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43 results on '"M. Aïche"'

1. Energy dependence of processing and breakdown properties of Cu and Mo

Author

H. Timko, M. Aicheler, P. Alknes, S. Calatroni, A. Oltedal, A. Toerklep, M. Taborelli, W. Wuensch, F. Djurabekova, and K. Nordlund

Subjects
Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Obtaining basic knowledge of breakdowns is desirable in many fields of physics; however, often the energy absorbed by a breakdown is not known or can vary by large amounts. We have therefore investigated how processing and breakdown properties scale with available energy for two materials, Cu and Mo, in the energy range of about 1 mJ to 1 J. A central result obtained is that there appears to be an optimum energy for processing and thus the highest possible electric field a processed material can sustain without breaking down depends on energy accordingly; what this implies for radio frequency cavity processing is discussed as well. For Cu, both the local field and the field enhancement factor showed only a weak dependence on energy; the average of the local field over the entire energy range investigated was (9.6±0.4) GV/m at breakdown. For Mo, the local field increased with increasing energy, while the field enhancement factor remained constant at 34±2. Finally, a possible explanation of the direct current (DC) processing mechanism—at least in the case of Mo—as an oxide removal process is presented.

Published
2011
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2. Development of a Gaseous Proton-Recoil Detector for neutron flux measurements between 0.2 and 2 MeV neutron energy

Author

P. Marini, L. Mathieu, M. Aïche, T. Chiron, P. Hellmuth, J.-L. Pedroza, G. Kessedjian, S. Czajkowski, B. Jurado, I. Tsekhanovich, 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 Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)

Subjects
[PHYS]Physics [physics], 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Physics, QC1-999, Astrophysics::High Energy Astrophysical Phenomena, 0103 physical sciences, Nuclear Theory, Physics::Accelerator Physics, 010306 general physics, Nuclear Experiment, 01 natural sciences
Abstract

International audience; Absolute measurements of neutron fluence are an essential prerequisite of neutron-induced cross section measurements, dosimetric investigations and neutron beam lines characterisation. Independent and precise neutron flux measurements can be performed with respect to the H(n,p) elastic cross section. However, the use of silicon proton recoil detectors is not straightforward below incident neutron energy of 1 MeV, due to a high background in the detected proton spectrum. A new gaseous proton-recoil detector has been designed to answer the challenge. The detector is described in details and results of the commissioning tests are presented.

Published
2018

3. The extrapolated-efficiency method, a new technique to determine the detection efficiency in experiments based on the surrogate-reaction method

Author

I. Companis, G. Barreau, C. Theroine, G. Boutoux, L. Mathieu, M. Aïche, Beatriz Jurado, O. Roig, V. Méot, A. Blanc, 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), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Physics, Nuclear and High Energy Physics, Work (thermodynamics), 010308 nuclear & particles physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Computational physics, Weighting, Cascade, 0103 physical sciences, Neutron, 010306 general physics, Indirect Technique, Instrumentation, Energy (signal processing)
Abstract

The surrogate-reaction method is an indirect technique to extract neutron-induced cross-sections of short-lived nuclei. In the last years several experiments have been performed to investigate whether this technique can be applied to infer radiative-capture cross-sections. A major difficulty in this type of measurements is the determination of the gamma-cascade detection efficiency. The pulse-height weighting technique (PHWT) has been previously used to determine this quantity in surrogate experiments. In this work, we present a new method to determine the gamma-cascade detection efficiency in the vicinity of the neutron-separation energy that is much simpler than the PHWT. We also investigate the possibility to apply this new technique in standard experiments using neutron beams.

Published
2013

4. Investigation of the U 238 ( d , p ) surrogate reaction via the simu

Author

Q. Ducasse, B. Jurado, M. Aïche, P. Marini, L. Mathieu, A. Görgen, M. Guttormsen, A. C. Larsen, T. Tornyi, J. N. Wilson, G. Barreau, G. Boutoux, S. Czajkowski, F. Giacoppo, F. Gunsing, T. W. Hagen, M. Lebois, J. Lei, V. Méot, B. Morillon, A. M. Moro, T. Renstrøm, O. Roig, S. J. Rose, O. Sérot, S. Siem, I. Tsekhanovich, G. M. Tveten, and M. Wiedeking

Published
2016
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5. Experimental level densities of atomic nuclei

Author

F. L. Bello Garrote, S. J. Rose, Ann-Cecilie Larsen, Magne Guttormsen, F. Giacoppo, L. Lebois, Sunniva Siem, Trine Wiborg Hagen, D. L. Bleuel, L. A. Bernstein, B. Leniau, F. Gunsing, Andreas Görgen, Hilde Therese Nyhus, Therese Renstrøm, Y. Byun, E. Sahin, Beatriz Jurado, M. Klintefjord, M. Wiedeking, T. K. Eriksen, T. G. Tornyi, Q. Ducasse, A. Voinov, Gry Merete Tveten, M. Aïche, Jonathan Wilson, 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Basis (linear algebra), Atomic nucleus, FOS: Physical sciences, Neutron, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract

It is almost 80 years since Hans Bethe described the level density as a non-interacting gas of protons and neutrons. In all these years, experimental data were interpreted within this picture of a fermionic gas. However, the renewed interest of measuring level density using various techniques calls for a revision of this description. In particular, the wealth of nuclear level densities measured with the Oslo method favors the constant-temperature level density over the Fermi-gas picture. From the basis of experimental data, we demonstrate that nuclei exhibit a constant-temperature level density behavior for all mass regions and at least up to the neutron threshold., Comment: 8 pages, 8 figures

Published
2015

6. Development of ionisation chambers for the simultaneous measurement of the neutron-induced capture and fission cross section of 233U

Author

L. Mathieu, G. Barreau, Jan Heyse, F. Gunsing, G. Boutoux, A. J. M. Plompen, I. Tsekhanovitch, M. Aïche, I. Companis, Grégoire Kessedjian, Peter Schillebeeckx, Beatriz Jurado, S. Czajkowski, Vernay, Emmanuelle, 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), 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), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-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), Aval du cycle et Energie Nucléaire (ACEN), and Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Fission, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Astrophysics::High Energy Astrophysical Phenomena, Detector, Nuclear data, Scintillator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Coincidence, Nuclear physics, Cross section (physics), Computer Science::Hardware Architecture, Ionization, Neutron, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS
Abstract

A new simultaneous measurement of sigma(n,f) and sigma(n,gamma) will be performed at the neutron time-of-flight facility GELINA in Geel (Belgium). The fission events will be detected by a multi-plate high-efficiency ionisation chamber (IC). An efficient array of C6D6 scintillators will be used for the detection of gamma-rays. The disentanglement between fission and capture gamma-rays can be achieved by using anticoincidence events between the IC and the C6D6 detectors. Given the difference in the fission and capture cross sections, the assignment of a gamma-ray to one or the other reaction type has to be very efficient and reliable. The IC efficiency is not 100 % and a correction has to be applied to take into account the undetected fission events. To keep this correction factor low and reliable, the efficiency parameter of the IC should be high and known with a high degree of accuracy. The IC efficiency towards fission can be defined as a ratio between the number of detected neutrons in coincidence or not with fission fragments. It is therefore a value directly extractable from the experimental data. Results from test experiments of the IC will be presented and discussed, along with IC MCNPX simulations., JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Published
2014

