y., Kappeler, F., Karadimos, D., Karamanis, D., Kerveno, M., Koehler, P., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Massimi, C., Mastinu, P., Mengoni, A., Milazzo, P. M., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wiescher, M., and Wisshak, K.
Subjects: stars, elements, lead, galactic chemical evolution, neutron-capture, chronometers
Abstract: The neutron capture cross section of (206)Pb has been measured at the CERN n_TOF spectrometer using a setup of two C(6)D(6) detectors. In the energy interval from 1 eV to 600 keV the cross section is dominated by resonances, which were analyzed via the R-matrix analysis code SAMMY. In the relevant energy ranges for stellar nucleosynthesis, i. e., at thermal energies of kT = 8 keV and kT = 23 keV, the present Maxwellian average cross section differs by 20% and 9% from the recommended values of Bao et al respectively. From the new cross section the s-abundance of (206)Pb could be reliably determined as 70( 4)%. This result is of importance in order to test and constrain r-process abundance calculations in the actinide region, because the r-process portion of (206)Pb is dominated by alpha-back decays of short-lived transbismuth isotopes. Journal of Physics G-Nuclear and Particle Physics
Published: 2008

72. The measurement of the Pb-206(n,gamma) cross section and stellar implications

Author: Domingo Pardo, C., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Bisterzo, Sara, Calvino, F., Calviani, M., Cano Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dridi, W., Duran, I., Eleftheriadis, C., Embid Segura, M., Ferrant, L., Ferrari, Attilio, Ferreira Marques, R., Fujii, K., Furman, W., Gallino, Roberto, Goncalves, I., Gonzalez Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera Martinez, A., Igashira, M., Jericha, E., Kadi, Y., Kappeler, F., Karadimos, D., Karamanis, D., Kerveno, M., Koehler, P., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Massimi, C., Mastinu, P., Mengoni, A., Milazzo, P. M., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wiescher, M., and Wisshak, K.
Published: 2008

73. Neutron capture cross section of Zr-90: Bottleneck in the s-process reaction flow

Author: Tagliente, G., Fujii, K., Milazzo, P. M., Moreau, C., Aerts, G., Abbondanno, U., Alvarez, H., Alvarez Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Bisterzo, S., Calvino, F., Calviani, M., Cano Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillman, I., Domingo Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid Segura, M., Ferrant, L., Ferrari, Attilio, Ferreira Marques, R., Furman, W., Gallino, Roberto, Goncalves, I., Gonzalez Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera Martinez, A., Igashira, M., Jericha, E., Kaeppeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Koehler, P., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mengoni, A., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tain, J. L., Tassan Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.
Published: 2008

74. Neutron capture cross section of 90Zr: Bottleneck in the s-process reaction flow

Author: Tagliente, G., Fujii, K., Milazzo, P.M., Moreau, C., Aerts, G., Abbondanno, U., Álvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Bečvá&#345, F., Berthoumieux, E., Bisterzo, S., Calviño, F., Calviani, M., Cano-Ott, D., Capote, R., Carrapiço, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillman, I., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, Anthony, Ferreira-Marques, R., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Gramegna, F., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Jericha, E., Käppeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Koehler, P., Kossionides, E., Krtička, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martínez, T., Massimi, C., Mastinu, P., Mengoni, A., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., T. Pigni, M., Plag, R., Plompen, A., Plukis, A., Poch, A., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Savvidis, I., Stephan, C., Tain, J.L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M.C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Pole Universitaire Leonard de Vinci, Pôle Universitaire Léonard de Vinci (PULV), nTOF, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: zr isotopes, facility, Astrophysics::High Energy Astrophysical Phenomena, nucleosynthesis, valence component, system, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 25.40.Lw, 25.70.Ef, 27.60.+j, 97.10.Cv, n-tof, massive stars, energy range, evolution, Nuclear Physics - Experiment, giant branch stars, Nuclear Experiment
Abstract: The neutron capture cross sections of the Zr isotopes have important implications in nuclear astrophysics and for reactor design. The small cross section of the neutron magic nucleus (90)Zr, which accounts for more than 50% of natural zirconium represents one of the key isotopes for the stellar s-process, because it acts as a bottleneck in the neutron capture chain between the Fe seed and the heavier isotopes. The same element, Zr, also is an important component of the structural materials used in traditional and advanced nuclear reactors. The (n, gamma) cross section has been measured at CERN, using the n_TOF spallation neutron source. In total, 45 resonances could be resolved in the neutron energy range below 70 keV, 10 being observed for the first time thanks to the high resolution and low backgrounds at n_TOF. On average, the Gamma(gamma) widths obtained in resonance analyses with the R-matrix code SAMMY were 15% smaller than reported previously. By these results, the accuracy of the Maxwellian averaged cross section for s-process calculations has been improved by more than a factor of 2. Physical Review C
Published: 2008

75. Measurement of the radiative neutron capture cross section of Pb-206 and its astrophysical implications

Author: Domingo Pardo, César, Abbondanno, U., Aerts, G., Álvarez-Pol, H., Álvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Kadi, Y., Gunsing, F., Haas, B., Haight, R., n_TOF Collaboration, Herrera-Martínez, A., Leeb, H., Igashira, M., Isaev, S., Kappeler, F., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Mastinu, P., Koehler, P., Konovalov, V., Lindote, A., Kossionides, E., Mosconi, M., Krticka, M., Lamboudis, C., Lopes, I., Lozano, M., Neves, F., Lukic, S., Marganiec, J., Marrone, S., Mengoni, A., Milazzo, P. M., Plag, R., Moreau, C., Oberhummer, H., Oshima, M., O'Brien, S., Pancin, J., Papachristodoulou, C., Rauscher, T., Papadopoulos, C., Paradela, C., Patronis, N., Plompen, A., Rudolf, G., Pavlik, A., Pavlopoulos, P., Perrot, L., Plukis, A., Rullhusen, P., Poch, A., Pretel, C., Quesada, J., Reifarth, R., Rosetti, M., Rubbia, C., Villamarin, D., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Walter, S., Taín, José Luis, Tassan-Got, L., Tavora, L., Becvar, F., Vincente, M. C., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Berthoumieux, E., Vlachoudis, V., Vlastou, R., Voss, F., Wendler, H., Wiescher, M., Wisshak, K., Bisterzo, S., Dillmann, I., Calvino, F., Cano Ott, Daniel, Capote, R., Carrapico, C., Eleftheriadis, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortés Rossell, Guillem, Embid-Segura, M., Couture, A., Cox, J., Dahlfors, M., David, S., Dolfini, R., Dridi, W., Durán, Ignacio, Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Heil, M., Fujii, K., Furman, W., Gallino, R., Jericha, E., Goncalves, I., and González-Romero, E.
Subjects: n_TOF Collaboration, Neutron capture cross sections, Pulse height weighting technique, [PACS] Stellar structure, interiors, evolution, nucleosynthesis, ages, C6D6 scintillation detectors, Nuclear astrophysics, [PACS] Nucleon radiative capture, [PACS] Properties of nuclei with 190 ≤ A ≤ 219, Monte Carlo simulations
Abstract: 10 pages, 6 figures.-- PACS nrs.: 25.40.Lw; 27.80.+w; 97.10.Cv.-- ISI Article Identifier: 000250620900078.-- ArXiv pre-print available at: http://arxiv.org/abs/0707.3679, The (n,γ) cross section of Pb-206 has been measured at the CERN n_TOF facility with high resolution in the energy range from 1 eV to 620 keV by using two optimized C6D6 detectors. In the investigated energy interval about 130 resonances could be observed, from which 61 had enough statistics to be reliably analyzed via the R-matrix analysis code SAMMY. Experimental uncertainties were minimized, in particular with respect to (i) angular distribution effects of the prompt capture γ-rays, and to (ii) the TOF-dependent background due to sample-scattered neutrons. Other background components were addressed by background measurements with an enriched Pb-208 sample. The effect of the lower energy cutoff in the pulse height spectra of the C6D6 detectors was carefully corrected via Monte Carlo simulations. Compared to previous Pb-206 values, the Maxwellian averaged capture cross sections derived from these data are about 20% and 9% lower at thermal energies of 5 keV and 30 keV, respectively. These new results have a direct impact on the s-process abundance of Pb-206, which represents an important test for the interpretation of the cosmic clock based on the decay of U-238.
Published: 2007

76. Measurement of the radiative neutron capture cross section of 206Pb and its astrophysical implications

Author: Domingo-Pardo, C., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Bisterzo, S., Calvino, F., Calviani, M., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillman, I., Dolfini, R., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, M., Jericha, E., Kappeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Massimi, C., Mastinu, P., Mengoni, A., Milazzo, P.M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., Oshima, M., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J.L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M.C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), nTOF, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 25.40.Lw,27.80.+w,97.10.Cv, Neutron capture cross sections, Pulse height weighting technique, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, C6D6 scintillation detectors, Nuclear Physics - Experiment, Nuclear astrophysics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Monte Carlo simulations
Abstract: The (n, gamma) cross section of 206Pb has been measured at the CERN n_TOF facility with high resolution in the energy range from 1 eV to 600 keV by using two optimized C6D6 detectors. In the investigated energy interval about 130 resonances could be observed, from which 61 had enough statistics to be reliably analyzed via the R-matrix analysis code SAMMY. Experimental uncertainties were minimized, in particular with respect to (i) angular distribution effects of the prompt capture gamma-rays, and to (ii) the TOF-dependent background due to sample-scattered neutrons. Other background components were addressed by background measurements with an enriched 208Pb sample. The effect of the lower energy cutoff in the pulse height spectra of the C6D6 detectors was carefully corrected via Monte Carlo simulations. Compared to previous 206Pb values, the Maxwellian averaged capture cross sections derived from these data are about 20% and 9% lower at thermal energies of 5 keV and 30 keV, respectively. These new results have a direct impact on the s-process abundance of 206Pb, which represents an important test for the interpretation of the cosmic clock based on the decay of 238U., Comment: 11 pages, 8 figures, paper to be submitted to Phys. Rev. C
Published: 2007

