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1. Neutron capture measurements for s-process nucleosynthesis; A review about CERN n_TOF developments and contributions

Author

Domingo-Pardo, C., Aberle, O., Alcayne, V., Alpar, G., Halabi, M. Al, Amaducci, S., Babiano, V., Bacak, M., Balibrea-Correa, J., Bartolomé, J., Bernardes, A. P., Gameiro, B. Bernardino, Berthoumieux, E., Beyer, R., Birch, M., Boromiza, M., Bosnar, D., Brusasco, B., Caamaño, M., Cahuzac, A., Calviño, F., Calviani, M., Cano-Ott, D., Casanovas, A., Castelluccio, D. M., Catlett, D., Cerutti, F., Cescutti, G., Chiaveri, E., Claps, G., Colombetti, P., Colonna, N., Camprini, P. Console, Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., D'Ottavi, A., Rosales, G. de la Fuente, Dellmann, S. F., Diakaki, M., Di Castro, M., Di Chicco, A., Dietz, M., Dupont, E., Durán, I., Eleme, Z., Eslami, M., Fargier, S., Fernández-Domínguez, B., Finocchiaro, P., Flanagan, W., Furman, V., Gandhi, A., García-Infantes, F., Gawlik-Ramiega, A., Gervino, G., Gilardoni, S., González-Romero, E., Goula, S., Griesmayer, E., Guerrero, C., Gunsing, F., Gustavino, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Kelly, I., Kokkoris, M., Kopatch, Y., Krtička, M., Kyritsis, N., Lederer-Woods, C., Lerendegui-Marco, J., Manna, A., Martínez, T., Martínez-Cañada, M., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Moldenhauer, J., Mucciola, R., González, E. Musacchio, Musumarra, A., Negret, A., Odusina, E., Papanikolaou, D., Patronis, N., Pavón-Rodríguez, J. A., Pellegriti, M. G., Pérez-Maroto, P., Fiol, A. Pérez de Rada, Perfetto, G., Perkowski, J., Petrone, C., Pieretti, N., Piersanti, L., Pirovano, E., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rooney, A., Rovira, G., Rubbia, C., Sánchez-Caballero, A., Sahoo, R. N., Scarpa, D., Schillebeeckx, P., Smith, A. G., Sosnin, N. V., Spelta, M., Stamati, M. E., Stasiak, K., Tagliente, G., Tarifeño-Saldivia, A., Tarrío, D., Torres-Sánchez, P., Tosi, S., Tsiledakis, G., Valenta, S., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, A., Weiss, C., Woods, P. J., Wright, T., Wu, R., Žugec, P., and Collaboration, The n\_TOF

Subjects
Nuclear Experiment, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

This article presents a review about the main CERN n\_TOF contributions to the field of neutron-capture experiments of interest for $s$-process nucleosynthesis studies over the last 25 years, with special focus on the measurement of radioactive isotopes. A few recent capture experiments on stable isotopes of astrophysical interest are also discussed. Results on $s$-process branching nuclei are appropriate to illustrate how advances in detection systems and upgrades in the facility have enabled increasingly challenging experiments and, as a consequence, have led to a better understanding and modeling of the $s$-process mechanism of nucleosynthesis. New endeavors combining radioactive-ion beams from ISOLDE for the production of radioisotopically pure samples for activation experiments at the new NEAR facility at n\_TOF are briefly discussed. On the basis of these new exciting results, also current limitations of state-of-the-art TOF and activation techniques will be depicted, thereby showing the pressing need for further upgrades and enhancements on both facilities and detection systems. A brief account of the potential technique based on inverse kinematics for direct neutron-capture measurements is also presented., Comment: submitted to Eur. Phys. Jour. Topical Collection

Published
2025

2. Radiative neutron capture cross section of $^{242}$Pu measured at n_TOF-EAR1 in the unresolved resonance region up to 600 keV

Author

Lerendegui-Marco, J., Guerrero, C., Mendoza, E., Quesada, J. M., Eberhardt, K., Junghans, A. R., Alcayne, V., Babiano, V., Aberle, O., Andrzejewski, J., Audouin, L., Becares, V., Bacak, M., Balibrea-Correa, J., Barbagallo, M., Barros, S., Becvar, F., Beinrucker, C., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Castelluccio, D. M., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Damone, L. A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Furman, V., Göbel, K., García, A. R., Gawlik, A., Glodariu, T., Goncalves, I. F., González-Romero, E., Goverdovski, A., Griesmayer, E., Gunsing, F., Harada, H., Heftrich, T., Heinitz, S., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Kokkoris, M., Krticka, M., Leal-Cidoncha, E., Lederer-Woods, C., Leeb, H., Meo, S. Lo, Lonsdale, S. J., Losito, R., Macina, D., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E. A., Mengoni, A., Milazzo, P. M., Mingrone, F., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, J. I., Praena, J., Rajeev, K., Rauscher, T., Reifarth, R., Riego-Perez, A., Rout, P. C., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A. G., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Weiss, C., Wolf, C., Woods, P. J., Wright, T., Zugec, P., and Collaboration, the n_TOF

Subjects
Nuclear Experiment
Abstract

The design of fast reactors burning MOX fuels requires accurate capture and fission cross sections. For the particular case of neutron capture on 242Pu, the NEA recommends that an accuracy of 8-12% should be achieved in the fast energy region (2 keV-500 keV) compared to their estimation of 35% for the current uncertainty. Integral irradiation experiments suggest that the evaluated cross section of the JEFF-3.1 library overestimates the 242Pu(n,{\gamma}) cross section by 14% in the range between 1 keV and 1 MeV. In addition, the last measurement at LANSCE reported a systematic reduction of 20-30% in the 1-40 keV range relative to the evaluated libraries and previous data sets. In the present work this cross section has been determined up to 600 keV in order to solve the mentioned discrepancies. A 242Pu target of 95(4) mg enriched to 99.959% was irradiated at the n TOF-EAR1 facility at CERN. The capture cross section of 242Pu has been obtained between 1 and 600 keV with a systematic uncertainty (dominated by background subtraction) between 8 and 12%, reducing the current uncertainties of 35% and achieving the accuracy requested by the NEA in a large energy range. The shape of the cross section has been analyzed in terms of average resonance parameters using the FITACS code as implemented in SAMMY, yielding results compatible with our recent analysis of the resolved resonance region.The results are in good agreement with the data of Wisshak and K\"appeler and on average 10-14% below JEFF-3.2 from 1 to 250 keV, which helps to achieve consistency between integral experiments and cross section data. At higher energies our results show a reasonable agreement within uncertainties with both ENDF/B-VII.1 and JEFF-3.2. Our results indicate that the last experiment from DANCE underestimates the capture cross section of 242Pu by as much as 40% above a few keV., Comment: 20 pages, 19 figures, submitted to Phys. Rev. C

Published
2024

3. Towards a new generation of solid total-energy detectors for neutron-capture time-of-flight experiments with intense neutron beams

Author

Balibrea-Correa, J., Babiano-Suarez, V., Lerendegui-Marco, J., Domingo-Pardo, C., Ladarescu, I., Tarifeño-Saldivia, A., de la Fuente-Rosales, G., Gameiro, B., Zaitseva, N., Alcayne, V., Cano-Ott, D., González-Romero, E., Martínez, T., Mendoza, E., de Rada, A. Pérez, del Olmo, J. Plaza, Sánchez-Caballero, A., Casanovas, A., Calviño, F., Valenta, S., Aberle, O., Altieri, S., Amaducci, S., Andrzejewski, J., Bacak, M., Beltrami, C., Bennett, S., Bernardes, A. P., Berthoumieux, E., Beyer, R., Boromiza, M., Bosnar, D., Caamaño, M., Calviani, M., Castelluccio, D. M., Cerutti, F., Cescutti, G., Chasapoglou, S., Chiaveri, E., Colombetti, P., Colonna, N., Camprini, P. Console, Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Dellmann, S., Di Castro, M., Di Maria, S., Diakaki, M., Dietz, M., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fargier, S., Fernández, B., Fernández-Domínguez, B., Finocchiaro, P., Fiore, S., Furman, V., García-Infantes, F., Gawlik-Ramikega, A., Gervino, G., Gilardoni, S., Guerrero, C., Gunsing, F., Gustavino, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Kaur, G., Kimura, A., Knapová, I., Kokkoris, M., Kopatch, Y., Krtìvcka, M., Kyritsis, N., Lederer-Woods, C., Lerner, G., Manna, A., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mucciola, R., Murtas, F., Musacchio-Gonzalez, E., Musumarra, A., Negret, A., Pérez-Maroto, P., Patronis, N., Pavón-Rodríguez, J. A., Pellegriti, M. G., Perkowski, J., Petrone, C., Pirovano, E., Pomp, S., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sabaté-Gilarte, M., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N. V., Stamati, M. E., Sturniolo, A., Tagliente, G., Tarrío, D., Torres-Sánchez, P., Vagena, E., Variale, V., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., Zarrella, R., and Zugec, P.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

Challenging neutron-capture cross-section measurements of small cross sections and samples with a very limited number of atoms require high-flux time-of-flight facilities. In turn, such facilities need innovative detection setups that are fast, have low sensitivity to neutrons, can quickly recover from the so-called $\gamma$-flash, and offer the highest possible detection sensitivity. In this paper, we present several steps toward such advanced systems. Specifically, we describe the performance of a high-sensitivity experimental setup at CERN n\_TOF EAR2. It consists of nine sTED detector modules in a compact cylindrical configuration, two conventional used large-volume C$_{6}$D$_{6}$ detectors, and one LaCl$_{3}$(Ce) detector. The performance of these detection systems is compared using $^{93}$Nb($n$,$\gamma$) data. We also developed a detailed \textsc{Geant4} Monte Carlo model of the experimental EAR2 setup, which allows for a better understanding of the detector features, including their efficiency determination. This Monte Carlo model has been used for further optimization, thus leading to a new conceptual design of a $\gamma$ detector array, STAR, based on a deuterated-stilbene crystal array. Finally, the suitability of deuterated-stilbene crystals for the future STAR array is investigaged experimentally utilizing a small stilbene-d12 prototype. The results suggest a similar or superior performance of STAR with respect to other setups based on liquid-scintillators, and allow for additional features such as neutron-gamma discrimination and a higher level of customization capability.

Published
2024

4. Measurement and analysis of the $^{246}$Cm and $^{248}$Cm neutron capture cross-sections at the EAR2 of the n TOF facility

Author

Alcayne, V., Kimura, A., Mendoza, E., Cano-Ott, D., Aberle, O., Álvarez-Velarde, F., Amaducci, S., Andrzejewski, J., Audouin, L., Bécares, V., Babiano-Suarez, V., Bacak, M., Barbagallo, M., Bečvář, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Busso, M., Caamaño, M., Caballero-Ontanaya, L., Calviño, F., Calviani, M., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Damone, L. A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fernández-Domınguez, B., Ferrari, A., Finocchiaro, P., Furman, V., Göbel, K., Garg, R., Gawlik-Ramiega, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kivel, N., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Ladarescu, I., Lederer-Woods, C., Leeb, H., Lerendegui-Marco, J., Meo, S. Lo, Lonsdale, S. J., Macina, D., Manna, A., Martınez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E. A., Mazzone, A., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Ogállar, F., Oprea, A., Patronis, N., Pavlik, A., de Rada, A. Pérez, Perkowski, J., Persanti, L., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Ramos-Doval, D., Rauscher, T., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Talip, T., Tarifeño-Saldivia, A., Tassan-Got, L., Torres-Sánchez, P., Tsinganis, A., Ulrich, J., Urlass, S., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Nuclear Experiment
Abstract

The $^{246}$Cm(n,$\gamma$) and $^{248}$Cm(n,$\gamma$) cross-sections have been measured at the Experimental Area 2 (EAR2) of the n_TOF facility at CERN with three C$_6$D$_6$ detectors. This measurement is part of a collective effort to improve the capture cross-section data for Minor Actinides (MAs), which are required to estimate the production and transmutation rates of these isotopes in light water reactors and innovative reactor systems. In particular, the neutron capture in $^{246}$Cm and $^{248}$Cm open the path for the formation of other Cm isotopes and heavier elements such as Bk and Cf and the knowledge of (n,$\gamma$) cross-sections of these Cm isotopes plays an important role in the transport, transmutation and storage of the spent nuclear fuel. The reactions $^{246}$Cm(n,$\gamma$) and $^{248}$Cm(n,$\gamma$) have been the two first capture measurements analyzed at n_TOF EAR2. Until this experiment and two recent measurements performed at J-PARC, there was only one set of data of the capture cross-sections of $^{246}$Cm and $^{248}$Cm, that was obtained in 1969 in an underground nuclear explosion experiment. In the measurement at n_TOF a total of 13 resonances of $^{246}$Cm between 4 and 400 eV and 5 of $^{248}$Cm between 7 and 100 eV have been identified and fitted. The radiative kernels obtained for $^{246}$Cm are compatible with JENDL-5, but some of them are not with JENDL-4, which has been adopted by JEFF-3.3 and ENDF/B-VIII.0. The radiative kernels obtained for the first three $^{248}$Cm resonances are compatible with JENDL-5, however, the other two are not compatible with any other evaluation and are 20% and 60% larger than JENDL-5.

Published
2024
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5. Pushing the high count rate limits of scintillation detectors for challenging neutron-capture experiments

Author

Correa, J. Balibrea, Lerendegui-Marco, J., Babiano-Suarez, V., Domingo-Pardo, C., Ladarescu, I., Tarifeño-Saldivia, A., Alcayne, V., Cano-Ott, D., González-Romero, E., Martínez, T., Mendoza, E., de Rada, A. Pérez, del Olmo, J. Plaza, Sánchez-Caballero, A., Casanovas, A., Calviño, F., Valenta, S., Aberle, O., Altieri, S., Amaducci, S., Andrzejewski, J., Bacak, M., Beltrami, C., Bennett, S., Bernardes, A. P., Berthoumieux, E., Beyer, R., Boromiza, M., Bosnar, D., Caamaño, M., Calviani, M., Castelluccio, D. M., Cerutti, F., Cescutti, G., Chasapoglou, S., Chiaveri, E., Colombetti, P., Colonna, N., Camprini, P. Console, Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Dellmann, S., Di Castro, M., Di Maria, S., Diakaki, M., Dietz, M., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fargier, S., Fernández, B., Fernández-Domínguez, B., Finocchiaro, P., Fiore, S., Furman, V., García-Infantes, F., Gawlik-Ramikega, A., Gervino, G., Gilardoni, S., Guerrero, C., Gunsing, F., Gustavino, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Kaur, G., Kimura, A., Knapová, I., Kokkoris, M., Kopatch, Y., Krtička, M., Kyritsis, N., Lederer-Woods, C., Lerner, G., Manna, A., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mucciola, R., Murtas, F., Musacchio-Gonzalez, E., Musumarra, A., Negret, A., Pérez-Maroto, P., Patronis, N., Pavón-Rodríguez, J. A., Pellegriti, M. G., Perkowski, J., Petrone, C., Pirovano, E., Pomp, S., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sabaté-Gilarte, M., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N. V., Stamati, M. E., Sturniolo, A., Tagliente, G., Tarrío, D., Torres-Sánchez, P., Vagena, E., Variale, V., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., Zarrella, R., and Žugec, P.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

One of the critical aspects for the accurate determination of neutron capture cross sections when combining time-of-flight and total energy detector techniques is the characterization and control of systematic uncertainties associated to the measuring devices. In this work we explore the most conspicuous effects associated to harsh count rate conditions: dead-time and pile-up effects. Both effects, when not properly treated, can lead to large systematic uncertainties and bias in the determination of neutron cross sections. In the majority of neutron capture measurements carried out at the CERN n\_TOF facility, the detectors of choice are the C$_{6}$D$_{6}$ liquid-based either in form of large-volume cells or recently commissioned sTED detector array, consisting of much smaller-volume modules. To account for the aforementioned effects, we introduce a Monte Carlo model for these detectors mimicking harsh count rate conditions similar to those happening at the CERN n\_TOF 20~m fligth path vertical measuring station. The model parameters are extracted by comparison with the experimental data taken at the same facility during 2022 experimental campaign. We propose a novel methodology to consider both, dead-time and pile-up effects simultaneously for these fast detectors and check the applicability to experimental data from $^{197}$Au($n$,$\gamma$), including the saturated 4.9~eV resonance which is an important component of normalization for neutron cross section measurements.

Published
2023

6. First measurement of the $^{94}$Nb($n$,$\gamma$) cross section at the CERN n\_TOF facility

Author

Balibrea-Correa, J., Babiano-Suarez, V., Lerendegui-Marco, J., Domingo-Pardo, C., Ladarescu, I., Tarifeño-Saldivia, A., Alcayne, V., Cano-Ott, D., González-Romero, E., Martínez, T., Mendoza, E., Plaza, J., Sánchez-Caballero, A., Calviño, F., Casanovas, A., Guerrero, C., Heinitz, S., Köster, U., Maugeri, E. A., Dressler, R., Schumann, D., Mönch, I., Cristallo, S., Lederer-Woods, C., Aberle, O., Altieri, S., Amaducci, S., Andrzejewski, J., Bacak, M., Beltrami, C., Bennett, S., Bernardes, A. P., Berthoumieux, E., Boromiza, M., Bosnar, D., Caamaño, M., Calviani, M., Cerutti, F., Cescutti, G., Chasapoglou, S., Chiaveri, E., Colombetti, P., Colonna, N., Camprini, P. Console, Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Dellmann, S., Di Castro, M., Di Maria, S., Diakaki, M., Dietz, M., Dupont, E., Durán, I., Eleme, Z., Fargier, S., Fernández, B., Fernández-Domínguez, B., Finocchiaro, P., Fiore, S., Furman, V., García-Infantes, F., Gawlik-Ramięga, A., Gervino, G., Gilardoni, S., Gunsing, F., Gustavino, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Kaur, G., Kimura, A., Knapová, I., Kokkoris, M., Kopatch, Y., Krtička, M., Kyritsis, N., Lerner, G., Manna, A., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Mazzone, A., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mucciola, R., Murtas, F., Musacchio-Gonzalez, E., Musumarra, A., Negret, A., de Rada, A. Pérez, Pérez-Maroto, P., Patronis, N., Pavón-Rodríguez, J. A., Pellegriti, M. G., Perkowski, J., Petrone, C., Pirovano, E., Pomp, S., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sabaté-Gilarte, M., Schillebeeckx, P., Sekhar, A., Smith, A. G., Sosnin, N. V., Stamati, M. E., Sturniolo, A., Tagliente, G., Tarrío, D., Torres-Sánchez, P., Urlass, S., Vagena, E., Valenta, S., Variale, V., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, T., Woods, P. J., Wright, T., Zarrella, R., Žugec, P., and Collaboration, the n_TOF

Subjects
Nuclear Experiment
Abstract

One of the crucial ingredients for the improvement of stellar models is the accurate knowledge of neutron capture cross-sections for the different isotopes involved in the $s$-,$r$- and $i$- processes. These measurements can shed light on existing discrepancies between observed and predicted isotopic abundances and help to constrain the physical conditions where these reactions take place along different stages of stellar evolution.In the particular case of the radioactive $^{94}$Nb, the $^{94}$Nb($n$,$\gamma$) cross-section could play a role in the determination of the $s$-process production of $^{94}$Mo in AGB stars, which presently cannot be reproduced by state-of-the-art stellar models. There are no previous $^{94}$Nb($n$,$\gamma$) experimental data for the resolved and unresolved resonance regions mainly due to the difficulties in producing high-quality samples and also due to limitations in conventional detection systems commonly used in time-of-flight experiments.Motivated by this situation, a first measurement of the $^{94}$Nb($n$,$\gamma$) reaction was carried out at CERN n\_TOF, thereby exploiting the high luminosity of the EAR2 area in combination with a new detection system of small-volume C6D6-detectors and a high quality $^{94}$Nb-sample. The latter was based on hyper-pure $^{93}$Nb material activated at the high-flux reactor of ILL-Grenoble. An innovative ring-configuration detection system in close geometry around the capture sample allowed us to significantly enhance the signal-to-background ratio. This set-up was supplemented with two conventional C$_{6}$D$_{6}$ detectors and a high-resolution LaCl$_{3}$(Ce)-detector, which will be employed for addressing reliably systematic effects and uncertainties.At the current status of the data analysis, 18 resonance in $^{94}$Nb+$n$ have been observed for the first time in the neutron energy range from thermal up to 10 keV., Comment: NPA-X conference proceeding

Published
2023
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7. Measurement of the $^{14}$N(n,p)$^{14}$C cross section at the CERN n_TOF facility from sub-thermal energy to 800 keV

Author

Torres-Sánchez, P., Praena, J., Porras, I., Sabaté-Gilarte, M., Lederer-Woods, C., Aberle, O., Alcayne, V., Amaducci, S., Andrzejewski, J., Audouin, L., Bécares, V., Babiano-Suarez, V., Bacak, M., Barbagallo, M., Bečvář, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Busso, M., Caamaño, M., Caballero, L., Calviño, F., Calviani, M., Cano-Ott, D., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Damone, L. A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fernández-Domínguez, B., Ferrari, A., Ferrer, F. J., Finocchiaro, P., Furman, V., Göbel, K., Garg, R., Gawlik-Ramięga, A., Geslot, B., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kimura, A., Kivel, N., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Ladarescu, I., Leeb, H., Lerendegui-Marco, J., Meo, S. Lo, Lonsdale, S. J., Macina, D., Manna, A., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Ogállar, F., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Piersanti, L., Quesada, J. M., Radeck, D., Ramos-Doval, D., Rauscher, T., Reifarth, R., Rochman, D., Rubbia, C., Saxena, A., Schillebeeckx, P., Schumann, D., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Talip, T., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Ulrich, J., Urlass, S., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Nuclear Experiment
Abstract

