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151. Measurement of the 236U(n,f) cross section from 170 meV to 2 MeV at the CERN n_TOF facility

Author

Sarmento, R., Calviani, M., Praena, J., Colonna, N., Belloni, F., F. Gonçalves, I., Vaz, P., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Barbagallo, M., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calvino, F., Cano-Ott, D., Capote, R., Carrapiço, C., Carrillo De Albornoz, A., Cennini, P., Chepel, V., Chiaveri, E., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Diakaki, M., Dillmann, I., Dolfini, R., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Ferrant, L., Ferrari, Anthony, Ferreira-Marques, R., Frais-Koelbl, H., Fuji, K., Furman, W., 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., Krticka, M., Lampoudis, C., Lederer, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mendoza, E., Mengoni, A., M. Milazzo, P., 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., T. Pigni, 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., L. Tain, J., Tarrio, D., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Ventura, A., Villamarin, D., C. Vicente, M., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), 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), Département Recherches Subatomiques (DRS-IPHC), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Aval du cycle et Energie Nucléaire (ACEN), 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)-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), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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)-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), R. Sarmento, M. Calviani, J. Praena, N. Colonna, F. Belloni, I. F. Gonçalve, P. Vaz, G. Aert, H. Alvarez, F. Alvarez-Velarde, S. Andriamonje, J. Andrzejewski, P. Assimakopoulo, L. Audouin, M. Barbagallo, G. Badurek, P. Baumann, F. Becvar, E. Berthoumieux, F. Calvino, D. Cano-Ott, R. Capote, C. Carrapiço, A. Carrillo de Albornoz, P. Cennini, V. Chepel, E. Chiaveri, G. Corte, A. Couture, J. Cox, M. Dahlfor, S. David, M. Diakaki, I. Dillmann, R. Dolfini, C. Domingo-Pardo, W. Dridi, I. Duran, C. Eleftheriadi, L. Ferrant, A. Ferrari, R. Ferreira-Marque, H. Frais-Koelbl, K. Fuji, W. Furman, 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, F. Käppeler, Y. Kadi, D. Karadimo, D. Karamani, M. Kerveno, V. Ketlerov, P. Koehler, V. Konovalov, E. Kossionide, M. Krticka, C. Lampoudi, C. Lederer, H. Leeb, A. Lindote, I. Lope, M. Lozano, S. Lukic, J. Marganiec, L. Marque, S. Marrone, T. Martinez, C. Massimi, P. Mastinu, E. Mendoza, A. Mengoni, P. M. Milazzo, C. Moreau, M. Mosconi, F. Neve, H. Oberhummer, S. O’Brien, M. Oshima, J. Pancin, C. Papachristodoulou, C. Papadopoulo, C. Paradela, N. Patroni, A. Pavlik, P. Pavlopoulo, L. Perrot, M. T. Pigni, 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, D. Tarrio, L. Tassan-Got, L. Tavora, R. Terlizzi, G. Vannini, A. Ventura, D. Villamarin, M. C. Vicente, V. Vlachoudi, R. Vlastou, F. Vo, S. Walter, H. Wendler, M. Wiescher, and K. Wisshak

Subjects
NEUTRON TIME-OF-FLIGHT, Nuclear Theory, neutron-induced fission cross section, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, EMERGING NUCLEAR TECHNOLOGIES
Abstract

The neutron-induced fission cross section of 236U was measured at the neutron Time-of-Flight (n_TOF) facility at CERN relative to the standard 235U(n,f) cross section for neutron energies ranging from above thermal to several MeV. The measurement, covering the full range simultaneously, was performed with a fast ionization chamber, taking advantage of the high resolution of the n_TOF spectrometer. The n_TOF results confirm that the first resonance at 5.45 eV is largely overestimated in some nuclear data libraries. The resonance triplet around 1.2 keV was measured with high resolution and resonance parameters were determined with good accuracy. Resonances at high energy have also been observed and characterized and different values for the cross section are provided for the region between 10 keV and the fission threshold. The present work indicates various shortcomings of the current nuclear data libraries in the subthreshold region and provides the basis for an accurate re-evaluation of the 236U(n,f) cross section, which is of great relevance for the development of emerging or innovative nuclear reactor technologies.

