Author: "M.-G. Porquet" / Topic: physics - Searchworks@Jio Institute Digital Library Search Results

1. Backbending in the pear-shaped Th90223 nucleus: Evidence of a high-spin octupole to quadrupole shape transition in the actinides

Author: M. G. Porquet, Sanna Stolze, Panu Rahkila, Jan Sarén, A. Astier, Paul Greenlees, M. Rousseau, D. Guinet, L. Augey, Panu Ruotsalainen, G. Duchêne, Mikael Sandzelius, A. Lopez-Martens, Paivi Nieminen, D. Curien, Rauno Julin, C. Ducoin, Ulrika Jakobsson, Andrej Herzan, O. Dorvaux, Tuomas Grahn, K. Hauschild, Pauli Peura, Peter B. Jones, F. Azaiez, O. Stezowski, Juha Uusitalo, S. Courtin, G. Maquart, Sami Rinta-Antila, J. Dudouet, Matti Leino, L. Chaix, B. J. P. Gall, A. Vancraeyenest, G. Lehaut, Steffen Ketelhut, N. Redon, Catherine Scholey, I. Deloncle, Juha Sorri, P. Petkov, I. Companis, C. Mancuso, and Sakari Juutinen
Subjects: Physics, Spins, 010308 nuclear & particles physics, Yrast, Nuclear Theory, Actinide, 01 natural sciences, medicine.anatomical_structure, 0103 physical sciences, Quadrupole, medicine, Level structure, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleus, Isotopes of thorium, Spin-½
Abstract: Relatively neutron-rich thorium isotopes lie at the heart of a nuclear region of nuclei exhibiting octupole correlation effects. The detailed level structure of Th223 has been investigated in measurements of γ radiation following the fusion-evaporation channel of the Pb208(O18,3n)Th223 reaction at 85 MeV beam energy. The level structure has been extended up to spin 49/2, and 33 new γ rays have been added using triple-γ coincidence data. The spins and parities of the newly observed states have been confirmed by angular distribution ratios. In addition to the two known yrast bands based on a K=5/2 configuration, a non-yrast band has been established up to spin 35/2. We interpret this new structure as based on the same configuration as the yrast band in Th221 having dominant K=1/2 contribution. At the highest spin a backbending occurs around a rotational frequency of ℏω=0.23 MeV, very close to the one predicted in Th222, where a sharp transition to a reflection-symmetric shape is expected.
Published: 2017
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2. Nuclear magic numbers: New features far from stability

Author: O. Sorlin, M.-G. Porquet, 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 de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), 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 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), 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 and High Energy Physics, Nuclear Theory, Shell (structure), Stability (learning theory), FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Theoretical physics, Magic number (programming), Bounding overwatch, 0103 physical sciences, Isotonic, Nuclear structure, Tensor, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, nuclear spectroscopy, Physics, 010308 nuclear & particles physics, shell closures, single-particle states, exotic nuclei, magic numbers, Atomic nucleus, Nucleon
Abstract: The main purpose of the present manuscript is to review the structural evolution along the isotonic and isotopic chains around the "traditional" magic numbers 8; 20; 28; 50; 82 and 126. The exotic regions of the chart of nuclides have been explored during the three last decades. Then the postulate of permanent magic numbers was de nitely abandoned and the reason for these structural mutations has been in turn searched for. General trends in the evolution of shell closures are discussed using complementary experimental information, such as the binding energies of the orbits bounding the shell gaps, the trends of the rst collective states of the even-even semi-magic nuclei, and the behavior of certain single-nucleon states. Each section is devoted to a particular magic number. It describes the underlying physics of the shell evolution which is not yet fully understood and indicates future experimental and theoretical challenges. The nuclear mean eld embodies various facets of the Nucleon- Nucleon interaction, among which the spin-orbit and tensor terms play decisive roles in the shell evolutions. The present review intends to provide experimental constraints to be used for the re nement of theoretical models aiming at a good description of the existing atomic nuclei and at more accurate predictions of hitherto unreachable systems., to be published in Prog. Part. Nucl. Phys
Published: 2008
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3. A new high-spin level scheme for 149Nd from a fusion-fission reaction

Author: John Durell, M. G. Porquet, Ch. Theisen, Ts. Venkova, M. Houry, R. Lucas, and A. Roach
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, Isotope, Excited state, Yrast, Hadron, Nuclear fusion, Atomic physics, Spin (physics), Spectral line
Abstract: A new high-spin level scheme of 149Nd has been identified, which is at variance with the one previously published. The states have been populated in the 12C + 238U fusion-fission reaction at 90MeV bombarding energy and the emitted I³-transitions were detected using the Euroball III array. The yrast band is built on the I½i13/2 sub-shell as in the neighbouring isotones. Moreover, sign of octupole vibrations has been found in 149Nd, as well as in 147Ce, where several new states decaying to the yrast band have been newly observed.
Published: 2006
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4. Magnetic dipole bands in : first evidence of excitations across the Z=82 sub-shell in Hg nuclei

Author: F. Hannachi, B. Crowell, A. Korichi, R. V. F. Janssens, T. Lauritsen, F. Azaiez, J.F. Sharpey-Schafer, M. G. Porquet, M. Bergstrom, József Tímár, H. Hübel, I. Ahmad, Nadine Redon, M. P. Carpenter, D. J. Blumenthal, B. J. P. Gall, J.N. Wilson, Ingemar Ragnarsson, R. Wadsworth, A. Lopez-Martens, Anna Wilson, Matthias Meyer, E. S. Paul, D. T. Nisius, Laurent Ducroux, T. L. Khoo, and A. Astier
Subjects: Physics, Nuclear and High Energy Physics, Dipole, Isotope, Proton, Excited state, Potential energy surface, Atomic physics, Spin (physics), Magnetic dipole, Excitation
Abstract: An experiment aimed at studying high-spin states in 190 Hg was performed with the Eurogam II array. The data have revealed the presence of cascades of magnetic dipole transitions with some unexpected properties. Unlike the M1 bands previously observed in the heavier Hg isotopes, these structures have extremely large B(M1)/B(E2) ratios. The observation of a third dipole band with much lower B(M1)/B(E2) values in the same spin/excitation energy regime suggests that the bands may represent configurations occurring in different minima in the potential energy surface. Configuration-dependent Cranked Nilsson–Strutinsky calculations predict the presence of a minimum in the nuclear potential energy surface at a deformation of e≈0.2, γ≈−90°, occurring when a proton is excited across the Z=82 shell-gap into an h9/2 orbital. It is suggested that the bands exhibiting anomalously large B(M1)/B(E2) ratios may be associated with this minimum.
Published: 2001
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5. γ-ray Spectroscopy of Proton Drip-Line Nuclei in the A∼130 Region using SPIRAL beams

Author: O. Stézowski, D. Guinet, Ph. Lautesse, M. Meyer, N. Redon, B. Rossé, Ch. Schmitt, P. J. Nolan, A. J. Boston, R. Cooper, M. Dimmock, S. Gros, B. McGuirck, E. S. Paul, M. Petri, H. Scraggs, G. Turk, G. De France, S. Bhattachasyya, G. Mukherjee, F. Rejmund, M. Rejmund, H. Savajols, J. N. Scheurer, B. M. Nyakó, J. Gál, J. Molnár, J. Timár, L. Zolnai, A. Astier, I. Deloncle, M. G. Porquet, A. Prévost, K. Juhasz, R. Wadsworth, P. Joshi, G. La Rana, R. Moro, M. Trotta, E. Vardaci, G. Hackman, G. Ball, Ismail Boztosun, A. B. Balantekin, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), 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), 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), I. Boztosun, A.B. Balantekin, SPIRAL, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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 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), O., Stezowski, D., Guinet, Lautesse, P. h., M., Meyer, N., Redon, B., Rosse, Schmitt, C. h., P. J., Nolan, A. J., Boston, R., Cooper, M., Dimmock, S., Gro, B., Mcguirck, E. S., Paul, M., Petri, H., Scragg, G., Turk, G., De France, S., Bhattachasyya, G., Mukherjee, F., Rejmund, M., Rejmund, H., Savajol, J. N., Scheurer, B. M., Nyako, J., Gal, J., Molnar, J., Timar, L., Zolnai, A., Astier, I., Deloncle, M. G., Porquet, A., Prevost, K., Juhasz, R., Wadsworth, P., Joshi, LA RANA, Giovanni, Moro, RENATA EMILIA MARIA, M., Trotta, Vardaci, Emanuele, G., Hackman, and G., Ball
Subjects: Physics, Spectrometer, Proton, DRIP LINE, 010308 nuclear & particles physics, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Charged particle, Properties of nuclei, nuclear energy level, Nuclear physics, 0103 physical sciences, Gamma spectroscopy, X- and γ-ray spectroscopy, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy, Nucleon, Beam (structure)
Abstract: Expérience GANIL; International audience; A fusion-evaporation experiment has been performed with a SPIRAL 76Kr radioactive beam in order to study the deformation of rare-earth nuclei near the proton drip-line. The experimental setup consisted in the EXOGAM gamma-array, coupled to the light-charged particles (LCP) DIAMANT detector and to the VAMOS heavy-ion spectrometer. The difficulties inherent to such measurements are enlightened. The coupling between EXOGAM and DIAMANT has been used to decrease the huge background caused by the radioactivity of the beam. It further permits assigning new gamma-ray transitions to specific residual nuclei. A gamma-ray belonging to the 130Pm level scheme has thus been observed for the first time.
Published: 2008
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6. Recent developments of multi e-γ spectrometers