Background: The $^{14}$N(n,p)$^{14}$C reaction is of interest in neutron capture therapy, where nitrogen-related dose is the main component due to low-energy neutrons, and in astrophysics, where 14N acts as a neutron poison in the s-process. Several discrepancies remain between the existing data obtained in partial energy ranges: thermal energy, keV region and resonance region. Purpose: Measuring the 14N(n,p)14C cross section from thermal to the resonance region in a single measurement for the first time, including characterization of the first resonances, and providing calculations of Maxwellian averaged cross sections (MACS). Method: Time-of-flight technique. Experimental Area 2 (EAR-2) of the neutron time-of-flight (n_TOF) facility at CERN. $^{10}$B(n,${\alpha}$)$^7$Li and $^{235}$U(n,f) reactions as references. Two detection systems running simultaneously, one on-beam and another off-beam. Description of the resonances with the R-matrix code sammy. Results: The cross section has been measured from sub-thermal energy to 800 keV resolving the two first resonances (at 492.7 and 644 keV). A thermal cross-section (1.809$\pm$0.045 b) lower than the two most recent measurements by slightly more than one standard deviation, but in line with the ENDF/B-VIII.0 and JEFF-3.3 evaluations has been obtained. A 1/v energy dependence of the cross section has been confirmed up to tens of keV neutron energy. The low energy tail of the first resonance at 492.7 keV is lower than suggested by evaluated values, while the overall resonance strength agrees with evaluations. Conclusions: Our measurement has allowed to determine the $^{14}$N(n,p) cross-section over a wide energy range for the first time. We have obtained cross-sections with high accuracy (2.5 %) from sub-thermal energy to 800 keV and used these data to calculate the MACS for kT = 5 to kT = 100 keV., Comment: 18 pages, 15 figures, 4 tables

Published
2022
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8. The CERN n TOF NEAR station for astrophysics- and application-related neutron activation measurements

Author

Patronis, N., Mengoni, A., Colonna, N., Cecchetto, M., Domingo-Pardo, C., Aberle, O., Lerendegui-Marco, J., Gervino, G., Stamati, M. E., Goula, S., Bernardes, A. P., Mastromarco, M., Manna, A., Vlastou, R., Massimi, C., Calviani, M., Alcayne, V., Altieri, S., Amaducci, S., Andrzejewski, J., Babiano-Suarez, V., Bacak, M., Balibrea, J., Beltrami, C., Bennett, S., Berthoumieux, E., Boromiza, M., Bosnar, D., Caamano, M., Calvino, F., Cano-Ott, D., Casanovas, A., Cerutti, F., Cescutti, G., Chasapoglou, S., Chiaveri, E., Colombetti, P., Camprini, P. Console, Cortes, G., Cortes-Giraldo, M. A., Cosentino, L., Cristallo, S., Dellmann, S., Di Castro, M., Di Maria, S., Diakaki, M., Dietz, M., Dressler, R., Dupont, E., Duran, I., Eleme, Z., Fargier, S., Fernandez, B., Fernandez-Dominguez, B., Finocchiaro, P., Fiore, S., Furman, V., Garcia-Infantes, F., Gawlik-Ramiega, A., Gilardoni, S., Gonzalez-Romero, E., Guerrero, C., Gunsing, F., Gustavino, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Kaur, G., Kimura, A., Knapova, I., Kokkoris, M., Kopatch, Y., Krticka, M., Kyritsis, N., Ladarescu, I., Lederer-Woods, C., Lerner, G., Martınez, T., Masi, A., Mastinu, P., Maugeri, E. A., Mazzone, A., Mendoza, E., Milazzo, P. M., Mucciola, R., Murtas, F., Musacchio-Gonzalez, E., Musumarra, A., Negret, A., de Rada, A. Perez, Perez-Maroto, P., Pavon-Rodrıguez, J. A., Pellegriti, M. G., Perkowski, J., Petrone, C., Pirovano, E., Plaza, J., Pomp, S., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sanchez, A., Sabate-Gilarte, M., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N. V., Sturniolo, A., Tagliente, G., Tarrio, D., Torres-Sanchez, P., Urlass, S., Vagena, E., Valenta, S., Variale, V., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Wallner, T., Woods, P. J., Wright, T., Zarrella, R., and Zugec, P.

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, Nuclear Experiment
Abstract

A new experimental area, the NEAR station, has recently been built at the CERN n TOF facility, at a short distance from the spallation target (1.5 m). The new area, characterized by a neutron beam of very high flux, has been designed with the purpose of performing activation measurements of interest for astrophysics and various applications. The beam is transported from the spallation target to the NEAR station through a hole in the shielding wall of the target, inside which a collimator is inserted. The new area is complemented with a {\gamma}-ray spectroscopy laboratory, the GEAR station, equipped with a high efficiency HPGe detector, for the measurement of the activity resulting from irradiation of a sample in the NEAR station. The use of a moderator/filter assembly is envisaged, in order to produce a neutron beam of Maxwellian shape at different thermal energies, necessary for the measurement of Maxwellian Averaged Cross Sections of astrophysical interest. A new fast-cycling activation technique is also being investigated, for measurements of reactions leading to isotopes of very short half life.

Published
2022

9. Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF

Author

Domingo-Pardo, C., Babiano-Suarez, V., Balibrea-Correa, J., Caballero, L., Ladarescu, I., Lerendegui-Marco, J., Tain, J. L., Tarifeño-Saldivia, A., Aberle, O., Alcayne, V., Altieri, S., Amaducci, S., Andrzejewski, J., Bacak, M., Beltrami, C., Bennett, S., Bernardes, A. P., Berthoumieux, E., Boromiza, M., Bosnar, D., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Casanovas, A., Cerutti, F., Cescutti, G., Chasapoglou, S., Chiaveri, E., Chiera, N. M., Colombetti, P., Colonna, N., Camprini, P. Console, Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Dellmann, S., Di Castro, M., Di Maria, S., Diakaki, M., Dietz, M., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fargier, S., Fernández, B., Fernández-Domínguez, B., Finocchiaro, P., Fiore, S., Furman, V., García-Infantes, F., Gawlik-Ramiega, A., Gervino, G., Gilardoni, S., González-Romero, E., Guerrero, C., Gunsing, F., Gustavino0, C., Heyse, J., Hillman, W., Jenkins, D. G., Jericha, E., Junghans, A., Kadi, Y., Kaperoni, K., Käppeler, F., Kaur, G., Kimura, A., Knapová, I., Koester, U., Kokkoris, M., Kopatch, Y., Krtička, M., Kyritsis, N., Lederer-Woods, C., Lerner, G., Manna, A., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mönch, I., Mucciola, R., Murtas, F., Musacchio-Gonzalez, E., Musumarra, A., Negret, A., de Rada, A. Pérez, Pérez-Maroto, P., Patronis, N., Pavón-Rodríguez, J. A., Pellegriti, M. G., Perkowski, J., Petrone, C., Pirovano, E., Plaza, J., Pomp, S., Porras, I., Praena, J., Quesada, J. M., Reifarth, R., Rochman, D., Romanets, Y., Rubbia, C., Sánchez, A., Sabaté-Gilarte, M., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N. V., Stamati, M., Sturniolo, A., Tagliente, G., Tarrío, D., Torres-Sánchez, P., Turko, J., Urlass, S., Vagena, E., Valenta, S., Variale, V., Vaz, P., Vecchio, G., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, T., Woods, P. J., Wright, T., Zarrella, R., and Žugec, P.

Subjects
Nuclear Experiment
Abstract

This article presents a few selected developments and future ideas related to the measurement of $(n,\gamma)$ data of astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for the use of low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with particular emphasis on the systematic accuracy. Several recent instrumental advances are also presented, such as the development of total-energy detectors with $\gamma$-ray imaging capability for background suppression, and the development of an array of small-volume organic scintillators aimed at exploiting the high instantaneous neutron-flux of EAR2. Finally, astrophysics prospects related to the intermediate $i$ neutron-capture process of nucleosynthesis are discussed in the context of the new NEAR activation area., Comment: preprint submitted to the European Physical Journal A, 11 pages, 4 figures

Published
2022
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10. High accuracy, high resolution 235U(n,f) cross section from n_TOF (CERN) in the thermal to 10 keV energy range

Author

collaboration, n_TOF, Mastromarco, M., Amaducci, S., Colonna, N., Finocchiaro, P., Cosentino, L., Aberle, O., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Cortés, G., Cortés-Giraldo, M. A., Damone, L. A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Furman, V., Göbel, K., García, A. R., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Knapova, I., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Lederer, C., Leeb, H., Lerendegui-Marco, J., Meo, S. Lo, Lonsdale, S. J., Macina, D., Manna, A., Marganiec, J., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rauscher, T., Reifarth, R., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sedyshev, P., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weiss, C., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Nuclear Experiment
Abstract

The 235U(n,f) cross section was measured in a wide energy range (25 meV - 170 keV) at the n_TOF facility at CERN, relative to 6Li(n,t) and 10B(n,alpha) standard reactions, with high resolution and accuracy, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. In this paper we report on the results in the region between thermal and 10 keV neutron energy. A resonance analysis has been performed up to 200 eV, with the code SAMMY. The resulting fission kernels are compared with the ones extracted on the basis of the resonance parameters of the most recent major evaluated data libraries. A comparison of the n_TOF data with the evaluated cross sections is also performed from thermal to 10 keV neutron energy for the energy-averaged cross section in energy groups of suitably chosen width. A good agreement is found in average between the new results and the latest evaluated data files ENDF-B/VIII and JEFF-3.3, as well as with respect to the IAEA reference files. However, some discrepancies are still present in some specific energy regions. The new dataset here presented, characterized by unprecedented resolution and accuracy, can help improving the evaluations in the Resolved Resonance Region and up to 10 keV, and reduce the uncertainties that affect this region.

Published
2022

11. Imaging neutron capture cross sections: i-TED proof-of-concept and future prospects based on Machine-Learning techniques

Author

Babiano-Suárez, V., Lerendegui-Marco, J., Balibrea-Correa, J., Caballero, L., Calvo, D., Ladarescu, I., Domingo-Pardo, C., Calviño, F., Casanovas, A., Tarifeño-Saldivia, A., Alcayne, V., Guerrero, C., Millán-Callado, M. A., González, M. T. Rodríguez, Barbagallo, M., Aberle, O., Amaducci, S., Andrzejewski, J., Audouin, L., Bacak, M., Bennett, S., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Busso, M., Caamaño, M., Calviani, M., Cano-Ott, D., Cerutti, F., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Damone, L. A., Davies, P. J., Diakaki, M., Dietz, M., Dressler, R., Ducasse, Q., Dupont, E., Durán, I., Eleme, Z., Fern\', B., ez-Domínguez, Ferrari, A., Finocchiaro, P., Furman, V., Göbel, K., Garg, R., Gawlik, A., Gilardoni, S., Gonçalves, I. F., González-Romero, E., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D. G., Junghans, A., Käppeler, F., Kadi, Y., Kimura, A., Knapova, I., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Lederer-Woods, C., Leeb, H., Lonsdale, S. J., Macina, D., Manna, A., Martinez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mingrone, F., Moreno-Soto, J., Musumarra, A., Negret, A., Ogállar, F., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Persanti, L., Petrone, C., Pirovano, E., Porras, I., Praena, J., Quesada, J. M., Ramos-Doval, D., Rauscher, T., Reifarth, R., Rochman, D., Rubbia, C., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N. V., Sprung, P., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tassan-Got, L., Thomas, Th., Torres-Sánchez, P., Tsinganis, A., Ulrich, J., Urlass, S., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, Nuclear Experiment
Abstract

i-TED is an innovative detection system which exploits Compton imaging techniques to achieve a superior signal-to-background ratio in ($n,\gamma$) cross-section measurements using time-of-flight technique. This work presents the first experimental validation of the i-TED apparatus for high-resolution time-of-flight experiments and demonstrates for the first time the concept proposed for background rejection. To this aim both $^{197}$Au($n,\gamma$) and $^{56}$Fe($n, \gamma$) reactions were measured at CERN n\_TOF using an i-TED demonstrator based on only three position-sensitive detectors. Two \cds detectors were also used to benchmark the performance of i-TED. The i-TED prototype built for this study shows a factor of $\sim$3 higher detection sensitivity than state-of-the-art \cds detectors in the $\sim$10~keV neutron energy range of astrophysical interest. This paper explores also the perspectives of further enhancement in performance attainable with the final i-TED array consisting of twenty position-sensitive detectors and new analysis methodologies based on Machine-Learning techniques., Comment: 16 pages, 16 figures

Published
2020
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12. Unrecognized Sources of Uncertainties (USU) in Experimental Nuclear Data

Author

Capote, R., Badikov, S., Carlson, A., Duran, I., Gunsing, F., Neudecker, D., Pronyaev, V. G., Schillebeeckx, P., Schnabel, G., Smith, D. L., and Wallner, A.

Subjects
Physics - Data Analysis, Statistics and Probability, Nuclear Experiment, Nuclear Theory
Abstract

Evaluated nuclear data uncertainties are often perceived as unrealistic, most often because they are thought to be too small. The impact of this issue in applied nuclear science has been discussed widely in recent years. Commonly suggested causes are: poor estimates of specific error components, neglect of uncertainty correlations, and overlooked known error sources. However, instances have been reported where very careful, objective assessments of all known error sources have been made with realistic error magnitudes and correlations provided, yet the resulting evaluated uncertainties still appear to be inconsistent with observed scatter of predicted mean values. These discrepancies might be attributed to significant unrecognized sources of uncertainty (USU) that limit the accuracy to which these physical quantities can be determined. The objective of our work has been to develop procedures for revealing and including USU estimates in nuclear data evaluations involving experimental input data. We conclude that the presence of USU may be revealed, and estimates of magnitudes made, through quantitative analyses. This paper identifies several specific clues that can be explored by evaluators in identifying the existence of USU. It then describes numerical procedures to generate quantitative estimates of USU magnitudes. Key requirements for these procedures to be viable are that sufficient numbers of data points be available, for statistical reasons, and that additional supporting information about the measurements be provided by the experimenters. Realistic examples are described to illustrate these procedures and demonstrate their outcomes as well as limitations. Our work strongly supports the view that USU is an important issue in nuclear data evaluation, with significant consequences for applications, and that this topic warrants further investigation by the nuclear science community., Comment: 39 pages, 16 figures, submitted to Nuclear Data Sheets

Published
2019
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13. Measurement of the 235U(n,f) cross section relative to the 6Li(n,t) and 10B(n,alpha) standards from thermal to 170 keV neutron energy range at n_TOF

Author

Amaducci, S., Cosentino, L., Barbagallo, M., Colonna, N., Mengoni, A., Massimi, C., Meo, S. Lo, Finocchiaro, P., Aberle, O., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Bečvář, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Cortés, G., Cortés-Giraldo, M. A., Damone, L. A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Furman, V., Göbel, K., García, A. R., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Knapova, I., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Lederer, C., Leeb, H., Lerendegui-Marco, J., Lonsdale, S. J., Macina, D., Manna, A., Marganiec, J., Martínez, T., Masi, A., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rauscher, T., Reifarth, R., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sedyshev, P., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weiss, C., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The 235U(n,f) cross section was measured in a wide energy range at n_TOF relative to 6Li(n,t) and 10B(n,alpha), with high resolution and in a wide energy range, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the reaction yields under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10{\div}30 keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the evaluated cross section in the 9{\div}18 keV neutron energy range is indeed overestimated, both in the recent updates of ENDF/B-VIII.0 and of the IAEA reference data. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The new, high accuracy results here reported may lead to a reduction of the uncertainty in the 1{\div}100 keV neutron energy region. Finally, the present data provide additional confidence on the recently re-evaluated cross section integral between 7.8 and 11 eV., Comment: 22 pages, 20 figures, submitted to PRC

Published
2019
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14. The $^{7}$Be($\boldsymbol{n,p}$)$^{7}$Li reaction and the Cosmological Lithium Problem: measurement of the cross section in a wide energy range at n_TOF (CERN)

Author

Damone, L., Barbagallo, M., Mastromarco, M., Mengoni, A., Cosentino, L., Maugeri, E., Heinitz, S., Schumann, D., Dressler, R., Käppeler, F., Colonna, N., Finocchiaro, P., Andrzejewski, J., Perkowski, J., Gawlik, A., Aberle, O., Altstadt, S., Ayranov, M., Audouin, L., Bacak, M., Balibrea-Correa, J., Ballof, J., Bécares, V., Bečvář, F., Beinrucker, C., Bellia, G., Bernardes, A. P., Berthoumieux, E., Billowes, J., Borge, M. J. G., Bosnar, D., Brown, A., Brugger, M., Busso, M., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Castelluccio, D. M., Catherall, R., Cerutti, F., Chen, Y. H., Chiaveri, E., Cortés, G., Cortés-Giraldo, M. A., Cristallo, S., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dorsival, A., Dupont, E., Duran, I., Fernandez-Dominguez, B., Ferrari, A., Ferreira, P., Furman, W., Ganesan, S., García-Rio, A., Gilardoni, S., Glodariu, T., Göbel, K., Gonçalves, I. F., González-Romero, E., Goodacre, T. D., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heftrich, T., Heyse, J., Jenkins, D. G., Jericha, E., Johnston, K., Kadi, Y., Kalamara, A., Katabuchi, T., Kavrigin, P., Kimura, A., Kivel, N., Kohester, U., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Lederer-Woods, C., Leeb, H., Lerendegui-Marco, J., Meo, S. Lo, Lonsdale, S. J., Losito, R., Macina, D., Marganiec, J., Marsh, B., Martíne, T., Correia, J. G. Martins, Masi, A., Massimi, C., Mastinu, P., Matteucci, F., Mazzone, A., Mendoza, E., Milazzo, P. M., Mingrone, F., Mirea, M., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Piersanti, L., Piscopo, M., Plompen, A., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rajeev, K., Rauscher, T., Reifarth, R., Riego-Perez, A., Rothe, S., Rout, P., Rubbia, C., Ryan, J., Sabaté-Gilarte, M., Saxena, A., Schell, J., Schillebeeckx, P., Schmidt, S., Sedyshev, P., Seiffert, C., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Stora, T., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Weiß, C., Wolf, C., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Nuclear Experiment
Abstract

We report on the measurement of the $^{7}$Be($n, p$)$^{7}$Li cross section from thermal to approximately 325 keV neutron energy, performed in the high-flux experimental area (EAR2) of the n\_TOF facility at CERN. This reaction plays a key role in the lithium yield of the Big Bang Nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements performed on this reaction did not cover the energy window of interest for BBN, and showed a large discrepancy between each other. The measurement was performed with a Si-telescope, and a high-purity sample produced by implantation of a $^{7}$Be ion beam at the ISOLDE facility at CERN. While a significantly higher cross section is found at low-energy, relative to current evaluations, in the region of BBN interest the present results are consistent with the values inferred from the time-reversal $^{7}$Li($p, n$)$^{7}$Be reaction, thus yielding only a relatively minor improvement on the so-called Cosmological Lithium Problem (CLiP). The relevance of these results on the near-threshold neutron production in the p+$^{7}$Li reaction is also discussed.

Published
2018
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15. Cross section measurements of $^{155,157}$Gd(n,$\gamma$) induced by thermal and epithermal neutrons

Author

Mastromarco, M., Manna, A., Aberle, O., Amaducci, S., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Becvar, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamano, M., Calvino, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Castelluccio, D. M., Cerutti, F., Chen, Y. H., Chiaveri, E., Clai, G., Colonna, N., Cortes, G., Cortes-Giraldo, M. A., Cosentino, L., Damone, L. A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Duran, I., Fernandez-Domnguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Furman, V., Gobel, K., Garca, A. R., Gawlik, A., Gilardoni, S., Glodariu, T., Goncalves, I. F., Gonzalez-Romero, E., Griesmayer, E., Guerrero, C., Guglielmelli, A., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D. G., Jericha, E., Kaeppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Kokkoris, M., Krticka, M., Kurtulgil, D., Leal-Cidoncha, E., Lederer-Woods, C., Leeb, H., Lerendegui-Marco, J., Lonsdale, S. J., Macina, D., Marganiec, J., Martnez, T., Masi, A., Massimi, C., Mastinu, P., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rauscher, T., Reifarth, R., Rocchi, F., Rubbia, C., Ryan, J. A., Sabate-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sedyshev, P., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeno-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weiss, C., Woods, P. J., Wright, T., and Zugec, P.

Subjects
Nuclear Experiment
Abstract

Neutron capture measurements on $^{155}$Gd and $^{157}$Gd were performed using the time-of-flight technique at the n\_TOF facility at CERN. Four samples in form of self-sustaining metallic discs isotopically enriched in $^{155}$Gd and $^{157}$Gd were used. The measurements were carried out at the experimental area (EAR1) at 185 m from the neutron source, with an array of 4 C$_6$D$_6$ liquid scintillation detectors. The capture cross sections of $^{155}$Gd and $^{157}$Gd at neutron kinetic energy of 0.0253 eV have been estimated to be 62.2(2.2) kb and 239.8(9.3) kb, respectively, thus up to 6\% different relative to the ones reported in the nuclear data libraries. A resonance shape analysis has been performed in the resolved resonance region up to 180 eV and 300 eV, respectively, in average resonance parameters have been found in good agreement with evaluations. Above these energies the observed resonance-like structures in the cross section have been tentatively characterised in terms of resonance energy and area up to 1 keV.

Published
2018
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16. Neutron capture cross section measurement of 238U at the n TOF CERN facility with C6D6 scintillation detectors in the energy region from 1 eV to 700 keV

Author

Collaboration, n_TOF, Mingrone, F., Massimi, C., Vannini, G., Colonna, N., Gunsing, F., Žugec, P., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M. A., Diakaki, M., Domingo-Pardo, C., Duran, I., Dressler, R., Eleftheriadis, C., Ferrari, A., Fraval, K., Ganesan, S., García, A. R., Giubrone, G., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Hernández-Prieto, A., Jenkins, D. G., Jericha, E., Kadi, Y., Käppeler, F., Karadimos, D., Kivel, N., Koehler, P., Kokkoris, M., Krtička, 1 M., Kroll, J., Lampoudis, C., Langer, C., Leal-Cidoncha, E., Lederer, C., Leeb, H., Leong, L. S., Meo, S. Lo, Losito, R., Mallick, A., Manousos, A., Marganiec, J., Martínez, T., Mastinu, P. F., Mastromarco, M., Mendoza, E., Mengoni, A., Milazzo, P. M., Mirea, M., Mondalaers, W., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A., Praena, J., Quesada, J. M., Rauscher, T., Reifarth, R., Riego, A., Robles, M. S., Rubbia, C., Sabaté-Gilarte, M., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J. L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Variale, V., Vaz, P., Ventura, A., Vermeulen, M. J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., and Wright, T.

