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6. Validation of an optical potential for incident and emitted low-energy α–particles in the A∼60 mass range: II. Neutron–induced reactions on Ni isotopes.

Author

Avrigeanu, V. and Avrigeanu, M.

Subjects
ISOTOPES, STABLE isotopes, QUADRUPOLES, RESONANCE
Abstract

The assessment of an α -particle optical model potential for nucleon–induced α -emission within the A ∼ 60 mass-number range [Avrigeanu and Avrigeanu (Eur. Phys. J. A 57:54, 2021)] is completed by analysis of neutron–induced reactions on stable Ni isotopes. The same consistent set of nuclear–model input parameters as well as first uncertainty analysis of calculated cross sections related to the accuracy of independent data formerly used within parameter setting up have been concerned. Description of absorption and emission of α -particles by the same potential is validated, while the pickup direct reaction and Giant Quadrupole Resonance (GQR) α -emission beyond the statistical predictions are confirmed by recent data around the GQR energies. [ABSTRACT FROM AUTHOR]

Published
2022
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7. The neutrons for science facility at SPIRAL-2

Author

Ledoux X., Aïche M., Avrigeanu M., Avrigeanu V., Balanzat E., Ban-d'Etat B., Ban G., Bauge E., Bélier G., Bém P., Borcea C., Caillaud T., Chatillon A., Czajkowski S., Dessagne P., Doré D., Fischer U., Frégeau M.O., Grinyer J., Guillous S., Gunsing F., Gustavsson C., Henning G., Jacquot B., Jansson K., Jurado B., Kerveno M., Klix A., Landoas O., Lecolley F.R., Lecouey J.L., Majerle M., Marie N., Materna T., Mrázek J., Negoita F., Novák J., Oberstedt S., Oberstedt A., Panebianco S., Perrot L., Plompen A.J.M., Pomp S., Prokofiev A.V., Ramillon J.M., Farget F., Ridikas D., Rossé B., Sérot O., Simakov S.P., Šimečková E., Štefánik M., Sublet J.C., Taïeb J., Tarrío D., Tassan-Got L., Thfoin I., and Varignon C.

Subjects
Physics, QC1-999
Abstract

Numerous domains, in fundamental research as well as in applications, require the study of reactions induced by neutrons with energies from few MeV up to few tens of MeV. Reliable measurements also are necessary to improve the evaluated databases used by nuclear transport codes. This energy range covers a large number of topics like transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. A new facility called Neutrons For Science (NFS) is being built for this purpose on the GANIL site at Caen (France). NFS is composed of a pulsed neutron beam for time-of-flight facility as well as irradiation stations for cross-section measurements. Neutrons will be produced by the interaction of deuteron and proton beams, delivered by the SPIRAL-2 linear accelerator, with thick or thin converters made of beryllium or lithium. Continuous and quasi-mono-energetic spectra will be available at NFS up to 40 MeV. In this fast energy region, the neutron flux is expected to be up to 2 orders of magnitude higher than at other existing time-of-flight facilities. In addition, irradiation stations for neutron-, proton- and deuteron-induced reactions will allow performing cross-section measurements by the activation technique. After a description of the facility and its characteristics, the experiments to be performed in the short and medium term will be presented.

Published
2017
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15. Comparative analysis of empirical parametrization and microscopical studies of deuteron-induced reactions

Author

Avrigeanu, M and Avrigeanu, V

Subjects
Nuclear Physics - Theory
Abstract

An extended analysis of the deuteron–induced reactions is carried out paying due consideration to both the reaction cross-section parametrization procedure and theoretical models associated to the deuteron interaction process. The key role of direct interactions, i.e., breakup, stripping and pickup processes is stressed out by the comparison of data with theoretical and evaluation predictions .

Published
2019

17. Validation of an optical potential for incident and emitted low-energy α-particles in the A∼60 mass range.

Author

Avrigeanu, V. and Avrigeanu, M.