77. The La-139(n,gamma) cross section: Key for the onset of the s-process

Author: Terlizzi, R., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calviani, M., Calvino, F., Cano-Ott, D., Capote, R., de Albornoz, A. C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dolfini, R., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kadi, Y., Kappeler, F., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Massimi, C., Mastinu, P., Mengoni, A., Milazzo, P. M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pignatari, M., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.
Subjects: resonance spectroscopy, n-tof, dispersion spectrograph, process nucleosynthesis, neutron-capture elements, cool dwarf stars, r-process elements, metal-poor stars, giant branch stars, galactic chemical evolution
Abstract: The nuclear resonance parameters and the capture cross section of the neutron magic isotope La-139 have been measured relative to Au-197 in the energy range of 0.6 eV to 9 keV at the neutron time-of-flight (n_TOF) facility at CERN. We describe the experimental apparatus and the data analysis procedures, which concerned mainly the efficiency correction by means of the pulse height weighting function technique and the determination of different background components. We extracted the resonance parameters and the main nuclear quantities such as the resonance integral RI=10.8 +/- 1.0b, the average gamma widths for s and p waves (l=0)=50.7 +/- 5.4 meV and (l=1)=33.6 +/- 6.9 meV, the nuclear level densities < D >(l=0)=252 +/- 22 eV and < D >(l=1)< 250 eV, and the neutron strength functions S-0=(0.82 +/- 0.05)x10(-4) and S-1=(0.55 +/- 0.04)x10(-4). These results represent a significant improvement over previous data. The deduced Maxwellian-averaged capture cross sections are important for the interpretation of the most recent spectroscopic observations in low-metallicity stars. ispartof: Physical Review. C, Nuclear physics vol:75 issue:3 pages:1-15 status: published
Published: 2007

78. Measurement of the neutron capture cross section of the s-only isotope Pb-204 from 1 eV to 440 keV

Author: Domingo Pardo, César, Abbondanno, U., Aerts, G., Álvarez-Pol, H., Álvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Berthoumieux, E., Vlachoudis, V., Vlastou, R., Voss, F., Wendler, H., Wiescher, M., Dahlfors, M., Wisshak, K., Bisterzo, S., Calvino, F., Cano Ott, Daniel, Capote, R., Carrapico, C., Eleftheriadis, C., Cennini, P., Chepel, V., Chiaveri, E., David, S., Colonna, N., Cortés Rossell, Guillem, Couture, A., Cox, J., Dillmann, I., Embid-Segura, M., Dolfini, R., Dridi, W., Durán, Ignacio, Ferrant, L., Ferrari, A., Ferreira-Marques, R., Haight, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Furman, W., Gallino, R., Jericha, E., Goncalves, I., González-Romero, E., Goverdovski, A., Gramegna, F., Heil, M., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Kadi, Y., Herrera-Martínez, A., Igashira, M., Isaev, S., Kappeler, F., Karamanis, D., Karadimos, D., Kerveno, M., Mastinu, P., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Mosconi, M., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Neves, F., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Mengoni, A., Milazzo, P. M., Moreau, C., Oberhummer, H., Oshima, M., O'Brien, S., Pancin, J., Papachristodoulou, C., Rauscher, T., Papadopoulos, C., Paradela, C., Patronis, N., Rudolf, G., Pavlik, A., Pavlopoulos, P., Perrot, L., Plag, R., Plompen, A., Plukis, A., Rullhusen, P., Poch, A., Pretel, C., Quesada, J., n_TOF Collaboration, Reifarth, R., Rosetti, M., Rubbia, C., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Walter, S., Taín, José Luis, Tassan-Got, L., Tavora, L., Becvar, F., Terlizzi, R., and Vannini, G.
Subjects: [PACS] Stellar structure, interiors, evolution, nucleosynthesis, ages, R-process, Abundances, Elements, [PACS] Nucleon radiative capture, Nucleosynthesis, [PACS] Properties of nuclei with 190 ≤ A ≤ 219, Galactic chemical evolution, Giant Branch Stars
Abstract: 9 pages, 3 figures.-- PACS nrs.: 25.40.Lw; 27.80.+w; 97.10.Cv.-- ISI Article Identifier: 000243896000061.-- ArXiv pre-print available at: http://arxiv.org/abs/nucl-ex/0610033, The neutron capture cross section of Pb-204 has been measured at the CERN n_TOF installation with high resolution in the energy range from 1 eV to 440 keV. An R-matrix analysis of the resolved resonance region, between 1 eV and 100 keV, was carried out using the SAMMY code. In the interval between 100 keV and 440 keV we report the average capture cross section. The background in the entire neutron energy range was reliably determined from the measurement of a Pb-208 sample. Other systematic effects in this measurement were investigated and precisely corrected by means of detailed Monte Carlo simulations. We obtain a Maxwellian average capture cross section for Pb-204 at kT=30 keV of 79(3) mb, in agreement with previous experiments. However our cross section at kT=5 keV is about 35% larger than the values reported so far. The implications of the new cross section for the s-process abundance contributions in the Pb/Bi region are discussed., This work was supported by the European Commission (FIKW-CT-2000-00107), by the Spanish Ministry of Science and Technology (FPA2001-0144-C05), and partly by the Italian MIUR-FIRB grant "The astrophysical origin of the heavy elements beyond Fe".
Published: 2007

79. Measurement of the neutron capture cross section of the s-only isotope Pb-204 from 1 eV to 440 keV

Author: Domingo-Pardo, C., Abbondanno, U., Aerts, G., Alvarez-Pol, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Bisterzo, S., Calvino, F., Cano-Ott, D., Capote, R., Carrapico, C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dolfini, R., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kadi, Y., Kappeler, F., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Mastinu, P., Mengoni, A., Milazzo, P. M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., Oshima, M., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.
Subjects: elements, lead, abundances, Astrophysics::High Energy Astrophysical Phenomena, r-process, cern, nucleosynthesis, giant branch stars, galactic chemical evolution, solar, chronometers
Abstract: The neutron capture cross section of Pb-204 has been measured at the CERN n_TOF installation with high resolution in the energy range from 1 eV to 440 keV. An R-matrix analysis of the resolved resonance region, between 1 eV and 100 keV, was carried out using the SAMMY code. In the interval between 100 keV and 440 keV we report the average capture cross section. The background in the entire neutron energy range was reliably determined from the measurement of a Pb-208 sample. Other systematic effects in this measurement were investigated and precisely corrected by means of detailed Monte Carlo simulations. We obtain a Maxwellian average capture cross section for Pb-204 at kT=30 keV of 79(3) mb, in agreement with previous experiments. However our cross section at kT=5 keV is about 35% larger than the values reported so far. The implications of the new cross section for the s-process abundance contributions in the Pb/Bi region are discussed. ispartof: Physical Review C vol:75 issue:1 pages:1-9 status: published
Published: 2007

80. Neutron reactions and nuclear cosmo-chronology

Author: Mosconi, M., Heil, M., Mengoni, A., Plag, R., Fujii, K., Gallino, R., Aerts, G., Terlizzi, R., Abbondanno, U., Rosetti, M., Marrone, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Berthoumieux, E., Bisterzo, S., Calvi?o, F., Cano-Ott, D., Capote, R., Dillman, I., Carrillo de Albornoz, A., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dolfini, R., Domingo Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Haight, R., Fitzpatrick, L., Frais-Koelbl, H., Furman, W., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Herrera-Martinez, A., Haas, B., Igashira, M., Isaev, S., Jericha, E., Kadi, Y., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Mastinu, P., Koehler, P., Konovalov, V., Kossionides, E., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Milazzo, P. M., Marganiec, J., Marques, L., Moreau, C., Neves, F., Oberhummer, H., Oshima, M., O Brien, S., Pancin, J., Papachristodoulou, C., Rubbia, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Plompen, A., Plukis, A., Poch, A., Pretel, C., Rudolf, G., Quesada, J., Rauscher, T., Reifarth, R., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Alvarez-Velarde, F., Tassan-Got, L., Tavora, L., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Andriamonje, S., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.
Subjects: Stellar cross sections, Neutron capture, Inelastic scattering, Re/Os cosmo-chronometer, s process
Abstract: The β -decay of 187Re ( t 1 / 2 = 42.3 Gyr ) represents a suited cosmo-chronometer for the age of the r -process abundances, since the radiogenic part of the daughter isotope 187Os is defined by the difference between the solar 187Os abundance and s -process contribution to 187Os. The latter component can be determined via the s -process systematics based on the stellar neutron capture cross sections of 186Os and 187Os. The laboratory cross section of 187Os requires a significant correction for the effect of the low-lying excited state at 9.75 keV, which is strongly populated under stellar conditions. This theoretical correction can be improved by an experimental cross section for inelastic scattering to the 9.75 keV state. High resolution time-of-flight measurements of ( n , γ ) cross sections of 186,187,188Os from 1 eV to 1 MeV at CERN n_TOF facility are reported. The inferred stellar cross sections differ from previously recommended values. In addition, the inelastic scattering cross section has been measured at 30 keV neutron energy via time-of-flight at the Karlsruhe 3.7 MV Van de Graaff. The implications of these results for the Re/Os clock are discussed. Progress in Particle and Nuclear Physics
Published: 2007