Subjects
Nuclear Experiment
Abstract

The aim of this work is to provide a precise and accurate measurement of the 238U(n,g) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behaviour of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the uncertainty in the radiative capture cross-section of 238U should be further reduced to 1-3% in the energy region from 20 eV to 25 keV. To this purpose, addressed by the Nuclear Energy Agency as a priority nuclear data need, complementary experiments, one at the GELINA and two at the n_TOF facility, were proposed and carried out within the 7th Framework Project ANDES of the European Commission. The results of one of these 238U(n,g) measurements performed at the n_TOF CERN facility are presented in this work. The gamma-ray cascade following the radiative neutron capture has been detected exploiting a setup of two C6D6 liquid scintillators. Resonance parameters obtained from this work are on average in excellent agreement with the ones reported in evaluated libraries. In the unresolved resonance region, this work yields a cross section in agreement with evaluated libraries up to 80 keV, while for higher energies our results are significantly higher., Comment: 15 pages, 10 captioned figures

Published
2016
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17. Integral measurement of the $^{12}$C(n,p)$^{12}$B reaction up to 10 GeV

Author

Žugec, P., Colonna, N., Bosnar, D., Ventura, A., Mengoni, A., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Diakaki, M., Domingo-Pardo, C., Dressler, R., Duran, I., Eleftheriadis, C., Ferrari, A., Finocchiaro, P., Fraval, K., Ganesan, S., García, A. R., Giubrone, G., Gómez-Hornillos, M. B., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Heinitz, S., Jenkins, D. G., Jericha, E., Käppeler, F., Karadimos, D., Kivel, N., Kokkoris, M., Krtička, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Leong, L. S., Meo, S. Lo, Losito, R., Manousos, A., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Mendoza, E., Milazzo, P. M., Mingrone, F., Mirea, M., Mondalaers, W., Musumarra, A., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A., Praena, J., Quesada, J., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J. L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Versaci, R., Vermeulen, M. J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., and Wright, T.

Subjects
Nuclear Experiment
Abstract

The integral measurement of the $^{12}$C(n,p)$^{12}$B reaction was performed at the neutron time of flight facility n_TOF at CERN. The total number of $^{12}$B nuclei produced per neutron pulse of the n_TOF beam was determined using the activation technique in combination with a time of flight technique. The cross section is integrated over the n_TOF neutron energy spectrum from reaction threshold at 13.6 MeV to 10 GeV. Having been measured up to 1 GeV on basis of the $^{235}$U(n,f) reaction, the neutron energy spectrum above 200 MeV has been reevaluated due to the recent extension of the cross section reference for this particular reaction, which is otherwise considered a standard up to 200 MeV. The results from the dedicated GEANT4 simulations have been used to evaluate the neutron flux from 1 GeV up to 10 GeV. The experimental results related to the $^{12}$C(n,p)$^{12}$B reaction are compared with the evaluated cross sections from major libraries and with the predictions of different GEANT4 models, which mostly underestimate the $^{12}$B production. On the contrary, a good reproduction of the integral cross section derived from measurements is obtained with TALYS-1.6 calculations, with optimized parameters., Comment: 14 pages, 11 figures, 3 tables

Published
2016
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18. Experimental setup and procedure for the measurement of the 7Be(n,{\alpha}){\alpha} reaction at n_TOF

Author

Cosentino, L., Musumarra, A., Barbagallo, M., Pappalardo, A., Colonna, N., Damone, L., Piscopo, M., Finocchiaro, P., Maugeri, E., Heinitz, S., Schumann, D., Dressler, R., Kivel, N., Aberle, O., Andrzejewski, J., Audouin, L., Ayranov, M., Bacak, M., Barros, S., Balibrea-Correa, J., Beecares, V., Becvar, F., Beinrucker, C., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamano, M., Calviani, M., Calvino, F., Cano-Ott, D., Cardella, R., Casanovas, A., Castelluccio, D. M., Cerutti, F., Chen, Y. H., Chiaveri, E., Cortes, G., Cortes-Giraldo, M. A., Diakaki, M., Domingo-Pardo, C., Dupont, E., Duran, I., Fernandez-Dominguez, B., Ferrari, A., Ferreira, P., Furman, W., Ganesan, S., Garcia-Rios, A., Gawlik, A., Gheorghe, I., Glodariu, T., Goebel, K., Goncalves, I. F., Gonzalez-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heftrich, T., Heyse, J., Jenkins, D. G., Jericha, E., Kaeppeler, F., Katabuchi, T., Kavrigin, P., Kimura, A., Kokkoris, M., Krticka, M., Leal-Chidonca, E., Lerendegui, J., Lederer, C., Leeb, H., Meo, S. Lo, Lonsdale, S., Losito, R., Macina, D., Marganiec, J., Martinez, T., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Mirea, M., Montesano, S., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Praena, J., Quesada, J., Rajeev, K., Rauscher, T., Reifarth, R., Riego-Perez, A., Rout, P., Rubbia, C., Ryan, J., Sabate-Gilarte, M., Saxena, A., Schillebeeckx, P., Schmidt, S., Sedyshev, P., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeno-Saldivia, A., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Vollaire, J., Wallner, A., Warren, S., Weigand, M., Weiß, C., Wolf, C., Woods, P. J., Wright, T., Zugec, P., and collaboration, n_TOF

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract

The newly built second experimental area EAR2 of the n_TOF spallation neutron source at CERN allows to perform (n, charged particles) experiments on short-lived highly radioactive targets. This paper describes a detection apparatus and the experimental procedure for the determination of the cross-section of the 7Be(n,{\alpha}) reaction, which represents one of the focal points toward the solution of the cosmological Lithium abundance problem, and whose only measurement, at thermal energy, dates back to 1963. The apparently unsurmountable experimental difficulties stemming from the huge 7Be {\gamma}-activity, along with the lack of a suitable neutron beam facility, had so far prevented further measurements. The detection system is subject to considerable radiation damage, but is capable of disentangling the rare reaction signals from the very high background. This newly developed setup could likely be useful also to study other challenging reactions requiring the detectors to be installed directly in the neutron beam., Comment: submitted to Nuclear Instruments and Methods in Physics Research A

Published
2016
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19. Measurement and analysis of the Am-243 neutron capture cross section at the n_TOF facility at CERN

Author

Collaboration, n_TOF, Mendoza, E., Cano-Ott, D., Guerrero, C., Berthoumieux, E., Abbondanno, U., Aerts, G., Alvarez-Velarde, F., Andriamonje, S., Andrzejewski, J., Assimakopoulos, P., Audouin, L., Badurek, G., Balibrea, J., Baumann, P., Becvar, F., Belloni, F., Calvino, F., Calviani, M., Capote, R., Carrapico, C., de Albornoz, A. Carrillo, 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., 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., 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., Ketlerov, V., Kerveno, M., Koehler, P., Konovalov, V., Kossionides, E., Krticka, M., Lampoudis, C., Leeb, H., Lindote, A., Lopes, I., Lossito, R., 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., Brien, S. O, 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., Savvidis, I., Stephan, C., Tagliente, G., Tain, J. L., Tassan-Got, L., Tavora, L., Terlizzi, R., Vannini, G., Vaz, P., Ventura, A., Villamarin, D., Vicente, M. C., Vlachoudis, V., Vlastou, R., Voss, F., Walter, S., Wendler, H., Wiescher, M., and Wisshak, K.

Subjects
Nuclear Experiment
Abstract

Background:The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Reduce the $^{243}$Am(n,$\gamma$) cross section uncertainty. Method: The $^{243}$Am(n,$\gamma$) cross section has been measured at the n_TOF facility at CERN with a BaF$_{2}$ Total Absorption Calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The $^{243}$Am(n,$\gamma$) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature has been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the $^{243}$Am(n,$\gamma$) cross section uncertainty and suggest that this cross section is underestimated up to 25% in the neutron energy range between 50 eV and a few keV in the present evaluated data libraries.

Published
2014
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20. High accuracy determination of the $^{238}$U/$^{235}$U fission cross section ratio up to $\sim$1 GeV at n_TOF (CERN)

Author

Paradela, C., Calviani, M., Tarrío, D., Leal-Cidoncha, E., Leong, L. S., Tassan-Got, L., Naour, C. Le, Duran, I., Colonna, N., Audouin, L., Mastromarco, M., Meo, S. Lo, Ventura, A., Altstadt, S., Andrzejewski, J., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Bosnar, D., Brugger, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Diakaki, M., Domingo-Pardo, C., Dressler, R., Eleftheriadis, C., Ferrari, A., Finocchiaro, P., Fraval, K., Ganesan, S., García, A. R., Giubrone, G., Gómez-Hornillos, M. B., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Heinitz, S., Jenkins, D. G., Jericha, E., Käppeler, F., Karadimos, D., Kivel, N., Kokkoris, M., Krtička, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Losito, R., Manousos, A., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Mirea, M., Mondalaers, W., Musumarra, A., Pavlik, A., Perkowski, J., Plompen, A., Praena, J., Quesada, J., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J. L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Versaci, R., Vermeulen, M. J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., Wright, T., and Žugec, P.

Subjects
Nuclear Experiment
Abstract

The $^{238}$U to $^{235}$U fission cross section ratio has been determined at n_TOF up to $\sim$1 GeV, with two different detection systems, in different geometrical configurations. A total of four datasets have been collected and compared. They are all consistent to each other within the relative systematic uncertainty of 3-4%. The data collected at n_TOF have been suitably combined to yield a unique fission cross section ratio as a function of the neutron energy. The result confirms current evaluations up to 200 MeV. A good agreement is also observed with theoretical calculations based on the INCL++/Gemini++ combination up to the highest measured energy. The n_TOF results may help solving a long-standing discrepancy between the two most important experimental dataset available so far above 20 MeV, while extending the neutron energy range for the first time up to $\sim$1 GeV.

Published
2014
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21. Measurement of the $^{12}$C($n,p$)$^{12}$B cross section at n_TOF (CERN) by in-beam activation analysis

Author

Žugec, P., Colonna, N., Bosnar, D., Mengoni, A., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Brugger, M., Calviani, M., Cano-Ott, F. Calviño D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Diakaki, M., Domingo-Pardo, C., Dressler, R., Duran, I., Eleftheriadis, C., Ferrari, A., Finocchiaro, P., Fraval, K., Ganesan, S., García, A. R., Giubrone, G., Gómez-Hornillos, M. B., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Heinitz, S., Jenkins, D. G., Jericha, E., Käppeler, F., Karadimos, D., Kivel, N., Kokkoris, M., Krtička, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Leong, L. S., LoMeo, S., Losito, R., Manousos, A., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Mendoza, E., Milazzo, P. M., Mingrone, F., Mirea, M., Mondalaers, W., Musumarra, A., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A., Praena, J., Quesada, J., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J. L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Versaci, R., Vermeulen, M. J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., and Wright, T.

Subjects
Nuclear Experiment
Abstract

The integral cross section of the $^{12}$C($n,p$)$^{12}$B reaction has been determined for the first time in the neutron energy range from threshold to several GeV at the n_TOF facility at CERN. The measurement relies on the activation technique, with the $\beta$-decay of $^{12}$B measured over a period of four half-lives within the same neutron bunch in which the reaction occurs. The results indicate that model predictions, used in a variety of applications, are mostly inadequate. The value of the integral cross section reported here can be used as a benchmark for verifying or tuning model calculations., Comment: 6 pages, 4 figures

Published
2014
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22. GEANT4 simulation of the neutron background of the C$_6$D$_6$ set-up for capture studies at n_TOF

Author

collaboration, n_TOF, Žugec, P., Colonna, N., Bosnar, D., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M. A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Duran, I., Dzysiuk, N., Eleftheriadis, C., Ferrari, A., Fraval, K., Ganesan, S., García, A. R., Giubrone, G., Gómez-Hornillos, M. B., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Heinitz, S., Jenkins, D. G., Jericha, E., Kadi, Y., Käppeler, F., Karadimos, D., Kivel, N., Koehler, P., Kokkoris, M., Krtička, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Leong, L. S., Meo, S. Lo, Losito, R., Manousos, A., Marganiec, J., Martìnez, T., Massimi, C., Mastinu, P. F., Mastromarco, M., Meaze, M., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Mirea, M., Mondalaers, W., Paradela, C., Pavlik, A., Perkowski, J., Plompen, A., Praena, J., Quesada, J. M., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J. L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Versaci, R., Vermeulen, M. J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., and Wright, T.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

The neutron sensitivity of the C$_6$D$_6$ detector setup used at n_TOF for capture measurements has been studied by means of detailed GEANT4 simulations. A realistic software replica of the entire n_TOF experimental hall, including the neutron beam line, sample, detector supports and the walls of the experimental area has been implemented in the simulations. The simulations have been analyzed in the same manner as experimental data, in particular by applying the Pulse Height Weighting Technique. The simulations have been validated against a measurement of the neutron background performed with a $^\mathrm{nat}$C sample, showing an excellent agreement above 1 keV. At lower energies, an additional component in the measured $^\mathrm{nat}$C yield has been discovered, which prevents the use of $^\mathrm{nat}$C data for neutron background estimates at neutron energies below a few hundred eV. The origin and time structure of the neutron background have been derived from the simulations. Examples of the neutron background for two different samples are demonstrating the important role of accurate simulations of the neutron background in capture cross section measurements.

Published
2014
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23. $^{62}$Ni($n,\gamma$) and $^{63}$Ni($n,\gamma$) cross sections measured at n_TOF/CERN

Author

Lederer, C., Massimi, C., Berthoumieux, E., Colonna, N., Dressler, R., Guerrero, C., Gunsing, F., Käppeler, F., Kivel, N., Pignatari, M., Reifarth, R., Schumann, D., Wallner, A., Altstadt, S., Andriamonje, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Becares, V., Becvar, F., Belloni, F., Berthier, B., Billowes, J., Boccone, V., Bosnar, D., Brugger, M., Calviani, M., Calvino, F., Cano-Ott, D., Carrapico, C., Cerutti, F., Chiaveri, E., Chin, M., Cortes, G., Cortes-Giraldo, M. A., Dillmann, I., Domingo-Pardo, C., Duran, I., Dzysiuk, N., Eleftheriadis, C., Fernandez-Ordonez, M., Ferrari, A., Fraval, K., Ganesan, S., Garcıa, A. R., Giubrone, G., Gomez-Hornillos, M. B., Goncalves, I. F., Gonzalez-Romero, E., Gramegna, F., Griesmayer, E., Gurusamy, P., Harrisopulos, S., Heil, M., Ioannides, K., Jenkins, D. G., Jericha, E., Kadi, Y., Karadimos, D., Korschinek, G., Krticka, M., Kroll, J., Langer, C., Lebbos, E., Leeb, H., Leong, L. S., Losito, R., Lozano, M., Manousos, A., Marganiec, J., Marrone, S., Martinez, T., Mastinu, P. F., Mastromarco, M., Meaze, M., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Mirea, M., Mondalaers, W., Paradela, C., Pavlik, A., Perkowski, J., Plag, R., Plompen, A., Praena, J., Quesada, J. M., Rauscher, T., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Schillebeeckx, P., Schmidt, S., Tagliente, G., Tain, J. L., Tarrıo, D., Tassan-Got, L., Tsinganis, A., Tlustos, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vermeulen, M. J., Versaci, R., Vlachoudis, V., Vlastou, R., Ware, T., Weigand, M., Weiß, C., Wright, T. J., and Zugec, P.

Subjects
Nuclear Experiment
Abstract

The cross section of the $^{62}$Ni($n,\gamma$) reaction was measured with the time-of-flight technique at the neutron time-of-flight facility n_TOF at CERN. Capture kernels of 42 resonances were analyzed up to 200~keV neutron energy and Maxwellian averaged cross sections (MACS) from $kT=5-100$ keV were calculated. With a total uncertainty of 4.5%, the stellar cross section is in excellent agreement with the the KADoNiS compilation at $kT=30$ keV, while being systematically lower up to a factor of 1.6 at higher stellar temperatures. The cross section of the $^{63}$Ni($n,\gamma$) reaction was measured for the first time at n_TOF. We determined unresolved cross sections from 10 to 270 keV with a systematic uncertainty of 17%. These results provide fundamental constraints on $s$-process production of heavier species, especially the production of Cu in massive stars, which serve as the dominant source of Cu in the solar system.

Published
2014
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24. Experimental neutron capture data of $^{58}$Ni from the CERN n_TOF facility

Author

collaboration, n_TOF, Žugec, P., Barbagallo, M., Colonna, N., Bosnar, D., Altstadt, S., Andrzejewski, J., Audouin, L., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Cortés, G., Cortés-Giraldo, M. A., Diakaki, M., Domingo-Pardo, C., Duran, I., Dzysiuk, N., Eleftheriadis, C., Ferrari, A., Fraval, K., Ganesan, S., García, A. R., Giubrone, G., Gómez-Hornillos, M. B., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Jenkins, D. G., Jericha, E., Kadi, Y., Käppeler, F., Karadimos, D., Koehler, P., Kokkoris, M., Krtička, M., Kroll, J., Langer, C., Lederer, C., Leeb, H., Leong, L. S., Losito, R., Manousos, A., Marganiec, J., Martìnez, T., Massimi, C., Mastinu, P. F., Mastromarco, M., Meaze, M., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Mirea, M., Mondalaers, W., Paradela, C., Pavlik, A., Perkowski, J., Pignatari, M., Plompen, A., Praena, J., Quesada, J. M., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Schillebeeckx, P., Schmidt, S., Tagliente, G., Tain, J. L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Versaci, R., Vermeulen, M. J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., and Wright, T.

Subjects
Nuclear Experiment
Abstract

The $^{58}$Ni $(n,\gamma)$ cross section has been measured at the neutron time of flight facility n_TOF at CERN, in the energy range from 27 meV up to 400 keV. In total, 51 resonances have been analyzed up to 122 keV. Maxwellian averaged cross sections (MACS) have been calculated for stellar temperatures of kT$=$5-100 keV with uncertainties of less than 6%, showing fair agreement with recent experimental and evaluated data up to kT = 50 keV. The MACS extracted in the present work at 30 keV is 34.2$\pm$0.6$_\mathrm{stat}\pm$1.8$_\mathrm{sys}$ mb, in agreement with latest results and evaluations, but 12% lower relative to the recent KADoNIS compilation of astrophysical cross sections. When included in models of the s-process nucleosynthesis in massive stars, this change results in a 60% increase of the abundance of $^{58}$Ni, with a negligible propagation on heavier isotopes. The reason is that, using both the old or the new MACS, 58Ni is efficiently depleted by neutron captures., Comment: 10 pages, 8 figures, 5 tables

Published
2014
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25. Neutron capture cross section of unstable 63Ni: implications for stellar nucleosynthesis

Author

Lederer, C., Massimi, C., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bevá, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Bosnar, D., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Diakaki, M., Domingo-Pardo, C., Duran, I., Dressler, R., Dzysiuk, N., Eleftheriadis, C., Ferrari, A., Fraval, K., Ganesan, S., García, A. R., Giubrone, G., Gómez-Hornillos, M. B., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Gurusamy, P., Jenkins, D. G., Jericha, E., Kadi, Y., Käppeler, F., Karadimos, D., Kivel, N., Koehler, P., Kokkoris, M., Korschinek, G., Krtika, M., Kroll, J., Langer, C., Leeb, H., Leong, L. S., Losito, R., Manousos, A., Marganiec, J., Martínez, T., Mastinu, P. F., Mastromarco, M., Meaze, M., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Mirea, M., Mondelaers, W., Paradela, C., Pavlik, A., Perkowski, J., Pignatari, M., Plompen, A., Praena, J., Quesada, J. M., Rauscher, T., Reifarth, R., Riego, A., Roman, F., Rubbia, C., Sarmento, R., Schillebeeckx, P., Schmidt, S., Schumann, D., Tagliente, G., Tain, J. L., Tarrío, D., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Versaci, R., Vermeulen, M. J., Vlachoudis, V., Vlastou, R., Wallner, A., Ware, T., Weigand, M., Weiß, C., Wright, T. J., and Zugec, P.

Subjects
Nuclear Experiment, Astrophysics - Solar and Stellar Astrophysics
Abstract

The $^{63}$Ni($n, \gamma$) cross section has been measured for the first time at the neutron time-of-flight facility n\_TOF at CERN from thermal neutron energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian Averaged Cross Sections were calculated for thermal energies from kT = 5 keV to 100 keV with uncertainties around 20%. Stellar model calculations for a 25 M$_\odot$ star show that the new data have a significant effect on the $s$-process production of $^{63}$Cu, $^{64}$Ni, and $^{64}$Zn in massive stars, allowing stronger constraints on the Cu yields from explosive nucleosynthesis in the subsequent supernova.

Published
2013
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26. Measurement of charged pions in 12C + 12C collisions at 1A GeV and 2A GeV with HADES

Author

The HADES Collaboration, Agakishiev, G., Agodi, C., Balanda, A., Bellia, G., Belver, D., Belyaev, A., Bielcik, J., Blanco, A., Bortolotti, A., Boyard, J. L., Braun-Munzinger, P., Cabanelas, P., Chernenko, S., Christ, T., Coniglione, R., Destefanis, M., Diaz, J., Dohrmann, F., Duran, I., Dybczak, A., Eberl, T., Fabbietti, L., Fateev, O., Ferreira-Marques, R., Finocchiaro, P., Fonte, P., Friese, J., Froehlich, I., Galatyuk, T., Garzon, J. A., Gernhaeuser, R., Gil, A., Gilardi, C., Golubeva, M., Gonzalez-Diaz, D., Grosse, E., Guber, F., Heilmann, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kaempfer, B., Kanaki, K., Karavicheva, T., Kirschner, D., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Kozuch, A., Krasa, A., Krizek, F., Kruecken, R., Kuehn, W., Kugler, A., Kurepin, A., Lamas-Valverde, J., Lang, S., Lange, J. S., Lapidus, K., Lopes, L., Lorenz, M., Maier, L., Maiolino, C., Mangiarotti, A., Marin, J., Markert, J., Metag, V., Michalska, B., Michel, J., Moriniere, E., Mousa, J., Muench, M., Muentz, C., Naumann, L., Novotny, R., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Cavalcanti, T. Perez, Piattelli, P., Pietraszko, J., Pospisil, V., Przygoda, W., Ramstein, B., Reshetin, A., Roy-Stephan, M., Rustamov, A., Sadovsky, A., Sailer, B., Salabura, P., Sapienza, P., Schmah, A., Schroeder, C., Schwab, E., Simon, R. S., Sobolev, Yu. G., Spataro, S., Spruck, B., Stroebele, H., Stroth, J., Sturm, C., Sudol, M., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Weber, M., Wisniowski, M., Wojcik, T., Wuestenfeld, J., Yurevich, S., Zanevsky, Y., Zhou, P., and Zumbruch, P.