Author: Jean Vanhorenbeeck, John Durell, B. J. Varley, Matthew Jones, Ch. Vieu, T. Rzaca-Urban, A. Minkova, W.R. Phillips, S.J. Dorning, C. Schück, E.B. Kharraja, P.G. Dagnall, E. Gueorguieva, M. Kaci, M. G. Porquet, J. C. S. Bacelar, J.S. Dionisio, Th. Venkova, Michèle Pautrat, A. Passoja, J.M. Lagrange, H. Folger, A. G. Smith, and W. Urban
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Spectrometer, Nuclear spectroscopy, Background suppression, Detector, Electron, Instrumentation, Selection (genetic algorithm), Coincidence
Abstract: A brief introductory survey of gamma-ray detector arrays and in-beam electron spectrometers developed during the last three lustra is followed by a broad discussion of the general requirements for single and multiple in-beam e-gamma spectrometers. A detailed analysis is made of a few important tools for reducing the low-energy electron background (i.e. simultaneous E-Bp selection, true and random coincidence rates, EM static fields around the target region). This survey and discussion are illustrated by the results of several in-beam e-gamma measurements dealing with nuclear spectroscogic investigations of a few medium and heavy nuclei. (C) 1999 Elsevier Science B.V. All rights reserved.
Published: 1999
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7. γ‐Spectroscopy and Radioactive Beams : How To Perform Channel Selection ?

Author: B. Rossé, N. Redon, O. Stézowski, C.h. Schmitt, D. Guinet, M. Meyer, P.h. Lautesse, P. J. Nolan, A. J. Boston, R. Cooper, M. Dimmock, S. Gros, B. McGuirck, E. S. Paul, M. Petri, H. Scraggs, G. Turk, G. De France, S. Bhattachasyya, G. Mukherjee, F. Rejmund, M. Rejmund, H. Savajols, J. N. Scheurer, A. Astier, I. Deloncle, M. G. Porquet, A. Prévost, B. M. Nyakó, J. Gál, J. Molnár, J. Timár, L. Zolnai, K. Juhasz, R. Wadsworth, P. Joshi, LA RANA, GIOVANNI, MORO, RENATA EMILIA MARIA, M. Trotta, VARDACI, EMANUELE, G. Hackman, G. Ball, B., Rossé, N., Redon, O., Stézowski, Schmitt, C. h., D., Guinet, M., Meyer, Lautesse, P. h., P. J., Nolan, A. J., Boston, R., Cooper, M., Dimmock, S., Gro, B., Mcguirck, E. S., Paul, M., Petri, H., Scragg, G., Turk, G., De France, S., Bhattachasyya, G., Mukherjee, F., Rejmund, M., Rejmund, H., Savajol, J. N., Scheurer, A., Astier, I., Deloncle, M. G., Porquet, A., Prévost, B. M., Nyakó, J., Gál, J., Molnár, J., Timár, L., Zolnai, K., Juhasz, R., Wadsworth, P., Joshi, LA RANA, Giovanni, Moro, RENATA EMILIA MARIA, M., Trotta, Vardaci, Emanuele, G., Hackman, G., Ball, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), 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), 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), S.V. Harissopulos, P. Demetriou, E. Julin, SPIRAL, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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 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, 29.30.Kv, 29.25.Rm, radioactive ion beam, Proton, Spectrometer, Channel (digital image), 010308 nuclear & particles physics, Detector, Nuclear Theory, Particle accelerator, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, law.invention, Nuclear physics, gamma-ray spectroscopy, law, 0103 physical sciences, Physics::Accelerator Physics, Gamma spectroscopy, sources of radioactive nuclei, 010306 general physics, Spectroscopy, Nuclear Experiment, radioactive ion beams, Beam (structure)
Abstract: International audience; An experiment has been performed using a SPIRAL $^{76}$Kr radioactive beam at GANIL to investigate rare-earth nuclei near the proton drip-line. The EXOGAM gamma array was coupled with the DIAMANT light charged-particle detector and the VAMOS spectrometer. We report here on the powerful of this setup to extract fusion-evaporation $\gamma$-rays from a large beam contamination.
Published: 2005
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8. Intrinsic proton states around the superdeformed shell closureZ=80

Author: Y. Le Coz, M. Meyer, J.F. Sharpey-Schafer, S. Bouneau, Christian Bourgeois, János Timár, Faiçal Azaiez, M. Kaci, H. Sergolle, N. Redon, Paul-Henri Heenen, Laurent Ducroux, M. Bergström, M. A. Riley, Isabelle Deloncle, B. J. P. Gall, Ramon Wyss, E. S. Paul, Josette Duprat, M. G. Porquet, Anna Wilson, and Alain Astier
Subjects: Physics, Nuclear and High Energy Physics, Proton, Spin states, Atomic orbital, Closure (mathematics), Shell (structure), Moment of inertia, Atomic physics, Spectroscopy, Signature (topology)
Abstract: High spin states in ${}^{193}\mathrm{Tl}$ have been populated by the ${}^{181}\mathrm{Ta}{(}^{16}\mathrm{O},6n)$ reaction at 110 MeV and \ensuremath{\gamma}-ray spectroscopy was performed using the EUROGAM II array. In addition to the two known superdeformed (SD) bands, three new superdeformed bands have been identified. The dynamic moments of inertia of two of these new bands display a sudden and opposite change of slope and two of them have identical transition energies within 2 keV. The behavior of their dynamic moments of inertia and their \ensuremath{\gamma} transitions allowed us to propose configurations for the proton orbitals involved around the SD shell closure $Z=80.$ The intrinsic proton states identified are the two signature partners of the $[411]1/2$ and the negative signature of the $[651]1/2$ orbitals. Their properties are compared to the predictions of two theoretical calculations.
Published: 1998
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9. Neutronh11/2band structures of109,111Pdobserved in heavy-ion induced fission

Author: H. Sergolle, N. Schulz, R. Lucas, Josette Duprat, F. Hoellinger, I. Deloncle, F. Azaiez, T. Kutsarova, M. G. Porquet, Ts. Venkova, B. J. P. Gall, C. Gautherin, E. Gueorguieva, S. Bouneau, A. Minkova, Ch. Bourgeois, and Anna Wilson
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Fission, Neutron, Heavy ion
Published: 1998
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10. Study of subshell closure atN = 40 by Coulomb excitation

Author: M. Lewitowicz, F. de Oliveira, A. Gillibert, C. Bourgeois, J. M. Daugas, J. C. Angélique, A.C. Mueller, F. Pougheon, C. Borcea, O. Sorlin, M. G. Saint-Laurent, C. Donzaud, Josette Duprat, J. Kiener, M. Belleguic, J. S. Winfield, Yu. Sobolev, Yu. E. Penionzhkevich, S. Leenhardt, N. A. Orr, M. G. Porquet, D. Guillemaud-Mueller, F. Azaiez, S. Grévy, I. Deloncle, and F. Marie
Subjects: Nuclear physics, Physics, High energy, Fragmentation (mass spectrometry), Spectrometer, Coulomb excitation, Atomic physics, Excitation, Beam (structure)
Abstract: A Coulomb excitation experiment has been performed in order to study the subshell closure atN = 40 for neutron-rich nuclei. This subshell effect is thought to be enhanced when largeN/Z ratios are encountered. Therefore, theZ = 2868Ni is of particular interest in order to test this behaviour. Some experimental information is already available for68Ni at low excitation energy: a 0+ 2 isomer, a 2+ state and a long-lived 5- state. The high energy of the 2+ state suggests the shell closure though its reduced transition probabilityB(E2) has never been mesured. The nuclei68Ni,70,72Zn,76Ge have been produced in the fragmentation of a86Kr beam at 60 MeV/A. The selection of these secondary beams has been performed by LISE3 spectrometer at GANIL. Performances of the detector system “Château de Cristal” and preliminary results on reduced transition probabilitiesB(E2) are presented and discussed.
Published: 1998
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11. Isomeric states in 66As