Subjects
QUADRUPOLES, RESONANCE, FORECASTING, NUCLEAR spectroscopy
Abstract

A consistent set of statistical-model input parameters, validated by analysis of various independent data, makes possible the assessment of an α -particle optical model potential [Phys. Rev. C 90, 044612 (2014)] also for nucleon-induced α -emission within the A ∼ 60 mass-number range. The advantage of recent data for low-lying states feeding is taken as well. Consideration of additional reaction channels leading to increase of the α -emission beyond the statistical predictions has concerned the pickup direct interaction and Giant Quadrupole Resonance similar features. [ABSTRACT FROM AUTHOR]

Published
2021
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18. Deuteron-induced reaction mechanisms at low energies

Author

Roman F.L., Avrigeanu V., and Avrigeanu M.

Subjects
Physics, QC1-999
Abstract

An extended analysis of the reaction mechanisms involved within deuteron interaction with nuclei is presented. An increased attention is devoted to the breakup mechanism, all its components, namely the elastic, inelastic (fusion), and total breakup being carefully considered. Next, the direct reactions represented by the stripping and pick-up mechanisms are discussed. Finally, the pre-equilibrium and compound-nucleus contributions, corrected for the breakup, stripping, and pick-up decrease of the total reaction cross section, complete the deuteron-induced reaction cross section analysis. The overall agreement between the measured data and model calculations validates the description of nuclear mechanisms taken into account for the deuteron-nucleus interaction.

Published
2012
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19. On neutron-induced reaction mechanisms at medium energies

Author

Roman F.L., Avrigeanu V., and Avrigeanu M.

Subjects
Physics, QC1-999
Abstract

Recent accurate data obtained for the isomeric cross section of the 197Au(n, 2n) reaction provides an effective opportunity to consider the question of the effective moment of inertia of the nucleus within a consistent model analysis of all available reaction data for the 197Au target nucleus. Moreover, since the corresponding model assumptions are better validated by analysis of the data above 20-30 MeV where only several data with large uncertainties are known, the usefulness of further measurements to be performed at large-scale facilities as SPIRAL-2 and n_TOF, for incident energies up to 40 as well as 100 MeV, are underlined.

Published
2012
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20. Consistent optical potential for incident and emitted low-energy $\alpha$ particles. II. $\alpha$-emission in fast-neutron induced reactions on Zr isotopes

Author

Avrigeanu, V. and Avrigeanu, M.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

Background: Challenging questions of the $\alpha$-particle optical-model potential (OMP) are still pointed out by recent high-precision measurements of $\alpha$-induced reaction data below the Coulomb barrier. Moreover, the reliability of a previous OMP for $\alpha$-particles on nuclei within the mass number range 45$\leq$$A$$\leq$209 has been recently proved for emitted $\alpha$ particles as well, but only in the case of proton-induced reactions on Zn isotopes [Phys. Rev. C {\bf 91}, 064611 (2015), Paper I]. Purpose: Analysis of most recent $(\alpha,\gamma)$ reaction data for Ge and Zr isotopes, which provides an additional validation of the above-mentioned potential, is related to a further account of $\alpha$-particle emission in neutron-induced reactions on Zr isotopes, at the same time with a suitable description of all competitive processes. Methods: A consistent parameter set, established or validated by independent analysis of recent various data, particularly $\gamma$-ray strength functions, have been involved within model calculation of the $(\alpha,\gamma)$ as well as $(n,\alpha)$ reaction cross sections. The latter are part of the whole analysis of the neutron activation of Zr isotopes, in order to avoid any error compensation or latent ambiguity. Results: The aforesaid potential provides a consistent description of recent $\alpha$-induced reaction data with no empirical rescaling factors of the $\gamma$ and/or nucleon widths. On the other hand, its use leads to underestimated predictions of the pre-equilibrium emission and statistical models for the $(n,\alpha)$ reaction cross sections. Conclusions: An optical potential with a volume imaginary component seems to be needed to describe the low-energy $\alpha$-particle evaporation, while only surface absorption occurs in $\alpha$-induced reactions at similar energies., Comment: 18 pages, 11 figures, accepted for publication in Phys. Rev. C

Published
2017

21. 65Cu(d,p)66Cu excitation function at deuteron energies up to 20 MeV

Author

Avrigeanu M., Závorka L., Štefánik M., Novák J., Mrázek J., Honusek M., Bém P., Götz M., Šimečková E., and Avrigeanu V.