81. Measurement of the neutron capture cross section of the s-only isotope 204Pb from 1 eV to 440 keV

Author: DOMINGO-PARDO, C., ABBONDANNO, U., AERTS, G., ÁLVAREZ-POL, H., ALVAREZ-VELARDE, F., ANDRIAMONJE, S., ANDRZEJEWSKI, J., ASSIMAKOPOULOS, P., AUDOUIN, L., BADUREK, G., BAUMANN, P., BE&#269VÁ, F., BERTHOUMIEUX, E., BISTERZO, S., CALVIÑO, F., CANO-OTT, D., CAPOTE, R., CARRAPIÇO, C., CENNINI, P., CHEPEL, V., CHIAVERI, E., COLONNA, N., CORTES, G., COUTURE, A., COX, J., DAHLFORS, M., DAVID, S., DILLMANN, I., DOLFINI, R., DRIDI, W., DURAN, I., ELEFTHERIADIS, C., EMBID-SEGURA, M., FERRANT, L., FERRARI, Anthony, FERREIRA-MARQUES, R., FITZPATRICK, L., FRAIS-KOELBL, H., FUJII, K., FURMAN, W., GALLINO, R., GONCALVES, I., GONZALEZ-ROMERO, E., GOVERDOVSKI, A., GRAMEGNA, F., GRIESMAYER, E., GUERRERO, C., GUNSING, F., HAAS, B., HAIGHT, R., HEIL, M., HERRERA-MARTINEZ, A., IGASHIRA, M., ISAEV, S., JERICHA, E., KADI, Y., KÄPPELER, F., KARAMANIS, D., KARADIMOS, D., KERVENO, M., KETLEROV, V., KOEHLER, P., KONOVALOV, V., KOSSIONIDES, E., KRTIČKA, M., LAMBOUDIS, C., LEEB, H., LINDOTE, A., LOPES, I., LOZANO, M., LUKIC, S., MARGANIEC, J., MARRONE, S., MASTINU, P., MENGONI, A., M. MILAZZO, P., MOREAU, C., MOSCONI, M., NEVES, F., OBERHUMMER, H., OSHIMA, M., O'BRIEN, S., PANCIN, J., PAPACHRISTODOULOU, C., PAPADOPOULOS, C., PARADELA, C., PATRONIS, N., PAVLIK, A., PAVLOPOULOS, P., PERROT, L., PLAG, R., PLOMPEN, A., PLUKIS, A., POCH, A., PRETEL, C., QUESADA, J., RAUSCHER, T., REIFARTH, R., ROSETTI, M., RUBBIA, C., RUDOLF, G., RULLHUSEN, P., SALGADO, J., SARCHIAPONE, L., SAVVIDIS, I., STEPHAN, C., TAGLIENTE, G., L. TAIN, J., TASSAN-GOT, L., TAVORA, L., TERLIZZI, R., VANNINI, G., VAZ, P., VENTURA, A., VILLAMARIN, D., VINCENTE, M.C., VLACHOUDIS, V., VLASTOU, R., VOSS, F., WALTER, S., WENDLER, H., WIESCHER, M., WISSHAK, K., C. Domingo-Pardo, U. Abbondanno, G. Aert, H. Álvarez-Pol, F. Alvarez-Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulo, L. Audouin, G. Badurek, P. Baumann, F. Becvár, E. Berthoumieux, S. Bisterzo, F. Calviño, D. Cano-Ott, R. Capote, C. Carrapiço, P. Cennini, V. Chepel, E. Chiaveri, N. Colonna, G. Corte, A. Couture, J. Cox, M. Dahlfor, S. David, I. Dillman, R. Dolfini, W. Dridi, I. Duran, C. Eleftheriadi, M. Embid-Segura, L. Ferrant, A. Ferrari, R. Ferreira-Marque, L. Fitzpatrick, H. Frais-Koelbl, K. Fujii, W. Furman, R. Gallino, I. Goncalve, E. Gonzalez-Romero, A. Goverdovski, F. Gramegna, E. Griesmayer, C. Guerrero, F. Gunsing, B. Haa, R. Haight, M. Heil, A. Herrera-Martinez, M. Igashira, S. Isaev, E. Jericha, Y. Kadi, F. Käppeler, D. Karamani, D. Karadimo, M. Kerveno, V. Ketlerov, P. Koehler, V. Konovalov, E. Kossionide, M. Krtička, C. Lamboudi, H. Leeb, A. Lindote, I. Lope, M. Lozano, S. Lukic, J. Marganiec, S. Marrone, P. Mastinu, A. Mengoni, P. M. Milazzo, C. Moreau, M. Mosconi, F. Neve, H. Oberhummer, M. Oshima, S. O'Brien, J. Pancin, C. Papachristodoulou, C. Papadopoulo, C. Paradela, N. Patroni, A. Pavlik, P. Pavlopoulo, L. Perrot, R. Plag, A. Plompen, A. Pluki, A. Poch, C. Pretel, J. Quesada, T. Rauscher, R. Reifarth, M. Rosetti, C. Rubbia, G. Rudolf, P. Rullhusen, J. Salgado, L. Sarchiapone, I. Savvidi, C. Stephan, G. Tagliente, J. L. Tain, L. Tassan-Got, L. Tavora, R. Terlizzi, G. Vannini, P. Vaz, A. Ventura, D. Villamarin, M. C. Vincente, V. Vlachoudi, R. Vlastou, F. Vo, S. Walter, H. Wendler, M. Wiescher, K. Wisshak(n_TOF Collaboration), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), nTOF, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 25.40.Lw, 27.80.+w, 97.10.Cv, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], NEUTRON TIME OF FLIGHT, Nuclear Experiment, S-PROCESS, NEUTRON CAPTURE CROSS SECTION
Abstract: The neutron capture cross section of 204Pb has been measured at the CERN n_TOF installation with high resolution in the energy range from 1 eV to 440 keV. An R-matrix analysis of the resolved resonance region, between 1 eV and 100 keV, was carried out using the SAMMY code. In the interval between 100 keV and 440 keV we report the average capture cross section. The background in the entire neutron energy range could be reliably determined from the measurement of a 208Pb sample. Other systematic effects in this measurement could be investigated and precisely corrected by means of detailed Monte Carlo simulations. We obtain a Maxwellian average capture cross section for 204Pb at kT=30 keV of 79(3) mb, in agreement with previous experiments. However our cross section at kT=5 keV is about 35% larger than the values reported so far. The implications of the new cross section for the s-process abundance contributions in the Pb/Bi region are discussed., Comment: 8 pages, 3 figures, article submitted to Phys. Rev. C
Published: 2007

82. Status and outlook of the neutron time-of-flight facility

Author: Gunsing, F., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calvino, F., Cano-Ott, D., Capote, R., de Albornoz, A. C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillman, I., Dolfini, R., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Frais-Koelbl, H., Fujii, K., Furman, W., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kappeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lampoudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mengoni, A., Milazzo, P. M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Oshima, M., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.
Subjects: n-tof, elements, detector, neutrons, cern, n_tof, beam, time-of-flight, capture, spallation
Abstract: The neutron time-of-flight facility n_TOF at CERN, fully operational since 2002, combines a high instantaneous neutron flux with high energy resolution. The wide energy range and the high neutron flux per time-of-flight burst result in a much enhanced signal to background ratio for neutron capture of radioactive isotopes and makes this facility well suited for the measurement of high quality neutron-induced reaction cross-sections. Neutrons are created by spallation reactions induced by a pulsed 20 GeV/c proton beam impinging on a lead target. A 5 cm water slab surrounding the lead target serves as a coolant and at the same time as a moderator of the spallation neutron spectrum, providing a wide energy spectrum from 0.1 eV to about 250 MeV. By the end of 2005, a first phase of data taking has been successfully terminated. Fission and capture experiments have been performed on a variety of isotopes of interest for nuclear astrophysics, advanced nuclear technologies and for basic nuclear physics. The instrumentation developed for this facility consists of parallel plate avalanche counter and fission ionization chamber detectors for the fission experiments and of low mass C6D6 detectors and a 4 pi BaF2 total absorption calorimeter for capture experiments. A new data acquisition system, based on sampling of the detector signals, has been developed to cope with the high count rates and to minimize the effective dead time to only a few tens of nanosecond. A second phase of data taking is planned to start in 2007, after an upgrade of the spallation target. On the longer term, the construction of a flight path at 20 in resulting in an increased neutron flux of about a factor of 100 opens new possibilities. (c) 2007 Elsevier B.V. All rights reserved. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms
Published: 2007

83. The 139Lan,gamma cross section: Key for the onset of the s-process

Author: Terlizzi, R., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calviani, M., Calvino, F., Cano-Ott, D., Capote, R., De Albornoz, A.C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillmann, I., Dolfini, R., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, Anthony, Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kadi, Y., Kappeler, F., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Massimi, C., Mastinu, P., Mengoni, A., Milazzo, P.M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pignatari, M., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J.L., Tassan-Got, L., Tavora, L., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M.C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), nTOF, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: level density, Nuclear Theory, s and r process, FOS: Physical sciences, nucleosynthesis, 25.40.Lw, 26.20.+f, 27.60.+j, 97.10.Cv, Nuclear Experiment (nucl-ex), 139La, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, neutron capture, neutron strength function
Abstract: The nuclear resonance parameters and the capture cross section of the neutron magic isotope 139La has been measured n_TOF. The description of the experimental apparata is followed by the data analysis procedures. We extracted the resonance parameters, the main nuclear quantities such as the resonance integral, the average gamma widths for s- and p-waves, the nuclear level densities and the neutron strength functions. These results represent a signifcant improvement over previous data. The deduced Maxwellian-averaged capture cross sections are important for the interpretation of the most recent spectroscopic observations in low metallicity stars., Comment: 50 pages and 9 Figures
Published: 2007

84. New measurement of neutron capture resonances of 209Bi

Author: Domingo-Pardo, C., Abbondanno, U., Aerts, G., Alvarez-Pol, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calvino, F., Cano-Ott, D., Capote, R., Carrillode Albornoz, A., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillman, I., Dolfini, R., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Furman, W., Gallino, R., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kadi, Y., Kappeler, F., Karamanis, D., Karadimos, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Mastinu, P., Mengoni, A., Milazzo, P.M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., Oshima, M., O'Brien, S., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Tagliente, G., Tain, J.L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, Alberto, Villamarin, D., Vincente, M.C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.
Subjects: Nuclear Physics - Experiment, Nuclear Experiment
Abstract: The neutron capture cross section of Bi209 has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. Gamma-ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha-decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19(3)% of the solar bismuth abundance, resulting in an r-process residual of 81(3)%. The present (n,gamma) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target. The neutron capture cross section of Bi209 has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. Gamma-ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha-decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19(3)% of the solar bismuth abundance, resulting in an r-process residual of 81(3)%. The present (n,gamma) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target.
Published: 2006