Published
2011

152. $^{197}$Au($n,\gamma$) cross section in the unresolved resonance region

Author

Poch Parés, Agustí, Praena, J., Pretel Sánchez, Carme|||0000-0001-6199-3366, Igashira, M., Quesada, J., Pigni, M.T., Jericha, E., Plag, R., Isaev, S., Plompen, A., Karadimos, D., Cennini, P., Carrapiço, C., Carrillo de Albornoz, A., Cano-Ott, D., Capote, R., Calviani, M., Calviño Tavares, Francisco|||0000-0002-7198-4639, Belloni, F., Berthoumieux, E., Perrot, L., Martínez, T., Pavlopoulos, P., Pancin, J., Papachristodoulou, C., O'Brien, S., Oshima, M., Patronis, N., Pavlik, A., Papadopoulos, C., Paradela, C., Oberhummer, H., Lozano, M., Neves, F., Mosconi, M., Tassan-Got, L., Mastinu, P., Tarrío, D., Mendoza, E., Terlizzi, R., Milazzo, P.M., Tavora, L., Moreau, C., Losito, R., Vaz, P., Vannini, G., Márques, L., Villamarin, D., Marrone, S., Ventura, A., Tagliente, G., Marganiec, J., Lukic, S., Baumann, P., Barbagallo, M., Wisshak, K., Plukis, A., Badurek, G., Lindote, A., Wiescher, M., Audouin, L., Lopes, I., Wendler, H., Assimakopoulos, P.A., Lampoudis, C., Walter, S., Andrzejewski, J., Kadi, Y., Leeb, H., Andriamonje, S., Kossionides, E., Krticka, M., Álvarez-Velarde, F., Álvarez, H., Aerts, G., Becvár, F., Konovalov, V., Vlastou, R., Rauscher, T., Koehler, P., Voss, F., Ketlerov, V., Kerveno, M., Vlachoudis, V., Karamanis, D., Reifarth, R., Abbondanno, U., Griesmayer, E., Lederer, C., Guerrero, C., Colonna, N., Haas, B., Domingo-Pardo, C., Haight, R., Gunsing, F., Heil, M., Käppeler, F., Herrera-Martinez, A., Massimi, C., Mengoni, A., Wallner, A., Sarmento, R., Savvidis, I., Santos, C., Sarchiapone, L., Rullhusen, P., Gramegna, F., Salgado, J., Goverdovski, A., Rubbia, C., Gonzalez-Romero, E., Rudolf, G., Goncalves, I., Stephan, C., Rosetti, M., Ferreira-Marques, R., Fitzpatrick, L., Ferrant, L., Ferrari, A., Furman, W., Frais-Koelbl, H., Fujiii, K., Duran, I., Embid-Segura, M., Eleftheriadis, C., David, S., Dillmann, I., Dolfini, R., Dridi, W., Cortés Rossell, Guillem Pere|||0000-0002-3648-5826, Couture, A., Cox, J., Dahlfors, M., Chiaveri, E., Chepel, V., Taín Enríquez, José Luis|||0000-0002-3263-6965, 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
Energies::Energia nuclear [Àrees temàtiques de la UPC], Energia nuclear, Nuclear energy, Nuclear Physics - Experiment
Abstract

The cross section of the reaction 197Au(n,γ ) was measured with the time-of-flight technique at the n TOF (neutron time-of-flight) facility in the unresolved resonance region between 5 and 400 keV using a pair of C6D6 (where D denotes 2H) liquid scintillators for the detection of prompt capture γ rays. The results with a total uncertainty of 3.9%–6.7% for a resolution of 20 bins per energy decade show fair agreement with the Evaluated Nuclear Data File Version B-VII.0 (ENDF/B-VII.0), which contains the standard evaluation. The Maxwellianaveraged cross section (MACS) at 30 keV is in excellent agreement with the one according to the ENDF/B-VII.0 evaluation and 4.7% higher than the MACS measured independently by activation technique. Structures in the cross section, which had also been reported earlier, have been interpreted as being due to clusters of resonances.