7. Scissors resonance in the quasi-continuum of Th, Pa and U isotopes

Author

Sunniva Siem, Q. Ducasse, L. A. Bernstein, Ann-Cecilie Larsen, Trine Wiborg Hagen, Therese Renstrøm, F. Gunsing, M. Wiedeking, F. Giacoppo, J.N. Wilson, Tamas Gabor Tornyi, Gry Merete Tveten, Andreas Görgen, Magne Guttormsen, M. Lebois, M. Aïche, Beatriz Jurado, S. J. Rose, B. Leniau, Aval du cycle et Energie Nucléaire (ACEN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Isotope, Astrophysics::High Energy Astrophysical Phenomena, Strength function, FOS: Physical sciences, Resonance, Fizikai tudományok, Moment of inertia, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Omega, Természettudományok, Total strength, Nuclear Experiment (nucl-ex), Atomic physics, Nuclear Experiment
Abstract

The gamma-ray strength function in the quasi-continuum has been measured for 231-233Th, 232,233Pa and 237-239U using the Oslo method. All eight nuclei show a pronounced increase in gamma strength at omega_SR approx 2.4 MeV, which is interpreted as the low-energy M1 scissors resonance (SR). The total strength is found to be B_SR = 9-11 mu_N^2 when integrated over the 1 - 4 MeV gamma-energy region. The SR displays a double-hump structure that is theoretically not understood. Our results are compared with data from (gamma, gamma') experiments and theoretical sum-rule estimates for a nuclear rigid-body moment of inertia., Comment: 11 pages, 9 figures

Published
2014

9. The Neutrons For Science facility at SPIRAL-2

Author

Julien Taieb, T. Materna, A. Chatillon, I. Thfoin, L. Perrot, Stanislav Simakov, T. Caillaud, X. Ledoux, Eric Bauge, A. Takibayev, Eva Simeckova, Andreas Oberstedt, Cecilia Gustavsson, B. Jacquot, Jan Novák, Danas Ridikas, A. G. Smith, G. Rudolf, B. Ban-d'Etat, Marilena Avrigeanu, D. Dore, V. Blideanu, J.M. Ramillon, C. Borcea, A. Klix, F. Gunsing, L. Giot, F. Farget, G. Bélier, I. Tsekhanovich, Diego Tarrio, J. C. Sublet, S. Czajkowski, Stephan Pomp, Olivier Serot, Beatriz Jurado, S. Bouffard, Muriel Fallot, G. Ban, O. Landoas, P. Dessagne, Stephan Oberstedt, J. Mrazek, François-René Lecolley, S. Guillous, Mitja Majerle, C. Varignon, S. Panebianco, Emmanuel Balanzat, Vlad Avrigeanu, M. Kerveno, Kaj Jansson, J.L. Lecouey, L. Audouin, B. Rossé, L. Tassan-Got, M. Aïche, T. Granier, G. Barreau, F. Negoita, Ulrich Fischer, Nathalie Marie, Pavel Bem, A. J. M. Plompen, 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), 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), 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), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), 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), Laboratoire de physique corpusculaire de Caen (LPCC), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), 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 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), 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), 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)-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), Normandie Université (NU), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, High intensity, Nuclear Theory, Nuclear data, Astrophysics::Cosmology and Extragalactic Astrophysics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Ion, Nuclear physics, Component (UML), Physics::Accelerator Physics, Neutron, Spiral (railway), Nuclear Experiment, Astrophysics::Galaxy Astrophysics
Abstract

The Neutrons For Science (NFS) facility is a component of SPIRAL-2 laboratory under construction at Caen (France). SPIRAL-2 is dedicated to the production of high intensity Radioactive Ions Beams (RIB). It is based on a high-power linear accelerator (LINAG) to accelerate deuterons beams in order to produce neutrons by breakup reactions on a C converter. These neutrons will induce fission in 238U for production of radioactive isotopes. Additionally to the RIB production, the proton and deuteron beams delivered by the accelerator will be used in the NFS facility. NFS is composed of a pulsed neutron beam and irradiation stations for cross-section measurements and material studies. The beams delivered by the LINAG will allow producing intense neutron beams in the 100 keV-40 MeV energy range with either a continuous or quasi-mono-energetic spectrum. At NFS available average fluxes will be up to 2 orders of magnitude higher than those of other existing time-of-flight facilities in the 1 MeV - 40 MeV range. NFS will be a very powerful tool for fundamental physics and application related research in support of the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. The facility and its characteristics are described, and several examples of the first potential experiments are presented., JRC.D.4-Standards for Nuclear Safety, Security and Safeguards

Published
2013

10. Dipole bands in the oblate-shaped195Pb

Author

M. Kaci, H. Sergolle, Marco Meyer, C. W. Beausang, F. Azaiez, N. Redon, N. Poffé, A. G. Smith, A. Korichi, R. Wadsworth, J.F. Sharpey-Schafer, Malcolm J. Joyce, Josette Duprat, M. Aïche, B. J. P. Gall, K. Hauschild, M. G. Porquet, R. Duffait, N. Perrin, G. Bastin, F. Hannachi, R. M. Clark, E. S. Paul, I. Deloncle, C. Bourgeois, J. Simpson, Y. Le Coz, and C. Schück

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Dipole, Spectrometer, Oblate spheroid, Nuclear fusion, Neutron, Atomic physics
Abstract

The nucleus195Pb has been populated with the184W+16O reaction at 113 MeV. Two dipole γ-ray cascades have been observed using the EUROGAM spectrometer. A comprehensive level scheme related to these structures has been established. Multiparticle configurations are attributed to these high-spin structures from detailed comparison with the neighbouring nuclei,193Hg,194Pb and195Tl. Band crossings due to i13/2 neutron pair breaking are observed in195Pb at about the same frequencies as in the isotone193Hg.

Published
1996

11. M1 transitions between superdeformed states in194, 195Tl: The fingerprint of thei13/2proton intruder orbital

Author

N. Poffé, F. Azaiez, A. Kaci, N. Redon, S.J. Gale, H. Sergolle, G. Bastin, M. G. Porquet, C. Schück, A. Korichi, Josette Duprat, R. Duffait, F. Hannachi, Y. Le Coz, Malcolm J. Joyce, N. Perrin, C. Bourgeois, J.F. Sharpey-Schafer, R. Wadsworth, Marco Meyer, W. H. Kelly, C. W. Beausang, I. M. Hibbert, J. Simpson, M. Aïche, I. Deloncle, R. M. Clark, and B. J. P. Gall

Subjects
Physics, Dipole, Spins, Nuclear Theory, Quadrupole, Strong coupling, Neutron, Atomic physics, Nuclear Experiment, Condensed Matter Physics, Mathematical Physics, Atomic and Molecular Physics, and Optics
Abstract

Recent data from the EUROGAM array have revealed dipole transitions linking signature partner superdeformed bands in 194Tl and 195Tl nuclei. Measurements of the decay branching ratios, taken together with the average quadrupole moment of the neighboring superdeformed nuclei, enable the absolute M1 strengths to be determined. From these data and using the strong coupling model, we find that two SD bands in 195Tl are due to the 81st proton being in the [642]5/2+ orbital and four from the six SD bands in 194Tl correspond to a configuration where the intrinsic spins of the single proton and single neutron are aligned.