Subjects
Physics, QC1-999
Abstract

The proton and deuteron induced reactions have a great interest for the assessment of induced radioactivity of accelerator components. Such data are needed for estimation of the potential radiation hazard from the accelerating cavities and beam transport elements. Continuing previous irradiation experiments on copper, we provided two short run to obtain cross-section data for 65Cu(d, p)66Cu reaction. We carried out irradiation experiments with the variable-energy cyclotron U-120M of the Nuclear Physics Institute Řež. The stacked-foil technique was utilized. Because of a relatively short half life (T1/2 = 5, 120 min) and a strong annihilation peak, we placed the 1 cm Pb plate between the irradiated sample and the gamma-ray detector to reduce the dead time. The absolute values of cross-sections were calculated from the induced activities measured by the calibrated HPGe detector. The comparison of present results with data of other authors and prediction of different libraries and model calculation is discussed.

Published
2010
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23. Assessment of deuteron-induced reaction mechanisms at low and medium energies

Author

Avrigeanu V. and Avrigeanu M.

Subjects
Physics, QC1-999
Abstract

An extended analysis of the nuclear reaction mechanisms involved in the deuterons interaction with 63,65Cu is presented. First, the available elastic-scattering data analysis provided us the optical potential for reaction cross sections calculations. An increased effort has been devoted to the breakup mechanism, both the elastic breakup and the breakup fusion contributions to the different activation cross sections being carefully considered. Next, the direct reaction contributions through the one nucleon stripping reaction cross sections have been calculated. Finally, the pre-equilibrium and compound-nucleus cross-section calculation, corrected for the breakup and stripping decrease of the total reaction cross section, completed the deuteron activation cross-section analysis. The overall agreement between the measured and calculated deuteron activation cross sections proves the correctness of the nuclear mechanisms account.

Published
2010
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26. Consistent Assessment of Deuteron Interactions at Low and Medium Energies.

Author

Avrigeanu, M. and Avrigeanu, V.

Subjects
*DEUTERON reactions, *PARTICLE emissions, *COULOMB barriers (Nuclear fusion), *STRIPPING reaction (Nuclear physics), *COMPOUND nucleus
Abstract

An extended analysis of the reaction mechanisms involved within deuteron interaction with nuclei, namely the breakup, stripping, pick-up, pre-equilibrium emission, as well as the evaporation from fully equilibrated compound nucleus, is presented, stressing out the key role of the direct interactions. Particular comments concern the deuteron breakup, a comparison of the corresponding parametrization predictions involved in actual model calculations and those of the microscopical models being shown. The overall agreement between the measured data and model calculations validates the description of nuclear mechanisms taken into account for the deuteron-nucleus interaction. Consequently, the lack of direct interactions (especially of the breakup mechanism) in the theoretical frame of the deuteron surrogate reactions should be considered among the main reasons of the failure of associated validation tests. [ABSTRACT FROM AUTHOR]

Published
2019
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27. On the Physics Beyond the a-particle Optical Potential Parameters.

Author

Avrigeanu, V., Avrigeanu, M., and Mănăilescu, C.

Subjects
*NUCLEAR optical potentials, *COULOMB barriers (Nuclear fusion), *NUCLEAR reactions, *ALPHA rays, *NUCLEAR models, *NUCLEAR astrophysics
Abstract

Further high-precision measurements of α-induced reactions on 64Zn, 108Cd,113,115In, 121,123Sb, and 191,193Ir below the Coulomb barrier have been considered within statistical-model analyses using the previous optical potential. The focus of the work is on eventual uncertainties and/or systematic errors of the OMP assessment at low energies due to the limits in the knowledge of the rest of nuclear model parameters. These parameters were analyzed anyway in advance using independent data, particularly γ-ray strength functions, including their uncertainties. [ABSTRACT FROM AUTHOR]

Published
2019
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28. Comment on 'Solution of the $\alpha$-Potential Mystery in the $\gamma$ Process and Its Impact on the Nd/Sm Ratio in Meteorites'

Author

Avrigeanu, V., Avrigeanu, M., and Mănăilescu, C.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