Author: S. Andriamonje, F. Davi, A. Musquère, J. E. Sauvestre, B. Blank, M. Lewitowicz, C. Donzaud, Andreas Martin Heinz, F. Boué, Arnd R. Junghans, M. Karny, A. Grewe, H. Grawe, A. Fleury, Z. Janas, R. Del Moral, M.S. Pravikoff, M. Pfützner, S. Czajkowski, K. Sümmerer, Robert Grzywacz, J.P. Dufour, M. G. Porquet, 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), 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), 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), 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 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, Decay scheme, Spectrometer, 010308 nuclear & particles physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, medicine.anatomical_structure, Fragmentation (mass spectrometry), 0103 physical sciences, medicine, Atomic physics, 010306 general physics, Nucleus, Excitation
Abstract: Two new isomeric states in the self-conjugate nucleus 66As have been observed at the final focus of the LISE3 spectrometer at GANIL. The nucleus has been produced in a fragmentation reaction of 78Kr at 73A MeV. The 66m1,m2As isomeric levels are placed at excitation energies of E ∗m1 =3023.9 keV and E ∗m2 =1356.7 keV. Half-lives of T1/2m1=17.5(15) μs and T1/2m2=1.9(5) μs have been measured for the isomers and a decay scheme has been established.
Published: 1998
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12. A study of fusion - fission atZ= 107

Author: F. Hoellinger, Peter M. Jones, G. Duchêne, F. D. Smit, D. M. Cullen, J.F. Sharpey-Schafer, M. G. Porquet, T Stevens, B. J. P. Gall, Neil Rowley, Anna Wilson, P. A. Butler, R. T. Newman, A. Minkova, T. Kutsarova, S. Naguleswaran, N. Schulz, and J. V. Pilcher
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Fission products, Cold fission, Cluster decay, Neutron emission, Fission, Nuclear Theory, Fission product yield, Nuclear Experiment, Delayed neutron, Fast fission
Abstract: An experiment was performed with the EUROGAM II array to investigate the reaction channels that are open in the fusion of a beam on the actinide target at a series of energies around the Coulomb barrier. The symmetric fission products identified from the level structures seem to suggest that a proton and neutrons are emitted prior to fission.
Published: 1997
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13. 31S(p,γ)32Cl reaction in explosive hydrogen burning

Author: J. P. Thibaud, G. Bogaert, A. Lefebvre, P. Aguer, Michael Wiescher, L. Rosier, Joachim Görres, F. de Oliveira, S. Vouzoukas, S. Fortier, M. G. Porquet, J.M. Maison, Andrea Denker, J. Kiener, A. Coc, and Vincent Tatischeff
Subjects: Physics, Nuclear and High Energy Physics, Work (thermodynamics), Explosive material, Hydrogen, Proton, White dwarf, chemistry.chemical_element, Nova (laser), Reaction rate, chemistry, Astrophysics::Solar and Stellar Astrophysics, Atomic physics, Nuclear Experiment, Excitation
Abstract: In the present work we attempted to determine excitation energies and widths of proton unbound states in 32 Cl. These states may contribute as resonances to the 31 S(p,γ) reaction and will determine the reaction rate. Results were used to evaluate the reaction flow in the Si to Ar region obtained by nova outbursts in the case of an ONeMg white dwarf of 1.35 M ⊙ .
Published: 1997
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14. 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
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15. Collective and quasiparticle excitations in superdeformedHg190

Author: A. Korichi, D. T. Nisius, T. Lauritsen, Takashi Nakatsukasa, M. Bergström, Laurent Ducroux, T. L. Khoo, A. Lopez-Martens, Anna Wilson, J. N. Wilson, M. P. Carpenter, M. G. Porquet, B. Crowell, B. J. P. Gall, D. J. Blumenthal, F. Azaiez, Iftikhar Ahmad, N. Redon, J.F. Sharpey-Schafer, R. V. F. Janssens, József Tímár, A. Astier, Matthias Meyer, E. S. Paul, and F. Hannachi
Subjects: Physics, Nuclear and High Energy Physics, Yrast, Excited state, Phase (waves), Quasiparticle, Neutron, Moment of inertia, Atomic physics, Random phase approximation, Excitation
Abstract: Superdeformed (SD) states of {sup 190}Hg have been studied with the Eurogam Phase 2 {gamma}-ray spectrometer using the {sup 160}Gd({sup 34}S,4{ital n}) reaction. Two new excited SD bands have been found and identified as belonging to this nucleus, bringing the total number of SD bands in {sup 190}Hg to 4. One of the new bands has a dynamic moment of inertia that is very similar to that of the yrast SD band of {sup 190}Hg and most other SD bands in the {ital A}{approximately}190 region. In contrast, the other band has a dynamic moment of inertia which is mainly constant as a function of rotational frequency and exhibits a dramatic increase at the lowest frequencies. The observed dynamic moments of inertia are compared with the results of random phase approximation calculations based on the cranked shell model. Finally, the known excited SD band has been extended towards lower frequencies and new transitions have been found linking this band to the yrast SD band. The extracted {ital B}({ital E}1) values of the new linking transitions give further support for the possible octupole vibrational character of this band. {copyright} {ital 1996 The American Physical Society.}
Published: 1996
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16. Configurations of superdeformed bands inPb193

Author: S. Bouneau, F. Hannachi, Meot, C. Schück, F. Azaiez, N. Redon, N. Poffé, Matthias Meyer, Stephane Perries, Anna Wilson, M. G. Porquet, A. Lopez-Martens, C. Bourgeois, R. Collatz, Le Coz Y, A. Astier, J.F. Sharpey-Schafer, H. Sergolle, A. Korichi, Laurent Ducroux, R. Lucas, B. J. P. Gall, Hibbert I I, R. Wadsworth, Deloncle I I, and R. Duffait
Subjects: Physics, Nuclear and High Energy Physics, Dipole, Branching fraction, Moment of inertia, Atomic physics, Quasi particles, Rotational frequency
Abstract: The six superdeformed bands in {sup 193}Pb have been studied with the EUROGAM 2 {gamma}-ray spectrometer using the {sup 168}Er({sup 30}Si,5{ital n}){sup 193}Pb reaction. The results are discussed in terms of cranked-Hartree-Fock-Bogolioubov-Lipkin-Nogami calculations. From the @FF {sup (2)} moment of inertia behavior as function of the rotational frequency and the {ital M}1 and {ital E}2 decay competition of the superdeformed states, the bands are interpreted as three pairs of signature partners based on quasineutron excitations. Dipole transitions linking two signature partner superdeformed bands have been observed and, for the first time in lead isotopes, the branching ratio {ital B}({ital M}1)/{ital B}({ital E}2)=0.15{plus_minus}0.04 {mu}{sup 2}{sub {ital N}}/{ital e}{sup 2}b{sup 2} has been extracted. {copyright} {ital 1996 The American Physical Society.}
Published: 1996
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17. Rotational high spin structures in doubly-oddAu184

Author: M. E. Debray, F. Ibrahim, M. G. Porquet, H. Sergolle, I. Deloncle, A. Korichi, F. Le Blanc, J. Oms, A. J. Kreiner, Daniel Hojman, Ch. Bourgeois, N. Perrin, A. Knipper, J. Sauvage, G. Marguier, Jorge Davidson, M. Davidson, H. Somacal, and B. Roussière
Subjects: Physics, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Spectroscopy, Spin (physics), 01 natural sciences
Abstract: Excited states in the doubly-odd{sup 184}Au nucleus have been studied by in-beam {gamma}-ray spectroscopy. This nucleus was produced through the fusion-evaporation reactions {sup 165}Ho({sup 24}Mg, 5{ital n}), {sup 170}Yb({sup 19}F, 5{ital n}), and {sup 161}Dy({sup 27}Al, 4{ital n}). Different rotational band structures have been observed and interpreted as specific couplings of proton and neutron single-particle excitations present in neighboring odd Au and Pt nuclei. {copyright} {ital 1996 The American Physical Society.}
Published: 1996
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18. Thei132proton intruder orbital in the superdeformedTl193nucleus: Effective magnetic moment and blocking of proton pairing