Published
1995

12. Study of the surrogate-reaction method applied to neutron-induced capture cross sections

Author

I. Companis, P. Morel, X. Derkx, C. Theroine, S. Czajkowski, G. Boutoux, J. M. Daugas, I Matea, V. Méot, N. Capellan, L. Tassan-Got, J.T. Burke, O. Roig, A. Bail, Olivier Serot, T. Faul, K.-H. Schmidt, N. Pillet, M. Aïche, Beatriz Jurado, L. Mathieu, G. Barreau, Aval du cycle et Energie Nucléaire (ACEN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), 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), Service de Physique des Réacteurs et du Cycle (SPRC), Département Etude des Réacteurs (DER), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), 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), 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), and 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)

Subjects
Physics, Nuclear and High Energy Physics, Angular-momentum distribution, 010308 nuclear & particles physics, Neutron emission, Astrophysics::High Energy Astrophysical Phenomena, chemistry.chemical_element, Germanium, Neutron-induced capture cross section, Scintillator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Residual, 01 natural sciences, Gamma-decay probability, chemistry, Excited state, Surrogate-reaction method, 0103 physical sciences, Neutron, Atomic physics, Experimental methods, 010306 general physics, Nuclear Experiment, Spin-½
Abstract

Gamma-decay probabilities of 173Yb and 176Lu have been measured using the surrogate reactions 174Yb(3He,αγ)173Yb* and 174Yb(3He,pγ)176Lu*, respectively. For the first time, the gamma-decay probabilities have been obtained with two independent experimental methods based on the use of C6D6 scintillators and Germanium detectors. Our results for the radiative-capture cross sections are several times higher than the corresponding neutron-induced data. To explain these differences, we have used our gamma-decay probabilities to extract rather direct information on the spin distributions populated in the transfer reactions used. They are about two times wider and the mean values are 3 to 4 ℏ higher than the ones populated in the neutron-induced reactions. As a consequence, in the transfer reactions neutron emission to the ground and first excited states of the residual nucleus is strongly suppressed and gamma-decay is considerably enhanced.

Published
2012

13. M1 transitions between superdeformed states in 195Tl: the fingerprint of the proton intruder orbital

Author

M. Aïche, R. Duffait, I. Deloncle, A. Korichi, F. Hannachi, M. G. Porquet, R. Wadsworth, C. Bourgeois, R. M. Clark, F. Azaiez, Malcolm J. Joyce, N. Perrin, J. Simpson, C. W. Beausang, I. M. Hibbert, N. Poffé, W.H. Kelly, Josette Duprat, S.J. Gale, J.F. Sharpey-Schafer, B. J. P. Gall, M. Kaci, H. Sergolle, M. Meyer, N. Redon, Y. Le Coz, and C. Schück

Subjects
Physics, Nuclear and High Energy Physics, Dipole, Photon, Spectrometer, Yrast, Nuclear Theory, Quadrupole, Atomic physics, Nuclear Experiment, Excitation
Abstract

Dipole transitions linking the superdeformed Yrast signature-partner bands in 195Tl have been observed using the EUROGAM 1 spectrometer. From the measurements of the photon decay branching ratios, taken together with the average quadrupole moment measured in neighbouring superdeformed nuclei, we find that the two signature partner superdeformed bands involve the excitation of the 81 st proton into the i 13 2 Ω= 5 2 intruder orbital

Published
1994

14. The Neutrons for Science Facility at SPIRAL‐2

Author

X. Ledoux, M. Aïche, M. Avrigeanu, V. Avrigeanu, L. Audouin, E. Balanzat, B. Ban-d'Etat, G. Ban, G. Barreau, E. Bauge, G. Bélier, P. Bem, V. Blideanu, J. Blomgren, C. Borcea, S. Bouffard, T. Caillaud, A. Chatillon, S. Czajkowski, P. Dessagne, D. Doré, M. Fallot, F. Farget, U. Fischer, L. Giot, T. Granier, S. Guillous, F. Gunsing, C. Gustavsson, S. Herber, B. Jacquot, B. Jurado, M. Kerveno, A. Klix, O. Landoas, F. R. Lecolley, J. F. Lecolley, J. L. Lecouey, M. Majerle, N. Marie, T. Materna, J. Mrazek, F. Negoita, J. Novak, S. Oberstedt, A. Oberstedt, S. Panebianco, L. Perrot, M. Petrascu, A. J. M. Plompen, S. Pomp, J. M. Ramillon, D. Ridikas, B. Rossé, G. Rudolf, O. Serot, O. Shcherbakov, S. P. Simakov, E. Simeckova, A. G. Smith, J. C. Steckmeyer, J. C. Sublet, J. Taïeb, L. Tassan-Got, A. Takibayev, E. Tungborn, I. Thfoin, I. Tsekhanovich, C. Varignon, J. P. Wieleczko, Marianne E. Hamm, Robert W. Hamm, 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), Aval du cycle et Energie Nucléaire (ACEN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), 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), Normandie Université (NU), 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), 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), 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), 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), 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), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), and 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)

Subjects
Physics, Nuclear transmutation, 010308 nuclear & particles physics, Fission, Nuclear Theory, Radioactive waste, Neutron radiation, Fusion power, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Linear particle accelerator, Nuclear physics, 0103 physical sciences, Physics::Accelerator Physics, Spallation, Neutron, 010306 general physics, Nuclear Experiment, Computer Science::Operating Systems
Abstract

International audience; The "Neutrons for Science" (NFS) facility will be a component of SPIRAL‐2, the future accelerator dedicated to the production of very intense radioactive ion beams, under construction at GANIL in Caen (France). NFS will be composed of a pulsed neutron beam for in‐flight measurements and irradiation stations for cross‐section measurements and material studies. Continuous and quasi‐monokinetic energy spectra will be available at NFS respectively produced by the interaction of deuteron beam on thick a Be converter and by the 7Li(p,n) reaction on a thin converter. The flux at NFS will be up to 2 orders of magnitude higher than those of other existing time‐of‐flight facilities in the 1 MeV to 40 MeV range. NFS will be a very powerful tool for physics and 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.