Published
2011

154. Neutron-induced fission cross section of (nat)Pb and (209)Bi from threshold to 1 GeV: An improved parametrization

Author

Tarrio, D, Tassan-Got, L, Audouin, L, Berthier, B, Duran, I, Ferrant, L, Isaev, S, Le Naour, C, Paradela, C, Stephan, C, Trubert, D, Abbondanno, U, Aerts, G, 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, 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, Domingo-Pardo, C, Dridi, W, Eleftheriadis, C, Embid-Segura, M, 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, Jericha, E, Kadi, Y, Kappeler, F, Karadimos, D, Karamanis, D, Kerveno, M, Ketlerov, V, Koehler, P, Konovalov, V, Kossionides, E, Krticka, M, Lampoudis, C, Leeb, H, Lederer, C, Lindote, A, Lopes, I, Losito, R, Lozano, M, Lukic, S, Marganiec, J, Marques, L, Marrone, S, Martinez, T, Massimi, C, Mastinu, P, Mendoza, E, 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, Rosetti, M, Rubbia, C, Rudolf, G, Rullhusen, P, Salgado, J, Santos, C, Sarchiapone, L, Sarmento, R, Savvidis, I, Tagliente, G, Tain, J.L, Tavora, L, Terlizzi, R, Vannini, G, Vaz, P, Ventura, A, Villamarin, D, Vlachoudis, V, Vlastou, R, Voss, F, Walter, S, Wendler, H, Wiescher, M, and Wisshak, K

Subjects
Physics::Instrumentation and Detectors, Nuclear Theory, Nuclear Experiment, XX
Abstract

Neutron-induced fission cross sections for (nat)Pb and (209)Bi were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n\_TOF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides the first results for these nuclei above 200 MeV. The cross sections were measured relative to (235)U and (238)U in a dedicated fission chamber with parallel plate avalanche counter detectors. Results are compared with previous experimental data. Upgraded parametrizations of the cross sections are presented, from threshold energy up to 1 GeV. The proposed new sets of fitting parameters improve former results along the whole energy range.

Published
2011

155. Measurement of the (236)U(n, f) cross section from 170 meV to 2 MeV at the CERN n_TOF facility

Author

Sarmento, R., Calviani, M., Praena, J., Colonna, N., Belloni, F., Goncalves, I. F., Vaz, P., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Barbagallo, M., Badurek, G., Baumann, P., Becvar, F., Berthoumieux, E., Calvino, F., Cano-Ott, D., Capote, R., Carrapico, C., de Albornoz, A. C., Cennini, P., Chepel, V., Chiaveri, E., Cortes, G., Couture, A., Cox, J., Dahlfors, M., David, S., Diakaki, M., Dillmann, I., Dolfini, R., Domingo-Pardo, C., Dridi, W., Duran, I., Eleftheriadis, C., Ferrant, L., Ferrari, A., Ferreira-Marques, R., Frais-Koelbl, H., Fuji, K., Furman, W., 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., Lampoudis, C., Lederer, C., Leeb, H., Lindote, A., Lopes, I., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Martinez, T., Massimi, C., Mastinu, P., Mendoza, E., 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., Tarrio, D., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Ventura, A., Villamarin, D., Vicente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., and N TOF Collaboration

Subjects
nuclear-data library, range, fission
Abstract

The neutron-induced fission cross section of (236)U was measured at the neutron Time-of-Flight (n_TOF) facility at CERN relative to the standard (235)U(n, f) cross section for neutron energies ranging from above thermal to several MeV. The measurement, covering the full range simultaneously, was performed with a fast ionization chamber, taking advantage of the high resolution of the n_TOF spectrometer. The n_TOF results confirm that the first resonance at 5.45 eV is largely overestimated in some nuclear data libraries. The resonance triplet around 1.2 keV was measured with high resolution and resonance parameters were determined with good accuracy. Resonances at high energy have also been observed and characterized and different values for the cross section are provided for the region between 10 keV and the fission threshold. The present work indicates various shortcomings of the current nuclear data libraries in the subthreshold region and provides the basis for an accurate re-evaluation of the (236)U(n, f) cross section, which is of great relevance for the development of emerging or innovative nuclear reactor technologies. Physical Review C