Author: J. Duprat, H. Sergolle, F. Azaiez, N. Redon, S. Pilotte, M. G. Porquet, Laurent Ducroux, C. Bourgeois, J.F. Sharpey-Schafer, M. Bergstrom, Y. Le Coz, N. Perrin, E. S. Paul, C. Schück, Marco Meyer, Ramon Wyss, Anna Wilson, S. Bouneau, F. Hannachi, M. A. Riley, B. J. P. Gall, Alain Astier, M. Kaci, János Timár, A. Lopez-Martens, I. Deloncle, and A. Korichi
Subjects: Physics, Nuclear and High Energy Physics, symbols.namesake, Pauli exclusion principle, Magnetic moment, Proton, Yrast, Pairing, symbols, Saturation (graph theory), Moment of inertia, Atomic physics, Omega
Abstract: From the observed competition between $M1$ and $E2$ $\ensuremath{\gamma}$ transitions deexciting the states of the two signature partner yrast superdeformed bands in $^{193}\mathrm{Tl}$, the ${i}_{\frac{13}{2}}$ ($\ensuremath{\Omega}=\frac{5}{2}$) intruder proton orbital is found to have $\frac{({g}_{K}\ensuremath{-}{g}_{R})K}{{Q}_{0}}=0.138\ifmmode\pm\else\textpm\fi{}0.008$. A model dependent value of ${g}_{s}^{\mathrm{eff}}=(0.7\ifmmode\pm\else\textpm\fi{}0.2){g}_{s}^{\mathrm{free}}$ is deduced. A saturation of the ${\mathcal{T}}^{2}$ moments of inertia, at rotational frequency $\ensuremath{\hbar}\ensuremath{\omega}g0.32$ MeV, is observed for the two bands. This feature is discussed in terms of exhausted quasineutron alignment in the presence of substantially reduced quasiproton alignment due to Pauli blocking.
Published: 1996
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19. New approach in the off-line treatment of high-fold data

Author: I. Deloncle, M. Dziri-Marce, M. G. Porquet, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), 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, 010308 nuclear & particles physics, Cascade, 0103 physical sciences, sort, Fold (geology), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 01 natural sciences, Instrumentation, Algorithm, Off line
Abstract: The data obtained with the new generation of Ge multidetectors, like EUROGAM, can be considered as multidimensional, or high fold, objects. New codes have been written for the handling of these data which remains very delicate. For example the data sort procedure can affect the relative intensities of γ -rays belonging to rare and long cascade of transitions, as a superdeformed band. A new code, FANTASTIC, devoted to the treatment of high-fold data, offers the possibility to perform such sensitive analyses as, for instance, the study of relative intensities or angular distributions of γ -transitions.
Published: 1995
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20. Relative spins and excitation energies of superdeformed bands inHg190: Further evidence for octupole vibration

Author: T. Lauritsen, M. P. Carpenter, B. Crowell, Takashi Nakatsukasa, A. Korichi, D. T. Nisius, T. L. Khoo, R. V. F. Janssens, D. J. Blumenthal, Alain Astier, E. S. Paul, B. J. P. Gall, I. Ahmad, Anna Wilson, F. Hannachi, A. Lopez-Martens, L. du Croux, M. G. Porquet, Marco Meyer, N. Redon, F. Azaiez, J. Timár, and J.F. Sharpey-Schafer
Subjects: Physics, Nuclear and High Energy Physics, Spins, Spectrometer, 010308 nuclear & particles physics, Phase (waves), 01 natural sciences, Vibration, Dipole, Excited state, 0103 physical sciences, Atomic physics, 010306 general physics, Spin (physics), Excitation
Abstract: An experiment using the Eurogam phase II \ensuremath{\gamma}-ray spectrometer confirms the existence of an excited superdeformed (SD) band in $^{190}\mathrm{Hg}$ and its very unusual decay into the lowest SD band over 3--4 transitions. The energies of the transitions linking the two SD bands have been firmly established, and their angular distributions are consistent with a dipole character. Comparisons with calculations using random-phase approximation indicate that the excited SD band can be interpreted as an octupole-vibrational structure.
Published: 1995
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21. 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
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22. Spectroscopy of26F

Author: F. Azaiez, C. N. Timis, D. Guillemaud-Mueller, M. Stanoiu, G. Sletten, B. A. Brown, P. Roussel-Chomaz, J. Mrazek, Zs. Podolyák, F. Ibrahim, M. G. Porquet, Zs. Fülöp, S. M. Lukyanov, Ch. Bourgeois, Z. Elekes, A. Krasznahorkay, F. Negoita, H. Savajols, M. G. Saint-Laurent, O. Sorlin, S. Grévy, Zs. Dombrádi, János Timár, M. Lewitowicz, Andras Kerek, Yu. E. Penionzhkevich, C. Borcea, Dóra Sohler, 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), 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), CSNSM SNO, 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)-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 Sciences Nucléaires et de Sciences de la Matière (CSNSM), 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 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 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 Sciences Nucléaires et de Sciences de la Matière (CSNSM)
Subjects: Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, SHELL model, 13.75.Cs, 13.85.-t, 23.20.Lv, 21.60.Cs, Parity (physics), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, medicine.anatomical_structure, Excited state, 0103 physical sciences, medicine, Atomic physics, 010306 general physics, Spectroscopy, Ground state, Nuclear Experiment, Nucleus
Abstract: The structure of the weakly-bound $^{26}_{\;\;9}$F$_{17}$ odd-odd nucleus, produced from $^{27,28}$Na nuclei, has been investigated at GANIL by means of the in-beam $\gamma$-ray spectroscopy technique. A single $\gamma$-line is observed at 657(7) keV in $^{26}_{9}$F which has been ascribed to the decay of the excited J=$2^+$ state to the J=1$^+$ ground state. The possible presence of intruder negative parity states in $^{26}$F is also discussed., Comment: 3 pages, 1 figure, accepted for publication in Physical Review C
Published: 2012
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23. 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
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24. The N = 7 unfavoured superdeformed band in 193Hg; coriolis splitting and neutron shell structure at extreme deformation

Author: C. A. Kalfas, J.F. Sharpey-Schafer, P.M. Jones, C. Schück, A. Korichi, P.D. Forsyth, N. Fotiades, C. W. Beausang, R. M. Clark, F. Azaiez, Y. Le Coz, Witold Nazarewicz, P. J. Dagnall, Sotirios Harissopulos, S.J. Gale, I. Deloncle, M. G. Porquet, D. M. Cullen, F. Hannachi, R. Vlastou, K. Hauschild, E. S. Paul, R. Wadsworth, P. Fallon, N. Redon, J. Simpson, Malcolm J. Joyce, M. Meyer, M. A. Riley, B. J. P. Gall, and Josette Duprat
Subjects: Physics, Nuclear and High Energy Physics, Mean field theory, Atomic orbital, Deformation (mechanics), Nuclear Theory, Neutron, Atomic physics, Nuclear Experiment
Abstract: A new superdeformed band is reported in 193Hg which has properties that are consistent with it being based on the unfavoured N = 7 (π, α) = (−, +12) intruder orbital. The signature splitting at hω = 200 keV of this intruder orbital and its favoured (−, −12) partner is estimated to be 160±30 keV, which is in agreement with cranked mean field calculations. This band completes the set of low-lying quasi-neutron orbitals predicted to be at the N = 113 superdeformed Fermi-surface. The previously known superdeformed bands in 193Hg have been extended to higher rotational frequencies, hω ⩾ 0.40 MeV.
Published: 1994
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25. Evidence for γ vibrations and shape evolutions through the transitionalHg184,186,188,190nuclei

Author: J. Sauvage, F. Hannachi, P. Kilcher, F. Le Blanc, I. Deloncle, B. Roussière, A. Korichi, Daniel Hojman, Ch. Bourgeois, H. Sergolle, J. P. Delaroche, J. Libert, N. Perrin, G. Bastin, M. G. Porquet, and Michel Girod
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Atomic physics
Published: 1994
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26. Spectrum ofγRays Connecting Superdeformed and Normal States inHg192