A competition of the low-energy Coulomb excitation (CE) with the compound nucleus (CN) formation in $\alpha$-induced reactions below the Coulomb barrier has been assumed by Rauscher [Phys. Rev. Lett. 111, 061104 (2013)] in order to use the same optical model (OM) potential for description of the latter and the alpha-particle emission as well. In this Comment we show that the corresponding partial waves and integration radii provide evidence for the distinct account of the CE cross section and OM total-reaction cross section., Comment: 2 pages, 1 figure. Reduced length, title changed

Published
2016

30. Role of the direct mechanisms in the deuteron-induced surrogate reactions

Author

Avrigeanu, M and Avrigeanu, V

Subjects
Nuclear Physics - Experiment
Abstract

An extended analysis of the key role of direct interactions, i.e., breakup, stripping and pick-up processes, for the deuteron–induced surrogate reactions is presented. Particular comments concern the deuteron breakup which is dominant in the case of the ( d; p g ) surrogate reactions on actinides target nuclei, around the Coulomb barrier.

Published
2015

31. The Neutrons for Science Facility at SPIRAL-2.

Author

Ledoux, X, Aïche, M, Avrigeanu, M, Avrigeanu, V, Balanzat, E, Ban-d’Etat, B, Ban, G, Bauge, E, Bélier, G, and Bém, P

Subjects
SCIENCE facilities (Education), SUPERCONDUCTING composites, DEUTERON scattering, NUCLEAR physics experiments, GAMMA rays
Abstract

The neutrons for science (NFS) facility is a component of SPIRAL-2, the new superconducting linear accelerator built at GANIL in Caen (France). The proton and deuteron beams delivered by the accelerator will allow producing intense neutron fields in the 100 keV–40 MeV energy range. Continuous and quasi-mono-kinetic energy spectra, respectively, will be available at NFS, produced by the interaction of a deuteron beam on a thick Be converter and by the 7Li(p,n) reaction on thin converter. The pulsed neutron beam, with a flux up to two orders of magnitude higher than those of other existing time-of-flight facilities, will open new opportunities of experiments in fundamental research as well as in nuclear data measurements. In addition to the neutron beam, irradiation stations for neutron-, proton- and deuteron-induced reactions will be available for cross-sections measurements and for the irradiation of electronic devices or biological cells. NFS, whose first experiment is foreseen in 2018, will be a very powerful tool for physics, fundamental research as well as applications like the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. [ABSTRACT FROM AUTHOR]

Published
2018
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32. The Neutrons for Science Facility at SPIRAL-2

Author

Ledoux, X., Aïche, M., Avrigeanu, M., Avrigeanu, V., Audouin, L., Balanzat, E., Ban-détat, B., Ban, G., Barreau, G., Bauge, E., Bélier, G., Bem, P., Blideanu, V., Borcea, C., Bouffard, S., Caillaud, T., Chatillon, A., Czajkowski, S., Dessagne, P., Doré, D., Fallot, M., Farget, F., Fischer, U., Giot, L., Granier, T., Guillous, S., Gunsing, F., Gustavsson, C., Jacquot, B., Jansson, K., Jurado, B., Kerveno, M., Klix, A., Landoas, O., Lecolley, F.R., Lecouey, J.L., Majerle, M., Marie, N., Materna, T., Mrazek, J., Negoita, F., Novak, J., Oberstedt, S., Oberstedt, A., Panebianco, S., Perrot, L., Plompen, A.J.M., Pomp, S., Ramillon, J.M., Ridikas, D., Rossé, B., Rudolf, G., Serot, O., Simakov, S.P., Simeckova, E., Smith, A.G., Sublet, J.C., Taieb, J., Tassan-Got, L., Tarrio, D., Takibayev, A., Thfoin, I., Tsekhanovich, I., and Varignon, C.

Published
2014
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35. Uncertainties of α-particle Optical Potential Assessment Around and Below the Coulomb Barrier.

Author

Avrigeanu, V., Avrigeanu, M., and Mănăilescu, C.