Published
2011

15. Neutron-induced cross sections of short-lived nuclei via the surrogate reaction method

Author

G. Barreau, Julien Taieb, L. Mathieu, E. Bauge, L. Gaudefroy, O. Roig, O. Sérot, I. Companis, Jason Burke, C. Theroine, I Matea, S. Czajkowski, G. Boutoux, V. Méot, N. Capellan, X. Derkx, N. Pillet, M. Aïche, L. Tassan-Got, Beatriz Jurado, F. Gunsing, P. Romain, P. Morel, J.M. Daugas, T. Faul, Aval du cycle et Energie Nucléaire (ACEN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), 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), 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), 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), 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), Laboratoire d'Etudes de PHysique (LEPH), Service de Physique des Réacteurs et du Cycle (SPRC), Département Etude des Réacteurs (DER), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département Etude des Réacteurs (DER), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Nuclear reaction, Fission, 020209 energy, QC1-999, Nuclear Theory, 02 engineering and technology, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, Nuclear physics, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, medicine, Neutron, 010306 general physics, Nuclear Experiment, Isotope, Chemistry, Stable isotope ratio, 010308 nuclear & particles physics, Physics, Actinide, medicine.anatomical_structure, Nucleus, Excitation
Abstract

The conference proceedings will be published (on-line) at the EPJ Web of Conferences.; Neutron-induced capture cross sections of short-lived nuclei are of great importance in many areas: fundamental nuclear physics, nuclear astrophysics and nuclear applications, such as nuclear reactors. However, very often the high radioactivity of the samples makes the direct measurement of these cross sections extremely difficult. The surrogate reaction method [1] is an indirect way of determining neutron-induced cross sections for reactions that proceed through a compound nucleus. In this method, the decaying nucleus of the desired reaction is produced via a transfer or an inelastic scattering reaction (figure 1). This technique presents the advantage that the target material can be stable or less radioactive than the material required for a neutron-induced measurement. Nevertheless, a significant question in the use of the surrogate reaction method lies in the difference between the spin and parity population in the neutron-induced and surrogate reactions. The CENBG collaboration has successfully applied this technique to determine the neutron-induced fission cross sections of several short-lived nuclei such as 233Pa[2], 242;243Cm and 241Am[3]. The results are in very good agreement with neutron-induced data. We are currently investigating whether this powerful technique can also be used to determine radiative capture cross sections. For this purpose, we have studied the transfer reactions 174Yb(3He,pg)176Lu and 174Yb(3He,4Heg)173Yb as surrogates for the 175Lu(n,g) and 172Yb(n,g) reactions, respectively. The g probabilities obtained in our experiment show clear discrepancies with already existing neutroninduced data. In this contribution we will present the experimental set-up and the data analysis. Then, we will focus on the origin of these discrepencies. Perspectives for the surrogate method applied to capture cross sections will be discussed.

Published
2011

16. Neutron-induced capture cross sections via the surrogate reaction method

Author

P. Morel, L. Tassan-Got, I. Companis, S. Czajkowski, D. Dassié, C. Theroine, Julien Taieb, Beatriz Jurado, J.T. Burke, V. Méot, J. M. Daugas, E. Bauge, G. Boutoux, B. Haas, N. Pillet, G. Barreau, M. Aïche, F. Gunsing, X. Derkx, Olivier Serot, T. Faul, O. Roig, A. Bail, N. Capellan, L. Mathieu, L. Gaudefroy, 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), 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), 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), T. Granier, B. Laurent, X. Ledoux and J.-G. Marmouget, X. Ledoux, J.-G. Marmouget, 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 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), 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), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Nuclear reaction, Nuclear transmutation, 010308 nuclear & particles physics, Neutron emission, Chemistry, Fission, Physics, QC1-999, Minor actinide, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Charged particle, Nuclear physics, Cross section (physics), 0103 physical sciences, Neutron, Atomic physics, 010306 general physics
Abstract

The full papers will be published in EPJ Web of Conferences.; International audience; The surrogate reaction method is an indirect way of determining cross sections for nuclear reactions that proceed through a compound nucleus. In this method, the compound nucleus is produced via an alternative (surrogate) reaction and its decay (by fission, gamma or neutron emission) is measured in coincidence with the outgoing appropriate charged particle. This technique has enabled neutron-induced cross sections to be extracted for nuclear reactions on short-lived nuclei that otherwise could not be measured. The CENBG collaboration has successfully applied this technique to determine the neutron-induced fission cross sections of several short-lived nuclei such as 233Pa, 242,243Cm and 241Am. These data are very important for the development of the Th/U cycle and for minor actinide transmutation. We currently investigate whether this powerful technique can also be used to determine the neutron-induced capture cross sections. For this purpose we will use the surrogate reaction 174Yb(3He,pγ)176Lu to infer the well known 175Lu(n,γ) cross section and compare the results with the directly measured neutron-induced data. The experimental set-up and the first results will be presented. We will also discuss our future plans to use the surrogate method for extracting actinides (n,γ) cross sections.

Published
2010

17. Sidebands inRa219

Author

F. Riess, J. Chevallier, J. C. Sens, N. Schulz, R. Kulessa, M. Wieland, M. Aïche, Ch. Briançon, E. Ruchowska, J. O. Fernández Niello, and A. Chevallier

Subjects
Baryon, Physics, Nuclear reaction, Nuclear and High Energy Physics, Excited state, Hadron, Elementary particle, Fermion, Atomic physics, Nucleon, Quantum number
Abstract

Excited states in {sup 219}Ra were studied by means of the {sup 208}Pb({sup 14}C, 3{ital n}) reaction at 65 MeV. The investigation was made with 12 Compton-suppressed Ge detectors and a multicounter array. Transitions in {sup 219}Ra were selected by requiring appropriate conditions on fold and sum energy. The proposed level scheme shows two sidebands with alternating parity structure decaying to the ground-state band. It is consistent with a recent description of {sup 219}Ra in the framework of the reflection-asymmetric mean-field approach, which predicts a {ital K}=1/2 ground-state band and two low-lying bands with quantum numbers {ital K}=3/2 and {ital K}=5/2.

Published
1992

18. Hybridized bands and parity splitting in the odd-odd nucleus220Ac

Author

N. Schulz, M. E. Debray, J. Chevallier, J. C. Sens, A. Chevallier, Vito R. Vanin, E. Ruchowska, Ch. Briançon, A. J. Kreiner, and M. Aïche

Subjects
Physics, Nuclear and High Energy Physics, medicine.anatomical_structure, Spin states, Gamma ray, medicine, Nuclear fusion, Parity (physics), Atomic physics, Spectroscopy, Nucleus, Coincidence
Abstract

The high spin state structure of the nucleus220Ac was investigated by means of the209Bi(14C, 3n) reaction. In beamγ ray spectroscopy was carried out using the Château de Cristal multidetector array. Gamma ray multipolarities were established by extracting directional correlation ratios from the Ge—Ge coincidence data and by intensity balance considerations. The level scheme, established up to 18 ħ above the lowest observed state, consists of three alternating parity bands. The data are interpreted in terms of the reflection asymmetric shapes of the nucleus. The analysis of the parity doublet candidates does not show the decrease of the parity splitting predicted for an odd-odd nucleus.