Author: F. Azaiez, N. Perrin, Y Lecoz, Marco Meyer, Ch. Bourgeois, C. Schück, P. Willsau, J. J. Simpson, A. Korichi, T. L. Khoo, Malcolm J. Joyce, A. G. Smith, T. Lauritsen, E. S. Paul, R. V. F. Janssens, B. J. P. Gall, N. Poffé, I. Deloncle, H. Sergolle, H. Hübel, R. G. Henry, M. P. Carpenter, N. Redon, J.F. Sharpey-Schafer, Thomas Døssing, Mohammed Kaci, B. Crowell, C. W. Beausang, M. G. Porquet, Iftikhar Ahmad, R. Béraud, F. Hannachi, Josette Duprat, R. M. Clark, and R. Wadsworth
Subjects: Coupling, Physics, Isotope, Spectrum (functional analysis), Nuclear structure, Gamma ray, General Physics and Astronomy, Atomic physics, Electromagnetic radiation, Spectral line, Excitation
Abstract: The complete spectrum of [gamma] rays following the decay of superdeformed (SD) states in [sup 192]Hg has been extracted. The spectrum, which comprises a quasicontinuous component and sharp lines, reveals the decay mechanism and defines the excitation energies of the SD band. The decay of SD states results from the coupling between a cold, ordered SD system with a hot, chaotic one with normal deformation.
Published: 1994
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27. Two proton high-spin excitations and dipole bands in192Hg

Author: Y. Le Coz, N. Redon, A. Astier, R. Béraud, R. Duffait, M. Meyer, F. Hannachi, G. Bastin, I. Deloncle, B. Gall, M. Kaci, M. G. Porquet, C. Schück, F. Azaiez, C. Bourgeois, J. Duprat, A. Korichi, N. Perrin, N. Poffé, H. Sergolle, J. F. Sharpey-Schafer, C. W. Beausang, S. J. Gale, M. J. Joyce, E. S. Paul, R. M. Clark, K. Hauschild, R. Wadsworth, J. Simpson, M. A. Bentley, A. G. Smith, H. Hübel, P. Willsau, G. De France, I. Ahmad, M. Carpenter, R. Henry, R. V. F. Janssens, T. L. Khoo, T. Lauritsen, Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), 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 National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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 Flores, Sylvie
Subjects: Physics, Nuclear and High Energy Physics, Proton, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], 010308 nuclear & particles physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Dipole, medicine.anatomical_structure, 0103 physical sciences, medicine, Nuclear fusion, Atomic physics, Nuclear Experiment, 010306 general physics, Spin (physics), Beam energy, Nucleus, Excitation
Abstract: The192Hg nucleus was populated in the160Gd(36S, 4n) reaction at a beam energy of E=159 MeV. Emittedγ-rays were detected with the EUROGAM array comprising 43 Compton-suppressed large volume Ge detectors. The level scheme of192Hg has been extended up to an excitation energy of E=10.4 MeV and spin I=34 ħ. Two new structures, made of competing ΔI=1 and ΔI=2 transitions have been observed and their connexions with the low-lying levels established. Their lowest levels are located at 6.304 MeV and 6.879 MeV excitation energy. The experimental results are compared with mean-field HF+BCS calculations. It is proposed that the new structures originate from deformation-aligned quasi-proton excitations π(i13/2 * h9/2)K=11 andπ (h9/2) K=8 2 , coupled to rotation-aligned quasi-neutron ν(i13/2)n and quasi-proton π(h11/2)2 excitations.
Published: 1994
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28. Two-proton high-K oblate structures in194Pb

Author: F. Azaiez, N. Perrin, A. Korichi, V Brindejonc, I. Deloncle, R. Wadsworth, J. Simpson, Malcolm J. Joyce, A. Astier, Marco Meyer, G. Bastin, B. J. P. Gall, F. Hannachi, Josette Duprat, C. Bourgeois, R. M. Clark, J.F. Sharpey-Schafer, M. G. Porquet, N. Redon, A. G. Smith, C. W. Beausang, N. Poffé, H. Sergolle, Y. Le Coz, and C. Schück
Subjects: Physics, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Isotone, Moment of inertia, 01 natural sciences, Dipole, 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Spin (physics), Excitation, High-κ dielectric
Abstract: Two regular dipole gamma -ray cascades have been observed in 194Pb. A comprehensive level scheme related to these structures has been built and first members of rotational bands built on K=8 and K=11 two-proton oblate states have been identified. From the excitation energies, spin values, behaviours of the moments of inertia and alignments, and from the comparison with the isotone 192Hg, multiparticle configurations can be attributed to three high-spin structures of 194Pb built respectively on the 4966 keV, 4334 keV and 6198 keV levels: ( pi 9/2(505) pi 13/2(606))(vi13/2)2, ( pi 9/2(505) pi 13/2(606))(vf5/2vi13/2), ( pi 9/2(505) pi 13/2(606)) (vf5/2(vi13/2)3). Within this interpretation, the regular dipole bands correspond to the presence of two or three i13/2 decoupled neutrons.
Published: 1994
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29. First measurement of magnetic properties in a superdeformed nucleus:Hg193

Author: J. Simpson, J.F. Sharpey-Schafer, Josette Duprat, P. J. Dagnall, I. Deloncle, R. M. Clark, Malcolm J. Joyce, Marco Meyer, M. A. Riley, F. Hannachi, S.J. Gale, E. S. Paul, M. G. Porquet, N. Fotiades, A. Korichi, R. Vlastou, B. J. P. Gall, Peter B. Jones, C. W. Beausang, P.D. Forsyth, C. A. Kalfas, N. Redon, P.J. Twin, Sotirios Harissopulos, D. M. Cullen, Y. Le Coz, C. Schück, R. Wadsworth, K. Hauschild, and P. Fallon
Subjects: Physics, Dipole, Photon, medicine.anatomical_structure, Isotope, Branching fraction, Quadrupole, medicine, General Physics and Astronomy, Parity (physics), Neutron, Atomic physics, Nucleus
Abstract: Dipole transitions linking signature partner superdeformed bands in 193Hg have been observed. Measurements of the photon decay branching ratios, taken together with the average superdeformed quadrupole moment measured in neighboring nuclei, enable the absolute M1 strengths to be determined. From these data, using the strong coupling model, we find (gK-gR)K/Q0=-0.14±0.01 (e b)−1, gK=-0.65±0.14 with Ω=2.8±0.8. These data are consistent with the superdeformed neutron orbital being [512]5/2− as predicted by cranked Woods-Saxon calculations.
Published: 1993
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30. Study of the superdeformed band in 194Pb and 192Hg with EUROGAM

Author: J. Simpson, N. Perrin, M. G. Porquet, Malcolm J. Joyce, F. Azaiez, G. Bastin, B. J. P. Gall, A. Astier, S.J. Gale, M. Meyer, C. Schück, N. Poffé, J.F. Sharpey-Schafer, F. Hannachi, P.M. Jones, Y. Le Coz, R. G. Henry, P. J. Dagnall, S. A. Forbes, N. Redon, M. P. Carpenter, P. Willsau, I. Deloncle, R. M. Clark, T. Lauritsen, M. A. Bentley, M. M. Aleonard, A. Korichi, C. Bourgeois, E. S. Paul, C. W. Beausang, G deFrance, H. Sergolle, D. Curien, AG Smith, R. Wadsworth, Josette Duprat, and Padraic G. Fallon
Subjects: Physics, Nuclear and High Energy Physics, Deformation (meteorology), Atomic physics
Abstract: A subset of the Eurogam array has been used to investigate the decay out of the superdeformed (SD) band in 194Pb. Two new band members and a new decay pattern into the low lying states at normal deformation (ND) have been established for this band. In the level scheme at normal deformation, the linking transitions between the previously known floating ΔI = 1 sequence and the lower states have been established for the first time. In this talk we will also report on the preliminary results of the search for the linking transitions between the SD and ND states in 192Hg with the fully operational EUROGAM array.
Published: 1993
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31. High-Spin Structures of the Odd-A 97 - 105 43 Tc Isotopes

Author: Stephane Perries, T. Kröll, A. J. Chewter, A. Astier, Josette Duprat, S. Courtin, Ts. Venkova, R. Cunningham, A. Nowak, N. Redon, N. Buforn, R-D Herzberg, N. Schulz, M. Houry, Marco Meyer, E. Piasecki, W. Urban, C. M. Petrache, B. J. P. Gall, P. A. Butler, G. Duchêne, R. Lucas, F. Hoellinger, I. Deloncle, A. Bauchet, N. Amzal, and M. G. Porquet
Subjects: Physics, Nuclear and High Energy Physics, Isotope, Proton, Fission, Yrast, Nuclear Theory, Hadron, General Physics and Astronomy, Nuclear physics, Neutron number, Nuclear fusion, Atomic physics, Nuclear Experiment, Spin-½
Abstract: The 99−105Tc isotopes have been produced at high spin as fission fragments following the fusion reaction 37Cl(170 MeV) + 176Yb and studied with the Euroball3 array. The high-spin structures of 103Tc have been identified for the first time. From the systematics of the yrast states of 97−105Tc, the location of individual proton states can be analyzed as a function of the neutron number.
Published: 2001
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32. Relative population of the oblate and prolate structures in187Au