85. Neutron capture cross section of Th-232 measured at the n_TOF facility at CERN in the unresolved resonance region up to 1 MeV

Author: Aerts, G, Abbondanno, U, Alvarez, H, Alvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Assimakopoulos, P, Audouin, L, Badurek, G, Baumann, P, Becvar, F, Walter, S, Calvino, F, Wendler, H, Wiescher, M, Wisshak, K, Cano-Ott, D, Capote, R, De Albornoz, AC, Cennini, P, Chepel, V, Embid-Segura, M, Chiaveri, E, Colonna, N, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, Solomon Arulraj, Dillman, I, Dolfini, R, Domingo-Pardo, C, Ferrant, L, Dridi, W, Duran, I, Eleftheriadis, C, Ferrari, A, Ferreira-Marques, R, Fitzpatrick, L, Frais-Koelbl, H, Fujii, K, Furman, W, Goncalves, I, Gonzalez-Romero, E, Kadi, Y, Goverdovski, A, Gramegna, F, Griesmayer, E, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Karadimos, D, Isaev, S, Jericha, E, Kappeler, F, Karamanis, D, Kerveno, M, Ketlerov, V, Koehler, P, Konovalov, V, Kossionides, E, Krticka, M, Lamboudis, C, Neves, F, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marques, L, Marrone, S, Mastinu, P, Mengoni, A, Oberhummer, H, Milazzo, PM, Moreau, C, Mosconi, M, O'Brien, S, Oshima, M, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, Nikolaos, Pavlik, A, Rudolf, G, Pavlopoulos, P, Perrot, L, Pigni, MT, Plag, R, Plompen, A, Plukis, A, Poch, A, Pretel, C, Quesada, J, Rauscher, T, Rullhusen, P, Reifarth, R, Rosetti, M, Rubbia, C, Salgado, J, Sarchiapone, L, Savvidis, I, Stephan, C, Taliente, G, Tain, JL, Tassan-Got, L, Tavora, L, Berthoumieux, E, Terlizzi, R, Vannini, G, Vaz, P, Ventura, A, Villamarin, D, Vincente, MC, Vlachoudis, V, Vlastou, R, and Voss, F
Subjects: parameters, elements, u-238, accelerator, range, system, Nuclear Experiment, transmutation, compound nucleus, parity violation
Abstract: We have measured the neutron capture reaction yield of Th-232 at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The average capture cross section has been extracted in the energy range from 4 keV up to 1 MeV with an overall accuracy better than 4%. An independent IAEA evaluation shows good agreement with the data. The average cross section has been expressed in terms of average resonance parameters using the partial waves l=0,1, and 2. ispartof: Physical Review. C, Nuclear physics vol:73 issue:5 pages:1-10 status: published
Published: 2006

86. Neutron capture cross section of Th-232 measured at the n_TOF facility at CERN in the unresolved resonance region up to 1 MeV

Author: Aerts, G., Abbondanno, U., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calvino, F., Cano-Ott, D., Capote, R., De Albornoz, A. C., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillman, I., Dolfini, R., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Furman, W., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Kappeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Mastinu, P., Mengoni, A., Milazzo, P. M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Oshima, M., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M. T., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Taliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., and n TOF Collaboration
Subjects: parameters, elements, u-238, accelerator, range, system, transmutation, compound nucleus, parity violation
Abstract: We have measured the neutron capture reaction yield of Th-232 at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The average capture cross section has been extracted in the energy range from 4 keV up to 1 MeV with an overall accuracy better than 4%. An independent IAEA evaluation shows good agreement with the data. The average cross section has been expressed in terms of average resonance parameters using the partial waves l=0,1, and 2. Physical Review C
Published: 2006

87. Measurement of the 151Sm n,gamma cross section from 0.6 eV to 1 MeV via the neutron time-of-flight technique at the CERN n_TOF facility

Author: Marrone, S., Abbondanno, U., Aerts, G., Alvarez-Velarde, F., Alvarez-Pol, H., Andriamonje, S., Andrzejewski, J., Badurek, G., Baumann, P., Bevá, F., Benlliure, J., Berthomieux, E., Calviño, F., Cano-Ott, D., Capote, R., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Cortina, D., Couture, A., Cox, J., Dababneh, S., Dahlfors, M., David, S., Dolfini, R., Domingo-Pardo, C., Duran-Escribano, I., Embid-Segura, M., Ferrant, L., Ferrari, Anthony, Ferreira-Marques, R., Frais-Koelbl, H., Fujii, K., I. Furman, W., Gallino, R., F. Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Isaev, S., Jericha, E., Käppeler, F., Kadi, Y., Karadimos, D., Kerveno, M., Ketlerov, V., E. Koehler, P., Konovalov, V., Kritka, M., Lamboudis, C., Leeb, H., Lindote, A., I. Lopes, M., Lozano, M., Lukic, S., Marganiec, J., Martinez-Val, J., F. Mastinu, P., Mengoni, A., M. Milazzo, P., Molina-Coballes, A., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papaevangelou, T., Paradela, C., Pavlik, A., Pavlopoulos, P., M. Perlado, J., Perrot, L., Pignatari, M., Pigni, M.T., Plag, R., Plompen, A., Plukis, A., Poch, A., Policarpo, A., Pretel, C., M. Quesada, J., Raman, S., Rapp, W., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., C. Soares, J., Stephan, C., Tagliente, G., Tain, J.L., Tassan-Got, L., Tavora, L.M.N., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin-Fernandez, D., Vincente-Vincente, M., Vlachoudis, V., Voss, F., Wendler, H., Wiescher, M., Wisshak, K., Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), nTOF, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 25.40.Lw, 26.20.+f, 27.70.+q, 28.41.Ak
Abstract: PACS; The 151Sm n,\gamma cross section was measured with the time-of-flight technique from 0.6 eV up to 1 MeV relative to the Au standard with an overall uncertainty of typically 6%. Neutrons were produced by spallation at the innovative n_TOF facility at CERN; the \gamma rays from capture events were detected with organic C_(6)D_(6)scintillators. Experimental setup and data analysis procedures are described with emphasis on the corrections for detection efficiency, background subtraction, and neutron flux determination. At low energies, resonances could be resolved up to about 1 keV, yielding a resonance integral of 3575±210 b, an average s-wave resonance spacing of langleD_(0)\rangle$=1.49±0.07 eV, and a neutron strength function of langleS_(0)\rangle=(3.87±0.33)×10-4. Maxwellian-averaged capture cross sections are reported for thermal energies between 5 and 100 keV. These results are of relevance for nuclear structure studies, nuclear astrophysics, and nuclear technology. The new value of the Maxwellian-averaged cross section at kT=30 keV is 3.08±0.15 b, considerably larger than previous theoretical estimates, and provides better constraints for the thermodynamic conditions during the occurrence of the it slow neutron capture process in low-mass stars during their asymptotic giant branch phase.
Published: 2006

88. Neutron capture cross section of 232Th measured at the n_TOF facility at CERN in the unresolved resonance region up to 1 MeV

Author: Aerts, G., Abbondanno, U., Álvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Baumann, P., Be Vá, F., Berthoumieux, E., Calviño, F., Cano-Ott, D., Capote, R., Carrillo De Albornoz, A., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Dillman, I., Dolfini, R., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, Anthony, Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Furman, W., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Guerrero, C., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Igashira, M., Isaev, S., Jericha, E., Käppeler, F., Kadi, Y., Karadimos, D., Karamanis, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Kossionides, E., Krti Ka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Mastinu, P., Mengoni, A., Milazzo, P.M., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Oshima, M., Pancin, J., Papachristodoulou, C., Papadopoulos, C., Paradela, C., Patronis, N., Pavlik, A., Pavlopoulos, P., Perrot, L., Pigni, M.T., Plag, R., Plompen, A., Plukis, A., Poch, A., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Sarchiapone, L., Savvidis, I., Stephan, C., Taliente, G., Tain, J.L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M.C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), nTOF, Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: 25.40.Lw, 25.40.Ny, 28.20.Fc, Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: We have measured the neutron capture reaction yield of 232Th$ at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The average capture cross section has been extracted in the energy range from 4 keV up to 1 MeV with an overall accuracy better than 4%. An independent IAEA evaluation shows good agreement with the data. The average cross section has been expressed in terms of average resonance parameters using the partial waves \ell =0,1, and 2.
Published: 2006