Subjects
Nuclear Experiment
Abstract

We present the results of a study of charged pion production in 12C + 12C collisions at incident beam energies of 1A GeV and 2A GeV using the HADES spectrometer at GSI. The main emphasis of the HADES program is on the dielectron signal from the early phase of the collision. Here, however, we discuss the data with respect to the emission of charged hadrons, specifically the production of pi+- mesons, which are related to neutral pions representing a dominant contribution to the dielectron yield. We have performed the first large-angular range measurement of the distribution of pi+- mesons for the 12C + 12C collision system covering a fairly large rapidity interval. The pion yields, transverse-mass and angular distributions are compared with calculations done within a transport model, as well as with existing data from other experiments. The anisotropy of pion production is systematically analyzed., Comment: 15 pages, 13 figures, v2 - the text unchanged, only full author list added to METADATA (in v1 only the first author and collaboration name), reference to published paper added

Published
2009
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27. Constraints on the dipole photon strength for the odd uranium isotopes

Author

N_TOF Collaboration, Moreno-Soto, J., Valenta, S., Berthoumieux, E., Chebboubi, A., Diakaki, M., Dridi, W., Dupont, E., Gunsing, F., Krticka, M., Litaize, O., Serot, O., Aberle, O., Alcayne, V., Amaducci, S., Andrzejewski, J., Audouin, L., Bécares, V., Babiano-Suarez, V., Bacak, M., Barbagallo, M., Benedikt, T., Bennett, S., Billowes, J., Bosnar, D., Brown, A., Busso, M., Caamaño, M., Caballero-Ontanaya, L., Calviño, F., Calviani, M., Cano-Ott, D., Casanovas, A., Cerutti, F., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Damone, L. A., Davies, P. J., Dietz, M., Domingo-Pardo, C., Dressler, R., Ducasse, Q., Durán, I., Eleme, Z., Fernández-Domínguez, B., Ferrari, A., Finocchiaro, P., Furman, V., Göbel, K., Gawlik-Ramiga, A., Gilardoni, S., Gonçalves, I. F., González-Romero, E., Guerrero, C., Heinitz, S., Heyse, J., Jenkins, D. G., Junghans, A., Käppeler, F., Kadi, Y., Kimura, A., Knapová, I., Kokkoris, M., Kopatch, Y., Kurtulgil, D., Ladarescu, I., Lampoudis, C., Lederer-Woods, C., Lonsdale, S. J., Macina, D., Manna, A., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Ogállar, F., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Piersanti, L., Petrone, C., Pirovano, E., Porras, I., Praena, J., Quesada, J. M., Ramos-Doval, D., Rauscher, T., Reifarth, R., Rochman, D., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N. V., Sprung, P., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Torres-Sánchez, P., Tsinganis, A., Ulrich, J., Urlass, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Physics, ddc:530, Nuclear Experiment
Abstract

Background: The photon strength functions (PSFs) and nuclear level density (NLD) are key ingredients for calculation of the photon interaction with nuclei, in particular the reaction cross sections. These cross sections are important especially in nuclear astrophysics and in the development of advanced nuclear technologies. Purpose: The role of the scissors mode in the M1 PSF of (well-deformed) actinides was investigated by several experimental techniques. The analyses of different experiments result in significant differences, especially on the strength of the mode. The shape of the low-energy tail of the giant electric dipole resonance is uncertain as well. In particular, some works proposed a presence of the E1 pygmy resonance just above 7 MeV. Because of these inconsistencies additional information on PSFs in this region is of great interest. Methods: The γ-ray spectra from neutron-capture reactions on the $^{234}$U, $^{236}$U, and $^{238}$U nuclei have been measured with the total absorption calorimeter of the n_TOF facility at CERN. The background-corrected sum-energy and multi-step-cascade spectra were extracted for several isolated s-wave resonances up to about 140 eV. Results: The experimental spectra were compared to statistical model predictions coming from a large selection of models of photon strength functions and nuclear level density. No combination of PSF and NLD models from literature is able to globally describe our spectra. After extensive search we were able to find model combinations with modified generalized Lorentzian (MGLO) E1 PSF, which match the experimental spectra as well as the total radiative widths. Conclusions: The constant temperature energy dependence is favored for a NLD. The tail of giant electric dipole resonance is well described by the MGLO model of the E1 PSF with no hint of pygmy resonance. The M1 PSF must contain a very strong, relatively wide, and likely double-resonance scissors mode. The mode is responsible for about a half of the total radiative width of neutron resonances and significantly affects the radiative cross section.

Published
2022

28. First 80Se(n,γ) cross section measurement with high resolution in the full stellar energy range 1 eV - 100 keV and its astrophysical implications for the s-process

Author

Babiano-Suarez, V, Balibrea-Correa, J, Caballero-Ontanaya, L, Domingo-Pardo, C, Ladarescu, I, Lerendegui-Marco, J, Tain, J L, Calviño, F, Casanovas, A, Tarifeño-Saldivia, A, Guerrero, C, Aberle, O, Alcayne, V, Amaducci, S, Andrzejewski, J, Audouin, L, Bacak, M, Barbagallo, M, Bennett, S, Berthoumieux, E, Billowes, J, Bosnar, D, Brown, A, Busso, M, Caamaño, M, Calviani, M, Cano-Ott, D, Cerutti, F, Chiaveri, E, Colonna, N, Cortés, G, CortésGiraldo, M A, Cosentino, L, Cristallo, S, Damone, L A, Davies, P J, Diakaki, M, Dietz, M, Dressler, R, Ducasse, Q, Dupont, E, Durán, I, Eleme, Z, Fernández-Domínguez, B, Ferrari, A, Finocchiaro, P, Furman, V, Göbel, K, Garg, R, Gawlik-Ramięga, A, Gilardoni, S, Gonçalves, I F, González-Romero, E, Gunsing, F, Harada, H, Heinitz, S, Heyse, J, Jenkins, D G, Junghans, A, Käppeler, F, Kadi, Y, Kimura, A, Knapová, I, Kokkoris, M, Kopatch, Y, Krtička, M, Kurtulgil, D, Lederer-Woods, C, Leeb, H, Lonsdale, S J, Macina, D, Manna, A, Martínez, T, Masi, A, Massimi, C, Mastinu, P, Mastromarco, M, Maugeri, E A, Mazzone, A, Mendoza, E, Mengoni, A, Michalopoulou, V, Milazzo, P M, Mingrone, F, Moreno-Soto, J, Musumarra, A, Negret, A, Nolte, R, Ogállar, F, Oprea, A, Patronis, N, Pavlik, A, Perkowski, J, Persanti, L, Petrone, C, Pirovano, E, Porras, I, Praena, J, Quesada, J M, Ramos-Doval, D, Rauscher, T, Reifarth, R, Rochman, D, Romanets, Y, Rubbia, C, Sabaté-Gilarte, M, Saxena, A, Schillebeeckx, P, Schumann, D, Sekhar, A, Smith, A G, Sosnin, N V, Sprung, P, Stamatopoulos, A, Tagliente, G, Tassan-Got, L, Thomas, Th, Torres-Sánchez, P, Tsinganis, A, Ulrich, J, Urlass, S, Valenta, S, Vannini, G, Variale, V, Vaz, P, Ventura, A, Vescovi, D, Vlachoudis, V, Vlastou, R, Wallner, A, Woods, P J, Wright, T, Žugec, P, Liu, W., Wang, Y., Guo, B., Tang, X., Zeng, S., 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 sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and n_TOF

Subjects
Physics::Instrumentation and Detectors, Nuclear Physics - Experiment, 80Se, neutron capture, n_TOF, s-process, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract

Most elements heavier than iron have been generated in the stellar media by means of neutron capture reactions, approximately half are produced by the slow neutron capture or s-process. Radiative neutron capture cross section measurements are of fundamental importance for the study of this mechanism. In this contribution we present a brief summary on the measurement and results for the 80Se(n,γ) cross-section. The experiment was carried out at CERN n_TOF EAR1 via the time of flight (ToF) technique, using four C6D6 scintillation detectors with very fast response. More than a hundred new resonances have been analyzed for the first time with a high accuracy. The MACS obtained at kT = 8 keV is 36% smaller than the recommended value in KADo-NiS. Some of the astrophysical implications of this result are elucidated in this contribution.

Published
2022
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29. Destruction of the cosmic γ-ray emitter $^{26}$Al in massive stars: Study of the key $^{26}$Al$(n,\alpha)$ reaction

Author

Lederer-Woods, C., Woods, P.J., Davinson, T., Estrade, A., Heyse, J., Kahl, D., Lonsdale, S.J., Paradela, C., Schillebeeckx, P., Aberle, O., Amaducci, S., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chen, Y.H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Cristallo, S., Damone, L.A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Ferrer, F.J., Finocchiaro, P., Furman, V., Göbel, K., García, A.R., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I.F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Macina, D., Manna, A., Marganiec, J., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E.A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P.M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Quesada, J.M., Radeck, D., Rauscher, T., Reifarth, R., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Saxena, A., Schumann, D., Sedyshev, P., Smith, A.G., Sosnin, N.V., Stamatopoulos, A., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weiss, C., Wright, T., Žugec, P., 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, n_TOF, and 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)

Subjects
Astrophysics and Astronomy, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Astrophysics::High Energy Astrophysical Phenomena, Nuclear Physics - Theory, Astrophysics::Cosmology and Extragalactic Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nuclear Experiment, Astrophysics::Galaxy Astrophysics
Abstract

International audience; Neutron destruction reactions of the cosmic $\gamma$-ray emitter $^{26}$Al are of importance to determine the amount of $^{26}$Al ejected into our galaxy by supernova explosions and for 26 Al production in asymptotic giant branch stars. We performed a new measurement of the $^{26}$Al$(n, \alpha)$ reaction up to 160-keV neutron energy at the neutron time-of-flight facilities n_TOF at CERN and GELINA at EC-JRC. We provide strengths for ten resonances, six of them for the first time. We use our data to calculate astrophysical reactivities for stellar temperatures up to 0.7 GK. Our results resolve a discrepancy between the two previous direct measurements of this reaction, and indicate higher stellar destruction rates than the most recently recommended reactivity.

Published
2021
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30. Measurement of the $^{76}\mathrm{Ge}(n,{\gamma})$ cross section at the n_TOF facility at CERN

Author

Gawlik-Ramięga, A., Lederer-Woods, C., Krtička, M., Valenta, S., Battino, U., Andrzejewski, J., Perkowski, J., Aberle, O., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Barros, S., Bécares, V., Bečvář, F., Beinrucker, C., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Castelluccio, D.M., Cerutti, F., Chen, Y.H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Damone, L.A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Furman, V., Göbel, K., García, A.R., Glodariu, T., Gonçalves, I.F., González-Romero, E., Goverdovski, A., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heftrich, T., Heinitz, S., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Knapová, I., Kokkoris, M., Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S.J., Losito, R., Macina, D., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E.a., Mendoza, E., Mengoni, A., Milazzo, P.M., Mingrone, F., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Porras, J.I., Praena, J., Quesada, J.M., Rajeev, K., Rauscher, T., Reifarth, R., Riego-Perez, A., Rout, P.C., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A.G., Stamatopoulos, A., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tassan-Got, L., Tattersall, A., Tsinganis, A., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Weiss, C., Wolf, C., Woods, P.J., Wright, T., Žugec, P., 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 sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, n_TOF, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics in General, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Experiment, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph]
Abstract

International audience; The $^{76}\mathrm{Ge}(n,{\gamma})$ reaction has been measured at the n_TOF facility at CERN via the time-of-flight technique. Neutron capture cross sections on $^{76}$Ge are of interest to a variety of low-background experiments, such as neutrinoless double β decay searches, and to nuclear astrophysics. We have determined resonance capture kernels up to 52 keV neutron energy and used the new data to calculate Maxwellian-averaged neutron capture cross sections for kBT values of 5 to 100 keV.

Published
2021
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31. Destruction of the cosmic γ -ray emitter $^{26}$Al in massive stars: Study of the key $^{26}$Al (n,α) reaction

Author

Lederer-Woods, C., Woods, P. J., Davinson, T., Estrade, A., Heyse, J., Kahl, D., Lonsdale, S. J., Paradela, C., Schillebeeckx, P., Aberle, O., Amaducci, S., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Damone, L. A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Ferrer, F. J., Finocchiaro, P., Furman, V., Göbel, K., García, A. R., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Macina, D., Manna, A., Marganiec, J., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rauscher, T., Reifarth, R., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A., Schumann, D., Sedyshev, P., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weiss, C., Wright, T., Žugec, P., and N_TOF Collaboration

Subjects
Astrophysics::High Energy Astrophysical Phenomena, ddc:000, Astrophysics::Cosmology and Extragalactic Astrophysics, Nuclear Experiment, Computer science, information & general works, Astrophysics::Galaxy Astrophysics
Abstract

Neutron destruction reactions of the cosmic γ-ray emitter $^{26}$Al are of importance to determine the amount of $^{26}$Al ejected into our galaxy by supernova explosions and for $^{26}$Al production in asymptotic giant branch stars. We performed a new measurement of the $^{26}$Al(n,α) reaction up to 160-keV neutron energy at the neutron time-of-flight facilities n_TOF at CERN and GELINA at EC-JRC. We provide strengths for ten resonances, six of them for the first time. We use our data to calculate astrophysical reactivities for stellar temperatures up to 0.7 GK. Our results resolve a discrepancy between the two previous direct measurements of this reaction, and indicate higher stellar destruction rates than the most recently recommended reactivity.

Published
2021

32. Destruction of the cosmic γ -ray emitter Al 26 in massive stars: Study of the key Al 26 (n,α) reaction

Author

Lederer-Woods, C., Woods, P. J., Davinson, T., Estrade, A., Heyse, J., Kahl, D., Lonsdale, S. J., Paradela, C., Schillebeeckx, P., Aberle, O., Amaducci, S., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Bečvář, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., CRISTALLO, Sergio, Damone, L. A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Ferrer, F. J., Finocchiaro, P., Furman, V., Göbel, K., García, A. R., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Macina, D., Manna, A., Marganiec, J., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rauscher, T., ITA, USA, GBR, FRA, DEU, and ESP

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Nuclear Experiment, Astrophysics::Galaxy Astrophysics
Abstract

Neutron destruction reactions of the cosmic γ-ray emitter Al26 are of importance to determine the amount of Al26 ejected into our galaxy by supernova explosions and for Al26 production in asymptotic giant branch stars. We performed a new measurement of the Al26(n,α) reaction up to 160-keV neutron energy at the neutron time-of-flight facilities n_TOF at CERN and GELINA at EC-JRC. We provide strengths for ten resonances, six of them for the first time. We use our data to calculate astrophysical reactivities for stellar temperatures up to 0.7 GK. Our results resolve a discrepancy between the two previous direct measurements of this reaction, and indicate higher stellar destruction rates than the most recently recommended reactivity.

Published
2021

33. Measurement of the ${}^{72}\mathrm{Ge}(n,\gamma)$ cross section over a wide neutron energy range at the CERN n_TOF facility

Author

DIETZ, M., LEDERER-WOODS, C., TATTERSALL, A., BATTINO, U., GUNSING, F., HEINITZ, S., KRTIČKA, M., LERENDEGUI-MARCO, J., REIFARTH, R., VALENTA, S., ABERLE, O., AMADUCCI, S., ANDRZEJEWSKI, J., AUDOUIN, L., BACAK, M., BALIBREA, J., BARBAGALLO, M., BEČVÁŘ, F., BERTHOUMIEUX, E., BILLOWES, J., BOSNAR, D., BROWN, A., CAAMAÑO, M., CALVIÑO, F., CALVIANI, M., CANO-OTT, D., CARDELLA, R., CASANOVAS, A., CERUTTI, F., CHEN, Y.H., CHIAVERI, E., COLONNA, N., CORTÉS, G., CORTÉS-GIRALDO, M.A., COSENTINO, L., DAMONE, L.A., DIAKAKI, M., DOMINGO-PARDO, C., DRESSLER, R., DUPONT, E., DURÁN, I., FERNÁNDEZ-DOMÍNGUEZ, B., FERRARI, A., FERREIRA, P., FINOCCHIARO, P., FURMAN, V., GÖBEL, K., GARCÍA, A.R., GAWLIK, A., GILARDONI, S., GLODARIU, T., GONÇALVES, I.F., GONZÁLEZ-ROMERO, E., GRIESMAYER, E., GUERRERO, C., HARADA, H., HEYSE, J., JENKINS, D.G., JERICHA, E., KÄPPELER, F., KADI, Y., KAHL, D., KALAMARA, A., KAVRIGIN, P., KIMURA, A., KIVEL, N., KOKKORIS, M., KURTULGIL, D., LEAL-CIDONCHA, E., LEEB, H., LO MEO, S., LONSDALE, S.J., MACINA, D., MANNA, A., MARGANIEC, J., MARTÍNEZ, T., MASI, A., MASSIMI, C., MASTINU, P., MASTROMARCO, M., MAUGERI, E.a., MAZZONE, A., MENDOZA, E., MENGONI, A., MILAZZO, P.M., MINGRONE, F., MUSUMARRA, A., NEGRET, A., NOLTE, R., OPREA, A., PATRONIS, N., PAVLIK, A., PERKOWSKI, J., PORRAS, I., PRAENA, J., QUESADA, J.M., RADECK, D., RAUSCHER, T., RUBBIA, C., RYAN, J.A., SABATÉ-GILARTE, M., SAXENA, A., SCHILLEBEECKX, P., SCHUMANN, D., SEDYSHEV, P., SMITH, A.G., SOSNIN, N.V., STAMATOPOULOS, A., TAGLIENTE, G., TAIN, J.L., TARIFEÑO-SALDIVIA, A., TASSAN-GOT, L., VANNINI, G., VARIALE, V., VAZ, P., VENTURA, A., VLACHOUDIS, V., VLASTOU, R., WALLNER, A., WARREN, S., WEISS, C., WOODS, P.J., WRIGHT, T., ŽUGEC, P., 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), n_TOF, and 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)

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Nuclear Astrophysics, Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract

International audience; The Ge72(n,γ) cross section was measured for neutron energies up to 300keV at the neutron time-of-flight facility n_TOF (CERN), Geneva, for the first time covering energies relevant to heavy-element synthesis in stars. The measurement was performed at the high-resolution beamline EAR-1, using an isotopically enriched GeO272 sample. The prompt capture γ rays were detected with four liquid scintillation detectors, optimized for low neutron sensitivity. We determined resonance capture kernels up to a neutron energy of 43keV, and averaged cross sections from 43 to 300keV. Maxwellian-averaged cross section values were calculated from kT=5 to 100keV, with uncertainties between 3.2% and 7.1%. The new results significantly reduce uncertainties of abundances produced in the slow neutron capture process in massive stars.

Published
2021
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34. Investigation of the $^{240}$Pu$(n,f)$ reaction at the n_TOF/EAR2 facility in the 9 meV–6 MeV range

Author

Stamatopoulos, A., Tsinganis, A., Colonna, N., Kokkoris, M., Vlastou, R., Diakaki, M., Žugec, P., Schillebeeckx, P., Gunsing, F., Sabaté-Gilarte, M., Barbagallo, M., Aberle, O., Andrzejewski, J., Audouin, L., Bécares, V., Bacak, M., Balibrea, J., Barros, S., Bečvář, F., Beinrucker, C., Belloni, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Lo Meo, S., Calviño, F., Calviani, M., Cano-Ott, D., Cerutti, F., Chiaveri, E., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Damone, L.A., Deo, K., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Frost, R.J.W., Furman, V., Göbel, K., García, A.R., Gheorghe, I., Glodariu, T., Gonçalves, I.F., González-Romero, E., Goverdovski, A., Griesmayer, E., Guerrero, C., Harada, H., Heftrich, T., Heinitz, S., Hernández-Prieto, A., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Knapova, I., Krtička, M., Leal-Cidoncha, E., Lederer, C., Leeb, H., Lerendegui-Marco, J., Licata, M., Losito, R., Macina, D., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Mendoza, E., Mengoni, A., Milazzo, P.M., Mingrone, F., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Palomo-Pinto, F.R., Paradela, C., Patronis, N., Pavlik, A., Perkowski, J., Plompen, A., Porras, J.I., Praena, J., Quesada, J.M., Rauscher, T., Reifarth, R., Riego-Perez, A., Robles, M., Rubbia, C., Ryan, J.A., Saxena, A., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A.G., Suryanarayana, S.V., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Wallner, A., Warren, S., Weigand, M., Weiss, C., Wright, T., 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), n_TOF, and 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)

Subjects
PRIRODNE ZNANOSTI. Fizika, Nuclear Theory, Nuclear Reactions, Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, NATURAL SCIENCES. Physics
Abstract

International audience; Background: Nuclear waste management is considered amongst the major challenges in the field of nuclear energy. A possible means of addressing this issue is waste transmutation in advanced nuclear systems, whose operation requires a fast neutron spectrum. In this regard, the accurate knowledge of neutron-induced reaction cross sections of several (minor) actinide isotopes is essential for design optimization and improvement of safety margins of such systems. One such case is Pu240, due to its accumulation in spent nuclear fuel of thermal reactors and its usage in fast reactor fuel. The measurement of the Pu240(n,f) cross section was previously attempted at the CERN n_TOF facility EAR1 measuring station using the time-of-flight technique. Due to the low amount of available material and the given flux at EAR1, the measurement had to last several months to achieve a sufficient statistical accuracy. This long duration led to detector deterioration due to the prolonged exposure to the high α activity of the fission foils, therefore the measurement could not be successfully completed. Purpose: It is aimed to determine whether it is feasible to study neutron-induced fission at n_TOF/EAR2 and provide data on the Pu240(n,f) reaction in energy regions requested for applications. Methods: The study of the Pu240(n,f) reaction was made at a new experimental area (EAR2) with a shorter flight path which delivered on average 30 times higher flux at fast neutron energies. This enabled the measurement to be performed much faster, thus limiting the exposure of the detectors to the intrinsic activity of the fission foils. The experimental setup was based on microbulk Micromegas detectors and the time-of-flight data were analyzed with an optimized pulse-shape analysis algorithm. Special attention was dedicated to the estimation of the non-negligible counting loss corrections with the development of a new methodology, and other corrections were estimated via Monte Carlo simulations of the experimental setup. Results: This new measurement of the Pu240(n,f) cross section yielded data from 9meV up to 6MeV incident neutron energy and fission resonance kernels were extracted up to 10keV. Conclusions: Neutron-induced fission of high activity samples can be successfully studied at the n_TOF/EAR2 facility at CERN covering a wide range of neutron energies, from thermal to a few MeV.