Author: D. Hojman, N. Perrin, A. Korichi, F. Hannachi, M. G. Porquet, C. Bourgeois, D. G. Popescu, H. Sergolle, 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), and Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM)
Subjects: Physics, Nuclear and High Energy Physics, education.field_of_study, 010308 nuclear & particles physics, Population, Prolate spheroid, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 0103 physical sciences, Oblate spheroid, Nuclear fusion, Atomic physics, 010306 general physics, education, Beam energy
Abstract: The population of the oblate and the prolate structures in187Au has been studied using the “Château de Cristal” set-up through the172Yb(19F, 4n) reaction at 90, 95 and 100 MeV beam energy. γ — γ, γ-Fold and γ -Sum energy coincidence measurements were performed, γ-ray intensity measurements showed that as the beam energy increases the prolate system is less populated than the oblate one. Fold and Sum-energy associated with oblate and prolate structures showed a different behaviour with increasing beam energy. Two mechanisms are suggested to explain these results.
Published: 1992
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33. High-spin study of186Hg

Author: C. Bourgeois, A. Korichi, G. Bastin, M. G. Porquet, H. Sergolle, F. Beck, and N. Perrin
Subjects: Physics, Nuclear and High Energy Physics, Nuclear magnetic resonance, 010308 nuclear & particles physics, Gamma ray spectrometer, 0103 physical sciences, Atomic physics, 010306 general physics, Spin (physics), 01 natural sciences, 3. Good health
Abstract: A detailed spectroscopic study of 186Hg has been performed using the 'Chateau de Cristal' 4 pi gamma spectrometer. High-spin levels of 186Hg are established up to spin 27h(cross). Several negative-parity bands are proposed. Properties of bands of 186Hg are compared to those of neighbouring nuclei.
Published: 1992
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34. High-spin states in the neutron-rich N = 50 region: nuclear structure close to [sup 78]Ni

Author: A. Astier, M.-G. Porquet, Ts. Venkova, A. Prévost, I. Deloncle, F. Azaiez, A. Buta, D. Curien, O. Dorvaux, G. Duche^ne, B. J. P. Gall, F. Khalfallah, I. Piqueras, M. Rousseau, M. Meyer, N. Redon, O. Stézowski, R. Lucas, A. Bogachev, Audrey Chatillon, Herbert Faust, Gabriele Fioni, Dominique Goutte, and Héloise Goutte
Subjects: Physics, Nuclear reaction, Nuclear physics, Spin states, Fission, Nuclear structure, Nuclear shell model, Neutron, Gamma spectroscopy, Atomic physics, Spectroscopy
Abstract: The spectroscopy of fission fragments, obtained by the 18O+208Pb fusion‐fission reaction at 85 MeV bombarding energy, has been performed with the Euroball IV γ‐array. High‐spin states in many neutron‐rich Se, Br, Kr and Rb of the 78Ni region nuclei have been identified for the first time. Several physical aspects which govern the nuclear structure in this mass region are underlined thanks to the new results. Among those, empirical values of the residual proton‐neutron interactions have been extracted for the πf5/2⊗vd5/2 and πp3/2⊗vd5/2 configurations.
Published: 2009
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35. High-spin structure ofTl189: Role ofh9/2protons in the prolate minimum of light Hg isotopes

Author: Jorge Davidson, M. E. Debray, M. G. Porquet, Ch. Bourgeois, A. Korichi, G. Falcone, F.A. Beck, H. Sergolle, Vito R. Vanin, N. Perrin, H. Mosca, J.C. Merdinger, F. Hannachi, A. J. Kreiner, and G. Bastin
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Proton, Hadron, Nuclear structure, Spin structure, Atomic physics, Nucleon, Spectroscopy, Spectral line
Abstract: High-spin states in $^{189}\mathrm{Tl}$ have been populated through the $^{165}\mathrm{Ho}$${(}^{28}$Si,4n) reaction and studied with in-beam \ensuremath{\gamma}-ray spectroscopy techniques. Both oblate and prolate structures associated with the i13/2 proton orbit are confirmed and extended to higher spins (19/2 and 41/2, respectively). However, only the oblate structure related to the \ensuremath{\pi}h9/2 has been observed meaning that the associated prolate structure is nonyrast contrary to expectation. This experimental result points clearly to a large amplitude of (\ensuremath{\pi}h9/2${)}^{2}$ in the wave function of the prolate minimum of $^{188}\mathrm{Hg}$.
Published: 1991
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36. High-spin structures observed in the 101Tc fission fragment

Author: N. Schulz, B. J. P. Gall, T. Kutsarova, A. Minkova, S. Courtin, F. Hoellinger, I. Deloncle, Josette Duprat, M. G. Porquet, H. Sergolle, Andrew A. Wilson, R. Lucas, and C. Gautherin
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, Fission, Excited state, Nuclear Theory, Gamma ray, Nuclear fusion, Atomic physics, Nuclear Experiment, Spin (physics), Spectral line, Excitation
Abstract: High-spin states have been studied in 101Tc produced as a fission fragment in the reaction 176Yb +28Si at 145 MeV. Gamma rays were detected with the EUROGAM2 array. The level scheme of 101Tc has been extended up to 4.2 MeV excitation energy and several band structures are observed. Configurations are assigned to two new bands on the basis of their behaviour and of cranked Hartree-Fock-Bogolyubov calculations.
Published: 1999
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37. Spin and parity values of states of dipole bands in 194Pb

Author: N. Perrin, J.S. Dionisio, F. Farget, A. Korichi, Josette Duprat, Y. Le Coz, M. G. Porquet, L. Han, I. Deloncle, Michèle Pautrat, Alain Astier, C. Schück, F. Azaiez, C. Bourgeois, D. Santos, Ch. Vieu, B. J. P. Gall, M. Kaci, H. Sergolle, 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 de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Joseph Fourier - Grenoble 1 (UJF)-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), 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 Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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)-Université Grenoble Alpes (UGA)
Subjects: Physics, Nuclear and High Energy Physics, Dipole, 010308 nuclear & particles physics, 0103 physical sciences, Hadron, Nuclear fusion, Parity (physics), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Atomic physics, 010306 general physics, 01 natural sciences
Abstract: Spin and parity values of the states of two dipole bands in 194Pb have been determined from internal conversion and linear polarisation measurements. The multiparticle configurations assigned previously to these dipole bands are discussed within these results.
Published: 1998
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38. First indication of population of superdeformed states by incomplete fusion reactions

Author: Alain Astier, I. Deloncle, Josette Duprat, M. Kaci, H. Sergolle, B. J. P. Gall, D. Prévost, S. Bouneau, N. Redon, M. M. Aleonard, U. J. van Severen, J.F. Sharpey-Schafer, E. Gueorguieva, Marco Meyer, C. W. Beausang, N. Dozié, F. Azaiez, W. Korten, Laurent Ducroux, D. Curien, C. Bourgeois, G. Baldsiefen, M. G. Porquet, and F.A. Beck
Subjects: Physics, Nuclear and High Energy Physics, education.field_of_study, Nuclear Theory, Recoil velocity, Population, Nuclear fusion, Atomic physics, Nuclear Experiment, education, Energy (signal processing)
Abstract: The high-spin normally deformed and superdeformed states of ${}^{194}\mathrm{Hg}$ have been populated in an exit channel of the ${}^{16}{\mathrm{O}+}^{186}\mathrm{W}$ reaction at 110 MeV bombarding energy. The Doppler shift analysis of the energies of the \ensuremath{\gamma} transitions de-exciting both normally deformed and superdeformed states in ${}^{194}\mathrm{Hg}$ indicates a lower recoil velocity of the ${}^{194}\mathrm{Hg}$ nucleus compared to that of the ${}^{196}\mathrm{Pb}$ nucleus obtained from the $6n$ exit channel of the complete-fusion compound nucleus. This suggests that incomplete fusion plays the main role in the population of normally deformed and superdeformed states of ${}^{194}\mathrm{Hg}$ in this reaction.
Published: 1997
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39. Superdeformed nuclear matter in nuclei with Z $\geq$ 82 : Magnetic properties and neutron shell gap

Author: H. Hübel, R. Lucas, D. Curien, N. Kintz, G. Duchêne, M. G. Porquet, E. Mergel, S. Neumann, F.A. Beck, N. Nenoff, J. Domscheit, O. Dorvaux, N. Buforn, J.P. Vivien, Anna Wilson, G. Schoenwasser, P. Bednardcyk, I. Deloncle, P. Lautesse, A. Prévost, Alain Astier, B. J. P. Gall, A. Goergen, R. Duffait, A. Bauchet, O. Stezowski, M. Meyer, N. Redon, D. Rossbach, D. M. Cullen, Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches 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), EUROBALL, Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Physics, Nuclear and High Energy Physics, Spectrometer, Isotope, 010308 nuclear & particles physics, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear matter, 01 natural sciences, Crosstalk, Nuclear physics, 0103 physical sciences, Quasiparticle, Nuclear fusion, Neutron, Atomic physics, 010306 general physics
Abstract: We report the results of an experiment, realized with the EUROBALL IV spectrometer, in which superdeformed (SD) states have been populated in 197,198Pb nuclei. Crosstalk transitions between two signature partner SD bands in 197Pb have been observed with an established M1 character, giving access to the magnetic properties of the $\nu$ [752]5/2 intruder orbital. Six new SD bands have been identified in 197,198Pb. The results are interpreted in the framework of cranked Hartree-Fock calculations. A mixing between quasi-particle excitations and an octupole vibration is suggested in the two SD isotopes.
Published: 2004
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40. High-spin states inAu191: Evidence for triaxial shape?