89. New measurement of neutron capture resonances in 209Bi

Author: DOMINGO-PARDO, C., ABBONDANNO, U., AERTS, G., ALVAREZ-POL, H., ALVAREZ-VELARDE, F., ANDRIAMONJE, S., ANDRZEJEWSKI, J., ASSIMAKOPOULOS, P., AUDOUIN, L., BADUREK, G., BAUMANN, P., BECVAR, F., BERTHOUMIEUX, E., CALVINO, F., CANO-OTT, D., CAPOTE, R., DE ALBORNOZ, A.C., CENNINI, P., CHEPEL, V., CHIAVERI, E., COLONNA, N., CORTES, G., COUTURE, A., COX, J., DAHLFORS, M., DAVID, S., DILLMAN, I., DOLFINI, R., DRIDI, W., DURAN, I., ELEFTHERIADIS, C., EMBID-SEGURA, M., FERRANT, L., FERRARI, Anthony, FERREIRA-MARQUES, R., FITZPATRICK, L., FRAIS-KOELBL, H., FUJII, K., FURMAN, W., GALLINO, R., GONCALVES, I., GONZALEZ-ROMERO, E., GOVERDOVSKI, A., GRAMEGNA, F., GRIESMAYER, E., GUERRERO, C., GUNSING, F., HAAS, B., HAIGHT, R., HEIL, M., HERRERA-MARTINEZ, A., IGASHIRA, M., ISAEV, S., JERICHA, E., KADI, Y., KAPPELER, F., KARAMANIS, D., KARADIMOS, D., KERVENO, M., KETLEROV, V., KOEHLER, P., KONOVALOV, V., KOSSIONIDES, E., KRTICKA, M., LAMBOUDIS, C., LEEB, H., LINDOTE, A., LOPES, I., LOZANO, M., LUKIC, S., MARGANIEC, J., MARQUES, L., MARRONE, S., MASTINU, P., MENGONI, A., MILAZZO, P.M., MOREAU, C., MOSCONI, M., NEVES, F., OBERHUMMER, H., OSHIMA, M., O'BRIEN, S., PANCIN, J., PAPACHRISTODOULOU, C., PAPADOPOULOS, C., PARADELA, C., PATRONIS, N., PAVLIK, A., PAVLOPOULOS, P., PERROT, L., PLAG, R., PLOMPEN, A., PLUKIS, A., POCH, A., PRETEL, C., QUESADA, J., RAUSCHER, T., REIFARTH, R., ROSETTI, M., RUBBIA, C., RUDOLF, G., RULLHUSEN, P., SALGADO, J., SARCHIAPONE, L., SAVVIDIS, I., STEPHAN, C., TAGLIENTE, G., TAIN, J.L., TASSAN-GOT, L., TAVORA, L., TERLIZZI, R., VANNINI, G., VAZ, P., VENTURA, A., VILLAMARIN, D., VINCENTE, M.C., VLACHOUDIS, V., VLASTOU, R., VOSS, F., WALTER, S., WENDLER, H., WIESCHER, M., WISSHAK, K., Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), European Organization for Nuclear Research (CERN), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Pôle Universitaire Léonard de Vinci (PôLE UNIVERSITAIRE LéONARD DE VINCI), Pôle Universitaire Léonard de Vinci (PULV), nTOF, Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), C.Domingo-Pardo, U.Abbondanno, G.Aert, H.Alvarez-Pol, F.Alvarez-Velarde, S.Andriamonje, J.Andrzejewski, P.Assimakopoulo, L.Audouin, G.Badurek, P.Baumann, F.Becvar, E.Berthomieux, F.Calvino, D.Cano-Ott, R.Capote, A.Carrillo de Albornoz, P.Cennini, V.Chepel, E.Chiaveri, N.Colonna, G.Corte, A.Couture, J.Cox, M.Dahlfor, S.David, I.Dilmann, R.Dolfini, W.Dridi, I.Duran, C.Eleftheriadi, M.Embid-Segura, L.Ferrant, A.Ferrari, R.Ferreira-Marque, L.Fritzpatrick, H.Frais-Koelbl, K.Fujii, W.Furman, R.Gallino, I.Goncalve, E.Gonzalez-Romero, A.Goverdovski, F.Gramegna, E.Griesmayer, C.Guerrero, F.Gunsing, B.Haa, R.Haight, M.Heil, A.Herrera-Martinez, M.Igashira, S.Isaev, E.Jericha, Y.Kadi, F.Käppeler, D.Karamani, D.Karadimo, M.Kerveno, V.Ketlerov, P.E.Koehler, V.Konovalov, E.Kossionide, M.Krticka, C.Lamboudi, H.Leeb, A.Lindote, I.Lope, M.Lozano, S.Lukic, J.Marganiec, L.Marque, S.Marrone, P.Mastinu, A.Mengoni, P.M.Milazzo, C.Moreau, M.Mosconi, F.Neve, H.Oberhummer, M.Oshima, S.O'Brien, J.Pancin, C.Papachristodoulou, C.Papadopoulo, C.Paradela, N.Patroni, A.Pavlik, P.Pavlopoulo, L.Perrot, R.Plag, A.Plompen, A.Pluki, A.Poch, C.Pretel, J.Quesada, T.Rauscher, R.Reifarth, M.Rosetti, C.Rubbia, G.Rudolf, P.Rullhusen, J.Salgado, L.Sarchiapone, I.Savvidi, C.Stephan, G.Tagliente, J.L.Tain, L.Tassan-Got, L.Tavora, R.Terlizzi, G.Vannini, P.Vaz, A.Ventura, D.Villamarin, M.C.Vincente, V.Vlachoudi, R.Vlastou, F.Vo, S.Walter, H.Wendler, and M.Wiescher and K. Wisshak
Subjects: 25.40.Lw, 25.40.Sc, 27.80.+w, 97.10.Cv, GALACTIC CHEMICAL EVOLUTION, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], ABUNDANCES, ELEMENTS, FACILITY, Nuclear Experiment (nucl-ex), Nuclear Experiment, CROSS-SECTION, S-PROCESS, DETECTOR, CHRONOMETERS, SYSTEM, STARS
Abstract: The neutron capture cross section of Bi209 has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. Gamma-ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha-decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19(3)% of the solar bismuth abundance, resulting in an r-process residual of 81(3)%. The present (n,gamma) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target., 10 pages, 5figures, recently published in Phys. Rev. C
Published: 2006

90. Resonance capture cross section of Pb-207

Author: Sarchiapone, L., Savvidis, I., Kerveno, M., Stephan, C., Tagliente, G., Koehler, P., Rubbia, C., Ketlerov, V., Rudolf, G., Kossionides, E., Rullhusen, P., Goncalves, I., Gallino, R., Ferreira-Marques, R., Fitzpatrick, L., Frais-Koelbl, H., Fujii, K., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Poch Parés, Agustí, Duran, I., Dridi, W., Dolfini, R., David, S., Dillmann, I., Cox, J., Dahlfors, M., Colonna, N., Couture, A., Chiaveri, E., Perrot, L., Cortés Rossell, Guillem Pere, Rosetti, M., Reifarth, R., Plompen, A., Plag, R., Quesada, J., Rauscher, T., Pretel Sánchez, Carme, Plukis, A., Pavlopoulos, P., Pavlik, A., Patronis, N., Mosconi, M., Pancin, J., Wisshak, K., Papachristodoulou, C., Wiescher, M., Papadopoulos, C., Paradela, C., The nTOF Collaborat, Oberhummer, H., Oshima, M., O'Brien, S., Wendler, H., Moreau, C., Milazzo, P.M., Neves, F., Voss, F., Cennini, P., Carrapico, C., Mastinu, P., Capote, R., Mengoni, A., Cano-Ott, D., Marganiec, J., Bisterzo, S., Konovalov, V., Marrone, S., Calviño Tavares, Francisco, Lozano, M., Berthoumieux, E., Lukic, S., Becvar, F., Baumann, P., Badurek, G., Chepel, V., Lopes, I., Salgado, J., Lindote, A., Leeb, H., Lamboudis, C., Krticka, M., Tain, J.L., Tassan-Got, L., Audouin, L., Isaev, S., Domingo-Pardo, C., Jericha, E., Abbondanno, U., Kadi, Y., Aerts, G., Kaeppeler, F., Álvarez-Pol, H., Karamanis, D., Álvarez-Velarde, F., Karadimos, D., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Vlachoudis, V., Vlastou, R., Villamarin, D., Vincente, M.C., Igashira, M., Vaz, P., Herrera-Martinez, A., Ventura, A., Heil, M., Terlizzi, R., Haight, R., Vannini, G., Walter, S., Gramegna, F., Tavora, L., Griesmayer, E., Gonzalez-Romero, E., Goverdovski, A., Haas, B., Guerrero, C., Gunsing, F., Furman, W., Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear, and Universitat Politècnica de Catalunya. GREENER - Grup de recerca d'estudis energètics i de les radiacions
Subjects: Estels -- Estructura, Física [Àrees temàtiques de la UPC], Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Radiative capture, Stars -- Structure, Radiació
Abstract: The radiative neutron capture cross section of 207Pb has been measured at the CERN neutron time of flight installation n TOF using the pulse height weighting technique in the resolved energy region. The measurement has been performed with an optimized setup of two C6D6 scintillation detectors, which allowed us to reduce scattered neutron backgrounds down to a negligible level. Resonance parameters and radiative kernels have been determined for 16 resonances by means of an R-matrix analysis in the neutron energy range from 3 keV to 320 keV. Good agreement with previous measurements was found at low neutron energies, whereas substantial discrepancies appear beyond 45 keV. With the present results, we obtain an s-process contribution of 77±8% to the solar abundance of 207Pb. This corresponds to an r-process component of 23 ± 8%, which is important for deriving the U/Th ages of metal poor halo stars.
Published: 2006
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91. Astrophysical Implications of the $^{139}La(n,\gamma)$ and $^{151}Sm(n,\gamma)$ Cross Sections Measured at n_TOF

Author: Marrone, S, Abbondanno, U, Aarts, G, Álvarez-Pol, H, Alvarez-Velarde, F, Andriamonje, Samuel A, Andrzejewski, J, Assimakopoulos, Panayiotis, Audouin, L, Badurek, G, Baumann, P, Becvár, F, Berthoumieux, E, Calviño, F, Cano-Ott, D, Capote, R, Carrapiço, C, Cennini, P, Chepel, V, Chiaveri, Enrico, Colonna, N, Cortés, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillmann, I, Dolfini, R, Domingo-Pardo, C, Dridi, W, Durán, I, Eleftheriadis, C, Embid-Segura, M, Ferrant, L, Ferrari, A, Ferreira-Marques, R, Fitzpatrick, L, Frais-Kölbl, H, Fujii, K, Furman, W, Gallino, R, Gonçalves, I, Gonzalez-Romero, E, Goverdovski, A, Gramegna, F, Griesmayer, E, Guerrero, C, Gunsing, F, Haas, B, Haight, R C, Heil, M, Herrera-Martínez, A, Igashira, M, Isaev, S, Jericha, E, Kadi, Y, Käppeler, F, Karamanis, D, Karadimos, D, Kerveno, M, Ketlerov, V, Köhler, P, Konovalov, V, Kossionides, E, Krticka, M, Lamboudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Mastinu, P, Mengoni, A, Milazzo, P M, Moreau, C, Mosconi, M, Neves, F, Oberhummer, Heinz, O'Brien, S, Oshima, M, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, N, Pavlik, A, Pavlopoulos, P, Perrot, L, Pignatari, M, Plag, R, Plompen, A, Plukis, A, Poch, A, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rosetti, M, Rubbia, Carlo, Rudolf, G, Rullhusen, P, Salgado, J, Sarchiapone, L, Savvidis, I, Stéphan, C, Tagliente, G, Taín, J L, Tassan-Got, L, Tavora, L, Terlizzi, R, Vannini, G, Vaz, P, Ventura, A, Villamarín, D, Vincente, M C, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wendler, H, Wiescher, M, and Wisshak, K
Subjects: Astrophysics and Astronomy
Published: 2006