Published
2011

156. Measurement of the neutron-induced fission cross-section of Am-243 relative to U-235 from 0.5 to 20 MeV

Author

Belloni, F., Calviani, M., Colonna, N., Mastinu, P., Milazzo, P. M., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Audouin, L., Badurek, G., Barbagallo, M., Baumann, P., Becvar, F., Berthoumieux, E., Calvino, F., Cano-Ott, D., Capote, R., Carrapico, 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., 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., 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., Meaze, M. H., 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., Tagliente, G., Tain, J. L., Tarrio, D., 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
n-tof, nuclear-science, standards, cern, library, energy-range, system
Abstract

The ratio of the neutron-induced fission cross-sections of Am-243 and U-235 was measured in the energy range from 0.5 to 20 MeV with uncertainties of approximate to 4%. The experiment was performed at the CERN n_TOF facility using a fast ionization chamber. With the good counting statistics that could be achieved thanks to the high instantaneous flux and the low backgrounds, the present results are useful for resolving discrepancies in previous data sets and are important for future reactors with improved fuel burn-up. European Physical Journal A

Published
2011

157. Drought at the global scale in the 2nd part of the 20th century (1963-2001)

Author

van Huijgevoort, M.H.J., Hazenberg, P., van Lanen, H.A.J., Bertrand, N., Clark, D., Folwell, S., Gosling, S., Hanasaki, N., Heinke, J., Stacke, T., and Voss, F.

Subjects
WIMEK, land surface, geschiedenis, climatology, hydrology, drought, Hydrology and Quantitative Water Management, hydrologie, models, klimatologie, droogte, history, hydrologische gegevens, hydrological data, aardoppervlak, modellen, Hydrologie en Kwantitatief Waterbeheer
Abstract

The large impacts of drought on society, economy and environment urge for a thorough investigation. A good knowledge of past drought events is important for both understanding of the processes causing drought, as well as to provide reliability assessments for drought projections for the future. Preferably, the investigation of historic drought events should rely on observations. Unfortunately, for a global scale these detailed observations are often not available. Therefore, the outcome of global hydrological models (GHMs) and off-line land surface models (LSMs) is used to assess droughts. In this study we have investigated to what extent simulated gridded time series from these large-scale models capture historic hydrological drought events. Results of ten different models, both GHMs and LSMs, made available by the WATCH project, were compared. All models are run on a global 0.5 degree grid for the period 1963-2000 with the same meteorological forcing data (WATCH forcing data). To identify hydrological drought events, the monthly aggregated total runoff values were used. Different methods were developed to identify spatio-temporal drought characteristics. General drought characteristics for each grid cell, as for example the average drought duration, were compared. These characteristics show that when comparing absolute values the models give substantially different results, whereas relative values lead to more or less the same drought pattern. Next to the general drought characteristics, some documented major historical drought events (one for each continent) were selected and described in more detail. For each drought event, the simulated drought clusters (spatial events) and their characteristics are given for one month during the event. It can be concluded that most major drought events are captured by all models. However, the spatial extent of the drought events differ substantially between the models. In general the models show a fast reaction to rainfall and therefore also capture drought events caused by large rainfall anomalies. More research is still needed, since here we only looked at a few selected number of documented drought events spread over the globe. To assess more in detail if these large-scale models are able to capture drought, additional quantitative analyses are needed together with a more elaborated comparison against observed drought events.

Published
2011

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

Author

Lederer, C., Colonna, N., Domingo-Pardo, C., Gunsing, F., Kappeler, F., Massimi, C., Mengoni, A., Wallner, A., Abbondanno, U., Aerts, G., Alvarez, H., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Barbagallo, M., Baumann, P., Becvar, F., Belloni, F., Berthoumieux, E., Calviani, M., Calvino, F., Cano-Ott, D., Capote, R., Carrapico, C., de Albornoz, A. C., Cennini, P., Chepel, V., Chiaveri, E., 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., 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., 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., Losito, R., Lozano, M., Lukic, S., Marganiec, J., Marques, L., Marrone, S., Martinez, T., Mastinu, P., Mendoza, E., 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., Praena, J., Pretel, C., Quesada, J., Rauscher, T., Reifarth, R., Rosetti, M., Rubbia, C., Rudolf, G., Rullhusen, P., Salgado, J., Santos, C., Sarchiapone, L., Sarmento, R., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tarrio, D., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., Wisshak, K., and n TOF Collaboration