Published
1991

19. Determination of minor-actinides fission cross sections by means of the surrogate reaction method

Author

Ch. Theisen, L. Tassan-Got, S. Czajkowski, John P. Greene, J.N. Wilson, B. Haas, Grégoire Kessedjian, Beatriz Jurado, N. Capellan, R. V. F. Janssens, Adrien Bidaud, L. Audouin, M. Aïche, B. Osmanov, G. Barreau, D. Dassié, L. Mathieu, Olivier Serot, F. Gunsing, E. Berthoumieux, I. Ahmad, and Eric Bauge

Subjects
Nuclear physics, Cross section (physics), Range (particle radiation), Fission, Chemistry, Nuclear Theory, Radiochemistry, Nuclear data, Actinide, Nuclear Experiment, Neutron temperature
Abstract

The surrogate reaction method has been used to determine neutron-induced fission cross sections for the short-lived minor actinides 242,243 Cm and 241 Am. These cross sections are highly relevant for the design of fast reactors capable of incinerating minor actinides. Our results for the fission cross section of 242 Cm extend up to the onset of second-chance fission. None of the existing neutron-induced fission data for 242 Cm go as high in neutron energy. The latest direct neutron-induced measurement for the 243 Cm fission cross section is questioned by our results since there exist differences of more than 60% in the 0.7 to 7 MeV neutron energy range.

Published
2007

21. High-spin states in155Er

Author

N. Nica, G. Duchêne, V. E. Iacob, J. Dudek, F. A. Beck, Th. Byrski, D. Curien, G. de France, B. Haas, B. Kharraja, D. Prévost, C. Petrache, H. Savajols, J. P. Vivien, L. Han, K. Zuber, M. Aïche, M. M. Aléonard, J. F. Chemin, C. W. Beausang, S. Clarke, P. J. Dagnall, M. Smith, P. J. Twin, J. Simpson, and M. A. Bentley

Subjects
Physics, Nuclear and High Energy Physics, Decay scheme, Proton, Spin states, Quadrupole, Order (ring theory), Neutron, Atomic physics, Energy (signal processing), Spin-½
Abstract

The high-spin decay scheme of ${}^{155}\mathrm{Er},$ known previously, has been considerably extended by using the EUROGAM II \ensuremath{\gamma}-ray array. The so-called quasi-isotropic gating data-analysis method, capable of providing spin and parity assignments with triple or quadruple coincidence data has been used. With such coincidence information, we have determined \ensuremath{\gamma}-ray angular distributions, DCO ratios, and linear polarizations for many of the observed transitions. The level scheme is interpreted by using the particle-hole analysis based on the deformed Woods-Saxon potential and the monopole pairing interaction. The results indicate that at $\ensuremath{\sim}12.3$ MeV excitation energy, all nine valence particles around the ${}_{64}^{146}{\mathrm{Gd}}_{82}$ core exhaust the maximum spin of $I=79/2\ensuremath{\Elzxh}.$ At higher spin, relatively high-energy transitions, of the order of $\ensuremath{\sim}1.5$ MeV, related to the breaking of the proton or neutron cores are observed. According to the calculations, this corresponds to an oblate-shape polarization of the nucleus with quadrupole deformation ${\ensuremath{\beta}}_{2}\ensuremath{\sim}\ensuremath{-}0.12.$

Published
2001

22. Search for theIπ=1−state inRa218

Author

J. Chevallier, Ch. Briançon, A. Chevallier, N. Schulz, F. Riess, J. O. Fernández Niello, E. Ruchowska, J. C. Sens, M. Aïche, M. Wieland, and B. von Fromberg

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, State (functional analysis)
Published
1992

23. The DIAMANT electronics and data acquisition system

Author

M Aïche, M.M Aléonard, B Balauge, G Barreau, F Bourgine, D Cabaussel, J.F Chemin, C Diarra, J.P Goudour, M Harston, H Rasolofo, J.N Scheurer, A Brondi, G La Rana, R Moro, E Vardaci, D Curien, 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), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), EUROGAM, M., Aiche, M. M., Aleonard, B., Balauge, M. M., Barreau, B., Bourgine, D., Cabaussel, J. F., Chemin, C., Diarra, J. P., Goudour, M., Harston, H., Rasolofo, J. N., Scheurer, Brondi, Augusto, LA RANA, Giovanni, Moro, RENATA EMILIA MARIA, Vardaci, Emanuele, and D., Curien

Subjects
Physics, Nuclear and High Energy Physics, data acquisition, business.industry, Detector, 32-bit, Modular design, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], light charged particle, DIAMANT, Data acquisition, Electronics, business, Instrumentation, multidetector, Computer hardware, Computer Automated Measurement and Control, VMEbus, Data transmission
Abstract

We describe the electronics and data acquisition system of the 4π light particle multidetector array DIAMANT. This system has been conceived to be very modular with regard to both the kind and number of detectors. The whole system is designed to run either with a few additional ancillary detectors (Ge) or linked to 4π γ arrays such as EUROGAM. Part of the electronics has been designed using SMD devices; the acquisition is based on CAMAC ADCs and VME units for data acquisition, data transfer is handled via a 32 bit ECL bus (DT32) used for EUROGAM. The data acquisition, distributed on a network, is based on the VxWorks Real Time kernel and the UNIX Operating System.

Published
1997

24. Development of an experimental set-up for the measurement of neutron-induced fission and capture cross sections of radioactive fissile nuclei

Author

G. Barreau, P. Schillebeeckx, S. Czajkowski, I. Tsekhanovich, F. Gunsing, Beatriz Jurado, A.J.M. Plompen, I. Companis, M. Aïche, L. Mathieu, J. Matarranz, Grégoire Kessedjian, J. Heyse, Q. Ducasse, Aval du cycle et Energie Nucléaire (ACEN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Range (particle radiation), [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Fissile material, 010308 nuclear & particles physics, Fission, QC1-999, 020209 energy, Detector, 02 engineering and technology, Scintillator, 01 natural sciences, Linear particle accelerator, Nuclear physics, 0103 physical sciences, Ionization chamber, 0202 electrical engineering, electronic engineering, information engineering, Neutron, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS
Abstract

A new experimental set-up for a simultaneous measurement of neutron induced capture and fission cross sections was designed, assembled and optimized. The measurements will be performed at GEel LINear Accelerator (GELINA) neutron time-of-flight facility in Belgium, where neutron cross sections can be measured over a wide energy range with high energy resolution. The fission events detector consists of a dedicated multi-plate high efficiency fission ionization chamber (IC). The γ-rays produced in capture reaction are detected by an efficient array of C6D6 scintillators. Fission γ-rays events are distinguished from capture events by the anticoincidence signals from the IC and the C6D6 detectors. For the undetected fission events a correction has to be applied with respect to the efficiency of the IC that should be high and known with a high precision. Another important issue is the good separation between fission-fragment (FF) and the high alpha pile-up. The performances of the IC during test experiments are presented, focusing in particular on the detection efficiency.