Subjects
*COULOMB barriers (Nuclear fusion), *NUCLEAR excitation, *PARTICLE emissions, *NUCLEAR optical models, *ASTROPHYSICS
Abstract

A competition of the low-energy Coulomb excitation (CE) with the compound nucleus (CN) formation in α-induced reactions below the Coulomb barrier has recently been assumed in order to make possible the description of the latter as well as the α-particle emission by the same optical model (OM) potential. However, we show in the present work that the corresponding partial waves and integration radii provide evidence for the distinct account of the CE cross section and OM total-reaction cross section σR. Thus the largest contribution to CE cross section comes by far from partial waves larger than the ones contributing to the σR values. Finally, effects of statistical model parameters are comparatively discussed. [ABSTRACT FROM AUTHOR]

Published
2017
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39. Report on the detection and acquisition systems at NFS

Author

Ledoux, X., Eric Bauge, Belier, G., Caillaud, T., Chatillon, A., Granier, T., Landoas, O., Taïeb, J., Rossé, B., Thfoin, I., Varignon, C., Blideanu, V., Doré, D., Gunsing, F., Panebianco, S., Ridikas, D., Takibayev, A., Aïche, M., Barreau, G., Czajkowski, S., Jurado, B., Ban, G., Lecolley, F. R., Lecolley, J. F., Lecouey, J. L., Nathalie Marie, Steckmeyer, J. C., Dessagne, P., Kerveno, M., Rudolf, G., Bem, P., Majerle, M., Mrazek, J., Novak, J., Simeckova, E., Gustavsson, C., Pomp, S., Fischer, U., Klix, K., Simakov, S. P., Jacquot, B., Farget, F., Wieleczko, J. P., Perrot, L., Tassan-Got, L., Avrigeanu, M., Avrigeanu, V., Borcea, C., Negoita, F., Petrascu, M., Oberstedt, S., Plompen, A. J. M., Muriel Fallot, Lydie Giot, Smith, G., Tsekhanovich, I., Olivier Serot, Balanzat, E., Ban-D État, B., Guillous, S., Ramillon, J. M., Oberstedt, A., Sublet, J. C., DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Aval du cycle et Energie Nucléaire (ACEN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)

Subjects
[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Published
2012

40. Does deuteron-induced fission on actinide nuclei prevails over the breakup at low incident energies?

Author

Avrigeanu, M., Avrigeanu, V., and Koning, A. J.

Subjects
Nuclear Theory (nucl-th), Nuclear Theory, FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment, eye diseases
Abstract

An analysis of the $^{231}$Pa$(d,3n)$$^{230}$U reaction excitation function at energies around the Coulomb barrier has taken into account the pre-equilibrium and compound-nucleus cross sections corrected for the deuteron-breakup decrease of the total reaction cross section, as well as the inelastic breakup enhancement. The analysis reveals the dominance of the deuteron breakup mechanism unlike a former assessment in this respect of the deuteron-induced fission process., 5 pages, 3 figures

Published
2011

41. Improved Neutron Capture Cross Section Measurements with the n_TOF Total Absorption Calorimeter

Author

Mendoza, E., Becares, V., Casado, A., Cano-Ott, D., Fernandez-Ordonez, M., Gonzalez-Romero, E., Guerrero, C., Martinez, T., Vidriales, J. J., Andrzejewski, J., Marganiec, J., Perkowski, J., Audouin, L., Berthier, B., Tassan-Got, L., Avrigeanu, V., Mirea, M., Becvar, F., Krticka, M., Belloni, F., Milazzo, P. M., Berthoumieux, E., Gunsing, F., Calvino, F., Cortes, G., Gomez-Hornillos, M. B., Andriamonje, S., Brugger, M., Calviani, M., Cerutti, F., Chiaveri, E., Ferrari, A., Kadi, Y., Lebbos, E., Losito, H., Vlachoudis, V., Carrapico, C., Goncalves, I. F., Saarmento, H., Vaz, P., Colonna, N., Marrone, S., Moinul, M., Tagliente, G., Variale, V., Dillmann, I., Domingo-Pardo, C., Heil, M., Duran, I., Paradela, C., Tarrio, D., Ganesan, S., Giubrone, G., Tain, J. L., Gramegna, F., Mastinu, P. F., Harrisopulos, S., Ioannides, K., Karadimos, D., Jericha, E., Leeb, H., Weiss, C., Kappeler, F., Lederer, C., Pavlik, A., Wallner, A., Lozano, M., Prena, J., Quesada, J. M., Massimi, C., Vannini, G., Mengoni, A., Ventura, A., Mosconi, M., Nolte, R., Vlastou, R., and n TOF Collaboration