Published
2020
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35. Investigation of the $^{240}$Pu(n,f) reaction at the n_TOF/EAR2 facility in the 9 meV-6 MeV range

Author

n_TOF Collaboration, Stamatopoulos, A., Tsinganis, A., Colonna, N., Kokkoris, M., Vlastou, R., Diakaki, M., Žugec, P., Schillebeeckx, P., Gunsing, F., Sabaté-Gilarte, M., Barbagallo, M., Aberle, O., Andrzejewski, J., Audouin, L., Bécares, V., Bacak, M., Balibrea, J., Barros, S., Bečvář, F., Beinrucker, C., Belloni, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Lo Meo, S., Calviño, F., Calviani, M., Cano-Ott, D., Cerutti, F., Chiaveri, E., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Damone, L. A., Deo, K., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Frost, R. J. W., Furman, V., Göbel, K., García, A. R., Gheorghe, I., Glodariu, T., Gonçalves, I. F., González-Romero, E., Goverdovski, A., Griesmayer, E., Guerrero, C., Harada, H., Heftrich, T., Heinitz, S., Hernández-Prieto, A., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Knapova, I., Krtička, M., Leal-Cidoncha, E., Lederer, C., Leeb, H., Lerendegui-Marco, J., Licata, M., Losito, R., Macina, D., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Palomo-Pinto, F. R., Paradela, C., Patronis, N., Pavlik, A., Perkowski, J., Plompen, A., Porras, J. I., Praena, J., Quesada, J. M., Rauscher, T., Reifarth, R., Riego-Perez, A., Robles, M., Rubbia, C., Ryan, J. A., Saxena, A., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A. G., Suryanarayana, S. V., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Wallner, A., Warren, S., Weigand, M., Weiss, C., and Wright, T.

Subjects
Physics, ddc:530, Nuclear Experiment
Abstract

Background: Nuclear waste management is considered amongst the major challenges in the field of nuclear energy. A possible means of addressing this issue is waste transmutation in advanced nuclear systems, whose operation requires a fast neutron spectrum. In this regard, the accurate knowledge of neutron-induced reaction cross sections of several (minor) actinide isotopes is essential for design optimization and improvement of safety margins of such systems. One such case is $^{240}$Pu, due to its accumulation in spent nuclear fuel of thermal reactors and its usage in fast reactor fuel. The measurement of the $^{240}$Pu(n,f) cross section was previously attempted at the CERN n_TOF facility EAR1 measuring station using the time-of-flight technique. Due to the low amount of available material and the given flux at EAR1, the measurement had to last several months to achieve a sufficient statistical accuracy. This long duration led to detector deterioration due to the prolonged exposure to the high α activity of the fission foils, therefore the measurement could not be successfully completed. Purpose: It is aimed to determine whether it is feasible to study neutron-induced fission at n_TOF/EAR2 and provide data on the $^{240}$Pu(n,f) reaction in energy regions requested for applications. Methods: The study of the $^{240}$Pu(n,f) reaction was made at a new experimental area (EAR2) with a shorter flight path which delivered on average 30 times higher flux at fast neutron energies. This enabled the measurement to be performed much faster, thus limiting the exposure of the detectors to the intrinsic activity of the fission foils. The experimental setup was based on microbulk Micromegas detectors and the time-of-flight data were analyzed with an optimized pulse-shape analysis algorithm. Special attention was dedicated to the estimation of the non-negligible counting loss corrections with the development of a new methodology, and other corrections were estimated via Monte Carlo simulations of the experimental setup. Results: This new measurement of the $^{240}$Pu(n,f) cross section yielded data from 9 meV up to 6 MeV incident neutron energy and fission resonance kernels were extracted up to 10 keV. Conclusions: Neutron-induced fission of high activity samples can be successfully studied at the n_TOF/EAR2 facility at CERN covering a wide range of neutron energies, from thermal to a few MeV.

Published
2020

36. Measurement of Ge( , ) Cross Sections and Implications for Stellar Nucleosynthesis

Author

Lederer-Woods, C., Battino, U., Ferreira, P., Gawlik, A., Guerrero, C., Gunsing, F., Heinitz, S., Lerendegui-Marco, J., Mengoni, A., Reifarth, R., Tattersall, A., Valenta, S., Weiss, C., Aberle, O., Andrzejewski, J., Audouin, L., Bécares, V., Bacak, M., Balibrea, J., Barbagallo, M., Barros, S., Bečvář, F., Beinrucker, C., Belloni, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cerutti, F., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Damone, L.A., Deo, K., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Finocchiaro, P., Frost, R.J.W., Furman, V., Göbel, K., García, A.R., Gheorghe, I., Glodariu, T., Gonçalves, I.F., González-Romero, E., Goverdovski, A., Griesmayer, E., Harada, H., Heftrich, T., Hernández-Prieto, A., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Knapova, I., Kokkoris, M., Krtička, M., Leal-Cidoncha, E., Leeb, H., Licata, M., Lo Meo, S., Losito, R., Macina, D., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Mendoza, E., Milazzo, P.M., Mingrone, F., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Palomo-Pinto, F.R., Paradela, C., Patronis, N., Pavlik, A., Perkowski, J., Porras, J.I., Praena, J., Quesada, J.M., Rauscher, T., Riego-Perez, A., Robles, M., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A.G., Stamatopoulos, A., Suryanarayana, S.V., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Wright, T., and Žugec, P.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Nuclear Experiment, Computer Science::Digital Libraries
Abstract

$^{73}$Ge(n,γ) cross sections were measured at the neutron time-of-flight facility n_TOF at CERN up to neutron energies of 300 keV, providing for the first time experimental data above 8 keV. Results indicate that the stellar cross section at kT=30 keV is 1.5 to 1.7 times higher than most theoretical predictions. The new cross sections result in a substantial decrease of $^{73}$Ge produced in stars, which would explain the low isotopic abundance of $^{73}$Ge in the solar system.

Published
2019

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

Author

n_TOF Collaboration, Gawlik, A., Lederer-Woods, C., Andrzejewski, J., Battino, U., Ferreira, P., Gunsing, F., Heinitz, S., Krtička, M., Massimi, C., Mingrone, F., Perkowski, J., Reifarth, R., Tattersall, A., Valenta, S., Weiss, C., Aberle, O., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Barros, S., Bécares, V., Bečvář, F., Beinrucker, C., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Castelluccio, D. M., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Damone, L. A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Finocchiaro, P., Furman, V., Göbel, K., García, A. R., Glodariu, T., Gonçalves, I. F., González-Romero, E., Goverdovski, A., Griesmayer, E., Guerrero, C., Harada, H., Heftrich, T., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Knapova, I., Kokkoris, M., Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S. J., Losito, R., Macina, D., Marganiec, J., Martínez, T., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E. A., Mendoza, E., Mengoni, A., Milazzo, P. M., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Porras, J. I., Praena, J., Quesada, J. M., Rajeev, K., Rauscher, T., Riego-Perez, A., Rout, P. C., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A. G., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Wolf, C., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Physics, Astrophysics::Solar and Stellar Astrophysics, ddc:530, Nuclear Experiment
Abstract

Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The (n,γ) cross section on 70Ge, which is mainly produced in the s process, was measured at the neutron time-of-flight facility n_TOF at CERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sections up to 300 keV. Stellar cross sections were calculated from kT=5 keV to kT=100 keV and are in very good agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average cross sections are in agreement with Walter and Beer (1985) over most of the neutron energy range covered, while they are systematically smaller for neutron energies above 150 keV. We have calculated isotopic abundances produced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close to solar model shows a good global match to solar system abundances in the range of mass numbers A=60–80.

Published
2019

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

Author

Lederer-Woods, C., Battino, U., Ferreira, P., Gawlik, A., Guerrero, C., Gunsing, F., Heinitz, S., Lerendegui-Marco, J., Mengoni, A., Reifarth, R., Tattersall, A., Valenta, S., Weiss, C., Aberle, O., Andrzejewski, J., Audouin, L., Bécares, V., Bacak, M., Balibrea, J., Barbagallo, M., Barros, S., Bečvář, F., Beinrucker, C., Belloni, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cerutti, F., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Damone, L. A., Deo, K., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Finocchiaro, P., Frost, R. J. W., Furman, V., Göbel, K., García, A. R., Gheorghe, I., Glodariu, T., Gonçalves, I. F., González-Romero, E., Goverdovski, A., Griesmayer, E., Harada, H., Heftrich, T., Hernández-Prieto, A., Heyse, J., Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Knapova, I., Kokkoris, M., Krtička, M., Leal-Cidoncha, E., Leeb, H., Licata, M., Lo Meo, S., Losito, R., Macina, D., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Mendoza, E., Milazzo, P. M., Mingrone, F., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Palomo-Pinto, F. R., Paradela, C., Patronis, N., Pavlik, A., Perkowski, J., Porras, J. I., Praena, J., Quesada, J. M., Rauscher, T., Riego-Perez, A., Robles, M., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A. G., Stamatopoulos, A., Suryanarayana, S. V., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Wright, T., and Žugec, P.

Subjects
Neutron capture, Germanium, Astrophysics::High Energy Astrophysical Phenomena, Physics, ddc:530, n_TOF, Nuclear Experiment, Nucleosynthesis, s process
Abstract

73Ge(n,γ) cross sections were measured at the neutron time-of-flight facility n_TOF at CERN up to neutron energies of 300 keV, providing for the first time experimental data above 8 keV. Results indicate that the stellar cross section at kT=30 keV is 1.5 to 1.7 times higher than most theoretical predictions. The new cross sections result in a substantial decrease of 73Ge produced in stars, which would explain the low isotopic abundance of 73Ge in the solar system.

Published
2019

39. Measurement of the $^{70}Ge(n,\gamma)$ cross section up to 300 keV at the CERN n_TOF facility

Author

Gawlik, A., Lederer-Woods, C., Andrzejewski, J., Battino, U., Ferreira, P., Gunsing, F., Heinitz, S., Krtička, M., Massimi, C., Mingrone, F., Perkowski, J., Reifarth, R., Tattersall, A., Valenta, S., Weiss, C., Aberle, O., Audouin, L., Bacak, M., Balibrea, J., Barbagallo, M., Barros, S., Bécares, V., Bečvář, F., Beinrucker, C., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Castelluccio, D.M., Cerutti, F., Chen, Y.H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Damone, L.A., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Finocchiaro, P., Furman, V., Göbel, K., García, A.R., Glodariu, T., Gonçalves, I.F., González-Romero, E., Goverdovski, A., Griesmayer, E., Guerrero, C., Harada, H., Heftrich, T., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Knapova, I., Kokkoris, M., Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S.J., Losito, R., Macina, D., Marganiec, J., Martínez, T., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E.a., Mendoza, E., Mengoni, A., Milazzo, P.M., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Porras, J.I., Praena, J., Quesada, J.M., Rajeev, K., Rauscher, T., Riego-Perez, A., Rout, P.C., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A.G., Stamatopoulos, A., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Wolf, C., Woods, P.J., Wright, T., Žugec, P., 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), n_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), Universitat Politècnica de Catalunya. Departament de Física, and Universitat Politècnica de Catalunya. ANT - Advanced Nuclear Technologies Research Group

Subjects
Neutrons, Energies::Energia nuclear [Àrees temàtiques de la UPC], Física [Àrees temàtiques de la UPC], Astrophysics::High Energy Astrophysical Phenomena, Nuclear Astrophysics, Nuclear physics, Astrophysics::Solar and Stellar Astrophysics, Nuclear Physics - Experiment, Física nuclear, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract

Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The $(n,\gamma)$ cross section on $^{70}Ge$, which is mainly produced in the s process, was measured at the neutron time-of-flight facility n_TOF at CERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sections up to 300 keV. Stellar cross sections were calculated from $kT=5 keV$ to $kT=100 keV$ and are in very good agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average cross sections are in agreement with Walter and Beer (1985) over most of the neutron energy range covered, while they are systematically smaller for neutron energies above 150 keV. We have calculated isotopic abundances produced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close to solar model shows a good global match to solar system abundances in the range of mass numbers A=60–80. Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The ($n,\gamma$) cross section on $^{70}$Ge, which is mainly produced in the $s$~process, was measured at the neutron time-of-flight facility n_TOF at CERN. Resonance capture kernels were determined up to 40~keV neutron energy, and average cross sections up to 300~keV. Stellar cross sections were calculated from $kT=5$~keV to $kT=100$ keV and are in very good agreement with a previous measurement by Walter and Beer (1985), and recent evaluations. Average cross sections are in agreement with Walter and Beer (1985) over most of the neutron energy range covered, while being systematically smaller for neutron energies above 150~keV. We have calculated isotopic abundances produced in $s$-process environments in a 25 solar mass star for two initial metallicities (below solar, and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances the close to solar model shows a good global match to solar system abundances between mass numbers A=60-80.

Published
2019
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40. Measurement of the radiative capture cross section of the s-process branching points 204Tl and 171Tm at the n-TOF facility (CERN)

Author

Casanovas, A., Domingo-Pardo, C., Guerrero, C., Lerendegui-Marco, J., Calviño, F., Tarifeño-Saldivia, A., Dressler, R., Heinitz, S., Kivel, N., Quesada, J. M., Schumann, D., Aberle, O., Alcayne, V., Andrzejewski, J., Audouin, L., Bécares, V., Bacak, M., Barbagallo, M., Bečvář, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Busso, M., Caamaño, M., Caballero-Ontanaya, L., Calviani, M., Cano-Ott, D., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Damone, L. A., Diakaki, M., Dietz, M., Dupont, E., Durán, I., Eleme, Z., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Furman, V., Göbel, K., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Gunsing, F., Heyse, J., Jenkins, D. G., Käppeler, F., Kadi, Y., Katabuchi, T., Kimura, A., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Ladarescu, I., Lederer-Woods, C., Meo, S. Lo, Lonsdale, S. J., Macina, D., Martínez, T., Masi, A., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Ogállar, F., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Persanti, L., Porras, I., Praena, J., Radeck, D., Ramos, D., Rauscher, T., Reifarth, R., Rochman, D., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Simone, S., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Talip, T., Tassan-Got, L., Tsinganis, A., Ulrich, J., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., Zugec, P., and Köster, U.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

The neutron capture cross section of some unstable nuclei is especially relevant for s-process nucleosynthesis studies. This magnitude is crucial to determine the local abundance pattern, which can yield valuable information of the s-process stellar environment. In this work we describe the neutron capture (n,γ) measurement on two of these nuclei of interest, 204Tl and 171Tm, from target production to the final measurement, performed successfully at the n-TOF facility at CERN in 2014 and 2015. Preliminary results on the ongoing experimental data analysis will also be shown. These results include the first ever experimental observation of capture resonances for these two nuclei.

Published
2018

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

Author

Barbagallo, M., Andrzejewski, J., Mastromarco, M., Perkowski, J., Damone, L. A., Gawlik, A., Cosentino, L., Finocchiaro, P., Maugeri, E. A., Mazzone, A., Dressler, R., Heinitz, S., Kivel, N., Schumann, D., Colonna, N., Aberle, O., Amaducci, S., Audouin, L., Bacak, M., Balibrea, J., Bečvář, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Cortés, G., Cortés-Giraldo, M. A., Cristallo, S., Diakaki, M., Dietz, M., Domingo-Pardo, C., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Furman, V., Göbel, K., García, A. R., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heyse, J., Jenkins, D. G., Jericha, E., Johnston, K., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Lederer, C., Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S. J., Macina, D., Manna, A., Marganiec, J., Martínez, T., Martins-Correia, J. G., Masi, A., Massimi, C., Mastinu, P., Mendoza, E., Mengoni, A., Milazzo, P. M., Mingrone, F., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Pappalardo, A. D., Patronis, N., Pavlik, A., Piscopo, M., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rauscher, T., Reifarth, R., Robles, M. S., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A., Schell, J., Schillebeeckx, P., Sedyshev, P., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weiss, C., Woods, P. J., Wright, T., and Žugec, P.

Subjects
Physics, ddc:530, Nuclear Experiment
Abstract

Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows to investigate neutron induced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the 7Be(n,𝛼)𝛼 cross section, the 7Be(n,p)7Li reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization.

Published
2018

42. $^7 \text{Be(n,} \alpha)$ and $^7 \text{Be(n,p)}$ cross-section measurement for the cosmological lithium problem at the n_TOF facility at CERN

Author

Barbagallo, M., Colonna, N., Aberle, O., Andrzejewski, J., Audouin, L., Bécares, V., Bacak, M., Balibrea, J., Barros, S., Bečvář, F., Beinrucker, C., Berthoumieux, E., Billowes, J., Bosnar, D., Brugger, M., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Castelluccio, D.M., Cerutti, F., Chen, Y.H., Chiaveri, E., Cortés, G., Cortés-Giraldo, M.A., Cosentino, L., Damone, L.A., Diakaki, M., Domingo-Pardo, C., Dressler, R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A., Ferreira, P., Finocchiaro, P., Furman, V., Göbel, K., García, A.R., Gawlik, A., Glodariu, T., Gonçalves, I.F., González, E., Goverdovski, A., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heftrich, T., Heinitz, S., Heyse, J., Jenkins, D.G., Jericha, E., Käppeler, F., Kadi, Y., Katabuchi, T., Kavrigin, P., Ketlerov, V., Khryachkov, V., Kimura, A., Kivel, N., Kokkoris, M., Krtička, M., Leal-Cidoncha, E., Lederer, C., Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S.J., Losito, R., Macina, D., Marganiec, J., Martínez, T., Massimi, C., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E.a., Mendoza, E., Mengoni, A., Milazzo, P.M., Mingrone, F., Mirea, M., Montesano, S., Musumarra, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, J.I., Praena, J., Quesada, J.M., Rajeev, K., Rauscher, T., Reifarth, R., Riego-Perez, A., Rout, P.C., Rubbia, C., Ryan, J.A., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schmidt, S., Schumann, D., Sedyshev, P., Smith, A.G., Stamatopoulos, A., Tagliente, G., Tain, J.L., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R., Wallner, A., Warren, S., Weigand, M., Weiss, C., Wolf, C., Woods, P.J., Wright, T., Žugec, P., 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 sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, n_TOF, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Astrophysics::Solar and Stellar Astrophysics, Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Astrophysics::Galaxy Astrophysics
Abstract

International audience; The Cosmological Lithium Problem refers to the large discrepancy between the abundance of primordial $^7$Li predicted by the standard theory of Big Bang Nucleosynthesis and the value inferred from the so-called “Spite plateau” in halo stars. A possible explanation for this longstanding puzzle in Nuclear Astrophysics is related to the incorrect estimation of the destruction rate of $^7$Be, which is responsible for the production of 95% of primordial Lithium. While charged-particle induced reactions have mostly been ruled out, data on the $^7 \text{Be(n,} \alpha)$ and $^7 \text{Be(n,p)}$ reactions are scarce or completely missing, so that a large uncertainty still affects the abundance of $^7$Li predicted by the standard theory of Big Bang Nucleosynthesis. Both reactions have been measured at the n_TOF facility at CERN, providing for the first time data in a wide neutron energy range.

Published
2016
Full Text
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43. Recent results in nuclear astrophysics at the n-TOF facility at CERN

Author

Tagliente, G., Aberle, O., Andrzejewski, J., Audouin, L., Bacak, M., Balibrea-Correa, J., Barbagallo, M., Bečváf, F., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Caamaño, M., Calviño, F., Calviani, M., Cano-Ott, D., Cardella, R., Casanovas, A., Cerutti, F., Chiaveri, E., Colonna, N., Cortés, G., Cortés-Giraldo, M. A., Cosentino, C., Damone, L. A., Diakaki, M., Domingo-Pardo, C., Dressler, L. R., Dupont, E., Durán, I., Fernández-Domínguez, B., Ferrari, A C, Ferreira, Paulo R., Finocchiaro, P., Furman, V., Göbel, K., García, A. R., Gawlik, A., Gilardoni, S, Glodariu, T., Gonçalves, I. F., González-Romero, E., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Heyse, J, Jenkins, D. G., Jericha, E., Käppeler, F., Kadi, Y., Kalamara, A., Kavrigin, P., Kimura, A., Kivel, N., Kokkoris, M., Krtička, M., Kurtulgil, D., Leal-Cidoncha, E., Lederer, C., Lerendegui-Marco, J., Leeb, H., Lo Meo, S., Lonsdale, S. J., Macina, D., Marganiec, J., Martínez, T., Masi, A., Massimi, C., Mastinu, P. F., Mastromarco, M., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Mingrone, F., Milazzo, P. M., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rauscher, T., Reifarth, R., Rubbia, C., Ryan, J. A., Sabaté-Gilarte, M., Saxena, A K, Schillebeeckx, P., Schumann, D., Sedyshev, P., Smith, A. G., Sosnin, N. V., Stamatopoulos, A., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vlachoudis, V., Vlastou, R, Wallner, A., Warren, S, Woods, P. J., Wright, T., and Zugec, P.