Published
2013

25. Measurement of neutron capture and fission cross sections of233U in the resonance region

Author

G. Boutoux, I. Companis, S. Czajkowski, L. Mathieu, I. Tsekhanovich, Beatriz Jurado, G. Barreau, V. Simutkin, B. Haas, M. Aïche, A.J.M. Plompen, Grégoire Kessedjian, P. Schillebeeckx, Aval du cycle et Energie Nucléaire (ACEN), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), and Vernay, Emmanuelle

Subjects
[PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], 010308 nuclear & particles physics, Fission, Chemistry, Physics, QC1-999, Nuclear Theory, Detector, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Resonance (particle physics), Nuclear physics, Neutron capture, 0103 physical sciences, Ionization chamber, Neutron cross section, Neutron, Nuclear Experiment, 010306 general physics
Abstract

In the framework of studies concerning new fuel cycles and nuclear wastes incineration experimental data of the α ratio between capture and fission cross sections of 233 U reactions play an important role in the Th/U cycle. The safety evaluation and the detailed performance assessment for the generation IV nuclear-energy system based on 232 Th cycle strongly depend on this ratio. Since the current data are scarce and sometimes contradictory, new experimental studies are required. The measurement will take place at the neutron time-of-flight facility GELINA at Geel, designed to perform neutron cross section measurements with high incident neutron-energy resolution. A dedicated high efficiency fission ionization chamber (IC) as fission fragment detector and six C6 D6 liquid scintilators sensitive to γ-rays and neutrons will be used. The method, based on the IC energy response study, allowing to distinguish between gammas originating from fission and capture, in the resonance region, will be presented.

Published
2012

26. High-spin spectroscopy of the reflection-asymmetric nucleus $^{221}$Ac

Author

R. Kulessa, F. Riess, J. Chevallier, Ch. Briançon, J.S. Dionisio, M. Wieland, E. Lubkiewicz, J. C. Sens, A. Seghour, Ch. Vieu, C. Mittag, M. Aïche, J. O. Fernández Niello, E. Ruchowska, A. Chevallier, N. Schulz, M. Bentaleb, Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Parity (physics), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 3. Good health, State structure, medicine.anatomical_structure, 0103 physical sciences, medicine, Atomic physics, 010306 general physics, Spectroscopy, Nucleus
Abstract

The high-spin state structure of the nucleus 221 Ac was investigated by means of the 209 Bi( 14 C, 2n) reaction at 63 and 65 MeV. Measurements consisted of in-beam γγ coincidences using the Château de Cristal multidetector array and of e − γ coincidences. Two alternating parity bands could be established in 221 Ac up to spin 35 2 h . Almost all of the states may be regrouped into parity doublets and the origin of these doublets is discussed.

Published
1994

27. Alternating parity bands in doubly odd $^{218}_{129}$Ac and octupole instability in the light actinide region

Author

J. Chevallier, M. Davidson, M. Aïche, N. Schulz, J. C. Sens, Daniel Hojman, A. J. Kreiner, Diego Martinez Santos, Vito R. Vanin, A. Chevallier, M. E. Debray, J. Davidson, Institut de Recherches Subatomiques (IReS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Isotone, Parity (physics), Actinide, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Electron spectroscopy, Instability, 3. Good health, 0103 physical sciences, Atomic physics, 010306 general physics
Abstract

High-spin states of doubly odd 218 Ac1 129 have been investigated using in-beam α, γ and conversion electron spectroscopy techniques through the 209 Bi( 12(13) C,3(4)n) fusion-evaporation reactions. The level scheme of 218 Ac shows three interconnected, alternating parity structures, each one linked by strong El transitions. Two of these bands are strikingly similar to the known scheme of the isotone 217 Ra and this analogy is shown to persist for the pair 220 Ac, 219 Ra. The relation between the structure of 218 Ac and its neighbors is thoroughly discussed showing that the first signals of octupole collectivity appear for N = 129.

Published
1994

28. Observation of parity doublets in the odd-odd nucleus $^{220}$Ac

Author

J. C. Sens, A. Chevallier, M. E. Debray, J. Chevallier, M. Aïche, E. Ruchowska, N. Schulz, A. J. Kreiner, Vito R. Vanin, Ch. Briançon, Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université 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 Lorgeril, Jocelyne

Subjects
Physics, Nuclear and High Energy Physics, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], 010308 nuclear & particles physics, Gamma ray, Elementary particle, Parity (physics), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear shape, 3. Good health, medicine.anatomical_structure, Excited state, 0103 physical sciences, medicine, Nuclear fusion, Atomic physics, 010306 general physics, Nucleus
Abstract

Excited states of220Ac have been investigated by means of the209Bi(14C,3n) reaction and using the “Château de Cristal” gamma ray facility. The observation of bands with alternating parity states reveals the reflection asymmetric nuclear shape of220Ac. The extracted B(E1)/B(E2) ratios display a clear spin dependence.

Published
1990

29. New results on the superdeformed band in192Hg

Author

J. Simpson, M. Aïche, A. Korichi, T. Lauritsen, C. Schück, T. L. Khoo, R. G. Henry, F. Hannachi, E. S. Paul, M. P. Carpenter, J.F. Sharpey-Schafer, I. Deloncle, R. V. F. Janssens, Y. Le Coz, Marco Meyer, C. W. Beausang, N. Poffé, Josette Duprat, F. Azaiez, G. Bastin, R. Béraud, N. Redon, A. G. Smith, K. Hauschild, N. Perrin, M. G. Porquet, R. M. Clark, M. Kaci, H. Sergolle, R. Duffait, P. Willsau, R. Wadsworth, I. Ahmad, C. Bourgeois, Malcolm J. Joyce, and B. J. P. Gall

Subjects
Baryon, Nuclear reaction, Physics, Nuclear and High Energy Physics, Excited state, Nuclear Theory, Hadron, Nuclear structure, Atomic physics, Moment of inertia, Nuclear Experiment, Nucleon, Spectral line
Abstract

New results on the192Hg superdeformed band have been obtained with EUROGAM. The experiment has been performed with the160Gd(36S,4n) reaction at 159 MeV. Above 800 keV the γ-ray energies differ from the previously published ones. Thus the rise of the dynamical moment of inertia\(\mathfrak{F}^{(2)} \) above ħω=0.4 MeV is no longer observed. This is in better agreement with recent cranked Hartree-Fock-Bogoliubov calculations.