Subjects
stars, detector, nuclear-science, cern, nucleosynthesis, library, gold, au-197, neutron-capture
Abstract

The cross section of the reaction Au-197(n,gamma) was measured with the time-of-flight technique at the n_TOF (neutron time-of-flight) facility in the unresolved resonance region between 5 and 400 keV using a pair of C6D6 (where D denotes H-2) liquid scintillators for the detection of prompt capture gamma rays. The results with a total uncertainty of 3.9%-6.7% for a resolution of 20 bins per energy decade show fair agreement with the Evaluated Nuclear Data File Version B-VII.0 (ENDF/B-VII.0), which contains the standard evaluation. The Maxwellian-averaged cross section (MACS) at 30 keV is in excellent agreement with the one according to the ENDF/B-VII.0 evaluation and 4.7% higher than the MACS measured independently by activation technique. Structures in the cross section, which had also been reported earlier, have been interpreted as being due to clusters of resonances. Physical Review C

Published
2011

159. Neutron Capture Measurements on Minor Actinides at the n_TOF Facility at CERN: Past, Present and Future

Author

Cano-Ott, D., Alvarez-Velarde, F., Gonzalez-Romero, E., Guerrero, C., Martinez, T., Mendoza, E., Villamarin, D., Vicente, M. C., Abbondanno, U., Colonna, N., Meaze, M. H., Marrone, S., Tagliente, G., Terlizzi, R., Belloni, F., Fujii, K., Milazzo, P. M., Moreau, C., Andriamonje, S., Calviani, M., Chiaveri, E., Kadi, Y., 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., Frais-Koelbl, H., Griesayer, E., Capote, R., Lozano, M., Quesada, J., Mengoni, A., De Albornoz, A. C., Maroues, L., Salgado, J., Tavora, L., Vaz, P., Cennini, P., Dahlfors, M., Ferrari, A., Gramegna, F., Herrera-Martinez, A., Mastinu, P., Praena, J., Sarchiapone, L., Wiendler, H., Chepel, V., Ferreira-Marques, R., Goncalves, I., Lindote, A., Lopes, I., Neves, F., Aerts, G., Berthoumieux, E., Dridi, W., Gunsing, F., Pancin, J., Perrot, L., Plukis, A., Lampoudis, C., Cortes, G., Poch, A., Pretel, C., Couture, A., Cox, J., O'Brien, S., Wiescher, M., Dillman, I., Heil, M., 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., Furman, W., Konovalov, V., Goverdovski, A., Ketlerov, V., Alvarez, H., Duran, I., Paradela, C., Haas, B., Haight, R., Reifarth, R., Igashira, M., Koehler, P., Kossionides, E., Massimi, C., Vannini, G., 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
nuclear waste, ads, cross section, actinides, plutonium, tac, generation iv, total absorption calorimeter, transmutation, nuclear data, nuclear energy, americium, uranium, accelerator driven system, n_tof, barium fluoride, nuclear reactor, neutron capture
Abstract

The successful development of advanced nuclear systems for sustainable energy production and nuclear waste management depends on high quality nuclear data libraries. Recent sensitivity studies and reports [1-3] have identified the need for substantially improving the accuracy of neutron cross-section data for minor actinides. The n_TOF collaboration has initiated an ambitious experimental program for the measurement of neutron capture cross sections of minor actinides. Two experimental setups have been constructed for this purpose: a Total Absorption Calorimeter (TAC) [4] for measuring neutron capture cross-sections of low-mass and/or radioactive samples and a set of two low neutron sensitivity C(6)D(6) detectors for the less radioactive materials. Journal of the Korean Physical Society

Published
2011

160. 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

161. (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

162. 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

163. 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

165. 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

166. 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

167. 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

168. 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

169. 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

170. 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

171. 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

172. 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

173. 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

174. 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

175. 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

176. 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

178. 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

179. 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

180. 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

181. 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

182. 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

183. 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

184. 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

185. 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

186. 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

187. 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

188. 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

189. 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

190. 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

191. 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

192. 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

194. 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

195. 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

197. 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

198. 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

200. 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

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