Subjects
Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Physics::Accelerator Physics, Nuclear Experiment
Abstract

The neutron time of flight (n-TOF) facility at CERN is a spallation source characterized by a white neutron spectrum. The innovative features of the facility, in the two experimental areas, (20 m and 185 m), allow for an accurate determination of the neutron cross section for radioactive samples or for isotopes with small neutron capture cross section, of interest for Nuclear Astrophysics. The recent results obtained at n-TOF facility are presented.

Published
2016

44. Determination of the number of light neutrino species from single photon production at LEP

Author

Acciarri, M, Adriani, O, Aguilar-Benítez, M, Ahlen, S P, Alcaraz, J, Alemanni, G, Allaby, James V, Aloisio, A, Alviggi, M G, Ambrosi, G, Anderhub, H, Andreev, V P, Angelescu, T, Anselmo, F, Arefev, A, Azemoon, T, Aziz, T, Bagnaia, P, Baksay, L, Ball, R C, Banerjee, S, Banerjee, Sw, Banicz, K, Barczyk, A, Barillère, R, Barone, L, Bartalini, P, Baschirotto, A, Basile, M, Battiston, R, Bay, A, Becattini, F, Becker, U, Behner, F, Berdugo, J, Berges, P, Bertucci, B, Betev, B L, Bhattacharya, S, Biasini, M, Biland, A, Bilei, G M, Bizzarri, R, Blaising, J J, Blyth, S C, Bobbink, Gerjan J, Böck, R K, Böhm, A, Boldizsar, L, Borgia, B, Bourilkov, D, Bourquin, Maurice, Boutigny, D, Braccini, S, Branson, J G, Brigljevic, V, Brock, I C, Buffini, A, Buijs, A, Burger, J D, Burger, W J, Busenitz, J K, Cai, X D, Campanelli, M, Capell, M, Cara Romeo, G, Carlino, G, Cartacci, A M, Casaus, J, Castellini, G, Cavallari, F, Cavallo, N, Cecchi, C, Cerrada-Canales, M, Cesaroni, F, Chamizo-Llatas, M, Chang, Y H, Chaturvedi, U K, Chekanov, S V, Chemarin, M, Chen, A, Chen, G, Chen, G M, Chen, H F, Chen, H S, Chen, M, Chiefari, G, Chien, C Y, Cifarelli, Luisa, Cindolo, F, Civinini, C, Clare, I, Clare, R, Cohn, H O, Coignet, G, Colijn, A P, Colino, N, Costantini, S, Cotorobai, F, de la Cruz, B, Csilling, Akos, Dai, T S, D'Alessandro, R, De Asmundis, R, Degré, A, Deiters, K, Denes, P, De Notaristefani, F, DiBitonto, Daryl, Diemoz, M, Van Dierendonck, D N, Di Lodovico, F, Dionisi, C, Dittmar, Michael, Dominguez, A, Doria, A, Dova, M T, Drago, E, Duchesneau, D, Duinker, P, Durán, I, Dutta, S, Easo, S, Efremenko, Yu V, El-Mamouni, H, Engler, A, Eppling, F J, Erné, F C, Ernenwein, J P, Extermann, Pierre, Fabre, M, Faccini, R, Falciano, S, Favara, A, Fay, J, Fedin, O, Felcini, Marta, Fenyi, B, Ferguson, T, Ferroni, F, Fesefeldt, H S, Fiandrini, E, Field, J H, Filthaut, Frank, Fisher, P H, Fisk, I, Forconi, G, Fredj, L, Freudenreich, Klaus, Furetta, C, Galaktionov, Yu, Ganguli, S N, García-Abia, P, Gau, S S, Gentile, S, Gerald, J, Gheordanescu, N, Giagu, S, Goldfarb, S, Goldstein, J, Gong, Z F, Gougas, Andreas, Gratta, Giorgio, Grünewald, M W, Gupta, V K, Gurtu, A, Gutay, L J, Haas, D, Hartmann, B, Hasan, A, Hatzifotiadou, D, Hebbeker, T, Hervé, A, Hirschfelder, J, Van Hoek, W C, Hofer, H, Hoorani, H, Hou, S R, Hu, G, Innocente, Vincenzo, Jenkes, K, Jin, B N, Jones, L W, de Jong, P, Josa-Mutuberria, I, Kasser, A, Khan, R A, Kamrad, D, Kamyshkov, Yu A, Kapustinsky, J S, Karyotakis, Yu, Kaur, M, Kienzle-Focacci, M N, Kim, D, Kim, D H, Kim, J K, Kim, S C, Kinnison, W W, Kirkby, A, Kirkby, D, Kirkby, Jasper, Kiss, D, Kittel, E W, Klimentov, A, König, A C, Kopp, A, Korolko, I, Koutsenko, V F, Krämer, R W, Krenz, W, Kunin, A, Lacentre, P E, Ladrón de Guevara, P, Landi, G, Lapoint, C, Lassila-Perini, K M, Laurikainen, P, Lavorato, A, Lebeau, M, Lebedev, A, Lebrun, P, Lecomte, P, Lecoq, P, Le Coultre, P, Lee, H J, Leggett, C, Le Goff, J M, Leiste, R, Leonardi, E, Levchenko, P M, Li Chuan, Lin, C H, Lin, W T, Linde, Frank L, Lista, L, Liu, Z A, Lohmann, W, Longo, E, Lu, W, Lü, Y S, Lübelsmeyer, K, Luci, C, Luckey, D, Luminari, L, Lustermann, W, Ma Wen Gan, Maity, M, Majumder, G, Malgeri, L, Malinin, A, Maña, C, Mangeol, D J J, Mangla, S, Marchesini, P A, Marin, A, Martin, J P, Marzano, F, Massaro, G G G, McNally, D, Mele, S, Merola, L, Meschini, M, Metzger, W J, Von der Mey, M, Mi, Y, Migani, D, Mihul, A, Van Mil, A J W, Milcent, H, Mirabelli, G, Mnich, J, Molnár, P, Monteleoni, B, Moore, R, Moulik, T, Mount, R, Muheim, F, Muijs, A J M, Nahn, S, Napolitano, M, Nessi-Tedaldi, F, Newman, H, Niessen, T, Nippe, A, Nisati, A, Nowak, H, Oh, Yu D, Opitz, H, Organtini, G, Ostonen, R, Palit, S, Palomares, C, Pandoulas, D, Paoletti, S, Paolucci, P, Park, H K, Park, I H, Pascale, G, Passaleva, G, Patricelli, S, Paul, T, Pauluzzi, M, Paus, C, Pauss, Felicitas, Peach, D, Pei, Y J, Pensotti, S, Perret-Gallix, D, Petersen, B, Petrak, S, Pevsner, A, Piccolo, D, Pieri, M, Piroué, P A, Pistolesi, E, Plyaskin, V, Pohl, M, Pozhidaev, V, Postema, H, Produit, N, Prokofev, D, Prokofiev, D O, Quartieri, J, Rahal-Callot, G, Raja, N, Rancoita, P G, Rattaggi, M, Raven, G, Razis, P A, Read, K, Ren, D, Rescigno, M, Reucroft, S, Van Rhee, T, Riemann, S, Riles, K, Rind, O, Robohm, A, Rodin, J, Roe, B P, Romero, L, Rosier-Lees, S, Rosselet, P, Van Rossum, W, Roth, S, Rubio, Juan Antonio, Ruschmeier, D, Rykaczewski, H, Salicio, J, Sánchez, E, Sanders, M P, Sarakinos, M E, Sarkar, S, Sauvage, G, Schäfer, C, Shchegelskii, V, Schmidt-Kärst, S, Schmitz, D, Schneegans, M, Scholz, N, Schopper, Herwig Franz, Schotanus, D J, Schwenke, J, Schwering, G, Sciacca, C, Sciarrino, D, Servoli, L, Shevchenko, S, Shivarov, N, Shoutko, V, Shukla, J, Shumilov, E, Shvorob, A V, Siedenburg, T, Son, D, Soulimov, V, Smith, B, Spillantini, P, Steuer, M, Stickland, D P, Stone, H, Stoyanov, B, Strässner, A, Sudhakar, K, Sultanov, G G, Sun, L Z, Susinno, G F, Suter, H, Swain, J D, Tang, X W, Tauscher, Ludwig, Taylor, L, Ting, Samuel C C, Ting, S M, Tonwar, S C, Tóth, J, Tully, C, Tuchscherer, H, Tung, K L, Uchida, Y, Ulbricht, J, Uwer, U, Valente, E, Vesztergombi, G, Vetlitskii, I, Viertel, Gert M, Vivargent, M, Vlachos, S, Völkert, R, Vogel, H, Vogt, H, Vorobev, I, Vorobyov, A A, Vorvolakos, A, Wadhwa, M, Wallraff, W, Wang, J C, Wang, X L, Wang, Z M, Weber, A, Wu, S X, Wynhoff, S, Xu, J, Xu, Z Z, Yang, B Z, Yang, C G, Yao, X Y, Ye, J B, Yeh, S C, You, J M, Zalite, A, Zalite, Yu, Zemp, P, Zeng, Y, Zhang, Z, Zhang, Z P, Zhou, B, Zhou, Y, Zhu, G Y, Zhu, R Y, Zichichi, Antonino, Ziegler, F, L3 (IHEF, IoP, FNWI), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), CMS, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), L3, IHEF (IoP, FNWI), Acciarri, M., Adriani, O., Aguilar Benitez, M., Ahlen, S., Alcaraz, J., Alemanni, G., Allaby, J., Aloisio, Alberto, Alviggi, Mariagrazia, Ambrosi, G., Anderhub, H., Andreev, V. P., Angelescu, T., Anselmo, F., Arefiev, A., Azemoon, T., Aziz, T., Bagnaia, P., Baksay, L., Ball, R. C., Banerjee, S., Banicz, K., Barczyk, A., Barillere, R., Barone, L., Bartalini, P., Baschirotto, A., Basile, M., Battiston, R., Bay, A., Becattini, F., Becker, U., Behner, F., Berdugo, J., Berges, P., Bertucci, B., Betev, B. L., Bhattacharya, S., Biasini, M., Biland, A., Bilei, G. M., Bizzarri, R., Blaising, J. J., Blyth, S. C., Bobbink, G. J., Bock, R., Bohm, A., Boldizsar, L., Borgia, B., Bourilkov, D., Bourquin, M., Boutigny, D., Braccini, S., Branson, J. G., Brigljevic, V., Brock, I. C., Buffini, A., Buijs, A., Burger, J. D., Burger, W. J., Busenitz, J., Cai, X. D., Campanelli, M., Capell, M., Romeo, G. C., Carlino, G., Cartacci, A. M., Casaus, J., Castellini, G., Cavallari, F., Cavallo, N., Cecchi, C., Cerrada, M., Cesaroni, F., Chamizo, M., Chang, Y. H., Chaturvedi, U. K., Chekanov, S. V., Chemarin, M., Chen, A., Chen, G., Chen, G. M., Chen, H. F., Chen, H. S., Chen, M., Chiefari, Giovanni, Chien, C. Y., Cifarelli, L., Cindolo, F., Civinini, C., Clare, I., Clare, R., Cohn, H. O., Coignet, G., Colijn, A. P., Colino, N., Costantini, S., Cotorobai, F., B. d., La, Csilling, A., Dai, T. S., D'Alessandro, R., Asmundis, R. d., Degre, A., Deiters, K., Denes, P., Denotaristefani, F., Dibitonto, D., Diemoz, M., Dierendonck, D. v., Lodovico, F. D., Dionisi, C., Dittmar, M., Dominguez, A., Doria, A., Dova, M. T., Drago, E., Duchesneau, D., Duinker, P., Duran, I., Dutta, S., Easo, S., Efremenko, Y., Mamouni, H. E., Engler, A., Eppling, F. J., Erne, F. C., Ernenwein, J. P., Extermann, P., Fabre, M., Faccini, R., Falciano, S., Favara, A., Fay, J., Fedin, O., Felcini, M., Fenyi, B., Ferguson, T., Ferroni, F., Fesefeldt, H., Fiandrini, E., Field, J. H., Filthaut, F., Fisher, P. H., Fisk, I., Forconi, G., Fredj, L., Freudenreich, K., Furetta, C., Galaktionov, Y., Ganguli, S. N., Garcia Abia, P., Gau, S. S., Gentile, S., Gerald, J., Gheordanescu, N., Giagu, S., Goldfarb, S., Goldstein, J., Gong, Z. F., Gougas, A., Gratta, G., Grunewald, M. W., Gupta, V. K., Gurtu, A., Gutay, L. J., Haas, D., Hartmann, B., Hasan, A., Hatzifotiadou, D., Hebbeker, T., Herve, A., Hirschfelder, J., Van, W. C., Hofer, H., Hoorani, H., Hou, S. R., Hu, G., Innocente, V., Jenkes, K., Jin, B. N., Jones, L. W., Jong, P. d., Josa Mutuberria, I., Kasser, A., Khan, R. A., Kamrad, D., Kamyshkov, Y., Kapustinsky, J. S., Karyotakis, Y., Kaur, M., Kienzle Focacci, M. N., Kim, D., Kim, D. H., Kim, J. K., Kim, S. C., Kinnison, W. W., Kirkby, A., Kirkby, D., Kirkby, J., Kiss, D., Kittel, W., Klimentov, A., Konig, A. C., Kopp, A., Korolko, I., Koutsenko, V., Kraemer, R. W., Krenz, W., Kunin, A., Lacentre, P., P. L., De, Landi, G., Lapoint, C., Lassila Perini, K., Laurikainen, P., Lavorato, A., Lebeau, M., Lebedev, A., Lebrun, P., Lecomte, P., Lecoq, P., Coultre, P. L., Lee, H. J., Leggett, C., J. M., Le, Leiste, R., Leonardi, E., Levtchenko, P., Li, C., Lin, C. H., Lin, W. T., Linde, F. L., Lista, L., Liu, Z. A., Lohmann, W., Longo, E., Lu, W., Y. S., Lu, Lubelsmeyer, K., Luci, C., Luckey, D., Luminari, L., Lustermann, W., W. G., Ma, Maity, M., Majumder, G., Malgeri, L., Malinin, A., Mana, C., Mangeol, D., Mangla, S., Marchesini, P., Marin, A., Martin, J. P., Marzano, F., G. G. G., Mcnally, D., Mele, S., Merola, Leonardo, Meschini, M., Metzger, W. J., Der, M. v., Mi, Y., Migani, D., Mihul, A., A. J. W., Milcent, H., Mirabelli, G., Mnich, J., Molnar, P., Monteleoni, B., Moore, R., Moulik, T., Mount, R., Muheim, F., A. J. M., Nahn, S., Napolitano, Marco, Nessi Tedaldi, F., Newman, H., Niessen, T., Nippe, A., Nisati, A., Nowak, H., Y. D., Oh, Opitz, H., Organtini, G., Ostonen, R., Palit, S., Palomares, C., Pandoulas, D., Paoletti, S., Paolucci, P., Park, H. K., Park, I. H., Pascale, G., Passaleva, G., Patricelli, Sergio, Paul, T., Pauluzzi, M., Paus, C., Pauss, F., Peach, D., Pei, Y. J., Pensotti, S., Perret Gallix, D., Petersen, B., Petrak, S., Pevsner, A., Piccolo, D., Pieri, M., Piroue, P. A., Pistolesi, E., Plyaskin, V., Pohl, M., Pojidaev, V., Postema, H., Produit, N., Prokofiev, D., Quartieri, J., Rahal Callot, G., Raja, N., Rancoita, P. G., Rattaggi, M., Raven, G., Razis, P., Read, K., Ren, D., Rescigno, M., Reucroft, S., Rhee, T. v., Riemann, S., Riles, K., Rind, O., Robohm, A., Rodin, J., Roe, B. P., Romero, L., Rosier Lees, S., Rosselet, P., Rossum, W. v., Roth, S., Rubio, J. A., Ruschmeier, D., Rykaczewski, H., Salicio, J., Sanchez, E., Sanders, M. P., Sarakinos, M. E., Sarkar, S., Sauvage, G., Schafer, C., Schegelsky, V., Schmidt Kaerst, S., Schmitz, D., Schneegans, M., Scholz, N., Schopper, H., Schotanus, D. J., Schwenke, J., Schwering, G., Sciacca, Crisostomo, Sciarrino, D., Servoli, L., Shevchenko, S., Shivarov, N., Shoutko, V., Shukla, J., Shumilov, E., Shvorob, A., Siedenburg, T., Son, D., Soulimov, V., Smith, B., Spillantini, P., Steuer, M., Stickland, D. P., Stone, H., Stoyanov, B., Straessner, A., Sudhakar, K., Sultanov, G., Sun, L. Z., Susinno, G. F., Suter, H., Swain, J. D., Tang, X. W., Tauscher, L., Taylor, L., S. C. C., Ting, S. M., Tonwar, S. C., Toth, J., Tully, C., Tuchscherer, H., Tung, K. L., Uchida, Y., Ulbricht, J., Uwer, U., Valente, E., Vesztergombi, G., Vetlitsky, I., Viertel, G., Vivargent, M., Vlachos, S., Volkert, R., Vogel, H., Vogt, H., Vorobiev, I., Vorobyov, A. A., Vorvolakos, A., Wadhwa, M., Wallraff, W., Wang, W. C., Wang, X. L., Wang, Z. M., Weber, A., S. X., Wu, Wynhoff, S., Xu, J., Z. Z., Xu, Yang, B. Z., Yang, C. G., Yao, X. Y., J. B., Ye, Yeh, S. C., You, J. M., Zalite, A., Zalite, Y., Zemp, P., Zeng, Y., Zhang, Z., Zhang, Z. P., Zhou, B., Zhou, Y., Zhu, G. Y., Zhu, R. Y., Zichichi, A., and Ziegler, F.

Subjects
Nuclear and High Energy Physics, Particle physics, Photon, Astrophysics::High Energy Astrophysical Phenomena, Electron–positron annihilation, light neutrino species, 01 natural sciences, 7. Clean energy, Resonance (particle physics), Standard Model, Luminosity, Nuclear physics, SEARCH, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], ANNIHILATION, Nuclear Experiment, 010306 general physics, DETECTOR, Ciencias Exactas, L3 EXPERIMENT, Physics, 010308 nuclear & particles physics, ANOMALOUS PRODUCTION, photon, Física, E+E COLLISIONS, LEP, TOP-QUARK, RESONANCE, SUPERSYMMETRIC PARTICLES, High Energy Physics::Experiment, Production (computer science), Neutrino, Particle Physics - Experiment, Energy (signal processing)
Abstract

A determination of the number of light neutrino families performed by measuring the cross section of single photon production in eqey collision near the Z resonance is reported. From an integrated luminosity of 100 pby1 , collected during the years 1991–94, we have observed 2091 single photon candidates with an energy above 1 GeV in the polar angular region 458-u -1358. From a maximum likelihood fit to the single photon cross section, the Z decay width into invisible particles g is measured to be G s498"12 stat Ž . Ž. "12 sys MeV. Using the Standard Model couplings of neutrinos to the Z, the inv number of light neutrino species is determined to be N s2.98"0.07 stat Ž . Ž. "0.07 sys., Facultad de Ciencias Exactas

Published
1998
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45. Measurement of radiative Bhabha and quasireal Compton scattering