Author: J. S. Dionisi, C. Schück, E. Gueorguieva, A. Korichi, M. G. Porquet, Ch. Vieu, A. Minkova, F. Hannachi, A. Lopez-Martens, Ramon Wyss, and Mohammed Kaci
Subjects: Physics, Nuclear and High Energy Physics, Electron spectrometer, Proton, Spin states, Omega, Molecular physics, medicine.anatomical_structure, Internal conversion, medicine, Gamma spectroscopy, Nuclear Experiment, Spin (physics), Nucleus
Abstract: The level scheme of Au-191 was considerably extended to high spin using gamma spectroscopy with the Eurogam-II array and internal conversion measurements with the Orsay electron spectrometer. Several bands that appear as strongly coupled were associated with low- Omega configurations in Au-191 . Using total routhian surface and cranked shell model calculations it was shown that these bands have a rotation-aligned nature and are most likely generated by the nonaxiallity of the nucleus induced by the odd proton. The predictions for the presence of such bands in Au-191 and in the oblate nuclei in the Pt-Au-Hg region found excellent agreement with the experimental data, as well as the predictions for their alignments and band-crossing frequencies in Au-191 .
Published: 2003
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41. Structure of polonium isotopes at high spin with RFD+Euroball IV

Author: B. Rossé, F. Camera, K. M. Spohr, P. Papka, D. Curien, A. Bracco, M. Brekiesz, M. Meyer, K. Keyes, M. Górska, I. Deloncle, J. Robin, A. Prévost, N. Redon, Alain Astier, W. Mȩczyński, P. Bednarczyk, M. G. Porquet, O. Dorvaux, M. Ziebliński, O. Stezowski, A. Maj, J.P. Vivien, J. E. Bastin, H. Hübel, Kai Zuber, B. J. P. Gall, T. Pawłat, A. Papenberg, J. Styczeń, J. Grȩbosz, Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), 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), EUROBALL, Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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 Heyd, Yvette
Subjects: Physics, Nuclear and High Energy Physics, Isotope, Spin states, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], 010308 nuclear & particles physics, General Physics and Astronomy, chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Recoil, chemistry, 0103 physical sciences, 010306 general physics, Spin (physics), Beam energy, Polonium
Abstract: An experiment has been performed to investigate the structure at high spin of the neutron-deficient polonium isotopes using the Recoil Filter Detector coupled to the EUROBALL IV gamma array. High spin states of 200,201 Po have been populated by the 30 Si +176 Yb reaction at a beam energy of 160 MeV. We report here the performances of the RFD + EUROBALL IV coupling.
Published: 2003

42. Cross sections relevant toγ-ray line emission in solar flares:3He-induced reactions on16Onuclei

Author: J. Kiener, Vincent Tatischeff, J. A. Scarpaci, F. Hammache, J. P. Thibaud, Ch. Bourgeois, Josette Duprat, Cécile Engrand, M. G. Porquet, A. Coc, Marlete Assunção, Marin Chabot, A. Lefebvre, N. de Sereville, and M. Gounelle
Subjects: Physics, Nuclear and High Energy Physics, Solar flare, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, 01 natural sciences, Nuclear physics, 0103 physical sciences, Electromagnetic shielding, Electronic anticoincidence, Atomic physics, Nuclear Experiment, 010303 astronomy & astrophysics, Excitation, Line (formation)
Abstract: Gamma-ray production cross sections have been measured for gamma-ray lines copiously emitted in the $^3$He bombardment of $^{16}$O nuclei: the 937, 1042 and 1081 keV lines of $^{18}$F and the 1887 keV line of $^{18}$Ne. Four Ge detectors with BGO shielding for Compton suppression were used to measure the angular distributions of the gamma-rays. The excitation functions have been obtained for $^3$He bombarding energies from 3.7 to 36 MeV. Total cross sections are tabulated for calculations relevant to gamma-ray astronomy. The importance of these lines as diagnosis for the presence and properties of accelerated $^3$He in solar flares is discussed in light of the measured cross sections.
Published: 2003
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43. COULOMB EXCITATION OF NI AND ZN ISOTOPES AROUND THE N=40 SUBSHELL CLOSURE

Author: C. Borcea, Z. Dlouhy, M. Belleguic, A. Astier, M. G. Saint-Laurent, E. Dragulescu, O. Sorlin, Oleg B. Tarasov, S. Grévy, C. Donzaud, S. Leenhardt, Zs. Dombrádi, F. Pougheon, P. Mayet, D. Baiborodin, F. Azaiez, J. A. Scarpaci, F. Amorini, Roy Crawford Lemmon, G. Sletten, M. Lewitowicz, S. M. Lukyanov, Ch. Bourgeois, L. Petizon, D. Pantalica, J. Kiener, D. Guillemaud-Mueller, G.B. Hagemann, Ch. Theisen, I. Deloncle, D. M. Cullen, M. Stanoiu, M. G. Porquet, Yu. E. Penionzhkevich, F. de Oliveira Santos, N. Redon, K. Bienczak, H. Brenning, H. Grawe, B. Herskind, M. Górska, and Josette Duprat
Subjects: Nuclear physics, Physics, Isotope, Closure (topology), Coulomb excitation, Atomic physics
Published: 2002
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44. HIGH-SPIN STRUCTURE OF SOME NEUTRON-RICH ODD-Z NUCLEI WITH A ≈ 100 FROM HEAVY-ION INDUCED FISSION

Author: G. Duchêne, N. Redon, P. Petkov, Ts. Venkova, M. G. Porquet, A. Bauchet, A. Nowak, T. Kröll, A. J. Chewter, Stephane Perries, E. Piasecki, W. Urban, Matthias Meyer, R. Cunningam, I. Deloncle, M. Houry, N. Amzal, C. M. Petrache, R. Herzgerg, P. A. Butler, B. J. P. Gall, N. Schulz, Josette Duprat, S. Courtin, R. Lucas, N. Buforn, F. Hoellinger, A. Minkova, and A. Astier
Subjects: Physics, Fission, Neutron, Heavy ion, Atomic physics, Spin structure
Published: 2001
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45. Evidence for deformation in $^{113-116}$Cd isotopes

Author: Stephane Perries, F. Hoellinger, N. Redon, H. Sergolle, E. Gueorguieva, B. J. P. Gall, I. Deloncle, T. Kutsarova, Jean-Arcady Meyer, N. Buforn, R. Lucas, A. Minkova, O. Stezowski, N. Schulz, Ts. Venkova, Alain Astier, A. Bauchet, Marco Meyer, Anna Wilson, Josette Duprat, C. Gautherin, M. G. Porquet, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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 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), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-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, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, Nuclear Theory, Hadron, Prolate spheroid, Deformation (meteorology), 01 natural sciences, 7. Clean energy, Isotopes of cadmium, 0103 physical sciences, Nuclear fusion, Atomic physics, Nuclear Experiment, 010306 general physics, Spin (physics), Nuclear Physics
Abstract: High-spin states in 113-116Cd have been investigated with the fusion-fission reaction 28Si +176Yb at 145 > MeV. The experiment has been performed with the Eurogam2 array. New rotational bands based on two quasi-particle states have been observed for even-even cadmium isotopes. A new level scheme based on the 11/2− isomeric state is proposed for 115Cd and the one of 113Cd has been extended to spin (31/2−). The decoupled bands identified in both odd-A nuclei are interpreted as being built upon a low-Ωh11/2 quasi-neutron configuration. Microscopic Hartree-Fock + BCS calculations confirm the prolate deformation in this mass region especially for the odd cadmium isotopes.
Published: 2000
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46. High-Spin States in the Transitional Palladium Nuclei Observed in Heavy-Ion Induced Fission

