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1. PROBING PRE-FORMED ALPHA PARTICLES IN THE GROUND STATE OF NUCLEI

Author

J. A. Scarpaci, M. Fallot, Denis Lacroix, J.L. Laville, A. Chbihi, D. Beaumel, J.D. Frankland, E. Plagnol, Ph. Chomaz, J.C. Roynette, P. Roussel-Chomaz, M. Assié, P. Désesquelle, Y. Blumenfeld, C. Bhar, T. Zerguerras, H. Idbarkach, Elias Khan, A. Shrivastava, E. C. Pollacco, N. Frascaria, L. Lefebvre, 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), 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), CSNSM SNO, 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)-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), Département d'Electronique, des Détecteurs et d'Informatique pour la Physique (ex SEDI) (DEDIP), 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, Laboratoire SUBATECH Nantes (SUBATECH), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, APC - Cosmologie, Physique Corpusculaire et Cosmologie - Collège de France (PCC), Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Collège de France (CdF)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), 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)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), CEA/DSM Centre de Saclay (CEA/DSM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire 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), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-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)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], 010308 nuclear & particles physics, FOS: Physical sciences, General Physics and Astronomy, Alpha particle, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear Theory (nucl-th), Angular distribution, medicine.anatomical_structure, Helium-4, 0103 physical sciences, medicine, Alpha decay, Nuclear Experiment (nucl-ex), Atomic physics, Nuclear Experiment, 010306 general physics, Ground state, Nucleus
Abstract

In this Letter, we report on alpha particle emission through the nuclear break-up in the reaction 40Ca on a 40Ca target at 50A MeV. It is observed that, similarly to nucleons, alpha particles can be emitted to the continuum with very specific angular distribution during the reaction. The alpha particle properties can be understood as resulting from an alpha cluster in the daughter nucleus that is perturbed by the short range nuclear attraction of the collision partner and emitted. A time-dependent theory that describe the alpha particle wave-function evolution is able to reproduce qualitatively the observed angular distribution. This mechanism offers new possibilities to study alpha particle properties in the nuclear medium., Comment: 4 pages, 3 figures

Published
2011
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2. Impact parameter dependence of linear momentum transfer and the role of two-body dissipation mechanisms in heavy ion collisions around the Fermi energy

Author

R. Coniglione, C. Agodi, G. Bellia, Y. Blumenfeld, R. Alba, Paolo Piattelli, T. Suomijärvi, Paolo Finocchiaro, K. Loukachine, N. Frascaria, A. Del Zoppo, J.H. Le Faou, F. Auger, Paolo Sapienza, Domenico Santonocito, N. Alamanos, Maria Colonna, J.A. Scarpaci, Ph. Chomaz, A. Gillibert, J.C. Roynette, E. Migneco, C. Maiolino, 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), 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), Robert, Suzanne, and 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)

Subjects
Physics, Nuclear and High Energy Physics, High energy, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], 010308 nuclear & particles physics, Nuclear Theory, Fermi energy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Dissipation, 01 natural sciences, 7. Clean energy, Coincidence, Nuclear physics, 0103 physical sciences, Transfer mechanism, Heavy ion, Impact parameter, Atomic physics, Multiplicity (chemistry), Nuclear Experiment, 010306 general physics
Abstract

High energy γ -rays ( E γ >35 MeV) have been measured in coincidence with heavy residues emitted in reactions induced by a 37 MeV/u 36 Ar beam on a 98 Mo target. The γ -ray yield increases strongly with increasing linear momentum transfer indicating the importance of two-body collisions in the transfer mechanism. The high energy γ -ray multiplicity has been used to correlate the linear momentum transfer to the impact parameter. This correlation is compared to dynamical BNV simulations to show the essential role of two body nucleon-nucleon collisions at these bombarding energies.

Published
1998
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3. A new phenomenon in heavy ion inelastic scattering: the towing mode

Author

J.A. Scarpaci, A. van der Woude, N. Frascaria, T. Suomijärvi, J.C. Roynette, F. Maréchal, D. Beaumel, Ph. Chomaz, V. Pascalon-Rozier, I. Lhenry, J.R. Jongman, Y. Blumenfeld, H. Laurent, Denis Lacroix, P. Roussel-Chomaz, Research unit Nuclear & Hadron Physics, 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), 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), Physique théorique, 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)-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 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)-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)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Mode (statistics), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Inelastic scattering, Deep inelastic scattering, 01 natural sciences, Inelastic neutron scattering, Spectral line, Coincidence, Nuclear physics, 0103 physical sciences, SPECTRA, Atomic physics, 010306 general physics, Nucleon, DECAY, Excitation
Abstract

The inelastic scattering of Ar-40 on Ni-58 has been studied at 44 MeV per nucleon incident energy in coincidence with light particle emission. Besides the well known mechanisms of inelastic excitation, pick up break up and nucleon knock out, a new phenomenon has been observed, giving rise to fast forward moving particles with specific angular correlations. This newly observed mechanism seems to be a generic phenomenon present for various projectile-target combinations and incident energies. Its contribution to the inelastic spectrum has been extracted and a tentative interpretation is given. (C) 1998 Elsevier Science B.V. All rights reserved.