92. New measurement of neutron capture resonances in Bi-209

Author: Domingo-Pardo, C, Abbondanno, U, Aerts, G, Alvarez-Pol, H, Alvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Assimakopoulos, P, Audouin, L, Badurek, G, Baumann, P, Rudolf, G, Rullhusen, P, Salgado, J, Sarchiapone, L, Savvidis, I, Stephan, C, Tagliente, G, Tain, JL, Tassan-Got, L, Tavora, L, Becvar, F, Terlizzi, R, Vannini, G, Vaz, P, Ventura, A, Villamarin, D, Vincente, MC, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Berthoumieux, E, Wendler, H, Wiescher, M, Wisshak, K, Calvino, F, Cano-Ott, D, Capote, R, de Albornoz, A Carrillo, Cennini, P, Chepel, V, Chiaveri, E, Colonna, N, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, Solomon Arulraj, Dillman, I, Dolfini, R, Dridi, W, Duran, I, Eleftheriadis, C, Embid-Segura, M, Ferrant, L, Ferrari, A, Ferreira-Marques, R, Fitzpatrick, L, Frais-Koelbl, H, Fujii, K, Furman, W, Gallino, R, Goncalves, I, Gonzalez-Romero, E, Goverdovski, A, Gramegna, F, Griesmayer, E, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Isaev, S, Jericha, E, Kadi, Y, Kappeler, F, Karamanis, D, Karadimos, D, Kerveno, M, Ketlerov, V, Koehler, P, Konovalov, V, Kossionides, E, Krticka, M, Lamboudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marques, L, Marrone, S, Mastinu, P, Mengoni, A, Milazzo, PM, Moreau, C, Mosconi, M, Neves, F, Oberhummer, H, Oshima, M, O'Brien, S, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, Nikolaos, Pavlik, A, Pavlopoulos, P, Perrot, L, Plag, R, Plompen, A, Plukis, A, Poch, A, Pretel, C, Quesada, J, Rauscher, T, Reifarth, R, Rosetti, M, and Rubbia, C
Subjects: cross-section, stars, elements, facility, detector, abundances, system, Nuclear Experiment, galactic chemical evolution, s-process, chronometers
Abstract: The neutron capture cross section of Bi-209 has been measured at the CERN n_TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. gamma-Ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi-209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19 +/- 3% of the solar bismuth abundance, resulting in an r-process residual of 81 +/- 3%. The present (n,gamma) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target. ispartof: Physical Review. C, Nuclear physics vol:74 issue:2 pages:1-10 status: published
Published: 2006

93. Resonance capture cross section of Pb-207

Author: Domingo-Pardo, C, Abbondanno, U, Aerts, Goele, Alvarez-Pol, H, Alvarez-Velarde, F, Andriamonje, S, Andrzejewski, J, Assimakopoulos, P, Audouin, L, Badurek, G, Baumann, P, Mosconi, M, Neves, F, Oberhummer, H, Oshima, M, O'Brien, S, Pancin, J, Papachristodoulou, C, Papadopoulos, C, Paradela, C, Patronis, Nikolaos, Rudolf, G, Pavlik, A, Pavlopoulos, P, Perrot, L, Plag, R, Plompen, A, Plukis, A, Poch, A, Pretel, C, Quesada, J, Rauscher, T, Rullhusen, P, Reifarth, R, Rosetti, M, Rubbia, C, Salgado, J, Sarchiapone, L, Savvidis, I, Stephan, C, Tagliente, G, Tain, JL, Tassan-Got, L, Tavora, L, Becvar, F, Terlizzi, R, Vannini, G, Vaz, P, Ventura, A, Villamarin, D, Vincente, MC, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Berthoumieux, E, Wendler, H, Wiescher, M, Wisshak, K, Bisterzo, S, Calvino, F, Cano-Ott, D, Capote, R, Carrapico, C, Cennini, P, Chepel, V, Chiaveri, E, Colonna, N, Cortes, G, Couture, A, Cox, J, Dahlfors, M, David, S, Dillman, I, Dolfini, R, Dridi, W, Duran, I, Eleftheriadis, C, Embid-Segura, M, Ferrant, L, Ferrari, A, Ferreira-Marques, R, Fitzpatrick, L, Frais-Koelbl, H, Fujii, K, Furman, W, Gallino, R, Goncalves, I, Gonzalez-Romero, E, Goverdovski, A, Gramegna, F, Griesmayer, E, Guerrero, C, Gunsing, F, Haas, B, Haight, R, Heil, M, Herrera-Martinez, A, Igashira, M, Isaev, S, Jericha, E, Kadi, Y, Kaeppeler, F, Karamanis, D, Karadimos, D, Kerveno, M, Ketlerov, V, Koehler, P, Konovalov, V, Kossionides, E, Krticka, M, Lamboudis, C, Leeb, H, Lindote, A, Lopes, I, Lozano, M, Lukic, S, Marganiec, J, Marrone, S, Mastinu, P, Mengoni, A, Milazzo, PM, and Moreau, C
Subjects: elements, abundances, nucleosynthesis, giant branch stars, galactic chemical evolution, neutron-capture, solar, chronometers
Abstract: The radiative neutron capture cross section of Pb-207 has been measured at the CERN neutron time of flight installation n_TOF using the pulse height weighting technique in the resolved energy region. The measurement has been performed with an optimized setup of two C6D6 scintillation detectors, which allowed us to reduce scattered neutron backgrounds down to a negligible level. Resonance parameters and radiative kernels have been determined for 16 resonances by means of an R-matrix analysis in the neutron energy range from 3 keV to 320 keV. Good agreement with previous measurements was found at low neutron energies, whereas substantial discrepancies appear beyond 45 keV. With the present results, we obtain an s-process contribution of 77 +/- 8% to the solar abundance of Pb-207. This corresponds to an r-process component of 23 +/- 8%, which is important for deriving the U/Th ages of metal poor halo stars. ispartof: Physical Review. C, Nuclear physics vol:74 issue:5 status: published
Published: 2006

94. Time-energy relation of the n_TOF neutron beam: Energy standards revisited

Author: Lorusso, G. Colonna, N. Marrone, S. Tagliente, G. Heil, M. Cano-Ott, D. Mosconi, M. Moreau, C. Mengoni, A. Abbondanno, U. Aerts, G. Alvarez-Pol, H. Alvarez-Velarde, F. Andriamonje, S. Andrzejewski, J. Angelopoulos, A. Assimakopoulos, P. Badurek, G. Baumann, P. Bečvár, F. Benlliure, J. Berthomieux, E. Bisceglie, E. Calviño, P. Capote, R. Cennini, P. Chepel, V. Chiaveri, E. Coceva, C. Cortes, G. Cortina, D. Couture, A. Cox, J. Dababneh, S. Dahlfors, M. David, S. Dolfini, R. Domingo-Pardo, C. Duran, I. Eleftheriadis, C. Embid-Segura, M. Ferrant, L. Ferrari, A. Ferreira-Marques, R. Frais-Koelbl, H. Furman, W.I. Goncalves, I.F. Gonzalez-Romero, E. Goverdovski, A. Gramegna, F. Griesmayer, E. Gunsing, F. Haas, B. Haight, R. Herrera-Martinez, A. Ioannides, K.G. Isaev, S. Jericha, E. Käppeler, F. Kadi, Y. Karamanis, D. Ketlerov, V. Kitis, G. Koehler, P.E. Konovalov, V. Kossionides, E. Krticka, M. Leeb, H. Lindote, A. Lopes, M.I. Lozano, M. Lukic, S. Marganiec, J. Mastinu, P.F. Milazzo, P.M. Molina-Coballes, A. Neves, F. Oberhummer, H. O'Brien, S. Pancin, J. Paradela, C. Pavlik, A. Pavlopoulos, P. Perrot, L. Peskov, V. Plag, R. Plompen, A. Plukis, A. Poch, A. Policarpo, A. Pretel, C. Quesada, J.M. Rapp, W. Rauscher, T. Reifarth, R. Rosetti, M. Rubbia, C. Rudolf, G. Rullhusen, P. Salgado, J. Savvidis, E. Soares, J.C. Stephan, C. Tain, J.L. Tassan-Got, L. Tavora, L.M.N. Terlizzi, R. Tsangas, N. Vannini, G. Vaz, P. Ventura, A. Villamarin, D. Vincente, M.C. Vlachoudis, V. Vlastou, R. Voss, F. Wendler, H. Wiescher, M. Wisshak, K.
Subjects: Physics::Accelerator Physics, Nuclear Experiment
Abstract: The accurate determination of neutron cross-sections as a function of the neutron energy at a time-of-flight facility requires a precise knowledge of the time-energy relation for the neutron beam. For the n_TOF neutron beam at CERN, produced by spallation of high-energy protons on a Pb target, the time-energy relation is connected to the production mechanism and to the subsequent moderation process. A calibration of the neutron energy scale is proposed based on detailed Monte Carlo simulations of the facility. This time-energy relation has been experimentally validated by means of dedicated measurements of standard energy resonances, from 1eV to approximately 1MeV. On the basis of the present measurements, it is proposed to correct the energy of the 1.3eV resonance of 193Ir, which is commonly considered as an energy standard. © 2004 Elsevier B.V. All rights reserved.
Published: 2004