Published
1994

30. First observation of a superdeformed nucleus produced in an α xn reaction channel

Author

J. Simpson, Malcolm J. Joyce, F. Hannachi, I. Deloncle, B. J. P. Gall, E. S. Paul, N. Perrin, F. Azaiez, R. Béraud, G. Bastin, K. Hauschild, N. Poffé, Y. Le Coz, Marco Meyer, H. Hübel, A. Korichi, R. M. Clark, C. W. Beausang, N. Redon, M. G. Porquet, J.F. Sharpey-Schafer, M. Kaci, C. Schück, H. Sergolle, Josette Duprat, R. Duffait, R. Wadsworth, A. G. Smith, M. Aïche, and C. Bourgeois

Subjects
Physics, Nuclear and High Energy Physics, education.field_of_study, Yrast, Population, Coincidence, medicine.anatomical_structure, medicine, Nuclear fusion, Channel (broadcasting), Atomic physics, education, Beam energy, Nucleus
Abstract

Recent data from the EUROGAM array have revealed the population of the yrast superdeformed (SD) band of192Hg in the α4n exit channel of the16O+184W reaction at 113 MeV beam energy. The nucleus assignment was made on the basis of the SD band transition energies, and the observation of characteristic X-rays and lowlying yrast γ-transition of192Hg in coincidence with the SD band γ-rays. Both the feeding and decay-out patterns of the observed SD band have been found similar to the ones previously measured in the (36S,4n) reaction.

Published
1994

31. Persisting domination of the octupole over the quadrupole degrees of freedom and the new type of transitional nuclei: High-spin behavior ofRa218

Author

J. Fernandez-Niello, Ch. Briançon, A. Chevallier, E. Ruchowska, C. Mittag, J. Dudek, S. Cwiok, J. Chevallier, N. Schulz, M. Aïche, J. C. Sens, and Vito R. Vanin

Subjects
Nuclear reaction, Physics, Angular momentum, Branching fraction, Quadrupole, General Physics and Astronomy, Charge density, Parity (physics), Atomic physics, Lambda, Intrinsic parity
Abstract

High-spin states up to I${=31}^{\mathrm{\ensuremath{-}}}$ have been studied in the $^{218}\mathrm{Ra}$ nucleus and the staggering sequence of levels of positive and negative parity persists up to highest level. This observation supports the idea that in some nuclei the high-spin excitations may primarily be dominated by deformations which do not conserve the intrinsic parity (such as octupole, \ensuremath{\lambda}=3, and higher odd-\ensuremath{\lambda} multipolarities) rather than by the ``usual'' quadrupole (\ensuremath{\lambda}=2) and possibly higher even-\ensuremath{\lambda} multipolarities.

Published
1989

32. Yrast states of217Fr and the onset of static intrinsic reflection asymmetric shapes in the light actinide region

Author

A Chevallier, S. Hulne, J. C. Sens, S. Khazrouni, N Schulz, J Chevallier, and M. Aïche

Subjects
Physics, Strongly coupled, Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, Yrast, Nuclear Theory, General Physics and Astronomy, Parity (physics), Actinide, Atomic physics, Nuclear Experiment, Excitation, Ion
Abstract

Yrast states in 217Fr have been populated by bombardment of a 210Pb radioactive target with 11B ions at energies in the range 52-68 MeV. Measurements of gamma -ray excitation functions, gamma -ray angular distributions and gamma - gamma coincidences were made. The proposed level spectrum exhibits at medium angular momenta alternating positive and negative parity levels strongly coupled by E1 transitions. A survey of the neighbouring nuclei leads to the conclusion that in the actinide region 217Fr and 217Ra are the lightest nuclei presenting properties which are generally related to static intrinsic reflection asymmetric shapes.

Published
1988

33. Neutron-induced fission cross sections of short-lived actinides with the surrogate reaction method

Author

J.N. Wilson, N. Capellan, S. Czajkowski, L. Mathieu, Beatriz Jurado, F. Gunsing, E. Berthoumieux, R. V. F. Janssens, L. Audouin, John P. Greene, Adrien Bidaud, I. Ahmad, G. Barreau, Ch. Theisen, L. Tassan-Got, B. Haas, M. Aïche, Olivier Serot, Grégoire Kessedjian, D. Dassié, E. Bauge, 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), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), 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), 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), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Surrogate reaction method, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Fission, Nuclear Theory, Actinide, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, neutron-induced fission cross sections, 0103 physical sciences, Neutron, Fission neutron, 010306 general physics, Nuclear Experiment, Excitation
Abstract

Neutron-induced fission cross sections for 242,243 Cm and 241 Am have been obtained with the surrogate reaction method. Recent results for the neutron-induced cross section of 243 Cm are questioned by the present data. For the first time, the 242 Cm cross section has been determined up to the onset of second-chance fission. The good agreement at the lowest excitation energies between the present results and the existing neutron-induced data indicates that the distributions in spin and parity of states populated with both techniques are similar.

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34. Dipole-octupole correlations in a boson model and evidence for their existence in nuclei

Author

I N Mikhailov, Ch. Briançon, N. Schulz, V Vanin, M. Aïche, E. Nadjakov, Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Dipole, Particle physics, 010308 nuclear & particles physics, Yrast, 0103 physical sciences, Parity (physics), Interacting boson model, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 01 natural sciences, Boson
Abstract

The interacting multiboson model (IMBM) introduced earlier (1987), in its spdf boson case, is applied to a new experiment on the vibrational nucleus88218Ra130. It is shown to describe in a natural way, with the essential participation of pf bosons, both the ground yrast bands with positive and negative parity, and the peculiar side yrare bands with the same space pi and opposite spin (-)I parity. So this experiment together with its boson interpretation can be viewed as evidence for the existence of combined dipole-octupole correlations in nuclei.

Published
1989

35. The yrast superdeformed band in $^{194}$Pb. Differences with $^{192}$Hg

Author

A. Korichi, M. Kaci, H. Sergolle, R. M. Clark, Josette Duprat, E. S. Paul, H. Hübel, J. Simpson, A. G. Smith, Y. Le Coz, R. Wadsworth, Marco Meyer, R. Béraud, C. W. Beausang, G. Bastin, N. Poffé, K. Hauschild, Malcolm J. Joyce, M. G. Porquet, F. Hannachi, J.F. Sharpey-Schafer, B. J. P. Gall, C. Schück, M. Aïche, R. Duffait, C. Bourgeois, I. Deloncle, N. Perrin, F. Azaiez, N. Redon, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Physique Nucléaire d'Orsay (IPNO), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, Yrast, 0103 physical sciences, Potential energy surface, Low frequency, Atomic physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 01 natural sciences, Spin-½
Abstract

The yrast superdeformed (SD) structure of 194Pb has been studied using the EUROGAM γ-ray spectrometer. New results have been obtained at low as well as at high spin values. At low frequency, the SD band has been extended to the lowest-spin SD state ever observed in the A ∼ 190 region. The energies of 194Pb and 192Hg SD bands are identical for ω < 0.25 MeV. However, they diverge for higher frequency, which rules out the idea that these two SD bands are identical. Moreover, the SD band of 194Pb is populated at lower spin values than that of 192Hg and de-excites towards normally-deformed (ND) states at a spin value lower than that of 192Hg. This suggests that the barrier separating the SD and ND minima in the potential energy surface is higher in 194Pb than in 192Hg.