Subjects
cross section, background, monte carlo, shielding, simulation, nuclear data, neutron, gamma ray, time of flight, calorimeter, n_tof, nd2010, total absorption, neutron capture
Abstract

The n_TOF collaboration operates a Total Absorption Calorimeter (TAC) [1] for measuring neutron capture cross-sections of low-mass and/or radioactive samples. The results obtained with the TAC have led to a substantial improvement of the capture cross sections of (237)Np and (240)Pu [2]. The experience acquired during the first measurements has allowed us to optimize the performance of the TAC and to improve the capture signal to background ratio, thus opening the way to more complex and demanding measurements on rare radioactive materials. The new design has been reached by a series of detailed Monte Carlo simulations of complete experiments and dedicated test measurements. The new capture setup will be presented and the main achievements highlighted. Journal of the Korean Physical Society

Published
2011

42. The Role of Fe and Ni for S-process Nucleosynthesis and Innovative Nuclear Technologies

Author

Giubrone, G., Tain, J. L., Lederer, C., Pavlik, A., Wallner, A., Andriamonje, S., Brugger, M., Calviani, M., Cerutti, F., Chiaveri, E., Ferrari, A., Kadi, Y., Lebbos, E., Vlachoudis, V., Andrzejewski, J., Marganiec, J., Perkowski, J., Audouin, L., Berthier, B., Tassan-Got, L., Avrigeanu, V., Mirea, M., Becares, V., Cano-Ott, D., Fernandez-Ordonez, M., Gonzalez-Romero, E., Guerrero, C., Martin-Fuertes, F., Martinez, T., Mendoza, E., Pina, G., Quinones, J., Becvar, F., Krticka, M., Belloni, F., Milazzo, P. M., Berthoumieux, E., Gunsing, F., Calvino, F., Cortes, G., Gomez-Hornillos, M. B., Carrapico, C., Goncalves, I. F., Sarmento, R., Vaz, P., Colonna, N., Marrone, S., Meaze, M. H., Tagliente, G., Variale, V., Dillman, I., Domingo-Pardo, C., Heil, M., Duran, I., Paradela, C., Tarrio, D., Ganesan, S., Gramegna, F., Mastinu, P. F., Harrisopulos, S., Ioannides, K., Karadimos, D., Jericha, E., Leeb, H., Weiss, C., Kappeler, F., Lozano, M., Praena, J., Quesada, J. M., Massimi, C., Vannini, G., Mengoni, A., Ventura, A., Mosconi, M., Nolte, R., Vlastou, R., and N Tof Collaboration

Subjects
neutron time of flight facility, neutron, facility, nuclear astrophysics, cern, c6d6 detectors, neutron capture cross sections, pulse height weighting technique, cross-sections, advanced nuclear systems, metal-poor
Abstract

The accurate measurement of neutron capture cross sections of all Fe and Ni isotopes is important for disentangling the contribution of the s-process and the r-process to the stellar nucleosynthesis of elements in the mass range 60 < A < 120. At the same time, Fe and Ni are important components of structural materials and improved neutron cross section data is relevant in the design of new nuclear systems. With the aim of obtaining improved capture data on all stable iron and nickel isotopes, a program of measurements has been launched at the CERN Neutron Time of Flight Facility n_TOF. Journal of the Korean Physical Society