Author

Acciarri, M, Adriani, O, Aguilar-Benítez, M, Ahlen, S P, Alcaraz, J, Alemanni, G, Allaby, James V, Aloisio, A, Alviggi, M G, Ambrosi, G, Anderhub, H, Andreev, V P, Angelescu, T, Anselmo, F, Arefev, A, Azemoon, T, Aziz, T, Bagnaia, P, Baksay, L, Banerjee, S, Banerjee, Sw, Banicz, K, Barczyk, A, Barillère, R, Barone, L, Bartalini, P, Baschirotto, A, Basile, M, Battiston, R, Bay, A, Becattini, F, Becker, U, Behner, F, Berdugo, J, Berges, P, Bertucci, B, Betev, B L, Bhattacharya, S, Biasini, M, Biland, A, Bilei, G M, Blaising, J J, Blyth, S C, Bobbink, Gerjan J, Böck, R K, Böhm, A, Boldizsar, L, Borgia, B, Bourilkov, D, Bourquin, Maurice, Braccini, S, Branson, J G, Brigljevic, V, Brock, I C, Buffini, A, Buijs, A, Burger, J D, Burger, W J, Busenitz, J K, Cai, X D, Campanelli, M, Capell, M, Cara Romeo, G, Carlino, G, Cartacci, A M, Casaus, J, Castellini, G, Cavallari, F, Cavallo, N, Cecchi, C, Cerrada-Canales, M, Cesaroni, F, Chamizo-Llatas, M, Chang, Y H, Chaturvedi, U K, Chemarin, M, Chen, A, Chen, G, Chen, G M, Chen, H F, Chen, H S, Chéreau, X J, Chiefari, G, Chien, C Y, Cifarelli, Luisa, Cindolo, F, Civinini, C, Clare, I, Clare, R, Coignet, G, Colijn, A P, Colino, N, Costantini, S, Cotorobai, F, de la Cruz, B, Csilling, Akos, Dai, T S, D'Alessandro, R, De Asmundis, R, Degré, A, Deiters, K, Della Volpe, D, Denes, P, De Notaristefani, F, Diemoz, M, Van Dierendonck, D N, Di Lodovico, F, Dionisi, C, Dittmar, Michael, Dominguez, A, Doria, A, Dova, M T, Duchesneau, D, Duinker, P, Durán, I, Easo, S, El-Mamouni, H, Engler, A, Eppling, F J, Erné, F C, Ernenwein, J P, Extermann, Pierre, Fabre, M, Faccini, R, Falagán, M A, Falciano, S, Favara, A, Fay, J, Fedin, O, Felcini, Marta, Ferguson, T, Ferroni, F, Fesefeldt, H S, Fiandrini, E, Field, J H, Filthaut, Frank, Fisher, P H, Fisk, I, Forconi, G, Fredj, L, Freudenreich, Klaus, Furetta, C, Galaktionov, Yu, Ganguli, S N, García-Abia, P, Gataullin, M, Gau, S S, Gentile, S, Gheordanescu, N, Giagu, S, Goldfarb, S, Goldstein, J, Gong, Z F, Gougas, Andreas, Gratta, Giorgio, Grünewald, M W, van Gulik, R, Gupta, V K, Gurtu, A, Gutay, L J, Haas, D, Hartmann, B, Hasan, A, Hatzifotiadou, D, Hebbeker, T, Hervé, A, Hidas, P, Hirschfelder, J, Van Hoek, W C, Hofer, H, Hoorani, H, Hou, S R, Hu, G, Iashvili, I, Jin, B N, Jones, L W, de Jong, P, Josa-Mutuberria, I, Kasser, A, Khan, R A, Kamrad, D, Kapustinsky, J S, Karyotakis, Yu, Kaur, M, Kienzle-Focacci, M N, Kim, D, Kim, D H, Kim, J K, Kim, S C, Kinnison, W W, Kirkby, A, Kirkby, D, Kirkby, Jasper, Kiss, D, Kittel, E W, Klimentov, A, König, A C, Kopp, A, Korolko, I, Koutsenko, V F, Krämer, R W, Krenz, W, Kunin, A, Lacentre, P E, Ladrón de Guevara, P, Laktineh, I, Landi, G, Lapoint, C, Lassila-Perini, K M, Laurikainen, P, Lavorato, A, Lebeau, M, Lebedev, A, Lebrun, P, Lecomte, P, Lecoq, P, Le Coultre, P, Lee, H J, Le Goff, J M, Leiste, R, Leonardi, E, Levchenko, P M, Li Chuan, Lin, C H, Lin, W T, Linde, Frank L, Lista, L, Liu, Z A, Lohmann, W, Longo, E, Lu, W, Lü, Y S, Lübelsmeyer, K, Luci, C, Luckey, D, Luminari, L, Lustermann, W, Ma Wen Gan, Maity, M, Majumder, G, Malgeri, L, Malinin, A, Maña, C, Mangeol, D J J, Marchesini, P A, Marian, G, Marin, A, Martin, J P, Marzano, F, Massaro, G G G, Mazumdar, K, McNeil, R R, Mele, S, Merola, L, Meschini, M, Metzger, W J, Von der Mey, M, Migani, D, Mihul, A, Van Mil, A J W, Milcent, H, Mirabelli, G, Mnich, J, Molnár, P, Monteleoni, B, Moore, R, Moulik, T, Mount, R, Muheim, F, Muijs, A J M, Nahn, S, Napolitano, M, Nessi-Tedaldi, F, Newman, H, Niessen, T, Nippe, A, Nisati, A, Nowak, H, Oh, Yu D, Organtini, G, Ostonen, R, Palit, S, Palomares, C, Pandoulas, D, Paoletti, S, Paolucci, P, Park, H K, Park, I H, Pascale, G, Passaleva, G, Patricelli, S, Paul, T, Pauluzzi, M, Paus, C, Pauss, Felicitas, Peach, D, Pei, Y J, Pensotti, S, Perret-Gallix, D, Petersen, B, Petrak, S, Pevsner, A, Piccolo, D, Pieri, M, Piroué, P A, Pistolesi, E, Plyaskin, V, Pohl, M, Pozhidaev, V, Postema, H, Pothier, J, Produit, N, Prokofev, D, Prokofiev, D O, Quartieri, J, Rahal-Callot, G, Raja, N, Rancoita, P G, Rattaggi, M, Raven, G, Razis, P A, Ren, D, Rescigno, M, Reucroft, S, Van Rhee, T, Riemann, S, Riles, K, Robohm, A, Rodin, J, Roe, B P, Romero, L, Rosier-Lees, S, Roth, S, Rubio, Juan Antonio, Ruschmeier, D, Rykaczewski, H, Sakar, S, Salicio, J, Sánchez, E, Sanders, M P, Sarakinos, M E, Schäfer, C, Shchegelskii, V, Schmidt-Kärst, S, Schmitz, D, Scholz, N, Schopper, Herwig Franz, Schotanus, D J, Schwenke, J, Schwering, G, Sciacca, C, Sciarrino, D, Servoli, L, Shevchenko, S, Shivarov, N, Shoutko, V, Shukla, J, Shumilov, E, Shvorob, A V, Siedenburg, T, Son, D, Smith, B, Spillantini, P, Steuer, M, Stickland, D P, Stone, A, Stone, H, Stoyanov, B, Strässner, A, Sudhakar, K, Sultanov, G G, Sun, L Z, Susinno, G F, Suter, H, Swain, J D, Tang, X W, Tauscher, Ludwig, Taylor, L, Timmermans, C, Ting, Samuel C C, Ting, S M, Tonwar, S C, Tóth, J, Tully, C, Tung, K L, Uchida, Y, Ulbricht, J, Valente, E, Vesztergombi, G, Vetlitskii, I, Viertel, Gert M, Vivargent, M, Vlachos, S, Vogel, H, Vogt, H, Vorobev, I, Vorobyov, A A, Vorvolakos, A, Wadhwa, M, Wallraff, W, Wang, J C, Wang, X L, Wang, Z M, Weber, A, Wu, S X, Wynhoff, S, Xu, J, Xu, Z Z, Yang, B Z, Yang, C G, Yang, H J, Yang, M, Ye, J B, Yeh, S C, You, J M, Zalite, A, Zalite, Yu, Zemp, P, Zeng, Y, Zhang, Z P, Zhou, B, Zhu, G Y, Zhu, R Y, Zichichi, Antonino, Ziegler, F, Zilizi, G, Acciarri, M., Adriani, O., Aguilar Benitez, M., Ahlen, S., Alcaraz, J., Alemanni, G., Allaby, J., Aloisio, Alberto, Alviggi, Mariagrazia, Ambrosi, G., Anderhub, H., Andreev, V. P., Angelescu, T., Anselmo, F., Arefiev, A., Azemoon, T., Aziz, T., Bagnaia, P., Baksay, L., Banerjee, S., Banicz, K., Barczyk, A., Barillere, R., Barone, L., Bartalini, P., Baschirotto, A., Basile, M., Battiston, R., Bay, A., Becattini, F., Becker, U., Behner, F., Berdugo, J., Berges, P., Bertucci, B., Betev, B. L., Bhattacharya, S., Biasini, M., Biland, A., Bilei, G. M., Blaising, J. J., Blyth, S. C., Bobbink, G. J., Bock, R., Bohm, A., Boldizsar, L., Borgia, B., Bourilkov, D., Bourquin, M., Braccini, S., Branson, J. G., Brigljevic, V., Brock, I. C., Buffini, A., Buijs, A., Burger, J. D., Burger, W. J., Busenitz, J., Button, A., Cai, X. D., Campanelli, M., Capell, M., Romeo, G. C., Carlino, G., Cartacci, A. M., Casaus, J., Castellini, G., Cavallari, F., Cavallo, N., Cecchi, C., Cerrada, M., Cesaroni, F., Chamizo, M., Chang, Y. H., Chaturvedi, U. K., Chemarin, M., Chen, A., Chen, G., Chen, G. M., Chen, H. F., Chen, H. S., Chereau, X., Chiefari, Giovanni, Chien, C. Y., Cifarelli, L., Cindolo, F., Civinini, C., Clare, I., Clare, R., Coignet, G., Colijn, A. P., Colino, N., Costantini, S., Cotorobai, F., B. d., La, Csilling, A., Dai, T. S., D'Alessandro, R., Asmundis, R. d., Degre, A., Deiters, K., DELLA VOLPE, Domenico, Denes, P., Denotaristefani, F., Diemoz, M., Dierendonck, D. v., Lodovico, F. D., Dionisi, C., Dittmar, M., Dominguez, A., Doria, A., Dova, M. T., Duchesneau, D., Duinker, P., Duran, I., Easo, S., Mamouni, H. E., Engler, A., Eppling, F. J., Erne, F. C., Ernenwein, J. P., Extermann, P., Fabre, M., Faccini, R., Falagan, M. A., Falciano, S., Favara, A., Fay, J., Fedin, O., Felcini, M., Ferguson, T., Ferroni, F., Fesefeldt, H., Fiandrini, E., Field, J. H., Filthaut, F., Fisher, P. H., Fisk, I., Forconi, G., Fredj, L., Freudenreich, K., Furetta, C., Galaktionov, Y., Ganguli, S. N., Garcia Abia, P., Gataullin, M., Gau, S. S., Gentile, S., Gheordanescu, N., Giagu, S., Goldfarb, S., Goldstein, J., Gong, Z. F., Gougas, A., Gratta, G., Grunewald, M. W., Gulik, R. v., Gupta, V. K., Gurtu, A., Gutay, L. J., Haas, D., Hartmann, B., Hasan, A., Hatzifotiadou, D., Hebbeker, T., Herve, A., Hidas, P., Hirschfelder, J., Van, W. C., Hofer, H., Hoorani, H., Hou, S. R., Hu, G., Iashvili, I., Jin, B. N., Jones, L. W., Jong, P. d., Josa Mutuberria, I., Khan, R. A., Kamrad, D., Kapustinsky, J. S., Kaur, M., Kienzle Focacci, M. N., Kim, D., Kim, D. H., Kim, J. K., Kim, S. C., Kinnison, W. W., Kirkby, A., Kirkby, D., Kirkby, J., Kiss, D., Kittel, W., Klimentov, A., Konig, A. C., Kopp, A., Korolko, I., Koutsenko, V., Kraemer, R. W., Krenz, W., Kunin, A., Lacentre, P., P. L., De, Laktineh, I., Landi, G., Lapoint, C., Lassila Perini, K., Laurikainen, P., Lavorato, A., Lebeau, M., Lebedev, A., Lebrun, P., Lecomte, P., Lecoq, P., Coultre, P. L., Lee, H. J., J. M., Le, Leiste, R., Leonardi, E., Levtchenko, P., Li, C., Lin, W. T., Linde, F. L., Lista, L., Liu, Z. A., Lohmann, W., Longo, E., Lu, W., Y. S., Lu, Lubelsmeyer, K., Luci, C., Luckey, D., Luminari, L., Lustermann, W., W. G., Ma, Maity, M., Majumder, G., Malgeri, L., Malinin, A., Mana, C., Mangeol, D., Marchesini, P., Marian, G., Marin, A., Martin, J. P., Marzano, F., G. G. G., Mazumdar, K., Mcneil, R. R., Mele, S., Merola, Leonardo, Meschini, M., Metzger, W. J., Der, M. v., Migani, D., Mihul, A., A. J. W., Milcent, H., Mirabelli, G., Mnich, J., Molnar, P., Monteleoni, B., Moore, R., Moulik, T., Mount, R., Mulheim, F., A. J. M., Nahn, S., Napolitano, Marco, Nessi Tedaldi, F., Newman, H., Niessen, T., Nippe, A., Nisati, A., Nowak, H., Y. D., Oh, Organtini, G., Ostonen, R., Palit, S., Palomares, C., Pandoulas, D., Paoletti, S., Paolucci, P., Park, H. K., Park, I. H., Pascale, G., Passaleva, G., Patricelli, Sergio, Paul, T., Pauluzzi, M., Paus, C., Pauss, F., Peach, D., Pei, Y. J., Pensotti, S., Perret Gallix, D., Petersen, B., Petrak, S., Pevsner, A., Piccolo, D., Pieri, M., Piroue, P. A., Pistolesi, E., Plyaskin, V., Pohl, M., Pojidaev, V., Postema, H., Pothier, J., Produit, N., Quartieri, J., Rahal Callot, G., Raja, N., Rancoita, P. G., Rattaggi, M., Raven, G., Razis, P., Ren, D., Rescigno, M., Reucroft, S., Rhee, T. v., Riemann, S., Riles, K., Robohm, A., Rodin, J., Roe, B. P., Romero, L., Rosier Lees, S., Roth, S., Rubio, J. A., Ruschmeier, D., Rykaczewski, H., Salicio, J., Sanchez, E., Sanders, M. P., Sarakinos, M. E., Schafer, C., Schegelsky, V., Schmidt Kaerst, S., Schmitz, D., Scholz, N., Schopper, H., Schotanus, D. J., Schwenke, J., Schwering, G., Sciacca, Crisostomo, Sciarrino, D., Servoli, L., Shevchenko, S., Shivarov, N., Shoutko, V., Shukla, J., Shumilov, E., Shvorob, A., Siedenburg, T., Son, D., Smith, B., Spillantini, P., Steuer, M., Stickland, D. P., Stone, A., Stone, H., Stoyanov, B., Straessner, A., Sudhakar, K., Sultanov, G., Sun, L. Z., Susinno, G. F., Suter, H., Swain, J. D., Tang, X. W., Tauscher, L., Taylor, L., Timmermans, C., S. C. C., Ting, S. M., Tonwar, S. C., Toth, J., Tully, C., Tung, K. L., Uchida, Y., Ulbricht, J., Valente, E., Vesztergombi, G., Vetlitsky, I., Viertel, G., Vivargent, M., Vlachos, S., Vogel, H., Vogt, H., Vorobiev, I., Vorobyov, A. A., Vorvolakos, A., Madhwa, M., Wallraff, W., Wang, J. C., Wang, X. L., Wang, Z. M., Weber, A., S. X., Wu, Wynhoff, S., Xu, J., Z. Z., Xu, Yang, B. Z., Yang, C. G., Yang, H. J., Yang, M., J. B., Ye, Yeh, S. C., You, J. M., Zalite, A., Zalite, Y., Zemp, P., Zeng, Y., Zhang, Z. P., Zhou, B., Zhu, G. Y., Zhu, R. Y., Zichichi, A., Ziegler, F., Zilizi, G., L3 (IHEF, IoP, FNWI), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), CMS, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), L3, and IHEF (IoP, FNWI)

Subjects
Nuclear and High Energy Physics, Particle physics, Astrophysics::High Energy Astrophysical Phenomena, STANDARD MODEL, PETRA ENERGIES, Inelastic scattering, 7. Clean energy, 01 natural sciences, CROSS-SECTIONS, Nuclear physics, E-STAR, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Radiative transfer, 010306 general physics, LEPTON-PAIR PRODUCTION, Nuclear Experiment, Ciencias Exactas, L3 EXPERIMENT, Physics, Coupling, Range (particle radiation), Luminosity (scattering theory), 010308 nuclear & particles physics, Detector, Compton scattering, Física, E(+)E(-) ANNIHILATION, OF-MASS ENERGIES, L3 detector, Excited state, radiative Bhabha, High Energy Physics::Experiment, ROOT-S=161 GEV, EXCITED LEPTONS, Particle Physics - Experiment
Abstract

We report on a study of radiative Bhabha and quasi-real Compton scattering at centre-of-mass energies between 50 GeV and 170 GeV, and 20 GeV and 140 GeV, respectively, using the L3 detector at LEP. The analysis is based on data corresponding to an integrated luminosity of 232.2 pb-1 . A total of 2856 radiative Bhabha and 4641 Compton scattering events are collected. Total and differential cross sections for both reactions are presented and found to be in good agreement with QED expectations. Our measurement of Compton scattering at the highest energies obtained so far is used to derive exclusion limits on the coupling λ for the on-shell production of an excited electron e★ decaying into a γe pair in the mass range 20 GeV < me★ < 170 GeV., Facultad de Ciencias Exactas

Published
1998
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46. Inclusive J, Psi' and Chi(c) production in hadronic Z decays