36. D+D fusion reactions in 1018 W/cm2 intensity and repetitive laser-plasma interactions.

Author

D. Giulietti, G. Boutoux, M. Aïche, G. Andrianaki, D. Batani, F. Burgy, M. Cipriani, F. Consoli, R. De Angelis, J. E. Ducret, S. Hulin, A. Jardin, F. Ingenito, K. Jakubowska, L. Mathieu, D. Mazon, A. Nguyen, C. Pejot, A. Solheilhac, and C. Verona

Abstract

We studied D + D fusion reactions at the CELIA/ECLIPSE laser facility. These reactions were triggered by focusing the ECLIPSE laser (up to 100 mJ on target, pulse duration of 40 fs and focal spot of FWHM) on a solid C2D4 target. By detecting the 2.5 MeV neutrons, produced in the D + D fusion reaction, using C6D6 scintillators in a time-of-flight experimental set-up, we measured a rate of a few hundred fusions per shot. At the same time, we detected also energetic ions (up to a few 100 keV) using time-of-flight diamond detectors. The experimental set-up will be presented and the results discussed and compared with dedicated simulations. [ABSTRACT FROM AUTHOR]

Published
2017
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37. Mesure de la section efficace de fission induite par neutrons rapides des noyaux 232Th / 233U dans le cadre des cycles de combustiblesinnovants

Author

GROSJEAN, Cédric, Mas, Virginie, Gérard BARREAU, J. Labarsouque, professeur, Université de Bordeaux 1 Président, M. Aïche, maître de conférence, Université de Bordeaux 1 Rapporteur, G. Barreau, Directeur de recherche CNRS, CENBG Examinateurs, T. Ethvignot, physicien chercheur, CEA/DAM île de France, E. Liatard, professeur, Université Joseph Fourier de Grenoble, and G. Rudolf, directeur de recherche CNRS, IRES de Strasbourg

Subjects
2n), [PHYS.NUCL] Physics [physics]/Nuclear Theory [nucl-th], Fission, diffusion inélastique, 233U(n, 234U, 233U, Nucléaire, p), Neutron, Mesures, Réacteurs, Sections efficaces, Diffusion élastique (n, Noyaux, capture radiative, Atomes, Modèle statistique, Hauser- Feshbach, Cycle du thorium, Combustible, 232Th, Agrégats et Plasmas
Abstract

The thorium- 233U fuel cycle might provided safer and cleaner nuclear energy than the present Uranium/ Pu fuelled reactors. Over the last 10 years, a vast campaign of measurements has been initiated to bring the precision of neutron data for the key nuclei (232Th, 233Pa and 233U) at the level of those of the U- Pu cycle. This is the framework of these measurements, the energy dependent neutron induced fission cross section of 232Th and 233U has been measured from 1 to 7 MeV with a target accuracy lesser than 5 %. These measurements imply the accurate determination of the fission rate, the number of the target nuclei as well as the incident neutron flux impinging on the target, the latter has been obtained using the elastic scattering (n, p). The cross section of which is the very well known in a large neutron energy domain (~ 0,5 % from 1 eV to 50 MeV) compared to the 235U(n, f) reaction. This technique has been applied for the first time to the 232Th(n, f) and 233U(n, f) cases. A Hauser- Feshbach statistical model has been developed. It consists of describing the different decay channels of the compound nucleus 234U from 0,01 to 10 MeV neutron energy. The parameters of this model were adjusted in order to reproduce the measured fission cross section of 233U. From these parameters, the cross sections from the following reactions could be extracted: inelastic scattering 233U(n, n'), radiative capture 233U(n, γ) and 233U(n, 2n). These cross sections are still difficult to measure by direct neutron reactions. The calculated values allow to fill the lack of experimental data for the major fissile nucleus of the thorium cycle., Le cycle du thorium (232Th/233U) présente des caractéristiques moins polluantes que celui utilisé actuellement dans les combustibles des réacteurs nucléaires (U/Pu). Depuis une dizaine d'années, il fait l'objet d'un vaste programme de mesures dont l'objectif est d'atteindre une précision des données neutroniques des noyaux clés du cycle (232Th, 233Pa et 233U) comparable à celles du cycle U/Pu. Ce travail s'inscrit dans ce cadre d'études et consiste à mesurer les sections efficaces de fission induites par neutrons rapides (de 1 à 7 MeV) des noyaux 232Th et 233U avec une incertitude inférieure à 5 %. Ces mesures impliquent de déterminer le taux de fission émis par la cible, le nombre d'atomes composant la cible et le flux de neutrons arrivant sur celle-ci. Cette dernière quantité a été obtenue en utilisant comme réaction de référence, la diffusion élastique (n, p) dont la section efficace est la mieux connue sur un large domaine en énergie de neutron (~ 0,5 % de 1 eV à 50 MeV) comparée à celle de la réaction 235U(n, f). Cette technique a été appliquée pour la première fois à ces deux noyaux. Un modèle statistique de type Hauser- Feshbach a été également développé dans ce travail. Il a permis de décrire les différentes voies de désexcitation du noyau composé 234U pour des énergies de neutron de 0,01 à 10 MeV. Les paramètres de ce modèle ont été ajustés afin de reproduire la section efficace de fission mesurée de 233U. A partir de ces paramètres, les sections efficaces des réactions suivantes ont pu être extraites : diffusion inélastique 233U(n, n'), capture radiative 233U(n, γ) et 233U(n, 2n). Ces sections efficaces évaluées, dont les mesures sont encore difficilement réalisables, permettent de combler le manque de données expérimentales concernant 233U, le noyau fissile de la filière thorium.

Published
2005

38. Simultaneous Determination of Neutron-Induced Fission and Radiative Capture Cross Sections from Decay Probabilities Obtained with a Surrogate Reaction.

Author

Pérez Sánchez R, Jurado B, Méot V, Roig O, Dupuis M, Bouland O, Denis-Petit D, Marini P, Mathieu L, Tsekhanovich I, Aïche M, Audouin L, Cannes C, Czajkowski S, Delpech S, Görgen A, Guttormsen M, Henriques A, Kessedjian G, Nishio K, Ramos D, Siem S, and Zeiser F

Abstract

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

Published
2020
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39. 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 MO, Grinyer J, Guillous S, Gunsing F, Gustavsson C, Henning G, Jacquot B, Jansson K, Jurado B, Kerveno M, Klix A, Landoas O, Lecolley FR, Lecouey JL, Majerle M, Marie N, Materna T, Mrázek J, Novák J, Oberstedt S, Oberstedt A, Panebianco S, Perrot L, Plompen AJM, Pomp S, Prokofiev AV, Ramillon JM, Farget F, Ridikas D, Rossé B, Serot O, Simakov SP, Šimecková E, Stanoiu M, Štefánik M, Sublet JC, Taïeb J, Tarrío D, Tassan-Got L, Thfoin I, and Varignon C

Subjects
Computer Simulation, Radiation Dosage, Deuterium analysis, Equipment Design, Lithium chemistry, Neutrons, Particle Accelerators instrumentation, Protons
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.

Published
2018
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42. Sidebands in 219Ra.

Author

Wieland M, Fernández Niello J, Riess F, Aïche M, Chevallier A, Chevallier J, Schulz N, Sens JC, Briançon C, Kulessa R, and Ruchowska E

Published
1992
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