Published
2011

43. Characterization of the New n_TOF Neutron Beam: Fluence, Profile and Resolution

Author

Guerrero, C., Becares, V., Cano-Ott, D., Fernandez-Ordonez, M., Gonzalez-Romero, E., Martin-Fuertes, F., Martinez, T., Mendoza, E., Pina, G., Quinones, J., Vlachoudis, V., Calviani, M., Andriamonje, S., Brugger, M., Cerutti, F., Chiaveri, E., Ferrari, A., Kadi, Y., Lebbos, E., Berthoumieux, E., Gunsing, F., Andrzejewski, J., Marganiec, J., Perkowski, J., Audouin, L., Berthier, B., Tassan-Got, L., Avrigeanu, V., Mirea, M., Becvar, F., Krticka, M., Belloni, F., Milazzo, P. M., Calvino, F., Cortes, G., Gomez-Hornillos, M. B., Carrapico, C., Goncalves, I. F., Sarmento, R., Vaz, P., Colonna, N., Marrone, S., Moinul, M., Tagliente, G., Variale, V., Dillmann, I., Domingo-Pardo, C., Heil, M., Duran, I., Paradela, C., Tarrio, D., Ganesan, S., Giubrone, G., Tain, J. L., Gramegna, F., Mastinu, P. F., Harrisopulos, S., Ioannides, K., Karadimos, D., Jericha, E., Leeb, H., Weiss, C., Kappeler, F., Lederer, C., Pavlik, A., Wallner, A., Lozano, M., Praena, J., Quesada, J. M., Massimi, C., Vannini, G., Mengoni, A., Ventura, A., Mosconi, M., Nolte, R., Vlastou, R., and N TOF Collaboration

Subjects
facility, n_tof, cross sections, neutron beam, time-of-flight, nuclear data
Abstract

After a halt of four years, the n_TOF spallation neutron facility at CERN has resumed operation in November 2008 with a new spallation target characterized by an improved safety and engineering design, resulting in a more robust overall performance and efficient cooling. The first measurement during the 2009 run has aimed at the full characterization of the neutron beam. Several detectors, such as calibrated fission chambers, the n_TOF Silicon Monitor, a MicroMegas detector with (10)B and (235)U samples, as well as liquid and solid scintillators have been used in order to characterize the properties of the neutron fluence. The spatial profile of the beam has been studied with a specially designed "X-Y" MicroMegas which provided a 2D image of the beam as a function of neutron energy. Both properties have been compared with simulations performed. with the FLUKA code. The characterization of the resolution function is based on results from simulations which have been verified by the study of narrow capture resonances. of (56)Fe, which were measured as part of a new campaign of (n,gamma) measurements on Fe and Ni isotopes. Journal of the Korean Physical Society

Published
2011

44. Optical potentials for alpha particles on heavy nuclei around the Coulomb barrier

Author

Avrigeanu, M, von Oertzen, W, Obreja, A C, Roman, F L, and Avrigeanu, V

Subjects
Nuclear Experiment, XX
Abstract

A previously semi-microscopic analysis of the -particle interaction with 50 A 124 target nuclei at energies from 8 to 50 MeV, based on the Double Folding Model (DFM) for the real part of the optical potential, is extended to heavy nuclei A 132 nuclei. The energy-dependent phenomenological imaginary part of the corresponding semi-microscopic optical model potential was obtained by taking into account also the dispersive correction to the DFM real potential, and used within a concurrent complete phenomenological analysis of the same data basis. Thus, a phenomenological optical potential was also obtained for the above-mentioned target-nuclei mass and energy ranges, while an ultimate assessment of ( , ), ( ,n) and ( ,p) reaction cross sections proves the suitable description of both the low energy elastic-scattering and -particle induced-reaction data.

Published
2010

46. A neutron beam facility at SPIRAL-2

Author

Ledoux, X., Aïche, M., Ban, G., Barreau, G., Baumann, P., Bem, P., Blideanu, V., Blomgren, J., Czajkowski, S., Dessagne, P., Dupont, E., Doré, D., Ethvignot, T., Fischer, U., Gunsing, F., Jacquot, B., Jurado, B., Kerveno, M., Lecolley, F.R., Lecouey, J.L., Negoita, F., Oberstedt, S., Petrascu, M., Plompen, A.J.M., Rejmund, F., Ridikas, D., Rudolf, G., Shcherbakov, O., Simakov, S.P., Taïeb, J., Avrigeanu, M., Avrigeanu, V., Audouin, L., Fallot, Muriel, Giot, Lydie, Perrot, L., Tassan-Got, L., Tsekhanovich, I., Département de Physique Théorique et Appliquée (DPTA), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Horia Hulubei National Institute of Physics and Nuclear Engineering (NIPNE), IFIN-HH, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), SPIRAL2, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Ion beam, [PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph], Nuclear Theory, Nuclear data, Neutron scattering, Neutron radiation, 7. Clean energy, Neutron time-of-flight scattering, Neutron temperature, Nuclear physics, Neutron source, Physics::Accelerator Physics, Neutron, Nuclear Experiment
Abstract

International audience; The future SPIRAL-2 facility is mainly composed of a high-power superconducting driver LINAC, delivering a high-intensity deuteron, proton and heavy ions beams. The first two beams are particularly well suited to the construction of a neutron beam and irradiation facility called Neutrons for Science (NFS). Thick C and Be target-converters with incident deuteron beam will produce an intense white neutron spectrum, while thin 7Li target and incident proton beam allows generating quasi-monoenergetic neutrons. The 1–40MeV neutron energy range will be covered and characterized by very intense fluxes available. The primary ion beam characteristics (energy, time resolution, intensity, etc.) are adequate to create a neutron time-of-flight facility. Irradiation stations for neutron, proton and deuteron induced reactions could also be built in order to perform cross-sections measurements by activation techniques. In this paper we will discuss the potential of this new installation to investigate numerous topics, both in fundamental and applied physics. In particular, cross section measurements could be performed for different purposes like nuclear data evaluation, fission and fusion technology, Accelerator Driven Systems, nuclear medicine, astrophysics, etc.

Published
2007

47. Enhanced ɑ-particle optical potential at low energies, for the mass range A~45-209.

Author

Avrigeanu, V., Avrigeanu, M., and Mănăilescu, C.

Subjects
*SPECIAL relativity (Physics), *NUCLEAR optical potentials, *NUCLEAR reactions, *NUCLEAR astrophysics, *RARE earth metals
Abstract

An updated optical potential is thus provided for ɑ-particles on nuclei within the mass number range 45≤A≤209, below the Coulomb barrier (B), on the basis of recent high-precision measurements of ɑ-particle induced reaction data below B that made possible the understanding of actual limits and possible improvement of the ɑ-particle optical-model potentials. The main revision concerns actually only the surface imaginary potential depth at the lowest ɑ-particle energies well below B, and in fact only for the mass range above A~130. A further regional point is the underestimation of reaction cross sections for the rare-earth nuclei by using the spherical optical potential unless a 7% larger value of the surface imaginary potential radius is taken into account. Involvement of this potential for further description of both the scattering and ɑ-particles induced reactions is moreover discussed in the present work, of equal interest for nuclear astrophysics and nuclear technology for fusion devices. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
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48. On Reaction Mechanisms Involved in the Deuteron-Induced Surrogate Reactions.

Author

Avrigeanu, M., Avrigeanu, V., and Mănăilescu, C.

Subjects
*NUCLEAR reactions, *DEUTERON reactions, *PARTICLE interactions, *COULOMB barriers (Nuclear fusion), *ACTINIDE elements
Abstract

An extended analysis of the nuclear reaction mechanisms involved within deuteron interaction with nuclei, namely the breakup, stripping, pick-up, pre-equilibrium emission, and evaporation from fully equilibrated compound nucleus, is presented in order to highlight the importance of the direct mechanisms still neglected in the analysis of deuteron-induced surrogate reactions. Particularly, the dominance of the breakup mechanism at low energies around the Coulomb barrier should be considered in the case of (d,x) surrogate reactions on actinide target nuclei. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

49. Energy dependence of the isomeric cross section ratio in the $^{58}$Ni$(n,p)^{58}$Co$^{m,g}$ reactions

Author

Avrigeanu, V., Sud��r, S., Buczk��, Cs. M., Csikai, J., Filatenkov, A. A., Chuvaev, S. V., D��czi, R., Semkova, V., and Zelenetsky, V. A.

Subjects
FOS: Physical sciences, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

Excitation functions of the $^{58}$Ni$(n,p)^{58}$Co$^{m,g}$ reactions were measured in the energy range from 2 to 15 MeV. The energy dependence of the isomeric cross-section ratio R=sigma_m/(sigma_m+sigma_g) is deduced from the measured data. The shape and magnitude of the R(E_n) function are described by model calculations using a consistent parameter set. Questions of the input level scheme were solved based on the accurate isomeric ratio measured at low energy region., 11 pages, 3 ps figures, REVTeX; shorter version submitted to Phys. Rev. C as Brief Report

Published
1998

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