Published
1998
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4. Proton emission in inelastic scattering of40Ca on40Ca at 50 MeV/nucleon

Author

A. van der Woude, J.C. Roynette, I. Lhenry, D. Beaumel, T. Suomijärvi, M. Lamehi-Rachti, J.A. Scarpaci, J.P. Garron, Ph. Chomaz, A. Gillibert, N. Frascaria, N. Alamanos, and Y. Blumenfeld

Subjects
Physics, Nuclear and High Energy Physics, Decay scheme, 010308 nuclear & particles physics, Nuclear Theory, Inelastic scattering, 01 natural sciences, 7. Clean energy, Resonance (particle physics), Charged particle, Nuclear physics, Giant resonance, 0103 physical sciences, Quadrupole, Proton emission, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Inelastic scattering of {sup 40}Ca on {sup 40}Ca at 50 MeV/nucleon has been measured in coincidence with light charged particles detected over a large angular domain. The giant resonance region of the inelastic spectrum is shown to be dominated by the isoscalar giant quadrupole resonance. The characteristics of the emitted protons allow us to separate four reaction mechanisms contributing to the high excitation energy region of the inelastic spectrum (E{sup {asterisk}}{gt} 30 MeV): pickup breakup, knockout, inelastic scattering to high-lying target states, and a new mechanism responsible for the emission of fast-moving protons. A sizable direct decay branch towards hole states of {sup 39}K is measured for the giant quadrupole resonance in {sup 40}Ca. Evidence is given for the excitation of the two-phonon giant quadrupole resonance, characterized by its direct decay scheme. The energy and width of this two-phonon state are in agreement with a harmonic picture for collective nuclear excitations. {copyright} {ital 1997} {ital The American Physical Society}

Published
1997
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5. Role of the breakup process in theCa48(20Ne,19Nen) reaction at 48AMeV

Author

T. Suomijärvi, [No Value] Lhenry, J.C. Roynette, J. A. Scarpaci, Sydney Gales, P. Roussel-Chomaz, J.P. Garron, A Vanderwoude, H. Laurent, Didier Beaumel, A. Gillibert, J.M. Maison, Jérôme Guillot, Y. Blumenfeld, S. Fortier, and N. Frascaria

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, Nuclear Theory, Neutron multiplicity, Breakup, Spectral line, Nuclear physics, Neutron, Atomic physics, Multiplicity (chemistry), Nuclear Experiment, Ground state, Excitation
Abstract

A study of the reaction {sup 48}Ca({sup 20}Ne,{sup 19}Ne {ital n}) at 48{ital A} MeV has been performed at the GANIL facility. The inclusive excitation spectrum above 12 MeV excitation is dominated by a broad structureless bump. Calculations performed in the framework of the Bonaccorso-Brink model predict that the absorption process (transfer+inelastic breakup) dominates over the elastic breakup process. Comparison of the neutron multiplicity calculated in a statistical model with the measured one confirms a significant contribution of the direct processes (elastic and inelastic breakup). The neutron yield to the ground state of the {sup 48}Ca is maximal in the forward direction. Comparisons with calculated neutron angular distributions show the effect of the final state interaction.

Published
1995
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6. The Giant Dipole Resonance at very high temperatures

Author

J.C. Roynette, Ph. Chomaz, K. Loukachine, T. Suomijärvi, G. V. Russo, Paolo Piattelli, N. Frascaria, J.H. Le Faou, A. Del Zoppo, A. Gillibert, E. Migneco, J.P. Garron, G. Bellia, Paolo Finocchiaro, Domenico Santonocito, C. Agodi, F. Auger, C. Maiolino, J.A. Scarpaci, J. J. Gaardhøje, R. Liguori-Neto, R. Alba, Paolo Sapienza, N. Alamanos, R. Coniglione, S. Montironi, Augusto Smerzi, M. Lamehi-Rachti, Y. Blumenfeld, 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), 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 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)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Evaporation, Resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Dipole, Yield (chemistry), 0103 physical sciences, Physics::Accelerator Physics, Astrophysics::Solar and Stellar Astrophysics, Atomic physics, Nuclear Experiment, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Excitation
Abstract

Gamma-rays emitted from hot nuclei of mass around 115 and excitation energies above 300 MeV, formed in the 36 Ar + 90 Zr at 27 MeV/u, 36 Ar + 94 Zr at 32 MeV/u and 36 Ar + 98 Mo at 37 MeV/u, have been measured with the MEDEA multidetector in coincidence with evaporation residues. The γ-ray yield from the decay of the Giant Dipole Resonance is independent of excitation energy and of bombarding energy.

