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1,694 results on '"AUDOUIN, L."'

1. 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

2. First simultaneous measurement of the gamma-ray and neutron emission probabilities in inverse kinematics at a heavy-ion storage ring

Author

Sguazzin, M., Jurado, B., Pibernat, J., Swartz, J. A., Grieser, M., Glorius, J., Litvinov, Yu. A., Berthelot, C., Włoch, B., Adamczewski-Musch, J., Alfaurt, P., Ascher, P., Audouin, L., Blank, B., Blaum, K., Brückner, B., Dellmann, S., Dillmann, I., Domingo-Pardo, C., Dupuis, M., Erbacher, P., Flayol, M., Forstner, O., Freire-Fernández, D., Gerbaux, M., Giovinazzo, J., Grévy, S., Griffin, C. J., Gumberidze, A., Heil, S., Heinz, A., Hess, R., Kurtulgil, D., Kurz, N., Leckenby, G., Litvinov, S., Lorentz, B., Méot, V., Michaud, J., Pérard, S., Petridis, N., Popp, U., Ramos, D., Reifarth, R., Roche, M., Sanjari, M. S., Sidhu, R. S., Spillmann, U., Steck, M., Stöhlker, Th., Thomas, B., Thulliez, L., and Versteegen, M.

Subjects
Nuclear Experiment
Abstract

The probabilities for gamma-ray and particle emission as a function of the excitation energy of a decaying nucleus are valuable observables for constraining the ingredients of the models that describe the de-excitation of nuclei near the particle emission threshold. These models are essential in nuclear astrophysics and applications. In this work, we have for the first time simultaneously measured the gamma-ray and neutron emission probabilities of 208Pb. The measurement was performed in inverse kinematics at the Experimental Storage Ring (ESR) of the GSI/FAIR facility, where a 208Pb beam interacted through the 208Pb(p,p') reaction with a hydrogen gas jet target. Instead of detecting the gamma-rays and neutrons emitted by 208Pb, we detected the heavy beam-like residues produced after gamma and neutron emission. These heavy residues were fully separated by a dipole magnet of the ESR and were detected with outstanding efficiencies. The comparison of the measured probabilities with model calculations has allowed us to test and select different descriptions of the gamma-ray strength function and the nuclear level density available in the literature., Comment: 23 pages, 14 figures

Published
2024

3. 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

4. First measurement of the neutron-emission probability with a surrogate reaction in inverse kinematics at a heavy-ion storage ring

Author

Sguazzin, M., Jurado, B., Pibernat, J., Swartz, J. A., Grieser, M., Glorius, J., Litvinov, Yu. A., Adamczewski-Musch, J., Alfaurt, P., Ascher, P., Audouin, L., Berthelot, C., Blank, B., Blaum, K., Brückner, B., Dellmann, S., Dillmann, I., Domingo-Pardo, C., Dupuis, M., Erbacher, P., Flayol, M., Forstner, O., Freire-Fernández, D., Gerbaux, M., Giovinazzo, J., Grévy, S., Griffin, C. J., Gumberidze, A., Heil, S., Heinz, A., Hess, R., Kurtulgil, D., Kurz, N., Leckenby, G., Litvinov, S., Lorentz, B., Méot, V., Michaud, J., Pérard, S., Petridis, N., Popp, U., Ramos, D., Reifarth, R., Roche, M., Sanjari, M. S., Sidhu, R. S., Spillmann, U., Steck, M., Stöhlker, Th., Thomas, B., Thulliez, L., Versteegen, M., and Włoch, B.

Subjects
Nuclear Experiment
Abstract

Neutron-induced reaction cross sections of short-lived nuclei are imperative to understand the origin of heavy elements in stellar nucleosynthesis and for societal applications, but their measurement is extremely complicated due to the radioactivity of the targets involved. One way of overcoming this issue is to combine surrogate reactions with the unique possibilities offered by heavy-ion storage rings. In this work, we describe the first surrogate-reaction experiment in inverse kinematics, which we successfully conducted at the Experimental Storage Ring (ESR) of the GSI/FAIR facility, using the 208Pb(p,p') reaction as a surrogate for neutron capture on 207Pb. Thanks to the outstanding detection efficiencies possible at the ESR, we were able to measure for the first time the neutron-emission probability as a function of the excitation energy of 208Pb. We have used this probability to select different descriptions of the gamma-ray strength function and nuclear level density, and provide reliable results for the neutron-induced radiative capture cross section of 207Pb at energies for which no experimental data exist., Comment: 10 pages and 5 figures

Published
2023

5. Measurement and analysis of the 246248Cm and 246248Cm neutron capture cross-sections at the EAR2 of the n_TOF facility at CERN

Author

Alcayne, V., Kimura, A., Mendoza, E., Cano-Ott, D., Martínez, T., Aberle, O., Álvarez-Velarde, F., 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., 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-Domínguez, B., Ferrari, A., Finocchiaro, P., Furman, V., Göbel, K., Gawlik, A., Gilardoni, S., Glodariu, T., Gonçalves, I. F., González-Romero, E., Guerrero, C., Gunsing, F., Harada, H., Heinitz, S., Heyse, J., Jenkins, D. G., Käppeler, F., Kadi, Y., Katabuchi, T., Kivel, N., Knapova, I., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Ladarescu, I., Lederer-Woods, C., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S. J., Macina, D., Manna, A., 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., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Simone, S., 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., Vescovi, D., Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., and Žugec, P.

Published
2024
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6. Experimental evidence of the effect of nuclear shells on fission dissipation and time

Author

Ramos, D., Caamano, M., Farget, F., Rodriguez-Tajes, C., Lemasson, A., Schmitt, C., Audouin, L., Benlliure, J., Casarejos, E., Clement, E., Cortina, D., Delaune, O., Derkx, X., Dijon, A., Dore, D., Fernandez-Dominguez, B., de France, G., Heinz, A., Jacquot, B., Paradela, C., Rejmund, M., Roger, T., and Salsac, M. -D.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Nuclear fission is still one of the most complex physical processes we can observe in nature due to the interplay of macroscopic and microscopic nuclear properties that decide the result. An example of this coupling is the presence of nuclear dissipation as an important ingredient that contributes to drive the dynamics and has a clear impact on the time of the process. However, different theoretical interpretations, and scarce experimental data make it poorly understood. In this letter, we present the first experimental determination of the dissipation energy in fission as a function of the fragment split, for three different fissioning systems. The amount of dissipation was obtained through the measurement of the relative production of fragments with even and odd atomic numbers with respect to different initial fission energies. The results reveal a clear effect of particular nuclear shells on the dissipation and fission dynamics. In addition, the relative production of fragments with even and odd atomic numbers appears as a potential contributor to the long-standing problem of the time scale in fission.

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. Quasi-free (p,2p) reactions in inverse kinematics for studying the fission yield dependence on temperature

Author

Graña-González, A., Rodríguez-Sánchez, J. L., Benlliure, J., García-Jiménez, G., Alvarez-Pol, H., Cortina-Gil, D., Atar, L., Audouin, L., Authelet, G., Besteiro, A., Blanchon, G., Boretzky, K., Cabanelas, P., Casarejos, E., Cederkall, J., Chatillon, A., Corsi, A., Feijoo, M., Galaviz, D., Gasparic, I., Gernhäuser, R., Heil, M., Heinz, A., Holl, M., Jenegger, T., Ji, L., Johansson, H. T., Kiselev, O. A., Klenze, P., Knyazev, A., Körper, D., Kröll, T., Lihtar, I., Litvinov, Y. A., Löher, B., Morfouace, P., Mücher, D., Murillo-Morales, S., Obertelli, A., Panin, V., Park, J., Paschalis, S., Perea, A., Petri, M., Pirrone, S., Ponnath, L., Revel, A., Rhee, H. B., Rose, L., Rossi, D. M., Russotto, P., Simon, H., Stott, A., Sun, Y., Sürder, C., Taïeb, J., Taniuchi, R., Tengblad, O., Törnqvist, H. T., Velardita, S., Vesic, J., and Voss, B.

Subjects
Nuclear Experiment
Abstract

Despite the recent experimental and theoretical progress in the investigation of the nuclear fission process, a complete description still represents a challenge in nuclear physics because it is a very complex dynamical process, whose description involves the coupling between intrinsic and collective degrees of freedom, as well as different quantum-mechanical phenomena. To improve on the existing data on nuclear fission, we produce fission reactions of heavy nuclei in inverse kinematics by using quasi-free (p,2p) scattering, which induce fission through particle-hole excitations that can range from few to ten's of MeV. The measurement of the four-momenta of the two outgoing protons allows to reconstruct the excitation energy of the fissioning compound nucleus and therefore to study the evolution of the fission yields with temperature. The realization of this kind of experiment requires a complex experimental setup, providing full isotopic identification of both fission fragments and an accurate measurement of the momenta of the two outgoing protons. This was realized recently at the GSI/FAIR facility and here some preliminary results are presented., Comment: 6 pages, 2 figures, FAIRNESS 2022. arXiv admin note: text overlap with arXiv:2210.04741

Published
2022

9. Comprehensive investigation of fission yields by using spallation- and (p,2p)-induced fission reactions in inverse kinematics

Author

Rodríguez-Sánchez, J. L., Graña-González, A., Benlliure, J., Chatillon, A., García-Jiménez, G., Taieb, J., Alvarez-Pol, H., Atar, L., Audouin, L., Authelet, G., Besteiro, A., Blanchon, G., Boretzky, K., Cabanelas, P., Casarejos, E., Cederkall, J., Cortina-Gil, D., Corsi, A., De Filippo, E., Feijoo, M., Galaviz, D., Gasparic, I., Gernhäuser, R., Haettner, E., Heil, M., Heinz, A., Holl, M., Jenegger, T., Ji, L., Johansson, H. T., Kelić-Heil, A., Kiselev, O. A., Klenze, P., Knyazev, A., Körper, D., Kröll, T., Lihtar, I., Litvinov, Y. A., Löher, B., Martorana, N., Morfouace, P., Mücher, D., Morales, S. Murillo, Obertelli, A., Panin, V., Park, J., Paschalis, S., Perea, A., Petri1, M., Pietri, S., Pirrone, S., Ponnath, L., Revel, A., Rhee, H. -B., Rose, L., Ross, D. M., Russotto, P., Simon, H., Stott, A., Sun, Y., Sürder, C., Taniuchi, R., Tengblad, O., Törnqvist, H. T., Trimarchi, M., Velardita, S., Vesic, J., Voss, B., and Weick, H.

Subjects
Nuclear Experiment
Abstract

In the last decades, measurements of spallation, fragmentation and Coulex induced fission reactions in inverse kinematics have provided valuable data to accurately investigate the fission dynamics and nuclear structure at large deformations of a large variety of stable and non-stable heavy nuclei. To go a step further, we propose now to induce fission by the use of quasi-free (p,2p) scattering reactions in inverse kinematics, which allows us to reconstruct the excitation energy of the compound fissioning system by using the four-momenta of the two outgoing protons. Therefore, this new approach might permit to correlate the excitation energy with the charge and mass distributions of the fission fragments and with the fission probabilities, given for the first time direct access to the simultaneous measurement of the fission yield dependence on temperature and fission barrier heights of exotic heavy nuclei, respectively. The first experiment based on this methodology was realized recently at the GSI/FAIR facility and a detailed description of the experimental setup is given here., Comment: 4 pages, 15th International Conference on Nuclear Data for Science and Technology (ND2022)

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. Measurement of the prompt fission γ235-rays from slow neutron-induced fission of γ235U with STEFF

Author

Wright, T., Smith, A. G., Sosnin, N. V., Bennett, S. A., Davies, P. J., Popescu, A. V., Ryan, J. A., Sekhar, A., Warren, 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-Ramięga, 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-Woods, 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., 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., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sedyshev, P., 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., Weiss, C., Woods, P. J., and Žugec, P.

Published
2024
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12. High-resolution cross section measurements for neutron interactions on 89Y with incident neutron energies up to 95 keV

Author

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

Published
2024
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13. 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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14. Evaluation of the $^{13}$N($\alpha$,p)$^{16}$O thermonuclear reaction rate and its impact on the isotopic composition of supernova grains

Author

Meyer, A., de Séréville, N., Laird, A. M., Hammache, F., Longland, R., Lawson, T., Pignatari, M., Audouin, L., Beaumel, D., Fortier, S., Kiener, J., Lefebvre-Schuhl, A., Pellegriti, M. G., Stanoiu, M., and Tatischeff, V.

Subjects
Nuclear Experiment, Astrophysics - Solar and Stellar Astrophysics
Abstract

It has been suggested that hydrogen ingestion into the helium shell of massive stars could lead to high $^{13}$C and $^{15}$N excesses when the shock of a core-collapse supernova passes through its helium shell. This prediction questions the origin of extremely high $^{13}$C and $^{15}$N abundances observed in rare presolar SiC grains which is usually attributed to classical novae. In this context $^{13}$N($\alpha$,p)$^{16}$O the reaction plays an important role since it is in competition with $^{13}$N $\beta^+$-decay to $^{13}$C. The $^{13}$N($\alpha$,p)$^{16}$O reaction rate used in stellar evolution calculations comes from the CF88 compilation with very scarce information on the origin of this rate. The goal of this work is to provide a recommended $^{13}$N($\alpha$,p)$^{16}$O reaction rate, based on available experimental data. Unbound nuclear states in the $^{17}$F compound nucleus were studied using the spectroscopic information of the analog states in $^{17}$O nucleus that were measured at the Alto facility using the $^{13}$C($^7$Li,t)$^{17}$O alpha-transfer reaction, and spectroscopic factors were derived using a DWBA analysis. This spectroscopic information was used to calculate a recommended $^{13}$N($\alpha$,p)$^{16}$O reaction rate with meaningful uncertainty using a Monte Carlo approach. The present $^{13}$N($\alpha$,p)$^{16}$O reaction rate is found to be within a factor of two of the previous evaluation, with a typical uncertainty of a factor 2-3. The source of this uncertainty comes from the three resonances at $E_r^{c.m.} = 221$, 741 and 959 keV. This new error estimation translates to an overall uncertainty in the $^{13}$C production of a factor of 50. The main source of uncertainty on the re-evaluated $^{13}$N($\alpha$,p)$^{16}$O reaction rate currently comes from the uncertain alpha-width of relevant $^{17}$F states.

Published
2020
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15. Scission configuration of $^{239}$U from yields and kinetic information of fission fragments

Author

Ramos, D., Caamano, M., Lemasson, A., Rejmund, M., Audouin, L., Alvarez-Pol, H., Frankland, J. D., Fernandez-Dominguez, B., Galiana-Baldo, E., Piot, J., Ackermann, D., Biswas, S., Clement, E., Durand, D., Farget, F., Fregeau, M. O., Galaviz, D., Heinz, A., Henriques, A. I., Jacquot, B., Jurado, B., Kim, Y. H., Morfouace, P., Ralet, D., Roger, T., Schmitt, C., Teubig, P., and Tsekhanovich, I.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The simultaneous measurement of the isotopic fission-fragment yields and fission-fragment velocities of $^{239}$U has been performed for the first time. The $^{239}$U fissioning system was produced in one-neutron transfer reactions between a $^{238}$U beam at 5.88 MeV/nucleon and a $^{9}$Be target. The combination of inverse kinematics at low energy and the use of the VAMOS++ spectrometer at the GANIL facility allows the isotopic identification of the full fission-fragment distribution and their velocity in the reference frame of the fissioning system. The proton and neutron content of the fragments at scission, their total kinetic and total excitation energy, as well as the neutron multiplicity were determined. Information from the scission point configuration is obtained from these observables and the correlation between them. The role of the octupole-deformed proton and neutron shells in the fission-fragment production is discussed., Comment: 8 pages, 7 figures

Published
2020
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16. Simultaneous determination of neutron-induced fission and radiative-capture cross sections from decay probabilities obtained with a surrogate reaction

Author

Sanchez, R. Perez, Jurado, B., Meot, V., Roig, O., Dupuis, M., Bouland, O., Denis-Petit, D., Marini, P., Mathieu, L., Tsekhanovich, I., Aiche, M., Audouin, L., Cannes, C., Czajkowski, S., Delpech, S., Gorgen, A., Guttormsen, M., Henriques, A., Kessedjian, G., Nishio, K., Ramos, D., Siem, S., and Zeiser, F.

Subjects
Nuclear Experiment
Abstract

Reliable neutron-induced reaction cross sections of unstable nuclei are essential for nuclear astrophysics and applications but their direct measurement is often impossible. The surrogate-reaction method is one of the most promising alternatives to access these cross sections. In this work, we successfully applied the surrogate-reaction method to infer for the first time both the neutron-induced fission and radiative-capture cross sections of 239Pu in a consistent manner from a single measurement. This was achieved by combining simultaneously-measured fission and gamma-emission probabilities for the 240Pu(4He,4He') surrogate reaction with a calculation of the angular-momentum and parity distributions populated in this reaction. While other experiments measure the probabilities for some selected gamma-ray transitions, we measure the gamma-emission probability. This enlarges the applicability of the surrogate-reaction method., Comment: 8 pages, 3 figures

Published
2020
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17. Review and new concepts for neutron-capture measurements of astrophysical interest

Author

Domingo-Pardo, C., Babiano-Suarez, V., Balibrea-Correa, J., Caballero, L., Ladarescu, I., Lerendegui-Marco, J., Tain, J. L., Calviño, F., Casanovas, A., Segarra, A., Tarifeño-Saldivia, A. E., Guerrero, C., Millán-Callado, M. A., Quesada, J. M., Rodríguez-González, M. T., Aberle, O., Alcayne, V., Amaducci, S., Andrzejewski, J., Audouin, L., Bacak, M., Barbagallo, M., Bennett, S., Berthoumieux, E., Bosnar, D., Brown, A. S., Busso, M., Caamaño, M., Calviani, M., Cano-Ott, D., Cerutti, F., Chiaveri, E., Colonna, N., Cortés, G. P., 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., Fernández-Domíngez, B., Ferrari, A., Ferro-Goncalves, I., Finocchiaro, P., Furman, V., Garg, R., Gawlik, A., Gilardoni, S., Göbel, K., González-Romero, E., Gunsing, F., Heyse, J., Jenkins, D. G., Jericha, E., Jiri, U., Junghans, A., Kadi, Y., Käppeler, F., Kimura, A., Knapová, I., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Lederer-Woods, C., Lonsdale, S. -J., Macina, D., Manna, A., Martínez, T., Masi, A., Massimi, C., Mastinu, P. F., Mastromarco, M., Maugeri, E., 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., Petrone, C., Piersanti, L., Pirovano, E., Porras, I., Praena, J., Doval, D. Ramos, Reifarth, R., Rochman, D., Rubbia, C., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sekhar, A., Smith, A. G., Sosnin, N., Sprung, P., Stamatopoulos, A., Tagliente, G., Tassan-Got, L., Thomas, B., Torres-Sánchez, P., Tsinganis, A., 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. J., Zugec, P. v, and Collaboration, The n_TOF

Subjects
Physics - Instrumentation and Detectors
Abstract

The idea of slow-neutron capture nucleosynthesis formulated in 1957 triggered a tremendous experimental effort in different laboratories worldwide to measure the relevant nuclear physics input quantities, namely ($n,\gamma$) cross sections over the stellar temperature range (from few eV up to several hundred keV) for most of the isotopes involved from Fe up to Bi. A brief historical review focused on total energy detectors will be presented to illustrate how, advances in instrumentation have led, over the years, to the assessment and discovery of many new aspects of $s$-process nucleosynthesis and to the progressive refinement of theoretical models of stellar evolution. A summary will be presented on current efforts to develop new detection concepts, such as the Total-Energy Detector with $\gamma$-ray imaging capability (i-TED). The latter is based on the simultaneous combination of Compton imaging with neutron time-of-flight (TOF) techniques, in order to achieve a superior level of sensitivity and selectivity in the measurement of stellar neutron capture rates., Comment: Nuclear Physics in Astrophysics IX - Conference Proceedings

Published
2019
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18. First direct measurement of isotopic fission-fragment yields of $^{239}$U

Author

Ramos, D., Caamano, M., Lemasson, A., Rejmund, M., Audouin, L., Alvarez-Pol, H., Frankland, J. D., Fernandez-Dominguez, B., Galiana-Baldo, E., Piot, J., Ackermann, D., Biswas, S., Clement, E., Durand, D., Farget, F., Fregeau, M. O., Galaviz, D., Heinz, A., Henriques, A. I., Jacquot, B., Jurado, B., Kim, Y. H., Morfouace, P., Ralet, D., Roger, T., Schmitt, C., Teubig, P., and Tsekhanovich, I.

Subjects
Nuclear Experiment
Abstract

A direct and complete measurement of isotopic fission-fragment yields of $^{239}$U has been performed for the first time. The $^{239}$U fissioning system was produced with an average excitation energy of 8.3 MeV in one-neutron transfer reactions between a $^{238}$U beam and a $^{9}$Be target at Coulomb barrier energies. The fission fragments were detected and isotopically identified using the VAMOS++ spectrometer at the GANIL facility. This measurement allows to directly evaluate the fission models at excitation energies of fast neutrons, relevant for next-generation nuclear reactors. The present data, in agreement with model calculations, do not support the recently reported anomaly in the fission-fragment yields of $^{239}$U and confirm the persistence of spherical shell effects in the Sn region at excitation energies exceeding the fission barrier by few MeV.

Published
2019
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19. 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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20. Connection between nuclear structure, dissipation, and time in fission data.

Author

Caamaño, M., Ramos, D., Fernández, D., Mantovani, G., Farget, F., Rodríguez-Tajes, C., Lemasson, A., Rejmund, M., Schmitt, C., Ackermann, D., Álvarez-Pol, H., Audouin, L., Benlliure, J., Biswas, S., Casarejos, E., Clement, E., Cortina, D., Delaune, O., Derkx, X., and Dijon, A.

Subjects
NUCLEAR structure, NUCLEAR fission, ENERGY dissipation, ATOMIC number, ATOMIC excitation
Abstract

Nuclear fission is still one of the most complex physical processes due to the interplay between macroscopic and microscopic nuclear properties that decide the output. An example of this coupling is the presence of nuclear dissipation as an important ingredient that contributes to drive the dynamics and has a clear impact on the time of the process. However, different theoretical interpretations and scarce experimental data make it poorly understood. At low excitation energy, the relative yields of fragments even and odd atomic numbers show a clear difference, which can be quantified with the so-called even-odd effect. This seemingly mundane property can be used to obtain information about the energy dissipated during the process and the role of structure in its dynamics. In this paper, the study of the even-odd effect for elasticand transfer-induced fission data is discussed. A clear connection with particular fragment shells and the dissipation energy is found, as detailed in Ref. [1]. In addition, preliminary results from quasi-fission data show the formation of a relatively large even-odd effect, which suggests a process with low dissipation mainly consisting in the exchange of nucleon pairs. [ABSTRACT FROM AUTHOR]

Published
2024
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21. 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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22. 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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23. Experimental setup and procedure for the measurement of the 7Be(n,p)7Li 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., Lederer, C., Leeb, H., Lerendegui-Marco, J., Meo, S. Lo, 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 - Instrumentation and Detectors
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 indiced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the 7Be(n,{\alpha}){\alpha} cross section, the 7Be(n,p)7Li reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization.

Published
2017
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24. 74n,γGe(74n,γ) cross section below 70 keV measured at n_TOF CERN

Author

Lederer-Woods, C., Aberle, O., Andrzejewski, J., Audouin, L., Bécares, V., Bacak, M., Balibrea, J., Barbagallo, M., Barros, S., Battino, U., 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., 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-Ramięga, A., 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., Kokkoris, M., Krtička, M., Leal-Cidoncha, E., Leeb, H., Lerendegui-Marco, J., 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., 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, 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., and Žugec, P.

Published
2022
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26. 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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27. 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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28. 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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29. High accuracy, high resolution 235U(n,f) cross section from n_TOF (CERN) from 18 meV to 10 keV

Author

Mastromarco, M., Amaducci, S., Colonna, N., Finocchiaro, P., Cosentino, L., Barbagallo, M., 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., Diacono, D., 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.

Published
2022
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30. Characterization of the scission point from fission-fragment velocities

Author

Caamaño, M., Farget, F., Delaune, O., Schmidt, K. -H., Schmitt, C., Audouin, L., Bacri, C. -O., Benlliure, J., Casarejos, E., Derkx, X., Fernández-Domínguez, B., Gaudefroy, L., Golabek, C., Jurado, B., Lemasson, A., Ramos, D., Rodríguez-Tajes, C., Roger, T., and Shrivastava, A.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The isotopic-yield distributions and kinematic properties of fragments produced in transfer-induced fission of 240Pu and fusion-induced fission of 250Cf, with 9 MeV and 45 MeV of excitation energy respectively, were measured in inverse kinematics with the spectrometer VAMOS. The kinematic properties of identified fission fragments allow to derive properties of the scission configuration such as the distance between fragments, the total kinetic energy, the neutron multiplicity, the total excitation energy, and, for the first time, the proton- and neutron-number sharing during the emergence of the fragments. These properties of the scission point are studied as functions of the fragment atomic number. The correlation between these observables, gathered in one single experiment and for two different fissioning systems at different excitation energies, give valuable information for the understanding and modeling of the fission process., Comment: 12 pages, 8 figures

Published
2015
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31. Characterization and First Test of an i-TED Prototype at CERN n_TOF

Author

Babiano-Suarez, V., Caballero, L., Domingo-Pardo, C., Ladarescu, I., Aberle, O., Alcayne, V., Amaducci, S., Andrzejewski, J., Audouin, L., Bacak, M., Barbagallo, M., Bécares, V., Bečvář, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A. S., Busso, M., Caamaño, M., Calviani, M., Calviño, F., Cano-Ott, D., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G. P., Cortés-Giraldo, M. A., Cosentino, L., Cristallo, S., Damone, L. A., Diakaki, M., Dietz, M., Dressler, R., Dupont, E., Durán, I., Eleme, Z., Fernández-Domíngez, B., Ferrari, A., Ferro-Gon calves, I., Finocchiaro, P., Furman, V., Gawlik, A., Gilardoni, S., Glodariu, T., Göbel, K., González-Romero, E., Guerrero, C., Gunsing, F., Heinitz, S., Heyse, J., Jenkins, D. G., Kadi, Y., Käppeler, F., Kimura, A., Kivel, N., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Lederer-Woods, C., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S.-J., Macina, D., Manna, A., Martínez, T., Masi, A., Massimi, C., Mastinu, P. F., Mastromarco, M., Matteucci, F., Maugeri, E., 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., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Ramos Doval, D., Rausher, T., Reifarth, R., Rochman, D., Rubbia, C., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Smith, A. G., Sosnin, N., Stamatopoulos, A., Tagliente, G., Tain, J. L., Talip, Z., Tarifeño-Saldivia, A. E., 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. J., Žugec, P., García-Ramos, José-Enrique, editor, Andrés, María V., editor, Valera, José A. Lay, editor, Moro, Antonio M., editor, and Pérez-Bernal, Francisco, editor

Published
2019
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32. Measurement of the Cm Neutron-Induced Cross Sections at the n_TOF Facility

Author

Alcayne, V., Kimura, A., Mendoza, E., Cano-Ott, D., Aberle, O., Amaducci, S., Andrzejewski, J., Audouin, L., Babiano-Suarez, V., Bacak, M., Barbagallo, M., Bécares, V., Bečvář, F., Bellia, G., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A. S., Busso, M., Caamaño, M., Caballero, L., Calviani, M., Calviño, F., Casanovas, A., Cerutti, F., Chen, Y. H., Chiaveri, E., Colonna, N., Cortés, G. P., 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-Domíngez, B., Ferrari, A., Ferro-Gon calves, I., Finocchiaro, P., Furman, V., Gawlik, A., Gilardoni, S., Glodariu, T., Göbel, K., González-Romero, E., Guerrero, C., Gunsing, F., Heinitz, S., Heyse, J., Jenkins, D. G., Kadi, Y., Käppeler, F., Kivel, N., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, D., Ladarescu, I., Lederer-Woods, C., Lerendegui-Marco, J., Meo, S. Lo, Lonsdale, S.-J., Macina, D., Manna, A., Martínez, T., Masi, A., Massimi, C., Mastinu, P. F., Mastromarco, M., Matteucci, F., Maugeri, E., 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., Perkowski, J., Piersanti, L., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Doval, D. Ramos, Rausher, T., Reifarth, R., Rochman, D., Rubbia, C., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Smith, A. G., Sosnin, N., Stamatopoulos, A., Tagliente, G., Tain, J. L., Talip, Z., Tarifeño-Saldivia, A. E., 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. J., Žugec, P., García-Ramos, José-Enrique, editor, Andrés, María V., editor, Valera, José A. Lay, editor, Moro, Antonio M., editor, and Pérez-Bernal, Francisco, editor

Published
2019
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33. TOF Facility at CERN

Author

The n_TOF Collaboration, Damone, L. A., Barbagallo, M., Mastromarco, M., Mengoni, A., Colonna, N., Cosentino, L., Maugeri, E. A., Heinitz, S., Schumann, D., Dressler, R., Käppeler, F., Finocchiaro, P., Andrzejewski, J., Perkowski, J., Gawlik, A., Aberle, O., Altstadt, S., Ayranov, M., Audouin, L., Bacak, M., Balibrea-Correa, J., Ballof, J., Bcares, V., Bečvař, F., Beinrucker, C., Bellia, G., Bernardes, A. P., Berthoumieux, E., Billowes, J., Borge, M. J. G., Bosnar, D., Brown, A., Brugger, M., Busso, Maurizio, 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., Corts, G., Cortès-Giraldo, M. A., Cristallo, Sergio, Diakaki, M., Dietz, M., Domingo-Pardo, C., Dorsival, A., Dupont, E., Durán, I., Fernàndez-Dominguez, B., Ferrari, A., Ferreira, P., Furman, W., Ganesan, S., Garca-Rios, A., Gilardoni, S., Glodariu, T., Göbel, Kathrin, Gonçalves, I. F., Gonzalez-Romero, E., Goodacre, T. D., Griesmayer, E., Guerrero, C., Gunsing, F., Harada, H., Heftrich, Tanja, 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, Deniz, Leal-Cidoncha, E., Lederer-Woods, Claudia, Leeb, H., Lerendegui-Marco, J., Lo Meo, S., Lonsdale, S. J., Losito, R., Macina, D., Marganiec, J., Marsh, B., Martínez, T., Martins Correia, J. G., Masi, A., Massimi, C., Mastinu, P., Matteucci, F., Mazzone, A., Mendoza, E., Milazzo, P. M., Mingrone, Federica, Mirea, M., Musumarra, A., Negret, A., Nolte, R., Oprea, A., Patronis, N., Pavlik, A., Piersanti, Luciano, Piscopo, M., Plompen, A., Porras, I., Praena, J., Quesada, J. M., Radeck, D., Rajeev, K., Rauscher, Thomas, Reifarth, René, 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, Mario, Weiß, C., Wolf, C., Woods, P. J., Wright, T., Žugec, P., Formicola, Alba, editor, Junker, Matthias, editor, Gialanella, Lucio, editor, and Imbriani, Gianluca, editor

Published
2019
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34. Data for the s Process from n_TOF

Author

The n_TOF Collaboration, Massimi, C., Aberle, O., Alcayne, V., Andrzejewski, J., Audouin, L., Bécares, V., Babiano-Suarez, V., Bacak, M., Barbagallo, M., Benedikt, Th., Bennett, S., Berthoumieux, E., Billowes, J., Bosnar, D., Brown, A., Busso, Maurizio, Caamaño, M., Caballero-Ontanaya, L., Calviño, F., Calviani, M., Cano-Ott, D., Casanovas, A., Castelluccio, D. M., Cerutti, F., Chiaveri, E., Clai, G., Colonna, N., Cortés, G., Cortès-Giraldo, M. A., Cosentino, L., Cristallo, Sergio, Damone, L. A., Davies, P. J., Dietz, M., Domingo-Pardo, C., Dressler, R., Ducasse, Q., Dupont, E., Durán, I., Eleme, Z., Fernàndez-Dominguez, B., Ferrari, A., Finocchiaro, P., Furman, V., Göbel, Kathrin, Gawlik, A., Gilardoni, S., Gonçalves, I. F., González-Romero, E., Guerrero, C., Gunsing, F., Heinitz, S., Heyse, J., Jenkins, D. G., Junghans, Arnd R., Käppeler, F., Kadi, Y., Kimura, A., Knapova, I., Kokkoris, M., Kopatch, Y., Krtička, M., Kurtulgil, Deniz, Ladarescu, I., Lederer-Woods, Claudia, Lonsdale, S. J., Macina, D., Manna, A., Martínez, T., Masi, A., Mastinu, P., Mastromarco, M., Matteucci, F., Maugeri, E. A., Mazzone, A., Mendoza, E., Mengoni, A., Michalopoulou, V., Milazzo, P. M., Mingrone, Federica, Moreno-Soto, J., Musumarra, A., Negret, A., Ogállar, F., Oprea, A., Patronis, N., Pavlik, A., Perkowski, J., Piersanti, Luciano, Petrone, C., Pirovano, E., Porras, I., Praena, J., Quesada, J. M., Ramos-Doval, D., Rauscher, Thomas, Reifarth, René, Rochman, D., Sabaté-Gilarte, M., Saxena, A., Schillebeeckx, P., Schumann, D., Sekhar, A., Simone, S., Smith, A. G., Sosnin, N. V., Sprung, P., Stamatopoulos, A., Tagliente, G., Tain, J. L., Tarifeño-Saldivia, A., Tassan-Got, L., Tsinganis, A., Ulrich, J., Urlass, Sebastian, Valenta, S., Vannini, G., Variale, V., Vaz, P., Ventura, A., Vescovi, Diego, Vlachoudis, V., Vlastou, R., Wallner, A., Woods, P. J., Wright, T., Žugec, P., Formicola, Alba, editor, Junker, Matthias, editor, Gialanella, Lucio, editor, and Imbriani, Gianluca, editor

Published
2019
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35. A compact fission detector for fission-tagging neutron capture experiments with radioactive fissile isotopes

Author

Bacak, M., Aïche, M., Bélier, G., Berthoumieux, E., Diakaki, M., Dupont, E., Gunsing, F., Heyse, J., Kopecky, S., Laurent, B., Leeb, H., Mathieu, L., Moens, A., Richter, S., Schillebeeckx, P., Serot, O., Sibbens, G., Taieb, J., Vanleeuw, D., Vlachoudis, V., Aberle, O., Amaducci, S., Andrzejewski, J., Audouin, L., Balibrea, J., Barbagallo, M., Bečvář, F., 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., Domingo-Pardo, C., Dressler, R., 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., Heinitz, S., 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., Lerendegui-Marco, J., 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., 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., Vlastou, R., Wallner, A., Warren, S., Weiss, C., Woods, P.J., Wright, T., and Žugec, P.

Published
2020
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36. 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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37. 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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38. 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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39. 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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40. $^{62}$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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41. 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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42. Fragmentation-induced fission reactions of 236U in inverse kinematics to investigate the pre-fragment angular momentum parameterizations

Author

Rodríguez-Sánchez J.L., Feijoo M., Benlliure J., Chatillon A., Taïeb J., Audouin L., Alvarez-Pol H., Ayyad Y., Bélier G., Boutoux G., Caamaño M., Casarejos E., Cortina-Gil D., Farget F., Fernández-Domínguez B., Gorbinet T., Grente L., Heinz A., Johansson H.T., Jurado B., Kelić-Heil A., Körper D., Kurz N., Laurent B., Lindberg S., Löher B., Martin J.-F., Nociforo C., Paradela C., Pietri S., Ramos D., Rodríguez-Tajes C., Simon H., Törnqvist H.T., Voss B., Weick H., and Yan Y.

Subjects
Physics, QC1-999
Abstract

In the last decades, measurements of spallation, fragmentation and Coulex induced fission reactions in inverse kinematics have provided valuable data to accurately investigate the fission dynamics and nuclear structure at large deformations of a large variety of stable and non-stable heavy nuclei. The collected data were used to constrain dynamic and nuclear structure parameters of different de-excitation models, such as ABLA and GEF, but the data can also be used to constrain the parameterizations describing the pre-fragment properties after the nuclear collision, such as the angular momentum gained by the pre-fragment. In this work, the fissioning system yields are compared to calculations assuming different parameterizations for modeling the angular momentum gained by the compound nuclei. Our findings indicate that the parameterizations utilized by abrasion models clearly underestimate the angular momentum, resulting in the underestimation of the production of lighter fissioning systems.

Published
2023
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43. Study of (p,2p) fission reactions in inverse kinematics using the R3B set-up

Author

García-Jiménez G., Alvarez-Pol H., Graña-González A., Rodríguez-Sánchez J.L., Benlliure J., Cortina-Gil D., Atar L., Audouin L., Authelet G., Besteiro A., Blanchon G., Boretzky K., Borge M.J.G., Cabanelas P., Casarejos E., Cederkall J., Chatillon A., Corsi A., Feijoo M., De Filippo E., Galaviz D., Gasparic I., Geraci E., Gernhäuser R., Gnoffo B., Heil M., Heinz A., Hensel T., Holl M., Jelavic Malenica D., Jenegger T., Ji L., Johansson H.T., Kiselev O.A., Klenze P., Knyazev A., Körper D., Kröll T., Lithar I., Litvinov Y.A., Löher B., Martorana N. S., Morfouace P., Mücher D., Murillo-Morales S., Obertelli A., Panin V., Park J., Paschalis S., Perea A., Petri M., Pirrone S., Ponnath L., Revel A., Rhee H., Rose L., Rossi D.M., Russotto P., Simon H., Stott A., Sun Y., Sürder C., Taïeb J., Taniuchi R., Tengblad O., Törnqvist H.T., Trimarchi M., Velardita S., Vesic J., and Voss B.

Subjects
Physics, QC1-999
Abstract

A new experimental fission approach is presented in the context of the R3B (Reactions with Relativistic Radioactive Beams) collaboration, at the GSI/FAIR facility, in which knockout reactions in inverse kinematics are used to induce fission of 238U that will allow to characterise the excitation energy of the fission process and all the fission products. The CALIFA (CALorimeter for In-Flight detection of γ-rays and high energy charged pArticles) calorimeter, a key part of the R3B set-up, is used to reconstruct the momenta of the two protons from the (p, 2p) reactions. Preliminary results show that kinematic variables and first estimates for nucleon-removal cross sections are well reconstructed and in good agreement with other experimental measurements.

Published
2023
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44. Fission studies in inverse kinematics with the R3B setup

Author

Graña-González A., Rodríguez-Sánchez J.L., Benlliure J., García-Jiménez G., Alvarez-Pol H., Cortina-Gil D., Atar L., Audouin L., Authelet G., Besteiro A., Blanchon G., Boretzky K., Borge M.J.G., Cabanelas P., Casarejos E., Cederkall J., Chatillon A., Corsi A., Feijoo M., De Filippo E., Galaviz D., Gasparic I., Geraci E., Gernhäuser R., Gnoffo B., Heil M., Heinz A., Hensel T., Holl M., Jelavic Malenica D., Jenegger T., Ji L., Johansson H., Kiselev O.A., Klenze P., Knyazev A., Körper D., Kröll T., Lihtar I., Litvinov Y., Löher B., Martorana N.S., Morfouace P., Mücher D., Murillo Morales S., Obertelli A., Panin V., Park J., Paschalis S., Perea A., Petri M., Pirrone S., Ponnath L., Revel A., Rhee H.-B., Rose L., Rossi D.M., Russotto P., Simon H., Stott A., Sun Y., Sürder C., Taïeb J., Taniuchi R., Tengblad O., Törnqvist H.T., Trimarchi M., Velardita S., Vesic J., and Voss B.

Subjects
Physics, QC1-999
Abstract

Nuclear fission is a complex dynamical process, whose description involves the coupling between intrinsic and collective degrees of freedom, as well as different quantum-mechanical phenomena. For this reason, to this day it still lacks a satisfactory and complete microscopic description. In addition to the importance of describing fission itself, studies of the r-process in astrophysics depend on fission observables to constrain the theoretical models that explain the isotopic abundances in the Universe. To improve on the existing data, fission reactions of heavy nuclei in inverse kinematics are produced in quasi-free (p,2p) scattering reactions, which induce fission through particle-hole excitations that can range from few to tens of MeV. In order to study the evolution of the fission yields with temperature, the excitation energy of the fissioning system must be reconstructed, which is possible by measuring the four-momenta of the two outgoing protons. Performing this kind of experiment requires a complex experimental setup, providing full isotopic identification of both fission fragments and an accurate measurement of the momenta of the two outgoing protons. This was realized recently at the GSI/FAIR facility and some of the results obtained for the charge distributions are presented in this work.

Published
2023
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45. Experimental study of high-energy fission and quasi-fission with fusion- induced fission reactions at VAMOS++

Author

Fernández D., Caamaño M., Ramos D., Lemasson A., Rejmund M., Álvarez-Pol H., Audouin L., Frankland J. D., Fernández-Domínguez B., Galiana-Baldó E., Piot J., Schmitt C., Ackermann D., Biswas S., Clement E., Durand D., Farget F., Fregeau M. O., Galaviz D., Heinz A., Henriques A., Jacquot B., Jurado B., Kim Y. H., Morfouace P., Ralet D., Roger T., Teubig P., and Tsekhanovich I.

Subjects
Physics, QC1-999
Abstract

Over the past decade, inverse kinematics has been increasingly employed in experimental studies of fission. This approach has yielded a wealth of new observables that can be obtained in single measurements, enabling their analysis and correlations. One ongoing application of this technique involves a series of experiments performed at GANIL using the variable-mode, large-acceptance VAMOS++ spectrometer. A recent experiment focused on examining the survival of nuclear structure effects at high excitation energy in both fission and quasi-fission. The results of the study involved a full isotopic identification of fragments, as well as an analysis of the elemental yields their relation to fission dynamics. The results indicate that fission and quasi-fission involve different mechanisms, which could be exploited to distinguish between the two phenomena.

Published
2023
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46. Measurement of the 241Am(n,γ) cross section at the n_TOF facility at CERN

Author

Oprea A., Gunsing F., Schillebeeckx P., Aberle O., Bacak M., Berthoumieux E., Cano-Ott D., Diakaki M., Dupont E., Geslot B., Glodariu† T., Heyse J., Mendoza E., Negret A., Alcayne V., Amaducci S., Andrzejewski J., Audouin L., Bécares V., Babiano-Suarez V., Barbagallo M., Bečvář F., Bellia G., 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., Dietz M., Domingo-Pardo C., Dressler R., 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., Guerrero C., Harada H., Heinitz S., Jenkins D. G., Jericha E., Käppeler† F., Kaur G., Kadi Y., Kimura A., Kivel N., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Leeb H., Lerendegui-Marco J., Lo Meo S., Lonsdale S. J., Macina D., Manna A., Martínez 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., Nolte R., Ogállar F., Patronis N., Pavlik A., Perkowski J., Piersanti L., Porras I., Praena J., Quesada J. M., Radeck D., Ramos-Doval D., Rauscher T., Reifarth R., Rochman D., Rubbia C., Sabaté-Gilarte M., Saxena A., 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
Physics, QC1-999
Abstract

The neutron capture cross section of 241Am is an important quantity for nuclear energy production and fuel cycle scenarios. Several measurements have been performed in recent years with the aim to reduce existing uncertainties in evaluated data. Two previous measurements, performed at the 185 m flight-path station EAR1 of the neutron time-of-flight facility n_TOF at CERN, have permitted to substantially extend the resolved resonance region, but suffered in the near-thermal energy range from the unfavorable signal-to-background ratio resulting from the combination of the high radioactivity of 241Am and the rather low thermal neutron flux. The here presented 241Am(n,γ) measurement, performed with C6D6 liquid scintillator gamma detectors at the 20 m flight-path station EAR2 of the n_TOF facility, took advantage of the much higher neutron flux. The current status of the analysis of the data, focussed on the low-energy region, will be described here.

Published
2023
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47. Results of the 244Cm, 246Cm and 248Cm neutron-induced capture cross sections measurements at EAR1 and EAR2 of the n_TOF facility

Author

Alcayne V., Mendoza E., Cano-Ott D., Kimura A., Aberle O., Amaducci S., Andrzejewski J., Audouin L., Babiano-Suarez V., Bacak M., Barbagallo M., Bécares V., Bečvář F., Bellia G., Berthoumieux E., Billowes J., Bosnar D., Brown A. S., Busso M., Caamaño M., Caballero L., Calviani M., Calviño F., Casanovas A., Cerutti F., Chen Y. H., Chiaveri E., Colonna N., Cortés G. P., 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-Domíngez B., Ferrari A., Ferro-Gonçalves I., Finocchiaro P., Furman V., Garg R., Gawlik A., Gilardoni S., Glodariu T., Göbel K., González-Romero E., Guerrero C., Gunsing F., Heinitz S., Heyse J., Jenkins D. G., Jericha E., Kadi Y., Käppeler F., Kivel N., Kokkoris M., Kopatch Y., Krtička M., Kurtulgil D., Ladarescu I., Lederer-Woods C., Lerendegui-Marco J., Lo Meo S., Lonsdale S.-J., Macina D., Manna A., Martínez T., Masi A., Massimi C., Mastinu P. F., Mastromarco M., Matteucci F., Maugeri E., 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., Perkowski J., Piersanti L., Porras I., Praena J., Quesada J. M., Radeck D., Ramos Doval D., Reifarth R., Rochman D., Rubbia C., Sabaté-Gilarte M., Saxena A., Schillebeeckx P., Schumann D., Smith A. G., Sosnin N., Stamatopoulos A., Tagliente G., Tain J. L., Talip Z., Tarifeño-Saldivia A. E., 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. J., and Žugec P.

Subjects
Physics, QC1-999
Abstract

Accurate neutron capture cross section data for minor actinides (MAs) are required to estimate the production and transmutation rates of MAs in light water reactors, critical fast reactors like Gen-IV systems, and other innovative reactor systems such as accelerator driven systems (ADS). In particular, 244Cm, 246Cm and 248Cm play a role in the transport, storage and transmutation of the nuclear waste of the current nuclear reactors, due to the contribution of these isotopes to the radiotoxicity, neutron emission, and decay heat in the spent nuclear fuel. Also, capture reactions in these Cm isotopes open the path for the formation of heavier elements. In this work, the results of the capture cross section measurement on 244Cm, 246Cm and 248Cm performed at the CERN n_TOF facility are presented. It is important to notice that the Cm samples used in the experiment at n_TOF have been used previously in an experiment at J-PARC, this experiment and the previous one done in the 70s with a nuclear explosion were the only previous capture experiments for these isotopes. At n_TOF, the capture cross section measurements of 244Cm, 246Cm and 248Cm were performed at the 20 m vertical flight path (EAR2) with three C6D6 total energy detectors. In addition, the cross section of 244Cm was measured at the 185 m flight path (EAR1) with a Total Absorption Calorimeter (TAC). The combination of measurements in EAR1 and EAR2 has contributed to controlling and reducing the systematic uncertainties in the results. The compatibility of the different measurements performed and the techniques to obtain the results are presented in this paper as well as the procedure to obtain the resonance parameters.

Published
2023
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48. The Stellar 72Ge(n, γ) Cross Section for weak s-process: A First Measurement at n_TOF

Author

Dietz M., Lederer-Woods C., Tattersall A., Battino U., Gunsing F., Heinitz S., Lerendegui-Marco J., Krtička M., 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., Göbel K., García A. R., Gawlik-Ramie˛ga 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., 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., and Žugec P.

Subjects
Physics, QC1-999
Abstract

The slow neutron capture process (s-process) is responsible for producing about half of the elemental abundances heavier than iron in the universe. Neutron capture cross sections on stable isotopes are a key nuclear physics input for s-process studies. The 72Ge(n, γ) Maxwellian-Averaged Cross Section (MACS) has an important influence on the production of isotopes between Ge and Zr in the weak s-process in massive stars and so far only theoretical estimations are available. An experiment was carried out at the neutron time-of-flight facility n_TOF at CERN to measure the 72Ge(n, γ) reaction for the first time at stellar neutron energies. The capture measurement was performed using an enriched 72GeO2 sample at a flight path length of 184 m, which provided high neutron energy resolution. The prompt gamma rays produced after neutron capture were detected with a set of liquid scintillation detectors (C6D6). The neutron capture yield is derived from the counting spectra taking into account the neutron flux and the gamma-ray detection efficiency using the Pulse Height Weighting Technique. Over 70 new neutron resonances were identified, providing an improved resolved reaction cross section to calculate experimental MACS values for the first time. The experiment, data analysis and the new MACS results will be presented including their impact on stellar nucleosynthesis, which was investigated using the post-processing nucleosynthesis code mppnp for a 25 solar mass model.

Published
2023
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49. Indirect measurements of neutron-induced reaction cross sections at heavy-ion storage rings

Author

Sguazzin M., Jurado B., Pibernat J., Swartz J. A., Grieser M., Glorius J., Litvinov Yu. A., Reifarth R., Blaum K., Alfaurt P., Ascher P., Audouin L., Berthelot C., Blank B., Bruckner B., Dellmann S., Dillmann I., Domingo-Pardo C., Dupuis M., Erbacher P., Flayol M., Forstner O., Freire-Fernández D., Gerbaux M., Giovinazzo J., Grévy S., Griffin C. J., Gumberidze A., Heil S., Heinz A., Kurtulgil D., Leckenby G., Litvinov S., Lorentz B., Méot V., Michaud J., Perard S., Petridis N., Popp U., Ramos D., Roche M., Sanjari M.S., Sidhu R.S., Spillmann U., Steck M., Stöhlker Th., Thomas B., Thulliez L., and Versteegen M.

Subjects
Physics, QC1-999
Abstract

Neutron-induced reaction cross sections of unstable nuclei are essential for understanding the synthesis of heavy elements in stars and for applications in nuclear technology. However, their measurement is very complicated due to the radioactivity of the targets involved. We propose to circumvent this problem by using the surrogate reaction method in inverse kinematics, where the nucleus formed in the neutron- induced reaction of interest is produced by a reaction involving a radioactive heavy-ion beam and a stable, light target nucleus. The probabilities as a function of the compound-nucleus excitation energy for γ-ray emission, neutron emission and fission, which can be measured with the surrogate reaction, are particularly useful to constrain model parameters and to obtain more accurate predictions of the neutron-induced reaction cross sections of interest. Yet, the full development of the surrogate method is hampered by numerous long- standing target issues, which can be solved by combining surrogate reactions with the unique and largely unexplored possibilities at heavy-ion storage rings. In this contribution, we describe the developments we are carrying out to measure for the first time simultaneously γ-ray emission, neutron emission and fission probabilities at the storage rings of the GSI/FAIR facility. In particular, we will present the first results of the proof of principle experiment, which we performed in June 2022 at the Experimental Storage Ring (ESR) of GSI/FAIR.

Published
2023
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50. Fission-fragment yields measured in Coulomb-induced fission of 234,235,236,238U and 237,238Np with the R3B/SOFIA setup

Author

Chatillon A., Boutoux G., Gorbinet T., Grente L., Martin J.-F., Pellereau E., Taieb J., Alvarez-Pol H., Audouin L., Ayyad Y., Bélier G., Benlliure J., Caamaño M., Casarejos E., Cortina-Gil D., Ebran A., Farget F., Fernández-Domínguez B., Heinz A., Johansson H. T., Jurado B., Kelić-Heil A., Kurz N., Laurent B., Loeher B., Nociforo C., Paradela C., Pietri S., Prochazka A., Ramos D., Rodríguez-Sànchez J. L., Rodriguez C., Rossi D., Simon H., Tassan-Got L., Toernqvist H., Vargas J., Voss B., and Weick H.

Subjects
Physics, QC1-999
Abstract

Low energy fission of 234,235,236,238U and 237,238Np radioactive beams, provided by the GSI/FRS facility, has been studied using the R3B/SOFIA setup. The latter allows, on an event-by-event basis, to simultaneously identify, in terms of their mass and atomic numbers, the fissioning nucleus in coincidence with both fission fragments after prompt-neutron emission. This presentation reports on new results on elemental, isobaric and isotopic yields.

Published
2023
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