Author: E. Gueorguieva, N. Schulz, T. Kutsarova, P. Petkow, H. Sergolle, M. G. Porquet, Josette Duprat, Anna Wilson, S. Bouneau, R. Lucas, A. Minkova, F. Hoellinger, I. Deloncle, C. Bourgeois, B. J. P. Gall, Ts. Venkova, C. Gautherin, F. Azaiez, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), 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), and Smit F.D. Lindsay R. Foertsch S.V.
Subjects: Physics, Spin states, 010308 nuclear & particles physics, Fission, Nuclear Theory, Radiochemistry, Gamma ray, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Molecular physics, Spectral line, 0103 physical sciences, Potential energy surface, Quasiparticle, Nuclear fusion, Nuclear Experiment, 010306 general physics, Spontaneous fission
Abstract: The low-spin collective excitations of even-even Pd nuclei in the A ≈ 110 mass region indicate a structural transition from an anharmonic vibrator to a gamma-soft rotor. This observation is supported by recent calculations of the potential energy surfaces using different types of mean field approaches. In particular, prolate-to-oblate shape transition has been predicted at 111Pd [1]. Experimental evidence for a shape change or shape coexistence can be obtained by high-spin studies of these transitional nuclei. Band crossings in the odd-N Pd nuclei are especially important to understand the origin of the alignments. No band structures built on the low-lying states were known in heavier odd Pd nuclei (A≥109). High-spin states in these nuclei cannot be populated using fusion-evaporation reactions. The heavier neutron-rich 112,114,116Pd nuclei have been studied from spontaneous fission of 252Cf [2]. In this work the less neutron-rich Pd nuclei have been produced as fission fragments following the fusion reactions 28Si + 176Yb at 145 MeV. The 28Si beam was provided by the Vivitron accelerator in Strasbourg. Gamma rays were recorded with the EUROGAM2 array [3]. The level schemes were constructed by examining γ- spectra extracted from two and three dimensional matrices.
Published: 2000
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47. Decay-out of the yrast superdeformed band in136Nd: Towards an experimental extraction of the neutron pairing gap at large deformation

Author: C. A. Ur, D. Foltescu, Zs. Podolyák, C. M. Petrache, Laurent Ducroux, N. Redon, S. Frattini, A. Johnson, M. De Poli, Bo Cederwall, M. Lunardon, A. Bracco, G. Viesti, CR Alvarez, S. Leoni, Napoli, Ramon Wyss, A. Astier, M. G. Porquet, S. Lunardi, Claes Fahlander, G. Falconi, R. Venturelli, I. Deloncle, G. de Angelis, Matthias Meyer, D. Bazzacco, A. Gadea, Stephane Perries, and E. Farnea
Subjects: Physics, Nuclear and High Energy Physics, Large deformation, Isotope, Yrast, Nuclear Theory, Parity (physics), Nuclear physics, Pairing, Major conclusion, Neutron, Atomic physics, Nuclear Experiment, Excitation
Abstract: A study of the Nd-136 nucleus has been performed with the EUROBALL III multidetector to establish the decay-out of the yrast superdeformed (SD) band. Three discrete linking transitions (754, 1456, and 1493 keV) have been discovered, establishing the position of the SD band at 7.03 MeV excitation energy with proposed spin and parity 17((-)) for the lowest observed SD state. Neutron pairing gap parameters for SD shapes have been extracted in Nd isotopes, using the strong-coupling model and odd-even mass difference formulas. The major conclusion of our phenomenological analysis is that the pairing correlations do subsist in the SD configurations of nuclei in the A = 130 mass region. [S0556-2813(99)01312-6].
Published: 1999
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48. In-beam gamma spectroscopy of very neutron-rich nuclei at GANIL

Author: C. Borcea, S. Leenhardt, I. Deloncle, M. G. Saint-Laurent, Z. Dlouhy, Yu-E. Penionzhkevich, M. Lewitowicz, O. Sorlin, M. Belleguic, M. J. Lopez, A. Gillibert, C. Donzaud, Ch. Bourgeois, F. Pougheon, H. Savajols, J. M. Daugas, F. Azaiez, M. Stanoiu, M. G. Porquet, F. de Oliveira, J. C. Angélique, S. Grévy, J. Kiener, Josette Duprat, D. Guillemaud-Mueller, A.C. Mueller, N. L. Achouri, J. E. Sauvestre, Yu. Sobolev, W. Shuying, 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 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), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Smit F.D. Lindsay R. Foertsch S.V., 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), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Robert, Suzanne
Subjects: Physics, Isotope, 010308 nuclear & particles physics, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Theory, Gamma ray, Coulomb excitation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Condensed Matter Physics, 01 natural sciences, Atomic and Molecular Physics, and Optics, Nuclear physics, Excited state, 0103 physical sciences, Neutron, Gamma spectroscopy, Atomic physics, Nuclear Experiment, 010306 general physics, Ground state, Mathematical Physics, Beam (structure)
Abstract: The structure of nuclei far from stability can be investigated by means of in-beam gamma spectroscopy using both stable and radioactive beams. Two such experiments have been recently performed at GANIL. i) Secondary beams of neutron-rich Ge, Zn and Ni isotopes around N=40 were produced from the fragmentation of a primary 86 Kr beam, and analyzed by means of the LISE3 spectrometer. For the transitions between the 0+ ground state and the first 2+ state, B(E2) values have been extracted from Coulomb excitation cross-section measurement. Some of the obtained results related to the effectiveness of the N=40 spherical sub-shell closure are discussed. ii) In-beam γ-spectroscopy of neutron-rich nuclei around 32Mg produced by fragmentation of 36S have been performed recently. Gamma decay of relatively higher excited states have been measured in a large number of exotic light nuclei. Preliminary results obtained in a number of neutron-rich nuclei around N=20 are presented.
Published: 1999

49. Gamma-ray spectroscopy of fission fragments induced by heavy ions: from nuclear structure of neutron-rich nuclei to mechanism studies

Author: M.-G Porquet, 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), F.D. Smit, R. Lindsay, and S.V. Fortsch
Subjects: Physics, Fusion, Spins, Isotope, 010308 nuclear & particles physics, Fission, Nuclear Theory, Nuclear structure, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Ion, Nuclear physics, 0103 physical sciences, Neutron, Gamma spectroscopy, Nuclear Experiment, 010306 general physics
Abstract: About eighty nuclei in the A ≈ 100 mass region have been observed as fission fragments following the fusion evaporation 28,30Si + 176Yb at 145 MeV bombarding energy. These nuclei have been identified from their γ-ray cascades detected with the EUROGAM2 array. The level schemes of several stable or neutron-rich nuclei have been extended to higher spins. From coincidences between transitions in complementary fragments, γ-rays de-exciting new high-spin states of hitherto unexplored isotopes can be assigned and some aspects of the fission mechanism can be studied.
Published: 1999

50. Decay-out of the yrast superdeformed band in 136Nd: towards an experimental extraction of the neutron pairing gap in the second well

Author: D. Bazzacco, Claes Fahlander, S. Leoni, M. G. Porquet, Alain Astier, N. Redon, C. M. Petrache, D. R. Napoli, S. Lunardi, Stephane Perries, Zs. Podolyák, G. Viesti, Bo Cederwall, M. Lunardon, Marco Meyer, A. Johnson, Ramon Wyss, A. Bracco, C. Rossi Alvarez, M. De Poli, G. Falconi, Laurent Ducroux, I. Deloncle, G. de Angelis, R. Venturelli, S. Frattini, A. Gadea, E. Farnea, C. A. Ur, D. Foltescu, Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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 Flores, Sylvie
Subjects: Physics, Nuclear and High Energy Physics, Isotope, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], 010308 nuclear & particles physics, Yrast, Nuclear Theory, Extraction (chemistry), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, mixture models, Pairing, textual data analysis, 0103 physical sciences, Physics::Atomic and Molecular Clusters, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Spin (physics), Excitation, clustering
Abstract: The automatic clustering of text segments into thematically homogeneous groups is a difficult problem. In this paper, we study the performance of a simple probabilistic model, the "monomaniac" model. We first describe the model and the related EM-based estimation procedures; an application of this model to a English corpus of texts imported from the CKM ("Customer Knowledge Management") literature is then presented.
Published: 1999

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