Author

Acciarri, M, Adriani, O, Aguilar-Benítez, M, Ahlen, S P, Alcaraz, J, Alemanni, G, Allaby, James V, Aloisio, A, Alverson, G, Alviggi, M G, Ambrosi, G, Anderhub, H, Andreev, V P, Angelescu, T, Anselmo, F, Arefev, A, Azemoon, T, Aziz, T, Bagnaia, P, Baksay, L, Ball, R C, Banerjee, S, Banerjee, Sw, Banicz, K, Barczyk, A, Barillère, R, Barone, L, Bartalini, P, Baschirotto, A, Basile, M, Battiston, R, Bay, A, Becattini, F, Becker, U, Behner, F, Berdugo, J, Berges, P, Bertucci, B, Betev, B L, Bhattacharya, S, Biasini, M, Biland, A, Bilei, G M, Blaising, J J, Blyth, S C, Bobbink, Gerjan J, Böck, R K, Böhm, A, Boldizsar, L, Borgia, B, Boucham, A, Bourilkov, D, Bourquin, Maurice, Boutigny, D, Braccini, S, Branson, J G, Brigljevic, V, Brock, I C, Buffini, A, Buijs, A, Burger, J D, Burger, W J, Busenitz, J K, Cai, X D, Campanelli, M, Capell, M, Cara Romeo, G, Carlino, G, Cartacci, A M, Casaus, J, Castellini, G, Cavallari, F, Cavallo, N, Cecchi, C, Cerrada-Canales, M, Cesaroni, F, Chamizo-Llatas, M, Chang, Y H, Chaturvedi, U K, Chekanov, S V, Chemarin, M, Chen, A, Chen, G, Chen, G M, Chen, H F, Chen, H S, Chen, M, Chiefari, G, Chien, C Y, Cifarelli, Luisa, Cindolo, F, Civinini, C, Clare, I, Clare, R, Cohn, H O, Coignet, G, Colijn, A P, Colino, N, Commichau, V, Costantini, S, Cotorobai, F, de la Cruz, B, Csilling, Akos, Dai, T S, D'Alessandro, R, De Asmundis, R, Degré, A, Deiters, K, Denes, P, De Notaristefani, F, DiBitonto, Daryl, Diemoz, M, Van Dierendonck, D N, Di Lodovico, F, Dionisi, C, Dittmar, Michael, Dominguez, A, Doria, A, Dorne, I, Dova, M T, Drago, E, Duchesneau, D, Duinker, P, Durán, I, Dutta, S, Easo, S, Efremenko, Yu V, El-Mamouni, H, Engler, A, Eppling, F J, Erné, F C, Ernenwein, J P, Extermann, Pierre, Fabre, M, Faccini, R, Falciano, S, Favara, A, Fay, J, Fedin, O, Felcini, Marta, Fenyi, B, Ferguson, T, Ferroni, F, Fesefeldt, H S, Fiandrini, E, Field, J H, Filthaut, Frank, Fisher, P H, Fisk, I, Forconi, G, Fredj, L, Freudenreich, Klaus, Furetta, C, Galaktionov, Yu, Ganguli, S N, García-Abia, P, Gau, S S, Gentile, S, Gerald, J, Gheordanescu, N, Giagu, S, Goldfarb, S, Goldstein, J, Gong, Z F, Gougas, Andreas, Gratta, Giorgio, Grünewald, M W, Gupta, V K, Gurtu, A, Gutay, L J, Hartmann, B, Hasan, A, Hatzifotiadou, D, Hebbeker, T, Hervé, A, Van Hoek, W C, Hofer, H, Hong, S J, Hoorani, H, Hou, S R, Hu, G, Innocente, Vincenzo, Janssen, H, Jenkes, K, Jin, B N, Jones, L W, de Jong, P, Josa-Mutuberria, I, Kasser, A, Khan, R A, Kamrad, D, Kamyshkov, Yu A, Kapustinsky, J S, Karyotakis, Yu, Kaur, M, Kienzle-Focacci, M N, Kim, D, Kim, D H, Kim, J K, Kim, S C, Kim, Y G, Kinnison, W W, Kirkby, A, Kirkby, D, Kirkby, Jasper, Kiss, D, Kittel, E W, Klimentov, A, König, A C, Kopp, A, Korolko, I, Koutsenko, V F, Krämer, R W, Krenz, W, Kunin, A, Ladrón de Guevara, P, Landi, G, Lapoint, C, Lassila-Perini, K M, Laurikainen, P, Lebeau, M, Lebedev, A, Lebrun, P, Lecomte, P, Lecoq, P, Le Coultre, P, Leggett, C, Le Goff, J M, Leiste, R, Leonardi, E, Levchenko, P M, Li Chuan, Lin, C H, Lin, W T, Linde, Frank L, Lista, L, Liu, Z A, Lohmann, W, Longo, E, Lu, W, Lü, Y S, Lübelsmeyer, K, Luci, C, Luckey, D, Luminari, L, Lustermann, W, Ma Wen Gan, Maity, M, Majumder, G, Malgeri, L, Malinin, A, Maña, C, Mangeol, D J J, Mangla, S, Marchesini, P A, Marin, A, Martin, J P, Marzano, F, Massaro, G G G, McNally, D, Mele, S, Merola, L, Meschini, M, Metzger, W J, Von der Mey, M, Mi, Y, Mihul, A, Van Mil, A J W, Mirabelli, G, Mnich, J, Molnár, P, Monteleoni, B, Moore, R, Morganti, S, Moulik, T, Mount, R, Müller, S, Muheim, F, Muijs, A J M, Nahn, S, Napolitano, M, Nessi-Tedaldi, F, Newman, H, Niessen, T, Nippe, A, Nisati, A, Nowak, H, Oh, Yu D, Opitz, H, Organtini, G, Ostonen, R, Palomares, C, Pandoulas, D, Paoletti, S, Paolucci, P, Park, H K, Park, I H, Pascale, G, Passaleva, G, Patricelli, S, Paul, T, Pauluzzi, M, Paus, C, Pauss, Felicitas, Peach, D, Pei, Y J, Pensotti, S, Perret-Gallix, D, Petersen, B, Petrak, S, Pevsner, A, Piccolo, D, Pieri, M, Pinto, J C, Piroué, P A, Pistolesi, E, Plyaskin, V, Pohl, M, Pozhidaev, V, Postema, H, Produit, N, Prokofev, D, Prokofiev, D O, Rahal-Callot, G, Raja, N, Rancoita, P G, Rattaggi, M, Raven, G, Razis, P A, Read, K, Ren, D, Rescigno, M, Reucroft, S, Van Rhee, T, Riemann, S, Riles, K, Rind, O, Robohm, A, Rodin, J, Roe, B P, Romero, L, Rosier-Lees, S, Rosselet, P, Van Rossum, W, Roth, S, Rubio, Juan Antonio, Ruschmeier, D, Rykaczewski, H, Salicio, J, Sánchez, E, Sanders, M P, Sarakinos, M E, Sarkar, S, Sassowsky, M, Sauvage, G, Schäfer, C, Shchegelskii, V, Schmidt-Kärst, S, Schmitz, D, Schmitz, P, Schneegans, M, Scholz, N, Schopper, Herwig Franz, Schotanus, D J, Schwenke, J, Schwering, G, Sciacca, C, Sciarrino, D, Servoli, L, Shevchenko, S, Shivarov, N, Shoutko, V, Shukla, J, Shumilov, E, Shvorob, A V, Siedenburg, T, Son, D, Sopczak, André, Soulimov, V, Smith, B, Spillantini, P, Steuer, M, Stickland, D P, Stone, H, Stoyanov, B, Strässner, A, Strauch, K, Sudhakar, K, Sultanov, G G, Sun, L Z, Susinno, G F, Suter, H, Swain, J D, Tang, X W, Tauscher, Ludwig, Taylor, L, Ting, Samuel C C, Ting, S M, Tonutti, M, Tonwar, S C, Tóth, J, Tully, C, Tuchscherer, H, Tung, K L, Uchida, Y, Ulbricht, J, Uwer, U, Valente, E, Van de Walle, R T, Vesztergombi, G, Vetlitskii, I, Viertel, Gert M, Vivargent, M, Völkert, R, Vogel, H, Vogt, H, Vorobev, I, Vorobyov, A A, Vorvolakos, A, Wadhwa, M, Wallraff, W, Wang, J C, Wang, X L, Wang, Z M, Weber, A, Wittgenstein, F, Wu, S X, Wynhoff, S, Xu, J, Xu, Z Z, Yang, B Z, Yang, C G, Yao, X Y, Ye, J B, Yeh, S C, You, J M, Zalite, A, Zalite, Yu, Zemp, P, Zeng, Y, Zhang, Z, Zhang, Z P, Zhou, B, Zhou, Y, Zhu, G Y, Zhu, R Y, Zichichi, Antonino, Ziegler, F, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), CMS, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), L3, Ambrosi, Giovanni, Bourquin, Maurice, Braccini, Saverio, Burger, William, Paus-Cecchi, Claudia, Extermann, Pierre, Field, John, Fredj, Lotfi, Kienzle, Maria-Novella, Muheim, Franz, Produit, Nicolas, Sciarrino, Deborah, Susinno, Gabriele, Flores, Sylvie, Acciarri, M., 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S., Gentile, S., Gerald, J., Gheordanescu, N., Giagu, S., Goldfarb, S., Goldstein, J., Gong, Z. F., Gougas, A., Gratta, G., Gruenewald, M. W., Gupta, V. K., Gurtu, A., Gutay, L. J., Hartmann, B., Hasan, A., Hatzifotiadou, D., Hebbeker, T., Herve, A., Vanhoek, W. C., Hofer, H., Hong, S. J., Hoorani, H., Hou, S. R., Hu, G., Innocente, V., Janssen, H., Jenkes, K., Jin, B. N., Jones, L. W., Dejong, P., Josamutuberria, I., Kasser, A., Khan, R. A., Kamrad, D., Kamyshkov, Y., Kapustinsky, J. S., Karyotakis, Y., Kaur, M., Kienzlefocacci, M. N., Kim, D., Kim, D. H., Kim, J. K., Kim, S. C., Kim, Y. G., Kinnison, W. W., Kirkby, A., Kirkby, D., Kirkby, J., Kiss, D., Kittel, W., Klimentov, A., Konig, A. C., Kopp, A., Korolko, I., Koutsenko, V., Kraemer, R. W., Krenz, W., Kunin, A., Deguevara, P. L., Landi, G., Lapoint, C., Lassilaperini, K., Laurikainen, P., Lebeau, M., Lebedev, A., Lebrun, P., Lecomte, P., Lecoq, P., Lecoultre, P., Leggett, C., Legoff, J. M., Leiste, R., Leonardi, E., Levtchenko, P., Li, C., Lin, C. H., Lin, W. T., Linde, F. L., Lista, L., Liu, Z. A., Lohmann, W., Longo, E., Lu, W., Y. S., Lu, Lubelsmeyer, K., Luci, C., Luckey, D., Luminari, L., Lustermann, W., W. G., Ma, Maity, M., Majumder, G., Malgeri, L., Malinin, A., Mana, C., Mangeol, D., Mangla, S., Marchesini, P., Marin, A., Martin, J. P., Marzano, F., G. G. G., Mcnally, D., Mele, S., Merola, Leonardo, Meschini, M., Metzger, W. J., Vondermey, M., Mi, Y., Mihul, A., A. J. W., Mirabelli, G., Mnich, J., Molnar, P., Monteleoni, B., Moore, R., Morganti, S., Moulik, T., Mount, R., Muller, S., Muheim, F., A. J. M., Nahn, S., Napolitano, Marco, Nessitedaldi, F., Newman, H., Niessen, T., Nippe, A., Nisati, A., Nowak, H., Y. D., Oh, Opitz, H., Organtini, G., Ostonen, R., Palomares, C., Pandoulas, D., Paoletti, S., Paolucci, P., Park, H. K., Park, I. H., Pascale, G., Passaleva, G., Patricelli, Sergio, Paul, T., Pauluzzi, M., Paus, C., Pauss, F., Peach, D., Pei, Y. J., Pensotti, S., Perretgallix, D., Petersen, B., Petrak, S., Pevsner, A., Piccolo, D., Pieri, M., Pinto, J. C., Piroue, P. A., Pistolesi, E., Plyaskin, V., Pohl, M., Pojidaev, V., Postema, H., Produit, N., Prokofiev, D., Rahalcallot, G., Raja, N., Rancoita, P. G., Rattaggi, M., Raven, G., Razis, P., Read, K., Ren, D., Rescigno, M., Reucroft, S., Vanrhee, T., Riemann, S., Riles, K., Rind, O., Robohm, A., Rodin, J., Roe, B. P., Romero, L., Rosierlees, S., Rosselet, P., Vanrossum, W., Roth, S., Rubio, J. A., Ruschmeier, D., Rykaczewski, H., Salicio, J., Sanchez, E., Sanders, M. P., Sarakinos, M. E., Sarkar, S., Sassowsky, M., Sauvage, G., Schafer, C., Schegelsky, V., Schmidtkaerst, S., Schmidtz, D., Schwering, G., Sciacca, Crisostomo, Sciarrino, D., Servoli, L., Shevchenko, S., Shivarov, N., Shoutko, V., Shukla, J., Shumilov, E., Shvorob, A., Siedenburg, T., Son, D., Sopczak, A., Soulimov, V., Smith, B., Spillantini, P., Steuer, M., Stickland, D. P., Stone, H., Stoyanov, B., Straessner, A., Strauch, K., Sudhakar, K., Sultanov, G., Sun, L. Z., Susinno, G. F., Suter, H., Swain, J. D., Tang, X. W., Tauscher, L., Taylor, L., S. C. C., Ting, S. M., Tonutti, M., Tonwar, S. C., Toth, J., Tully, C., Tuchscherer, H., Tung, K. L., Uchida, Y., Ulbricht, J., Uwer, U., Valente, E., Vandewalle, R. T., Vesztergombi, G., Vetlitsky, I., Viertel, G., Vivargent, M., Volkert, R., Vogel, H., Vogt, H., Vorobiev, I., Vorobyov, A. A., Vorvolakos, A., Wadhwa, M., Wallraff, W., Wang, J. C., Wang, X. L., Wang, Z. M., Weber, A., Wittgenstein, F., S. X., Wu, Wynhoff, S., Xu, J., Z. Z., Xu, Yang, B. Z., Yang, C. G., Yao, X. Y., J. B., Ye, Yeh, S. C., You, J. M., Zalite, A., Zalite, Y., Zemp, P., Zeng, Y., Zhang, Z., Zhang, Z. P., Zhou, B., Zhou, Y., Zhu, G. Y., Zhu, R. Y., Zichichi, A., and Ziegler, F.

Subjects
COLLISIONS, Nuclear and High Energy Physics, Particle physics, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], Meson, LUND MONTE-CARLO, Electron–positron annihilation, Hadron, ddc:500.2, 01 natural sciences, JET FRAGMENTATION, CHARMONIUM, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], 010306 general physics, Nuclear Experiment, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), L3 EXPERIMENT, Physics, E+E-PHYSICS, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, HEAVY QUARKONIUM, LEP, Z(0) DECAYS, High Energy Physics::Experiment, J/PSI-PRODUCTION, Atomic physics, Particle Physics - Experiment
Abstract

We report on measurements of the inclusive production of J, $\psi'$ and $\mathrm{\chi_c}$ mesons in hadronic Z decays, based on 3.2 million hadronic events collected using the L3 detector at LEP. The J and $\psi'$ mesons are reconstructed through their decays into lepton pairs, while the $\mathrm{\chi_c}$ mesons are reconstructed via the decay mode $ \mathrm{\chi_c} \rightarrow \mathrm{J} + \gamma $. The measured branching fractions are: \begin{eqnarray*} \mathrm{Br(Z \rightarrow J + X)} &=& (3.40 \pm 0.23\:(\mathrm {stat.}) \pm 0.27\:(\mathrm {sys.}))\,\times\,10^{-3} \\ \mathrm{Br(Z \rightarrow \psi' + X)} &=& (1.6 \pm 0.5\:(\mathrm {stat.}) \pm 0.3\:(\mathrm {sys.}))\,\times\,10^{-3} \\ \mathrm{Br(Z \rightarrow \chi_{c1} + X)} &=& (2.7 \pm 0.6\:(\mathrm {stat.})\pm 0.5\:(\mathrm {sys.}))\, \times\,10^{-3}. \\ \end{eqnarray*} In the absence of a clear $\mathrm{\chi_{c2}}$ signal, the upper limit at 90\% C.L. is set: \mathrm{ Br(Z \rightarrow \chi_{c2} + X) 3.2\,\times\,10^{-3}}. \end{document}

Published
1997

47. Measurement of charged pions in 12C + 12C collisions at 1A GeV and 2A GeV with HADES

Author

Krücken, R., Agakishiev, G., Agodi, C., Bałanda, A., Bellia, G., Belver, D., Belyaev, A., Bielčík, Jaroslav, Blanco, A., Bortolotti, A., Boyard, J. L., Braun-Munzinger, P., Cabanelas, Pablo, Chernenko, S., Christ, T., Coniglione, R., Destefanis, M., Diáz, J., Dohrmann, F., Durán, I., Dybczak, A., Eberl, T., Fabbietti, L., Fateev, O., Ferreira-Marques, R., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gil, A., Gilardi, C., Golubeva, M., González-Díaz, D., Grosse, E., Guber, F., Heilmann, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Kanaki, K., Karavicheva, T., Kirschner, D., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Kozuch, A., Krása, Antonín, Křížek, F., Kühn, W., Kugler, A., Kurepin, A., Lamas-Valverde, J., Lang, S., Lange, J. S., Lapidus, K., Lopes, L., Lorenz, M., Maier, L., Maiolino, C., Mangiarotti, A., Marín, J., Markert, J., Metag, V., Michalska, B., Michel, J., Morinière, E., Mousa, J., Münch, M., Müntz, C., Naumann, L., Novotny, R., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Yiannis, Pechenov, V., Pechenova, O., Pérez Cavalcanti, T., Piattelli, P., Pietraszko, J., Pospíšil, V., Przygoda, W., Ramstein, B., Reshetin, A., Roy-Stephan, M., Rustamov, A., Sadovsky, A., Sailer, B., Salabura, P., Sapienza, P., Schmah, A., Schroeder, C., Schwab, E., Simon, R. S., Sobolev, Yu G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Sudol, M., Tarantola, A., Teilab, K., Tlustý, P., Traxler, M., Trebacz, R., Tsertos, Haralambos, Wagner, V., Weber, M., Wisniowski, M., Wojcik, T., Wüstenfeld, J., Yurevich, S., Zanevsky, Y., Zhou, P., Zumbruch, P., Tsertos, Haralambos [0000-0001-5966-343X], 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), and HADES

Subjects
Nuclear and High Energy Physics, Meson, Hadron, Nuclear Theory, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Particle and resonance production, 01 natural sciences, Nuclear physics, Pion, 25.75.Dw, Relativistic heavy-ion collisions, 0103 physical sciences, Rapidity, Nuclear Experiment (nucl-ex), 010306 general physics, Anisotropy, Nuclear Experiment, Physics, Range (particle radiation), Spectrometer, 010308 nuclear & particles physics, 25.75.-q, Collision, High Energy Physics::Experiment
Abstract

We present the results of a study of charged pion production in 12C + 12C collisions at incident beam energies of 1A GeV and 2A GeV using the HADES spectrometer at GSI. The main emphasis of the HADES program is on the dielectron signal from the early phase of the collision. Here, however, we discuss the data with respect to the emission of charged hadrons, specifically the production of pi+- mesons, which are related to neutral pions representing a dominant contribution to the dielectron yield. We have performed the first large-angular range measurement of the distribution of pi+- mesons for the 12C + 12C collision system covering a fairly large rapidity interval. The pion yields, transverse-mass and angular distributions are compared with calculations done within a transport model, as well as with existing data from other experiments. The anisotropy of pion production is systematically analyzed., 15 pages, 13 figures, v2 - the text unchanged, only full author list added to METADATA (in v1 only the first author and collaboration name), reference to published paper added

Published
2009
Full Text
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48. The high-acceptance dielectron spectrometer HADES

Author

Hutsch, J., Krücken, R., Agakichiev, G., Agodi, C., Alvarez-Poll, H., Atkin, E., Badura, Eugen, Bałanda, A., Bassi, A., Bassini, R., Bellia, G., Belver, D., Belyaev, A. V., Benovic, M., Bertini, D., Bielčík, Jaroslav, Böhmer, M., Boiano, C., Bokemeyer, H., Bartolotti, A., Boyard, J. L., Brambilla, S., Braun-Munzinger, P., Cabanelas, Pablo, Castro, E., Chepurnov, V., Chernenko, S., Christ, T., Coniglione, R., Cosentino, L., Dahlinger, M., Daues, H. W., Destefanis, M., Diáz, J., Dohrmann, F., Dressler, R., Durán, I., Dybczak, A., Eberl, T., Enghardt, W., Fabbietti, L., Fateev, O. V., Fernández, C., Finocchiaro, P., Friese, J., Fröhlich, I., Fuentes, B., Galatyuk, T., Garabatos, Chilo, Garzón, J. A., Genolini, B., Gernhäuser, R., Gilardi, C., Gilg, H., Golubeva, M., González-Díaz, D., Grosse, E., Guber, F., Hehner, J., Heidel, K., Heinz, T., Hennino, T., Hlavac, S., Hoffmann, J., Holzmann, R., Homolka, J., Ierusalimov, A. P., Iori, I., Ivashkin, A., Jaskula, M., Jourdain, J. C., Jurkovic, M., Kämpfer, B., Kajetanowicz, M., Kanaki, K., Karavicheva, T., Kastenmüller, A., Kidon, L., Kienle, P., Kirschner, D., Koenig, I., Koenig, W., Körner, H. J., Kolb, B. W., Kopf, U., Korcyl, K., Kotte, R., Kozuch, A., Krizek, F., Kühn, W., Kugler, A., Kulessa, R., Kurepin, A., Kurtukian-Nieto, T., Lang, S., Lange, J. S., Lapidus, K., Lehnert, J., Leinberger, U., Lichtblau, C., Lins, E., Lippmann, C., Lorenz, M., Magestro, D., Maier, L., Maier-Komor, P., Maiolino, C., Malarz, A., Marek, T., Markert, J., Metag, V., Michalska, B., Michel, J., Migneco, E., Mishra, D., Morinière, E., Mousa, J., Münch, M., Müntz, C., Naumann, L., Nekhaev, A., Niebur, W., Novotny, J., Novotny, R., Ott, W., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Yiannis, Pechenov, V., Pechenova, O., Cavalcanti, T. P., Petri, M., Piattelli, P., Pietraszko, J., Pleskac, R., Ploskon, M., Pospísil, V., Pouthas, J., Prokopowicz, W., Przygoda, W., Ramstein, B., Reshetin, A., Ritman, J., Roche, G., Rodriguez-Prieto, G., Rosenkranz, K., Rosier, P., Roy-Stephan, M., Rustamov, A., Sabin-Fernandez, J., Sadovsky, A., Sailer, B., Salabura, P., Salz, C., Sánchez, M., Sapienza, P., Schäfer, D., Schicker, R. M., Schmah, A., Schön, H., Schön, W., Schroeder, C., Schroeder, S., Schwab, E., Senger, P., Shileev, K., Simon, R. S., Skoda, M., Smolyankin, V., Smykov, L., Sobiella, M., Sobolev, Y. G., Spataro, S., Spruck, B., Stelzer, H., Ströbele, H., Stroth, J., Sturm, C., Sudoł, M., Suk, M., Szczybura, M., Taranenko, A., Tarantola, A., Teilab, K., Tiflov, V., Tikhonov, A., Tlusty, P., Toia, A., Traxler, M., Trebacz, R., Troyan, A. Y., Tsertos, Haralambos, Turzo, I., Ulrich, A., Vassiliev, D., Vázquez, A., Volkov, Y., Wagner, V., Wallner, C., Walus, W., Wang, Y., Weber, M., Wieser, J., Winkler, S., Wisniowski, M., Wojcik, T., Wüstenfeld, J., Yurevich, S., Zanevsky, Y. V., Zeitelhack, K., Zentek, A., Zhou, P., Zovinec, D., Zumbruch, P., and Tsertos, Haralambos [0000-0001-5966-343X]

Subjects
Nuclear and High Energy Physics, Proton, data acquisition, Cherenkov detector, electron hadron, Hadron, Nuclear Theory, Mesons in nuclear matter, Photon lepton and heavy quark production in relativistic heavy ion collisions, Spectrometers and spectroscopic techniques, Data acquisition and sorting, FOS: Physical sciences, Electron, law.invention, Nuclear physics, Pion, scattering [heavy ion], law, ddc:530, tracking detector, interaction [hadron nucleus], pair production [electron], Vector meson, Nuclear Experiment (nucl-ex), performance [magnetic spectrometer], Nuclear Experiment, 25.75.Cj Photon, lepton, and heavy quark production in relativistic heavy ion collisions, trigger [electron], RICH, Darmstadt SIS, leptonic decay [vector meson], Physics, superconductivity [coil], Spectrometer, track data analysis, Detector, time-of-flight [detector], 29.30.-h Spectrometers and spectroscopic techniques, drift chamber, High Energy Physics::Experiment, particle identification, 29.85.Ca Data acquisition and sorting, 21.65.Jk Mesons in nuclear matter, mass spectrum [electron positron], hadronic [matter]
Abstract

HADES is a versatile magnetic spectrometer aimed at studying dielectron production in pion, proton and heavy-ion-induced collisions. Its main features include a ring imaging gas Cherenkov detector for electron-hadron discrimination, a tracking system consisting of a set of 6 superconducting coils producing a toroidal field and drift chambers and a multiplicity and electron trigger array for additional electron-hadron discrimination and event characterization. A two-stage trigger system enhances events containing electrons. The physics program is focused on the investigation of hadron properties in nuclei and in the hot and dense hadronic matter. The detector system is characterized by an 85% azimuthal coverage over a polar angle interval from 18° to 85°, a single electron efficiency of 50% and a vector meson mass resolution of 2.5%. Identification of pions, kaons and protons is achieved combining time-of-flight and energy loss measurements over a large momentum range (0.1 < p < 1.0 GeV/c). This paper describes the main features and the performance of the detector system. © Società Italiana di Fisica / Springer-Verlag 2009. 41 2 243 277

Published
2009
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49. Measurement of low-mass e+e− pair production in 1 and 2 A GeV C–C collision with HADES

Author

Krücken, R., Sudol, M., Agakishiev, G., Agodi, C., Bałanda, A., Bellia, G., Belver, D., Belyaev, A., Bielčík, Jaroslav, Blanco, A., Bortolotti, A., Boyard, J. L., Braun-Munzinger, P., Cabanelas, Pablo, Chernenko, S., Christ, T., Coniglione, R., Destefanis, M., Diáz, J., Dohrmann, F., Durán, I., Dybczak, A., Eberl, T., Fabbietti, L., Fateev, O., Ferreira-Marques, R., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gil, A., Gilardi, C., Golubeva, M., González-Díaz, D., Grosse, E., Guber, F., Heilmann, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Kanaki, K., Karavicheva, T., Kirschner, D., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Kozuch, A., Krása, Antonín, Křížek, F., Kühn, W., Kugler, A., Kurepin, A., Lamas-Valverde, J., Lang, S., Lange, J. S., Lapidus, K., Lopes, L., Lorenz, M., Maier, L., Maiolino, C., Mangiarotti, A., Marín, J., Markert, J., Metag, V., Michalska, B., Michel, J., Morinière, E., Mousa, J., Münch, M., Müntz, C., Naumann, L., Novotny, R., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Yiannis, Pechenov, V., Pechenova, O., Pérez Cavalcanti, T., Piattelli, P., Pietraszko, J., Pospíšil, V., Przygoda, W., Ramstein, B., Reshetin, A., Roy-Stephan, M., Rustamov, A., Sadovsky, A., Sailer, B., Salabura, P., Sapienza, P., Schmah, A., Schroeder, C., Schwab, E., Simon, R., Sobolev, Y. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlustý, P., Traxler, M., Trebacz, R., Tsertos, Haralambos, Wagner, V., Weber, M., Wisniowski, M., Wojcik, T., Wüstenfeld, J., Yurevich, S., Zanevsky, Y., Zhou, P., Zumbruch, P., 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), HADES, and Tsertos, Haralambos [0000-0001-5966-343X]

Subjects
Physics, Nuclear reaction, Particle physics, Physics and Astronomy (miscellaneous), Proton, ENERGIES, 010308 nuclear & particles physics, Hadron, PI(0), HEAVY-ION COLLISIONS, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Pair production, Pion, Antimatter, 0103 physical sciences, Mass spectrum, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, Engineering (miscellaneous), Lepton
Abstract

HADES is a secondary generation experiment operated at GSI Darmstadt with the main goal to study dielectron production in proton, pion and heavy ion induced reactions. The first part of the HADES mission is to reinvestigate the puzzling pair excess measured by the DLS collaboration in C+C and Ca+Ca collisions at 1A GeV. For this purpose dedicated measurements with the C+C system at 1 and 2A GeV were performed. The pair excess above a cocktail of free hadronic decays has been extracted and compared to the one measured by DLS. Furthermore, the excess is confronted with predictions of various model calculations. © 2009 Springer-Verlag / Società Italiana di Fisica. 62 1 81 84 Cited By :2

Published
2008
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50. 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
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