95. Measurement of the n_TOF beam profile with a micromegas detector

Author: Pancin, J. Abbondanno, U. Aerts, G. Alvarez, H. Andriamonje, S. Angelopoulos, A. Assimakopoulos, P. Bacri, C. Badurek, G. Baumann, P. Bečvář, F. Beer, H. Benlliure, J. Berthier, B. Berthoumieux, E. Boffi, S. Borcea, C. Boscolo-Marchi, E. Bustreo, N. Calvino, F. Cano-ott, D. Capote, R. Carlson, P. Cennini, P. Chepel, V. Chiaveri, E. Colonna, N. Cortes, G. Cortina, D. Couture, A. Cox, J. Dababneh, S. Dahlfors, M. David, S. Delbart, A. Derre, J. Dolfini, R. Domingo, C. Duran-Escribano, I. Eleftheriadis, C. Embid-Segura, M. Ferrant, L. Ferrari, A. Ferreira-Lourenco, L. Ferreiramarques, R. Frais-Koelbl, H. Furman, W. Giomataris, Y. Goncalves, I. Gonzalez-Romero, E. Goverdovski, A. Gramegna, F. Griesmayer, E. Gunsing, F. Haight, R. Heil, M. Herrera-Martinez, A. Ioannides, K. Janeva, N. Jeanneau, F. Jericha, E. Käppeler, F. Kadi, Y. Karamanis, D. Kelic, A. Ketlerov, V. Kitis, G. Koehler, P. Konovalov, V. Kossionides, E. Lacoste, V. Leeb, H. Lindote, A. Lopes, I. Lozano, M. Lukic, S. Markov, S. Marrone, S. Martinez-Val, J. Mastinu, P. Mengoni, A. Milazzo, P. Minguez, E. Molina-Coballes, A. Moreau, C. Neves, F. Oberhummer, H. O'brien, S. Papadopoulos, I. Papavengelou, T. Paradela, C. Pavlik, A. Pavlopoulos, P. Perez-Parra, A. Perlado, J. Peskov, V. Perrot, L. Peskov, V. Plag, R. Plompen, A. Plukis, A. Poch, A. Policarpo, A. Pretel, C. Quesada, J. Radici, M. Raman, S. Rapp, W. Reifarth, R. Rejmund, F. Rosetti, M. Rubbia, C. Rudolf, G. Rullhusen, P. Salgado, J. Savvidis, E. Stephan, C. Tagliente, G. Tain, J. Tapia, C. Tassan-Got, L. Tavora, L. Terlizzi, R. Terrani, M. Tsangas, N. Vannini, G. Vaz, P. Ventura, A. Villamarin-Fernandez, D. Vincente-Vincente, M. Vlachoudis, V. Vlastou, R. Voss, F. Wendler, H. Wiescher, M. Wisshak, K. Zanini, L.
Subjects: Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Nuclear Experiment
Abstract: A Micromegas detector was used in the neutron Time-Of-Flight (n_TOF) facility at CERN to evaluate the spatial distribution of the neutron beam as a function of its kinetic energy. This was achieved over a large range of neutron energies by using two complementary processes: at low energy by capture of a neutron via the 6Li(n,α)t reaction, and at high energy by elastic scattering of neutrons on gas nuclei (argon+isobutane or helium+isobutane). Data are compared to Monte Carlo simulations and an analytic function fitting the beam profile has been calculated with a sufficient precision to use in neutron capture experiments at the n_TOF facility. © 2004 Elsevier B.V. All rights reserved.
Published: 2004

96. Neutron capture cross section measurement of $^{151}$Sm at the CERN neutron time of flight facility (n_TOF)

Author: Abbondanno, U., Aerts, G., Alvarez-Velarde, F., Alvarez-Pol, H., Andriamonje, S., Andrzejewski, J., Badurek, G., Baumann, P., Becvar, F., Benlliure, J., Berthoumieux, E., Calvino, F., Cano-Ott, D., Capote, R., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Cortina, D., Couture, A., Cox, J., Dababneh, S., Dahlfors, M., David, S., Dolfini, R., Domingo-Pardo, C., Duran, I., Embid-Segura, M., Ferrant, L., Ferrari, Anthony, Ferreira-Marques, R., Frais-Koelbl, H., Furman, W., Goncalves, I., Gallino, R., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Gunsing, F., Haas, B., Haight, R., Heil, M., Herrera-Martinez, A., Isaev, S., Jericha, E., Käppeler, F., Kadi, Y., Kardimos, D., Kerveno, M., Ketlerov, V., Koehler, P., Konovalov, V., Krticka, M., Lamboudis, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marrone, S., Martinez-Val, J., Mastinu, P., Mengoni, A., Milazzo, P.M., Molina-Coballes, A., Moreau, C., Mosconi, M., Neves, F., Oberhummer, H., O'Brien, S., Pancin, J., Papaevangelou, T., Paradela, C., Pavlik, A., Pavlopoulos, P., Perlado, J.M., Perrot, L., Pignatari, M., Plag, R., Plompen, A., Plukis, A., Poch, A., Policarpo, A., Pretel, C., Quesada, J., Raman, S., Rapp, W., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Ruhlhusen, P., Salgado, J., Soares, J.C., Stephan, C., Tagliente, G., Tain, J., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vincente, M.C., Vlachoudis, V., Voss, F., Wendler, H., Wiescher, M., Wisshak, K., Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and TOF
Subjects: ComputingMethodologies_PATTERNRECOGNITION, TheoryofComputation_COMPUTATIONBYABSTRACTDEVICES, 25.40.L.w, 26.20.+f,27.70.+q,97.10.Cv, TheoryofComputation_GENERAL, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], ComputingMethodologies_ARTIFICIALINTELLIGENCE, Nuclear Physics
Abstract: The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions.
Published: 2004

97. A low-mass neutron flux monitor for the n_TOF facility at CERN

Author: Mastinu, P.F. Abbondanno, U. Aerts, G. Alvarez, H. Andriamonje, S. Angelopoulos, A. Assimakopoulos, P. Bacri, C.O. Badurek, G. Baumann, P. Bečvář, F. Beer, H. Benlliure, J. Berthier, B. Berthomieux, E. Boffi, S. Borcea, C. Boscolo-Marchi, E. Bustreo, N. Calviño, P. Cano-Ott, D. Capote, R. Carlson, P. Cennini, P. Chepel, V. Chiaveri, E. Coceva, C. Colonna, N. Cortes, G. Cortina, D. Couture, A. Cox, J. Dababneh, S. Dahlfors, M. David, S. Dolfini, R. Domingo-Pardo, C. Duran, I. Eleftheriadis, C. Embid-Segura, M. Ferrant, L. Ferrari, A. Ferreira-Lourenco, L. Ferreira-Marques, R. Frais-Koelbl, H. Furman, W.I. Giomataris, Y. Goncalves, I.F. Gonzalez-Romero, E. Goverdovski, A. Gramegna, F. Griesmayer, E. Gunsing, F. Haight, R. Heil, M. Herrera-Martinez, A. Ioannides, K.G. Janeva, N. Jericha, E. Käppeler, F. Kadi, Y. Karamanis, D. Kelic, A. Ketlerov, V. Kitis, G. Koehler, P.E. Konovalov, V. Kossionides, E. Lacoste, V. Leeb, H. Lindote, A. Lopes, M.I. Loriggiola, M. Lozano, M. Lukic, S. Markov, S. Marigo, S. Marrone, S. Martinez-Val, J. Mengoni, A. Milazzo, P.M. Minguez, E. Molina-Coballes, A. Moreau, C. Neves, F. Oberhummer, H. O'Brien, S. Pancin, J. Papaevangelou, T. Paradela, C. Pavlik, A. Pavlopoulos, P. Perez-Parra, A. Perlado, J.M. Perrot, L. Peskov, V. Plag, R. Plompen, A. Plukis, A. Poch, A. Policarpo, A. Pretel, C. Quesada, J.M. Radici, M. Raman, S. Rapp, W. Rauscher, T. Reifarth, R. Rejmund, F. Rosetti, M. Rubbia, C. Rudolf, G. Rullhusen, P. Salgado, J. Savvidis, E. Soares, J.C. Stephan, C. Tagliente, G. Tain, J.L. Tapia, C. Tassan-Got, L. Tavora, L.M.N. Terlizzi, R. Terrani, M. Tsangas, N. Vannini, G. Vaz, P. Ventura, A. Villamarin-Fernandez, D. Vincente-Vincente, M. Vlachoudis, V. Vlastou, R. Voss, F. Wendler, H. Wiescher, M. Wisshak, K. Zanini, L.
Subjects: Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Physics::Accelerator Physics, Nuclear Experiment
Abstract: A small-mass system has been developed for monitoring the flux of neutrons with energy up to 1 MeV at the new time-of-flight facility at CERN, n_TOF. The monitor is based on a thin Mylar foil with a 6Li deposit, placed in the neutron beam, and an array of Silicon detectors, placed outside the beam, for detecting the products of the 6Li(n, α)3H reaction. The small amount of material on the beam ensures a minimal perturbation of the flux and minimizes the background related to scattered neutrons. Moreover, a further reduction of the γ-ray background has been obtained by constructing the scattering chamber hosting the device in carbon fibre. A detailed description of the flux monitor is here presented, together with the characteristics of the device, in terms of efficiency, resolution and induced background. The use of the monitor in the measurement of neutron capture cross-sections at n-TOF is discussed.
Published: 2004