Published
1995
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7. Signature of a two-phonon state through its proton decay pattern

Author

M. Lamehi-Rachti, T. Suomijärvi, P. Massolo, Ph. Chomaz, A. Gillibert, A. van der Woude, J.C. Roynette, Didier Beaumel, Y. Blumenfeld, J. A. Scarpaci, I. Lhenry, J.P. Garron, N. Frascaria, N. Alamanos, 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), 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 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)

Subjects
Physics, Decay scheme, Proton, 010308 nuclear & particles physics, Proton decay, Isoscalar, Nuclear Theory, General Physics and Astronomy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Inelastic scattering, 01 natural sciences, 24.30.Cz, 25.70.Bc, 25.70.Ef, Giant resonance, Excited state, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Inelastic scattering of 50 MeV/nucleon [sup 40]Ca on [sup 40]Ca was measured in coincidence with protons in order to investigate the excitation and decay of highly excited states in [sup 40]Ca. The proton decay pattern corresponding to an excitation region around 34 MeV shows the characteristic behavior expected of the direct decay of a two-phonon state. Thus, by using this novel method, the presence of a double-phonon state built with isoscalar giant resonances in [sup 40]Ca is demonstrated.

Published
1993
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8. EDEN: a neutron time-of-flight multidetector for decay studies of giant states

Author

J. Guillot, J.C. Roynette, H. Lefort, H. Laurent, P. Volkov, S. Fortier, D. Beaumel, Y. Blumenfeld, Sijtze Brandenburg, S. Gales, KVI - Center for Advanced Radiation Technology, Damage and Repair in Cancer Development and Cancer Treatment (DARE), Institut de Physique Nucléaire d'Orsay (IPNO), 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, NUCLEI, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Resolution (electron density), Scintillator, 7. Clean energy, 01 natural sciences, Nuclear physics, Time of flight, 0103 physical sciences, Neutron, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], DETECTION EFFICIENCY, Nuclear Experiment, 010306 general physics, RESONANCES, Instrumentation, Overall efficiency
Abstract

A neutron time-of-flight multidetector has been built to study the decay of giant states. It is made of 40 individual detectors. A liquid scintillator is used for neutron-gamma-ray pulse shape discrimination. The overall efficiency of the multidetector (epsilonOMEGA/4pi) is 1% for 6 MeV neutrons and the energy resolution is about 60 keV and 500 keV for 1 MeV and 6 MeV neutrons respectively.

Published
1993
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9. Probing preformedαparticles in the ground state of nuclei

Author

P. Desesquelles, J.A. Scarpaci, M. Fallot, J. L. Laville, N. Frascaria, T. Zerguerras, J. Frankland, C. Bhar, E. Plagnol, P. Roussel-Chomaz, L. Lefebvre, A. Shrivastava, J.C. Roynette, H. Idbarkach, M. Assié, D. Beaumel, A. Chbihi, E. C. Pollacco, Ph. Chomaz, D. Lacroix, Elias Khan, and Y. Blumenfeld

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Elementary particle, Alpha particle, 01 natural sciences, Charged particle, Baryon, 0103 physical sciences, Continuum (set theory), Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Ground state
Abstract

In this Rapid Communication, we report on $\ensuremath{\alpha}$-particle emission through the nuclear breakup in the reaction $^{40}\mathrm{Ca}$ on a $^{40}\mathrm{Ca}$ target at 50 A MeV. It is observed that, similar to nucleons, $\ensuremath{\alpha}$ particles can be emitted to the continuum with very specific angular distribution during the reaction. The $\ensuremath{\alpha}$-particle properties seem to be compatible with an $\ensuremath{\alpha}$ cluster in the daughter nucleus that is perturbed and is emitted by the short-range nuclear attraction of the collision partner. A time-dependent theory that describes the $\ensuremath{\alpha}$-particle wave-function evolution is able to qualitatively reproduce the observed angular distribution. This mechanism offers new possibilities for studying $\ensuremath{\alpha}$-particle properties in the nuclear medium.

Published
2010
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10. Projectile like fragment production in14N-induced reactions at projectile energies of 60 MeV A

Author

J.P. Garron, J.C. Roynette, J.C. Jacmart, R. Glasow, W. von Oertzen, W. Weller, R. Santo, D. Grzonka, N. Frascaria, H. G. Bohlen, and Y. