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874 results on '"Caamaño, M."'

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

Author

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

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

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

Published
2024

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

Author

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

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

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

Published
2023

5. 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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6. Cross-shell states in $^{15}$C: a test for p-sd interactions

Author

Lois-Fuentes, J., Fernández-Domínguez, B., Pereira-López, X., Delaunay, F., Catford, W. N., Matta, A., Orr, N. A., Duguet, T., Otsuka, T., Somà, V., Sorlin, O., Suzuki, T., Achouri, N. L., Assié, M., Bailey, S., Bastin, B., Blumenfeld, Y., Borcea, R., Caamaño, M., Caceres, L., Clément, E., Corsi, A., Curtis, N., Deshayes, Q., Farget, F., Fisichella, M., de France, G., Franchoo, S., Freer, M., Gibelin, J., Gillibert, A., Grinyer, G. F., Hammache, F., Kamalou, O., Knapton, A., Kokalova, Tz., Lapoux, V., Crom, B. Le, Leblond, S., Marqués, F. M., Morfouace, P., Pancin, J., Perrot, L., Piot, J., Pollacco, E., Ramos, D., Regueira-Castro, D., Rodríguez-Tajes, C., Roger, T., Rotaru, F., Sénoville, M., de Séréville, N., Smith, R., Stanoiu, M., Stefan, I., Stodel, C., Suzuki, D., Thomas, J. C., Timofeyuk, N., Vandebrouck, M., Walshe, J., and Wheldon, C.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The low-lying structure of $^{15}$C has been investigated via the neutron-removal $^{16}$C$(d,t)$ reaction. Along with bound neutron sd-shell hole states, unbound p-shell hole states have been firmly confirmed. The excitation energies and the deduced spectroscopic factors of the cross-shell states are an important measure of the $[(p)^{-1}(sd)^{2}]$ neutron configurations in $^{15}$C. Our results show a very good agreement with shell-model calculations using the SFO-tls interaction for $^{15}$C. However, a modification of the $p$-$sd$ and $sd$-$sd$ monopole terms was applied in order to reproduce the $N=9$ isotone $^{17}$O. In addition, the excitation energies and spectroscopic factors have been compared to the first calculations of $^{15}$C with the $ab~ initio$ self-consistent Green's function method employing the NNLO$_{sat}$ interaction. The results show the sensitivity to the size of the $N=8$ shell gap and highlight the need of going beyond the current truncation scheme in the theory.

Published
2023

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

Author

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

Subjects
Nuclear Experiment
Abstract

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

Published
2023
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8. 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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9. The CERN n TOF NEAR station for astrophysics- and application-related neutron activation measurements

Author

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

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

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

Published
2022

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

Author

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

Subjects
Nuclear Experiment
Abstract

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

Published
2022
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11. Evidence of a near-threshold resonance in $^{11}$B relevant to the $\beta$-delayed proton emission of $^{11}$Be

Author

Ayyad, Y., Mittig, W., Tang, T., Olaizola, B., Potel, G., Rijal, N., Watwood, N., Alvarez-Pol, H., Bazin, D., Caamaño, M., Chen, J., Cortesi, M., Fernández-Domínguez, B., Giraud, S., Gueye, P., Heinitz, S., Jain, R., Kay, B. P., Maugeri, E. A., Monteagudo, B., Ndayisabye, F., Paneru, S. N., Pereira, J., Rubino, E., Santamaria, C., Schumann, D., Surbrook, J., Wagner, L., Zamora, J. C., and Zelevinsky, V.

Subjects
Nuclear Experiment
Abstract

A narrow near-threshold proton-emitting resonance (Ex = 11.4 MeV, J$^{\pi}$ = 1/2$^{+}$ and $\Gamma_{p}$ = 4.4 keV) was directly observed in $^{11}$B via proton resonance scattering. This resonance was previously inferred in the $\beta$-delayed proton emission of the neutron halo nucleus $^{11}$Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. $R$-matrix analysis shows a sizable partial decay width for both, proton and $\alpha$ emission channels.

Published
2022
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12. Towards a new generation of solid total-energy detectors for neutron-capture time-of-flight experiments with intense neutron beams

Author

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

Published
2025
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13. Recoil imaging for directional detection of dark matter, neutrinos, and physics beyond the Standard Model

Author

O'Hare, C. A. J., Loomba, D., Altenmüller, K., Álvarez-Pol, H., Amaro, F. D., Araújo, H. M., Sierra, D. Aristizabal, Asaadi, J., Attié, D., Aune, S., Awe, C., Ayyad, Y., Baracchini, E., Barbeau, P., Battat, J. B. R., Bell, N. F., Biasuzzi, B., Bignell, L. J., Boehm, C., Bolognino, I., Brunbauer, F. M., Caamaño, M., Cabo, C., Caratelli, D., Carmona, J. M., Castel, J. F., Cebrián, S., Cogollos, C., Collison, D., Costa, E., Dafni, T., Dastgiri, F., Deaconu, C., De Romeri, V., Desch, K., Dho, G., Di Giambattista, F., Díez-Ibáñez, D., D'Imperio, G., Dutta, B., Eldridge, C., Elliott, S. R., Ezeribe, A. C., Fava, A., Felkl, T., Fernández-Domínguez, B., Ribas, E. Ferrer, Flöthner, K. J., Froehlich, M., Galán, J., Galindo, J., García, F., Pascual, J. A. García, Gelli, B. P., Ghrear, M., Giomataris, Y., Gnanvo, K., Gramellini, E., Di Cortona, G. Grilli, Hall-Wilton, R., Harton, J., Hedges, S., Higashino, S., Hill, G., Holanda, P. C., Ikeda, T., Irastorza, I. G., Jackson, P., Janssens, D., Jones, B., Kaminski, J., Katsioulas, I., Kelly, K., Kemmerich, N., Kemp, E., Korandla, H. B., Kraus, H., Lackner, A., Lane, G. J., Lewis, P. M., Lisowska, M., Luzón, G., Lynch, W. A., Maccarrone, G., Mack, K. J., Majewski, P. A., Mano, R. D. P., Margalejo, C., Markoff, D., Marley, T., Marques, D. J. G., Massarczyk, R., Mazzitelli, G., McCabe, C., McKie, L. J., McLean, A. G., McNamara, P. C., Mei, Y., Messina, A., Mills, A. F., Mirallas, H., Miuchi, K., Monteiro, C. M. B., Mosbech, M. R., Muller, H., da Luz, H. Natal, Nakamura, K. D., Natochii, A., Neep, T., Newstead, J. L., Nikolopoulos, K., Obis, L., Oliveri, E., Orlandini, G., de Solórzano, A. Ortiz, von Oy, J., Papaevangelou, T., Pérez, O., Perez-Gonzalez, Y. F., Pfeiffer, D., Phan, N. S., Piacentini, S., Olloqui, E. Picatoste, Pinci, D., Popescu, S., Prajapati, A., Queiroz, F. S., Raaf, J. L., Resnati, F., Ropelewski, L., Roque, R. C., Ruiz-Choliz, E., Rusu, A., Ruz, J., Samarati, J., Santos, E. M., Santos, J. M. F. dos, Sauli, F., Scharenberg, L., Schiffer, T., Schmidt, S., Scholberg, K., Schott, M., Schueler, J., Segui, L., Sekiya, H., Sengupta, D., Slavkovska, Z., Snowden-Ifft, D., Soffitta, P., van Stenis, M., Spooner, N. J. C., Strigari, L., Stuchbery, A. E., Sun, X., Torelli, S., Tilly, E. G., Thomas, A. W., Thorpe, T. N., Urquijo, P., Utrobičić, A., Vahsen, S. E., Veenhof, R., Vogel, J. K., Williams, A. G., Wood, M. H., and Zettlemoyer, J.

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

Recoil imaging entails the detection of spatially resolved ionization tracks generated by particle interactions. This is a highly sought-after capability in many classes of detector, with broad applications across particle and astroparticle physics. However, at low energies, where ionization signatures are small in size, recoil imaging only seems to be a practical goal for micro-pattern gas detectors. This white paper outlines the physics case for recoil imaging, and puts forward a decadal plan to advance towards the directional detection of low-energy recoils with sensitivity and resolution close to fundamental performance limits. The science case covered includes: the discovery of dark matter into the neutrino fog, directional detection of sub-MeV solar neutrinos, the precision study of coherent-elastic neutrino-nucleus scattering, the detection of solar axions, the measurement of the Migdal effect, X-ray polarimetry, and several other applied physics goals. We also outline the R&D programs necessary to test concepts that are crucial to advance detector performance towards their fundamental limit: single primary electron sensitivity with full 3D spatial resolution at the $\sim$100 micron-scale. These advancements include: the use of negative ion drift, electron counting with high-definition electronic readout, time projection chambers with optical readout, and the possibility for nuclear recoil tracking in high-density gases such as argon. We also discuss the readout and electronics systems needed to scale-up such detectors to the ton-scale and beyond., Comment: 77 pages, 20 figures. Submitted to the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021)

Published
2022

14. 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

15. Systematic study of {\Delta}(1232) resonance excitations using single isobaric charge-exchange reactions induced by medium-mass projectiles of Sn

Author

Rodriguez-Sanchez, J. L., Benlliure, J., Vidana, I., Lenske, H., Vargas, J., Scheidenberger, C., Alvarez-Pol, H., Atkinson, J., Aumann, T., Ayyad, Y., Beceiro-Novo, S., Boretzky, K., Caamano, M., Casarejos, E., Cortina-Gil, D., Fernandez, P. Diaz, Estrade, A., Geissel, H., Haettner, E., Kelic-Heil, A., Litvinov, Yu. A., Paradela, C., Perez-Loureiro, D., Pietri, S., Prochazka, A., Takechi, M., Tanaka, Y. K., Weick, H., and Winfield, J. S.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The fragment separator FRS has been for the first time used to measure the (n,p) and (p,n)-type isobaric charge-exchange cross sections of stable 112,124Sn isotopes accelerated at 1A GeV with an uncertainty of 3% and to separate quasi-elastic and inelastic components in the missing-energy spectra of the ejectiles. The inelastic contribution can be associated to the excitation of isobar {\Delta}(1232) resonances and to the pion emission in s-wave, both in the target and projectile nuclei, while the quasi-elastic contribution is associated to the nuclear spin-isospin response of nucleon-hole excitations. The data lead to interesting results where we observe a clear quenching of the quasi-elastic component and their comparisons to theoretical calculations demonstrate that the baryonic resonances can be excited in the target and projectile nuclei. To go further in this investigation, we propose to study the excitation of baryonic resonances taking advantage of the combination of high-resolving power magnetic spectrometers with the WASA calorimeter. These new measurements will allow us to determine the momenta of the ejectiles and pions emitted in coincidence after the single isobaric charge-exchange collisions, providing us unique opportunities to study the evolution of the baryonic resonance dynamics with the neutron-proton asymmetry through the use of exotic radioactive ion beams., Comment: 14 pages, 9 figures. arXiv admin note: text overlap with arXiv:2004.06404

Published
2021
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16. Experimental investigation of ground-state properties of $^7$H with transfer reactions

Author

Caamaño, M., Roger, T., Moro, A. M., Grinyer, G. F., Pancin, J., Bagchi, S., Sambi, S., Gibelin, J., Fernandez-Dominguez, B., Itagaki, N., Benlliure, J., Cortina-Gil, D., Farget, F., Jacquot, B., Perez-Loureiro, D., Pietras, B., Raabe, R., Ramos, D., Tajes, C. Rodriguez, Savajols, H., and Vandebrouck, M.

Subjects
Nuclear Experiment
Abstract

The properties of nuclei with extreme neutron-to-proton ratios, far from those naturally occurring on Earth, are key to understand nuclear forces and how nucleons hold together to form nuclei. $^7$H, with six neutrons and a single proton, is the nuclear system with the most unbalanced neutron-to-proton ratio known so far. However, its sheer existence and properties are still a challenge for experimental efforts and theoretical models. Here we report experimental evidences on the formation of $^7$H as a resonance, detected with independent observables, and the first measurement of the structure of its ground state. The resonance is found at $\sim$0.7 MeV above the $^3$H+4n mass, with a narrow width of $\sim$0.2 MeV and a $1/2^+$ spin and parity. These data are consistent with a $^7$H as a $^3$H core surrounded by an extended four-neutron halo, with a unique four-neutron decay and a relatively long half-life thanks to neutron pairing; a prime example of new phenomena occurring in what would be the most pure-neutron nuclear matter we can access in the laboratory.

Published
2021
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17. Multi-section fission ionization chamber for measurement of [formula omitted] reaction in fission tagging method

Author

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

Published
2024
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18. 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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19. Neutron-proton pairing in the N=Z radioactive fp-shell nuclei 56Ni and 52Fe probed by pair transfer

Author

Le Crom, B, Assié, M, Blumenfeld, Y, Guillot, J, Sagawa, H, Suzuki, T, Honma, M, Achouri, NL, Bastin, B, Borcea, R, Catford, WN, Clément, E, Cáceres, L, Caamaño, M, Corsi, A, De France, G, Delaunay, F, De Séréville, N, Fernandez-Dominguez, B, Fisichella, M, Franchoo, S, Georgiadou, A, Gibelin, J, Gillibert, A, Hammache, F, Kamalou, O, Knapton, A, Lapoux, V, Leblond, S, Macchiavelli, AO, Marqués, FM, Matta, A, Ménager, L, Morfouace, P, Orr, NA, Pancin, J, Pereira-Lopez, X, Perrot, L, Piot, J, Pollacco, E, Ramos, D, Roger, T, Rotaru, F, Sánchez-Benítez, AM, Sénoville, M, Sorlin, O, Stanoiu, M, Stefan, I, Stodel, C, Suzuki, D, Thomas, J-C, and Vandebrouck, M

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract

The isovector and isoscalar components of neutron-proton pairing are investigated in the N=Z unstable nuclei of the fp-shell through the two-nucleon transfer reaction (p,3He) in inverse kinematics. The combination of particle and gamma-ray detection with radioactive beams of 56Ni and 52Fe, produced by fragmentation at the GANIL/LISE facility, made it possible to carry out this study for the first time in a closed and an open-shell nucleus in the fp-shell. The transfer cross-sections for ground-state to ground-state (J=0+, T=1) and to the first (J=1+, T=0) state were extracted for both cases together with the transfer cross-section ratios σ(0+,T=1)/σ(1+,T=0). They are compared with second-order distorted-wave born approximation (DWBA) calculations. The enhancement of the ground-state to ground-state pair transfer cross-section close to mid-shell, in 52Fe, points towards a superfluid phase in the isovector channel. For the “deuteron-like” transfer, very low cross-sections to the first (J=1+, T=0) state were observed both for 56Ni(p,3He) and 52Fe(p,3He) and are related to a strong hindrance of this channel due to spin-orbit effect. No evidence for an isoscalar deuteron-like condensate is observed.

Published
2022

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

Author

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

Published
2024
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21. Neutron-proton pairing in the N=Z radioactive fp-shell nuclei 56Ni and 52Fe probed by pair transfer

Author

Crom, B. Le, Assié, M., Blumenfeld, Y., Guillot, J., Sagawa, H., Suzuki, T., Honma, M., Achouri, N. L., Bastin, B., Borcea, R., Catford, W. N., Clement, E., Caceres, L., Caamano, M., Corsi, A., De France, G., Delaunay, F., De Séréville, N., Fernandez-Dominguez, B., Fisichella, M., Franchoo, S., Georgiadou, A., Gibelin, J., Gillibert, A., Hammache, F., Kamalou, O., Knapton, A., Lapoux, V., Leblond, S., Macchiavelli, A. O., Marques, F. M., Matta, A., Menager, L., Morfouace, P., Orr, N. A., Pancin, J., Pereira-Lopez, X., Perrot, L., Piot, J., Pollacco, E., Ramos, D., Roger, T., Rotaru, F., Sanchez-Benitez, A. M., Sénoville, M., Sorlin, O., Stanoiu, M., Stefan, I., Stodel, C., Suzuki, D., Thomas, J-C, and Vandebrouck, M.

Subjects
Nuclear Experiment
Abstract

The isovector and isoscalar components of neutron-proton pairing are investigated in the N=Z unstable nuclei of the \textit{fp}-shell through the two-nucleon transfer reaction (p,$^3$He) in inverse kinematics. The combination of particle and gamma-ray detection with radioactive beams of $^{56}$Ni and $^{52}$Fe, produced by fragmentation at the GANIL/LISE facility, made it possible to carry out this study for the first time in a closed and an open-shell nucleus in the \textit{fp}-shell. The transfer cross-sections for ground-state to ground-state (J=0$^+$,T=1) and to the first (J=1$^+$,T=0) state were extracted for both cases together with the transfer cross-section ratios $\sigma$(0$^+$,T=1) /$\sigma$(1$^+$,T=0). They are compared with second-order distorted-wave born approximation (DWBA) calculations. The enhancement of the ground-state to ground-state pair transfer cross-section close to mid-shell, in $^{52}$Fe, points towards a superfluid phase in the isovector channel. For the "deuteron-like" transfer, very low cross-sections to the first (J=1$^+$,T=0) state were observed both for \Ni\phe\, and \Fe\phe\, and are related to a strong hindrance of this channel due to spin-orbit effect. No evidence for an isoscalar deuteron-like condensate is observed., Comment: 7 pages, 4 figures

Published
2021
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22. Pseudo spin doublet bands and Gallagher Moszkowski doublet bands in $^{100}$Y

Author

Wang, E. H., Hamilton, J. H., Ramayya, A. V., Zachary, C. J., Lemasson, A., Navin, A., Rejmund, M., Bhattacharyya, S., Chen, Q. B., Zhang, S. Q., Eldridge, J. M., Hwang, J. K., Brewer, N. T., Luo, Y. X., Rasmussen, J. O., Zhu, S. J., Ter-Akopian, G. M., Oganessian, Yu. Ts., Caamaño, M., Clément, E., Delaune, O., Farget, F., de France, G., and Jacquot, B.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

New transitions in neutron rich $^{100}$Y have been identified in a $^9$Be+$^{238}$U experiment with mass- and Z- gates to provide full fragment identification. These transitions and high spin levels of $^{100}$Y have been investigated by analyzing the high statistics $\gamma$-$\gamma$-$\gamma$ and $\gamma$-$\gamma$-$\gamma$-$\gamma$ coincidence data from the spontaneous fission of $^{252}$Cf at the Gammasphere detector array. Two new bands, 14 new levels and 23 new transitions have been identified. The $K^{\pi}=4^+$ new band decaying to an 1s isomeric state is assigned to be the high-$K$ Gallagher-Moszkowski (GM) partner of the known $K^{\pi}=1^+$ band, with the $\pi 5/2[522] \otimes \nu 3/2[411]$ configuration. This 4$^+$ band is also proposed to be the pseudo spin partner of the new $K^{\pi}=5^+$ band with a 5$^{+}$ $\pi 5/2[422] \otimes \nu 5/2[413]$ configuration, to form a $\pi 5/2[422] \otimes \nu [312$ $5/2,3/2]$ neutron pseudospin doublet. Constrained triaxial covariant density functional theory and quantal particle rotor model calculations have been applied to interpret the band structure and available electromagnetic transition probabilities and are found in good agreement with experimental values.

Published
2021
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23. A Segmented Total Energy Detector (sTED) optimized for (n, [formula omitted]) cross-section measurements at n_TOF EAR2

Author

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

Published
2024
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24. 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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25. 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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26. Low-lying single-particle structure of 17C and the N = 14 sub-shell closure

Author

Pereira-López, X., Fernández-Domínguez, B., Delaunay, F., Achouri, N. L., Orr, N. A., Catford, W. N., Assié, M., Bailey, S., Bastin, B., Blumenfeld, Y., Borcea, R., Caamaño, M., Caceres, L., Clément, E., Corsi, A., Curtis, N., Deshayes, Q., Farget, F., Fisichella, M., de France, G., Franchoo, S., Freer, M., Gibelin, J., Gillibert, A., Grinyer, G. F., Hammache, F., Kamalou, O., Knapton, A., Kokalova, T., Lapoux, V., Lay, J. A., Crom, B. Le, Leblond, S., Lois-Fuentes, J., Marqués, F. M., Matta, A., Morfouace, P., Moro, A. M., Otsuka, T., Pancin, J., Perrot, L., Piot, J., Pollacco, E., Ramos, D., Rodríguez-Tajes, C., Roger, T., Rotaru, F., Sénoville, M., de Séréville, N., Smith, R., Sorlin, O., Stanoiu, M., Stefan, I., Stodel, C., Suzuki, D., Suzuki, T., Thomas, J. C., Timofeyuk, N., Vandebrouck, M., Walshe, J., and Wheldon, C.

Subjects
Nuclear Experiment
Abstract

The first investigation of the single-particle structure of the bound states of 17C, via the d(16C, p) transfer reaction, has been undertaken. The measured angular distributions confirm the spin-parity assignments of 1/2+ and 5/2+ for the excited states located at 217 and 335 keV, respectively. The spectroscopic factors deduced for these states exhibit a marked single-particle character, in agreement with shell model and particle-core model calculations, and combined with their near degeneracy in energy provide clear evidence for the absence of the N = 14 sub-shell closure. The very small spectroscopic factor found for the 3/2+ ground state is consistent with theoretical predictions and indicates that the {\nu}1d3/2 strength is carried by unbound states. With a dominant l = 0 valence neutron configuration and a very low separation energy, the 1/2+ excited state is a one-neutron halo candidate., Comment: 7 pages, 5 figures, Accepted for publication in Physics Letters B

Published
2020
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27. Signature of a possible $\alpha$-cluster state in $N=Z$ doubly-magic $^{56}$Ni

Author

Bagchi, S., Akimune, H., Gibelin, J., Harakeh, M. N., Kalantar-Nayestanaki, N., Achouri, N. L., Bastin, B., Boretzky, K., Bouzomita, H., Caamaño, M., Càceres, L., Damoy, S., Delaunay, F., Fernández-Domínguez, B., Fujiwara, M., Garg, U., Grinyer, G. F., Kamalou, O., Khan, E., Krasznahorkay, A., Lhoutellier, G., Libin, J. F., Lukyanov, S., Mazurek, K., Najafi, M. A., Pancin, J., Penionzkhevich, Y., Perrot, L., Raabe, R., Rigollet, C., Roger, T., Sambi, S., Savajols, H., Senoville, M., Stodel, C., Suen, L., Thomas, J. C., Vandebrouck, M., and Van de Walle, J.

Subjects
Nuclear Experiment
Abstract

An inelastic $\alpha$-scattering experiment on the unstable $N=Z$, doubly-magic $^{56}$Ni nucleus was performed in inverse kinematics at an incident energy of 50 A.MeV at GANIL. High multiplicity for $\alpha$-particle emission was observed within the limited phase-space of the experimental setup. This observation cannot be explained by means of the statistical-decay model. The ideal classical gas model at $kT$ = 0.4 MeV reproduces fairly well the experimental momentum distribution and the observed multiplicity of $\alpha$ particles corresponds to an excitation energy around 96 MeV. The method of distributed $m\alpha$-decay ensembles is in agreement with the experimental results if we assume that the $\alpha$-gas state in $^{56}$Ni exists at around $113^{+15}_{-17}$ MeV. These results suggest that there may exist an exotic state consisting of many $\alpha$ particles at the excitation energy of $113^{+15}_{-17}$ MeV., Comment: Accepted for publication in the European Physical Journal A

Published
2020
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28. Probing the Z = 6 spin-orbit shell gap with (p,2p) quasi-free scattering reactions

Author

Syndikus, I., Petri, M., Macchiavelli, A. O., Paschalis, S., Bertulani, C. A., Aumann, T., Alvarez-Pol, H., Atar, L., Beceiro-Novo, S., Benlliure, J., Boillos, J. M., Boretzky, K., Borge, M. J. G., Brown, B. A., Caamaño, M., Caesar, C., Casarejos, E., Catford, W., Cederkall, J., Chulkov, L. V., Cortina-Gil, D., Cravo, E., Crespo, R., Dillmann, I., Fernández, P. Díaz, Elekes, Z., Enders, J., Farinon, F., Fraile, L. M., Redondo, D. Galaviz, Geissel, H., Gernhäuser, R., Golubev, P., Göbel, K., Heil, M., Heine, M., Heinz, A., Henriques, A., Holl, M., Johansson, H. T., Jonson, B., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Kröll, T., Kurz, N., Langer, C., Bleis, T. Le, Machado, J. F. D. C., Marganiec-Gałazka, J., Nacher, E., Nilsson, T., Nociforo, C., Panin, V., Perea, A., Pietri, S. B., Plag, R., Reifarth, R., Revel, A., Ribeiro, G., Rigollet, C., Rossi, D. M., Savran, D., Scheit, H., Simon, H., Sorlin, O., Tengblad, O., Togano, Y., Vandebrouck, M., Volkov, V., Wheldon, F. Wamers C., Wilson, G. L., Winfield, J. S., Weick, H., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., and Zuber, K.

Subjects
Nuclear Experiment
Abstract

The evolution of the traditional nuclear magic numbers away from the valley of stability is an active field of research. Experimental efforts focus on providing key spectroscopic information that will shed light into the structure of exotic nuclei and understanding the driving mechanism behind the shell evolution. In this work, we investigate the Z = 6 spin-orbit shell gap towards the neutron dripline. To do so, we employed $^{A}$N(p,2p)$^{A-1}$C quasi-free scattering reactions to measure the proton component of the 2$^+_1$ state of $^{16,18,20}$C. The experimental findings support the notion of a moderate reduction of the proton 1p$_{1/2}$-1p$_{3/2}$ spin-orbit splitting, at variance to recent claims for a prevalent Z = 6 magic number towards the neutron dripline., Comment: 27 pages, 5 figures, 2 tables. Submitted to Physics Letter B

Published
2020
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29. Excitation of baryonic resonances in stable medium-mass nuclei of Sn

Author

Rodriguez-Sanchez, J L, Benlliure, J, Haettner, E, Scheidenberger, C, Vargas, J, Ayyad, Y, Alvarez-Pol, H, Atkinson, J, Aumann, T, Beceiro-Novo, S, Boretzky, K, Caamaño, M, Casarejos, E, Cortina-Gil, D, Fernandez, P Diaz, Estrade, A, Geissel, H, Itahashi, K, Kelic-Heil, A, Lenske, H, Litvinov, Yu A, Paradela, C, Perez-Loureiro, D, Pietri, S, Prochazka, A, Saito, T R, Takechi, M, Tanaka, Y K, Vidaña, I, Weick, H, Winfield, J S, and collaboration, the Super-FRS experiment

Subjects
Nuclear Experiment
Abstract

Isobaric charge-exchange reactions induced by beams of 112Sn have been investigated at the GSI facilities using the fragment separator FRS. The high-resolving power of this spectrometer makes it possible to obtain the isobaric charge-exchange cross sections with an accuracy of 3% and to separate quasi-elastic and inelastic contributions in the missing-energy spectra, in which the inelastic component is associated to the in-medium excitation of baryonic resonances such as the $\Delta$ resonance. We report on the results obtained for the (p,n) and (n,p) channels excited by using different targets that cover a large range in neutron excess., Comment: arXiv admin note: text overlap with arXiv:2004.06404

Published
2020

30. Study of $\Delta$ excitations in medium-mass nuclei with peripheral heavy ion charge-exchange reactions

Author

Rodriguez-Sanchez, J. L., Benlliure, J., Vidaña, I., Lenske, H., Scheidenberger, C., Vargas, J., Alvarez-Pol, H., Ayyad, Y., Atkinson, J., Aumann, T., Beceiro-Novo, S., Boretzky, K., Caamaño, M., Casarejos, E., Cortina-Gil, D., Fernandez, P. Diaz, Estrade, A., Geissel, H., Haettner, E., Kelic-Heil, A., Litvinov, Yu. A., Paradela, C., Perez-Loureiro, D., Pietri, S., Prochazka, A., Takechi, M., Tanaka, Y. K., Weick, H., and Winfield, J. S.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Isobaric single charge-exchange reactions, changing nuclear charges by one unit but leaving the mass partitions unaffected, have been for the first time investigated by peripheral collisions of $^{112}$Sn ions accelerated up to 1\textit{A} GeV at the GSI facilities. The high-resolving power of the FRS spectrometer allows us to obtain $(p, n)$-type isobaric charge-exchange cross sections with an uncertainty of $3.5\%$ and to separate quasi-elastic and inelastic components in the missing-energy spectra of the ejectiles. The inelastic component is associated to the excitation of the $\Delta$(1232) isobar resonance and the emission of pions in s-wave both in the target and projectile nucleus, while the quasi-elastic contribution is associated to the nuclear spin-isospin response of nucleon-hole excitations. An apparent shift of the $\Delta$-resonance peak of $\sim$63 MeV is observed when comparing the missing-energy spectra obtained from the measurements with proton and carbon targets. A detailed analysis, performed with a theoretical model for the reactions, indicates that this observation can be simply interpreted as a change in the relative magnitude between the contribution of the excitation of the resonance in the target and in the projectile.

Published
2020
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31. 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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32. Status report of the n_TOF facility after the 2nd CERN long shutdown period

Author

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

Published
2023
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33. Registro Español de Enfermos Renales (REER): informe del año 2022 y análisis evolutivo

Author

Quiroga, Borja, Mahíllo, Beatriz, Mazuecos (SENTRA), Auxiliadora, Ortiz, Alberto, Comas Farnés, Jordi, Hernández Marrero, Domingo, Trujillo Alemán, Sara, Santiuste de Pablos, M. Carmen, Rodríguez Arévalo, Olga Lucía, Marques Vidas, María, Slon-Roblero, M. Fernanda, Artamendi Larrañaga, Marta, Moina Eguren, Iñigo, Valentín Muñoz, María de la Oliva, Rodríguez Camblor, Marta, Moreno Alia, Inmaculada, Bouzas Caamaño, M. Encarnación, Blanco Galán, M. Antonia, Deira Lorenzo, Javier, García López, Héctor, Arribas Monzon, Federico Eduardo, Gómez Marqués, Gonzalo, Rodríguez-Benot, Alberto, Domínguez-Gil, Beatriz, and Sánchez Álvarez, Emilio

Published
2024
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34. 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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35. 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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36. Study of multi-neutron systems with SAMURAI spectrometer

Author

Yang, Z. H., Marqués, F. M., Achouri, N. L., Ahn, D. S., Aumann, T., Baba, H., Beaumel, D., Böhmer, M., Boretzky, K., Caamaño, M., Chen, S., Chiga, N., Cortés, M. L., Cortina, D., Doornenbal, P., Douma, C. A., Dufter, F., Feng, J., Fernández-Domínguez, B., Elekes, Z., Forsberg, U., Fujino, T., Fukuda, N., Gašparić, I., Ge, Z., Gernhäuser, R., Gheller, J. M., Gibelin, J., Gillibert, A., Godoy, B. M., Halász, Z., Harada, T., Harakeh, M. N., Hirayama, A., Huang, S. W., Inabe, N., Isobe, T., Kahlbow, J., Kalantar-Nayestanaki, N., Kim, D., Kim, S., Knösel, M. A., Kobayashi, T., Kondo, Y., Koseoglou, P., Kubota, Y., Kuti, I., Lehr, C., Li, P. J., Liu, Y., Maeda, Y., Masuoka, S., Matsumoto, M., Mayer, J., Miki, H., Miwa, M., Murray, I., Nakamura, T., Obertelli, A., Orr, N., Otsu, H., Panin, V., Park, S., Parlog, M., Paschalis, S., Potlog, M., Reichert, S., Revel, A., Rossi, D., Saito, A., Sasano, M., Sato, H., Scheit, H., Schindler, F., Shimada, T., Shimizu, Y., Shimoura, S., Stefan, I., Storck, S., Stuhl, L., Suzuki, H., Symochko, D., Takeda, H., Takeuchi, S., Tanaka, J., Togano, Y., Tomai, T., Tscheuschner, H. T. Törnqvsit. J., Uesaka, T., Wagner, V., Wimmer, K., Yamada, H., Yang, B., Yang, L., Yasuda, Y., Yoneda, K., Zanetti, L., and Zenihiro, J.

Subjects
Nuclear Experiment
Abstract

The tetraneutron has been drawing the attention of the nuclear physics community for decades, but a firm conclusion on its existence and properties is still far from being reached despite many experimental and theoretical efforts. New measurements have recently been performed at RIBF with the SAMURAI spectrometer by applying complementary reaction probes, which will help to pin down the properties of this four-neutron system., Comment: 5 pages, 2 figures, conference proceedings of XXII International Conference on Few-Body Problems in Physics (FB22), Caen, France, July 2018

Published
2019

37. 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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38. Nuclear physics midterm plan at Legnaro National Laboratories (LNL)

Author

Ballan, M., Bottoni, S., Caamaño, M., Caciolli, A., Campostrini, M., Cicerchia, M., Crespi, F. C. L., Cristallo, S., Dell’Aquila, D., Depalo, R., Fioretto, E., Galtarossa, F., Gasques, L. R., Gottardo, A., Gramegna, F., Gulminelli, F., Kurtukian-Nieto, T., La Cognata, M., Lenzi, S. M., Marchi, T., Mazurek, K., Mengoni, D., Mou, L., Nania, R., Pupillo, G., Valiente-Dobón, J. J., Zanon, I., Acosta, L., Alvarez, M. A. G., Andrighetto, A., Arazi, A., Arzenton, A., Assié, M., Bagatin, M., Barbaro, F., Barbieri, C., Barlini, S., Basiricò, L., Battistoni, G., Beaumel, D., Bentley, M. A., Benzoni, G., Bertoldo, S., Bertulani, C., Bonasera, A., Camaiani, A., Canton, L., Capirossi, V., Carante, M. P., Carraro, C., Carturan, S. M., Casini, G., Cavanna, F., Centofante, L., Chávez, E. R., Chbihi, A., Ciemała, M., Cisternino, S., Colombi, A., Colucci, M., Compagnucci, A., Corradetti, S., Corradi, L., D’Agata, G., de Angelis, G., De Dominicis, L., De Salvador, D., DeFilippo, E., Del Fabbro, M., Di Nitto, A., Ditalia Tchernij, S., Donzella, A., Duguet, T., Esposito, J., Favela, F., Fernández-García, J. P., Flavigny, F., Fontana, A., Fornal, B., Forneris, J., Fraboni, B., Frankland, J., Gamba, E., Geraci, E., Gerardin, S., Giuliani, S. A., Gnoffo, B., Groppi, F., Gruyer, D., Haddad, F., Isaak, J., Kmiecik, M., Koning, A., Lamia, L., Le Neindre, N., Leoni, S., Lépine-Szily, A., Lilli, G., Lombardo, I., Loriggiola, M., Loriggiola, L., Lunardon, M., Maggioni, G., Maj, A., Manenti, S., Manzolaro, M., Marcucci, L. E., Marín-Lámbarri, D. J., Mariotti, E., Martin Hernandez, G., Massimi, C., Mastinu, P., Mazzocco, M., Mazzolari, A., Mijatović, T., Mishenina, T., Mizuyama, K., Monetti, A., Montagnoli, G., Morselli, L., Moschini, L., Musacchio Gonzalez, E., Nannini, A., Niu, Y. F., Ota, S., Paccagnella, A., Palmerini, S., Pellegri, L., Perego, A., Piantelli, S., Piatti, D., Picollo, F., Pignatari, M., Pinna, F., Pirrone, S., Pizzone, R. G., Polettini, M., Politi, G., Popescu, L., Prete, G., Quaranta, A., Raabe, R., Ramos, J. P., Raniero, W., Rapisarda, G. G., Recchia, F., Rigato, V., Roca Maza, X., Rocchini, M., Rodriguez, T., Roncolato, C., Rudolph, D., Russotto, P., Sánchez-Benítez, Á. M., Savran, D., Scarpa, D., Scheck, M., Sekizawa, K., Sergi, M. L., Sgarbossa, F., Silvestrin, L., Singh Khwairakpam, O., Skowronski, J., Somà, V., Spartà, R., Spieker, M., Stefanini, A. M., Steiger, H., Stevanato, L., Stock, M. R., Vardaci, E., Verney, D., Vescovi, D., Vittone, E., Werner, V., Wheldon, C., Wieland, O., Wimmer, K., Wyss, J., Zago, L., and Zenoni, A.

Published
2023
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39. Probing the Z = 6 spin-orbit shell gap with (p,2p) quasi-free scattering reactions

Author

Syndikus, I, Petri, M, Macchiavelli, AO, Paschalis, S, Bertulani, CA, Aumann, T, Alvarez-Pol, H, Atar, L, Beceiro-Novo, S, Benlliure, J, Boillos, JM, Boretzky, K, Borge, MJG, Brown, BA, Caamaño, M, Caesar, C, Casarejos, E, Catford, W, Cederkall, J, Chakraborty, S, Chulkov, LV, Cortina-Gil, D, Cravo, E, Crespo, R, Datta Pramanik, U, Dillmann, I, Díaz Fernández, P, Elekes, Z, Enders, J, Farinon, F, Fraile, LM, Galaviz, D, Geissel, H, Gernhäuser, R, Golubev, P, Göbel, K, Heil, M, Heine, M, Heinz, A, Henriques, A, Holl, M, Johansson, HT, Jonson, B, Kalantar-Nayestanaki, N, Kanungo, R, Kelic-Heil, A, Kröll, T, Kurz, N, Langer, C, Le Bleis, T, Machado, J, Marganiec-Gałązka, J, Nacher, E, Nilsson, T, Nociforo, C, Panin, V, Perea, A, Pietri, SB, Plag, R, Rahaman, A, Reifarth, R, Revel, A, Ribeiro, G, Rigollet, C, Rossi, DM, Savran, D, Scheit, H, Simon, H, Sorlin, O, Tengblad, O, Togano, Y, Vandebrouck, M, Volkov, V, Wamers, F, Wheldon, C, Wilson, GL, Winfield, JS, Weick, H, Woods, P, Yakorev, D, Zhukov, M, Zilges, A, and Zuber, K

Subjects
Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

The evolution of the traditional nuclear magic numbers away from the valley of stability is an active field of research. Experimental efforts focus on providing key spectroscopic information that will shed light into the structure of exotic nuclei and understanding the driving mechanism behind the shell evolution. In this work, we investigate the Z=6 spin-orbit shell gap towards the neutron dripline. To do so, we employed NA(p,2p)CA−1 quasi-free scattering reactions to measure the proton component of the 21+ state of 16,18,20C. The experimental findings support the notion of a moderate reduction of the proton 1p1/2−1p3/2 spin-orbit splitting, at variance to recent claims for a prevalent Z=6 magic number towards the neutron dripline.

Published
2020

40. Deformed band structures in neutron-rich $^{152-158}$Pm isotopes

Author

Bhattacharyya, S., Wang, E. H., Navin, A., Rejmund, M., Hamilton, J. H., Ramayya, A. V., Hwang, J. K., Lemasson, A., Afanasjev, A. V., Bhattacharya, Soumik, Ranger, J., Caamaño, M., Clément, E., Delaune, O., Farget, F., de France, G., Jacquot, B., Luo, Y. X., Oganessian, Yu. Ts., Rasmussen, J. O., Ter-Akopian, G. M., and Zhu, S. J.

Subjects
Nuclear Experiment
Abstract

High spin band structures of neutron-rich $^{152-158}$Pm isotopes have been obtained from the measurement of prompt $\gamma$-rays of isotopically identified fragments produced in fission of $^{238}$U+$^{9}$Be and detected using the VAMOS++ magnetic spectrometer and EXOGAM segmented Clover array at GANIL and also from the high statistics $\gamma$-$\gamma$-$\gamma$ and $\gamma$-$\gamma$-$\gamma$-$\gamma$ data from the spontaneous fission of $^{252}$Cf using Gammasphere. The excited states in $^{157}$Pm and those above the isomers in even-A Pm isotopes $^{152,154,156,158}$Pm have been identified for the first time. The spectroscopic information on the rotational band structures in odd-A Pm isotopes has been extended considerably to higher spins and the possibility of the presence of reflection asymmetric shapes is explored. The configuration assignments are based on the results of Cranked Relativistic Hartree-Bogoliubov calculations. From the systematics of bands in odd-A Pm isotopes and weak population of opposite parity bands, octupole deformed shapes in neutron rich Pm isotopes beyond $N=90$ seem unlikely to be present.

Published
2019
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41. 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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42. 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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43. Strong neutron pairing in core+4n nuclei

Author

Revel, A., Marques, F. M., Sorlin, O., Aumann, T., Caesar, C., Holl, M., Panin, V., Vandebrouck, M., Wamers, F., Alvarez-Pol, H., Atar, L., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamano, M., Casarejos, E., Catford, W. N., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Pramanik, U. Datta, Fernandez, P. Diaz, Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz, D., Geissel, H., Gernhauser, R., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kroll, T., Kurz, N., Labiche, M., Langer, C., Bleis, T. Le, Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Movsesyan, A., Nacher, E., Najafi, M., Nikolskii, E., Nilsson, T., Nociforo, C., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Roder, M., Rossi, D., Savran, D., Scheit, H., Simon, H., Syndikus, I., Taylor, J. T., Tengblad, O., Thies, R., Togano, Y., Velho, P., Volkov, V., Wagner, A., Weick, H., Wheldon, C., Wilson, G., Winfield, J. S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., and Zuber, K.

Subjects
Nuclear Experiment
Abstract

The emission of neutron pairs from the neutron-rich $N\!=\!12$ isotones $^{18}$C and $^{20}$O has been studied by high-energy nucleon knockout from $^{19}$N and $^{21}$O secondary beams, populating unbound states of the two isotones up to 15~MeV above their two-neutron emission thresholds. The analysis of triple fragment-$n$-$n$ correlations shows that the decay $^{19}$N$(-1p)^{18}$C$^*\!\rightarrow^{16}$C+$n$+$n$ is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a $^{14}$C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay $^{21}$O$(-1n)^{20}$O$^*\!\rightarrow^{18}$O+$n$+$n$, attributed to its formation through the knockout of a deeply-bound neutron that breaks the $^{16}$O core and reduces the number of pairs., Comment: 6 pages, 4 figures, accepted for publication in Phys. Rev. Lett

Published
2018
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44. Re-examining the transition into the N=20 island of inversion: structure of $^{30}$Mg

Author

Fernández-Domínguez, B., Pietras, B., Catford, W. N., Orr, N. A., Petri, M., Chartier, M., Paschalis, S., Patterson, N., Thomas, J . S., Caamaño, M., Otsuka, T., Poves, A., Tsunoda, N., Achouri, N. L., Angélique, J-C., Ashwood, N. I., Banu, A ., Bastin, B., Borcea, R., Brown, J., Delaunay, F., Franchoo, S., Freer, M., Gaudefroy, L., Heil, S., Labiche, M., Laurent, B., Lemmon, R. C., Macchiavelli, A. O., Negoita, F., Paul, E. S., Rodríguez-Tajes, C., Roussel-Chomaz, P., Staniou, M., Taylor, M. J., Trache, L., and Wilson, G. L.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Intermediate energy single-neutron removal from $^{31}$Mg has been employed to investigate the transition into the N=20 island of inversion. Levels up to 5~MeV excitation energy in $^{30}$Mg were populated and spin-parity assignments were inferred from the corresponding longitudinal momentum distributions and $\gamma$-ray decay scheme. Comparison with eikonal-model calculations also permitted spectroscopic factors to be deduced. Surprisingly, the 0$^{+}_{2}$ level in $^{30}$Mg was found to have a strength much weaker than expected in the conventional picture of a predominantly $2p - 2h$ intruder configuration having a large overlap with the deformed $^{31}$Mg ground state. In addition, negative parity levels were identified for the first time in $^{30}$Mg, one of which is located at low excitation energy. The results are discussed in the light of shell-model calculations employing two newly developed approaches with markedly different descriptions of the structure of $^{30}$Mg. It is concluded that the cross-shell effects in the region of the island of inversion at Z=12 are considerably more complex than previously thought and that $np - nh$ configurations play a major role in the structure of $^{30}$Mg., Comment: Physics Letters B, Volume 779, 10 April 2018, Pages 124-129

Published
2018
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45. 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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46. Effective proton-neutron interaction near the drip line from unbound states in $^{25,26}$F

Author

Vandebrouck, M., Lepailleur, A., Sorlin, O., Aumann, T., Caesar, C., Holl, M., Panin, V., Wamers, F., Stroberg, S. R., Holt, J. D., Santos, F. De Oliveira, Alvarez-Pol, H., Atar, L., Avdeichikov, V., Beceiro-Novo, S., Bemmerer, D., Benlliure, J., Bertulani, C. A., Bogner, S. K., Boillos, J. M., Boretzky, K., Borge, M. J. G., Caamano, M., Casarejos, E., Catford, W., Cederkäll, J., Chartier, M., Chulkov, L., Cortina-Gil, D., Cravo, E., Crespo, R., Pramanik, U. Datta, Fernandez, P. Diaz, Dillmann, I., Elekes, Z., Enders, J., Ershova, O., Estrade, A., Farinon, F., Fraile, L. M., Freer, M., Galaviz, D., Geissel, H., Gernhauser, R., Gibelin, J., Golubev, P., Göbel, K., Hagdahl, J., Heftrich, T., Heil, M., Heine, M., Heinz, A., Henriques, A., Hergert, H., Hufnagel, A., Ignatov, A., Johansson, H. T., Jonson, B., Kahlbow, J., Kalantar-Nayestanaki, N., Kanungo, R., Kelic-Heil, A., Knyazev, A., Kröll, T., Kurz, N., Labiche, M., Langer, C., Bleis, T. Le, Lemmon, R., Lindberg, S., Machado, J., Marganiec, J., Marques, F. M., Movsesyan, A., Nacher, E., Najafi, M., Nikolskii, E., Nilsson, T., Nociforo, C., Paschalis, S., Perea, A., Petri, M., Pietri, S., Plag, R., Reifarth, R., Ribeiro, G., Rigollet, C., Röder, M., Rossi, D., Savran, D., Scheit, H., Schwenk, A., Simon, H., Syndikus, I., Taylor, J., Tengblad, O., Thies, R., Togano, Y., Velho, P., Volkov, V., Wagner, A., Weick, H., Wheldon, C., Wilson, G., Winfield, J. S., Woods, P., Yakorev, D., Zhukov, M., Zilges, A., and Zuber, K.

Subjects
Nuclear Experiment
Abstract

Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The $^{26}$F nucleus, composed of a deeply bound $\pi0d\_{5/2}$ proton and an unbound $\nu0d\_{3/2}$ neutron on top of an $^{24}$O core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The $J^{\pi} = 1^{+}\_1, 2^{+}\_1,4^{+}\_1$ bound states have been determined, and only a clear identification of the $J^{\pi} =3^{+}\_1$ is missing.Purpose: We wish to complete the study of the $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet in $^{26}$F, by studying the energy and width of the $J^{\pi} =3^{+}\_1$ unbound state. The method was firstly validated by the study of unbound states in $^{25}$F, for which resonances were already observed in a previous experiment.Method: Radioactive beams of $^{26}$Ne and $^{27}$Ne, produced at about $440A$\,MeV by the FRagment Separator at the GSI facility, were used to populate unbound states in $^{25}$F and $^{26}$F via one-proton knockout reactions on a CH$\_2$ target, located at the object focal point of the R$^3$B/LAND setup. The detection of emitted $\gamma$-rays and neutrons, added to the reconstruction of the momentum vector of the $A-1$ nuclei, allowed the determination of the energy of three unbound states in $^{25}$F and two in $^{26}$F. Results: Based on its width and decay properties, the first unbound state in $^{25}$F is proposed to be a $J^{\pi} = 1/2^-$ arising from a $p\_{1/2}$ proton-hole state. In $^{26}$F, the first resonance at 323(33)~keV is proposed to be the $J^{\pi} =3^{+}\_1$ member of the $J^{\pi} = 1^{+}\_1 - 4^{+}\_1$ multiplet. Energies of observed states in $^{25,26}$F have been compared to calculations using the independent-particle shell model, a phenomenological shell-model, and the ab initio valence-space in-medium similarity renormalization group method.Conclusions: The deduced effective proton-neutron interaction is weakened by about 30-40\% in comparison to the models, pointing to the need of implementing the role of the continuum in theoretical descriptions, or to a wrong determination of the atomic mass of $^{26}$F., Comment: 14 pages, 7 figures, 3 tables, submitted to PRC

Published
2017
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47. Measurement and analysis of the 246Cm and 248Cm 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., and Caamaño, M.

Subjects
LIGHT water reactors, NUCLEAR fuels, SPENT reactor fuels, HEAVY elements, ACTINIDE elements, NEUTRON capture, NUCLEAR explosions
Abstract

The 246 Cm(n, γ ) and 248 Cm(n, γ ) 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, γ ) 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, γ ) and 248 Cm(n, γ ) 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. [ABSTRACT FROM AUTHOR]

Published
2024
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48. The n_TOF facility at CERN

Author

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

Subjects
Physics, QC1-999
Abstract

The neutron Time-of-Flight facility (n_TOF) is an innovative facility operative since 2001 at CERN, with three experimental areas. In this paper the n_TOF facility will be described, together with the upgrade of the facility during the Long Shutdown 2 at CERN. The main features of the detectors used for capture fission cross section measurements will be presented with perspectives for the future measurements.

Published
2024
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49. Description and outlook of the 50,53Cr(n,γ) cross section measurement at n_TOF and HiSPANoS

Author

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

Subjects
Physics, QC1-999
Abstract

Chromium is a very relevant element regarding criticality safety in nuclear reactors because of its presence in stainless steel, an important structural material. Currently, there are serious discrepancies between the different evaluations regarding the neutron capture cross sections of 50Cr and 53Cr, most probably related to the difficulty of reducing and then estimating the very large neutron scattering effects on the shape of the resonances. In this context, there is a recent entry in the Nuclear Energy Agency (NEA) High Priority Request List (HPRL) to measure these reactions between 1 and 100 keV with an accuracy of 8-10%. In response to this request, we have performed a time-of-flight experiment at CERN n_TOF (Switzerland) and a complementary activation experimenton 50Crat30and90keVatCNAHiSPANoS(Spain).Theexperiments are presented herein, together with a discussion on the quality of the preliminary data and the results to be expected.

Published
2024
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50. 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., Dijon A., Doré D., Durand D., Frankland J. D., Fernández-Domínguez B., de France G., Fregeau M. O., Galaviz D., Galiana-Baldó E., Heinz A., Henriques A., Jacquot B., Jurado B., Kim Y. H., Morfouace P., Paradela C., Piot J., Ralet D., Roger T., Salsac M. D., Teubig P., and Tsekhanovich I.

Subjects
Physics, QC1-999
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.

Published
2024
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