98. A low-mass neutron flux monitor for the n_TOF facility at CERN

Author: Mastinu, Pf, Abbondanno, U., Aerts, G., Alvarez, H., Andriamonje, S., Angelopoulos, A., Assimakopoulos, P., Bacri, Co, Badurek, G., Baumann, P., Becvar, F., Beer, H., Benlliure, J., Berthier, B., Berthomieux, E., Boffi, S., Borcea, C., Boscolo-Marchi, E., Bustreo, N., Calvino, P., Cano-Ott, D., Capote, R., Carlson, P., Cennini, P., Chepel, V., Chiaveri, E., Coceva, C., Colonna, N., Cortes, G., Cortina, D., Couture, A., Cox, J., Dababneh, S., Dahlfors, M., David, S., Dolfini, R., Domingo-Pardo, C., Duran, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Lourenco, L., Ferreira-Marques, R., Frais-Koelbl, H., Furman, Wi, Giomataris, Y., Goncalves, If, Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Gunsing, F., Haight, R., Heil, M., Herrera-Martinez, A., Ioannides, Kg, Janeva, N., Jericha, E., Kappeler, F., Kadi, Y., Karamanis, D., Kelic, A., Ketlerov, V., Kitis, G., Koehler, Pe, Konovalov, V., Kossionides, E., Lacoste, V., Leeb, H., Lindote, A., Lopes, Mi, Loriggiola, M., Lozano, M., Lukic, S., Markov, S., Marigo, S., Marrone, S., Martinez-Val, J., Mengoni, A., Milazzo, Pm, Minguez, E., Molina-Coballes, A., Moreau, C., Neves, F., Oberhummer, H., O Brien, S., Pancin, J., Papaevangelou, T., Paradela, C., Pavlik, A., Pavlopoulos, P., Perez-Parra, A., Perlado, Jm, Perrot, L., Peskov, V., Plag, R., Plompen, A., Plukis, A., Poch, A., Policarpo, A., Pretel, C., Quesada, Jm, Radici, M., Raman, S., Rapp, W., Rauscher, T., Reifarth, R., Rejmund, F., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Savvidis, E., Soares, Jc, Stephan, C., Tagliente, G., Tain, Jl, Tapia, C., Tassan-Goth, L., Tavora, Lmn, Terlizzi, R., Terrani, M., Tsangas, N., Vannini, G., Vaz, P., Ventura, A., Villamarin-Fernandez, D., Vincente-Vincente, M., Vlachoudis, V., Vlastou, R., Voss, F., Wendler, H., Wiescher, M., Wisshak, K., Zanini, L., and nTOF Collaboration
Abstract: A small-mass system has been developed for monitoring the flux of neutrons with energy up to 1 MeV at the new time-of-flight facility at CERN, n_TOF. The monitor is based on a thin Mylar foil with a Li-6 deposit, placed in the neutron beam, and an array of Silicon detectors, placed outside the beam, for detecting the products of the Li-6(n, alpha)H-3 reaction. The small amount of material on the beam ensures a minimal perturbation of the flux and minimizes the background related to scattered neutrons. Moreover, a further reduction of the gamma-ray background has been obtained by constructing the scattering chamber hosting the device in carbon fibre. A detailed description of the flux monitor is here presented, together with the characteristics of the device, in terms of efficiency, resolution and induced background. The use of the monitor in the measurement of neutron capture cross-sections at n_TOF is discussed. Brazilian Journal of Physics
Published: 2004

99. Measurement of the n(-)TOF beam profile with a micromegas detector

Author: Pancin, J., Abbondanno, U., Aerts, G., Alvarez, H., Andriamonje, S., Angelopoulos, A., Assimakopoulos, P., Bacri, C. O., Badurek, G., Baumann, P., Becvar, F., Plukis, A., Poch, A., Policarpo, A., Pretel, C., Quesada, J., Radici, M., Raman, S., Rapp, W., Reifarth, R., Rejmund, F., Beer, H., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Savvidis, E., Stephan, C., Tagliente, G., Tain, J., Tapia, C., Benlliure, J., Tassan-Got, L., Tavora, L., Terlizzi, R., Terrani, M., Tsangas, N., Vannini, G., Vaz, P., Ventura, A., Villamarin-Fernandez, D., Vincente-Vincente, M., Berthier, B., Vlachoudis, V., Vlastou, R., Voss, F., Wendler, H., Wiescher, M., Wisshak, K., Zanini, L., Berthoumieux, E., Boffi, S., Borcea, C., Boscolo-Marchi, E., Bustreo, N., Calvino, F., Cano-ott, D., Capote, R., Carlson, P., Cennini, P., Chepel, V., Chiaveri, E., Colonna, N., Cortes, G., Cortina, D., Couture, A., Cox, J., Dababneh, S., Dahlfors, M., David, S., Delbart, A., Derre, J., Dolfini, R., Domingo, C., Duran-Escribano, I., Eleftheriadis, C., Embid-Segura, M., Ferrant, L., Ferrari, A., Ferreira-Lourenco, L., Ferreiramarques, R., Frais-Koelbl, H., Furman, W., Giomataris, Y., Goncalves, I., Gonzalez-Romero, E., Goverdovski, A., Gramegna, F., Griesmayer, E., Gunsing, F., Haight, R., Heil, M., Herrera-Martinez, A., Ioannides, K., Janeva, N., Jeanneau, F., Jericha, E., Kappeler, F., Kadi, Y., Karamanis, D., Kelic, A., Ketlerov, V., Kitis, G., Koehler, P., Konovalov, V., Kossionides, E., Lacoste, V., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Markov, S., Marrone, S., Martinez-Val, J., Mastinu, P., Mengoni, A., Milazzo, P., Minguez, E., Molina-Coballes, A., Moreau, C., Neves, F., Oberhummer, H., O'brien, S., Papadopoulos, I., Papavengelou, T., Paradela, C., Pavlik, A., Pavlopoulos, P., Perez-Parra, A., Perlado, J., Peskov, V., Perrot, L., Plag, R., and Plompen, A.
Subjects: micromegas, n(-)tof, beam profile, gaseous detector, neutron beam profiler
Abstract: A Micromegas detector was used in the neutron Time-Of-Flight (n-TOF) facility at CERN to evaluate the spatial distribution of the neutron beam as a function of its kinetic energy. This was achieved over a large range of neutron energies by using two complementary processes: at low energy by capture of a neutron via the Li-6(n, alpha)t reaction, and at high energy by elastic scattering of neutrons on gas nuclei (argon + isobutane or helium + isobutane). Data are compared to Monte Carlo simulations and an analytic function fitting the beam profile has been calculated with a sufficient precision to use in neutron capture experiments at the n-TOF facility. (C) 2004 Elsevier B.V. All rights reserved. Nuclear Instruments & Methods in Physics Research Section a-Accelerators Spectrometers Detectors and Associated Equipment
Published: 2004

100. New experimental validation of the pulse height weighting technique for capture cross-section measurements

Author: Abbondanno, U. Aerts, G. Alvarez, H. Andriamonje, S. Angelopoulos, A. Assimakopoulos, P. Bacri, C.O. Badurek, G. Baumann, P. Bečvář, F. Beer, H. Benlliure, J. Berthier, B. Berthomieux, E. Boffi, S. Borcea, C. Boscolo-Marchi, E. Bustreo, N. Calviño, P. Cano-Ott, D. Capote, R. Carlson, P. Cennini, P. Chepel, V. Chiaveri, E. Coceva, C. Colonna, N. Cortes, G. Cortina, D. Couture, A. Cox, J. Dababneh, S. Dahlfors, M. David, S. Dolfini, R. Domingo-Pardo, C. Duran, I. Eleftheriadis, C. Embid-Segura, M. Ferrant, L. Ferrari, A. Ferreira-Lourenco, L. Ferreira-Marques, R. Frais-Koelbl, H. Furman, W.I. Giomataris, Y. Goncalves, I.F. Gonzalez-Romero, E. Goverdovski, A. Gramegna, F. Griesmayer, E. Gunsing, F. Haight, R. Heil, M. Herrera-Martinez, A. Ioannides, K.G. Janeva, N. Jericha, E. Käppeler, F. Kadi, Y. Karamanis, D. Kelic, A. Ketlerov, V. Kitis, G. Koehler, P.E. Konovalov, V. Kossionides, E. Lacoste, V. Leeb, H. Lindote, A. Lopes, M.I. Lozano, M. Lukic, S. Markov, S. Marrone, S. Martinez-Val, J. Mastinu, P. Mengoni, A. Milazzo, P.M. Minguez, E. Molina-Coballes, A. Moreau, C. Neves, F. Oberhummer, H. O'Brien, S. Pancin, J. Papaevangelou, T. Paradela, C. Pavlik, A. Pavlopoulos, P. Perez-Parra, A. Perlado, J.M. Perrot, L. Peskov, V. Plag, R. Plompen, A. Plukis, A. Poch, A. Policarpo, A. Pretel, C. Quesada, J.M. Radici, M. Raman, S. Rapp, W. Rauscher, T. Reifarth, R. Rejmund, F. Rosetti, M. Rubbia, C. Rudolfh, G. Rullhusen, P. Salgado, J. Savvidis, E. Soares, J.C. Stephan, C. Tagliente, G. Tain, J.L. Tapia, C. Tassan-Got, L. Tavora, L.M.N. Terlizzi, R. Terrani, M. Tsangas, N. Vannini, G. Vaz, P. Ventura, A. Villamarin-Fernandez, D. Vincente-Vincente, M. Vlachoudis, V. Vlastou, R. Voss, F. Wendler, H. Wiescher, M. Wisshak, K. Zanini, L.
Abstract: The accuracy of the pulse height weighting technique for the determination of neutron capture cross-sections is investigated. The technique is applied to measurements performed with C6D6 liquid scintillation detectors of two different types using capture samples of various dimensions. The data for well-known (n,γ) resonances are analyzed using weighting functions obtained from Monte Carlo simulations of the experimental set-up. Several causes of systematic deviation are identified and their effect is quantified. In all the cases measured the reaction yield agrees with the standard value within 2%. © 2003 Elsevier B.V. All rights reserved.
Published: 2004

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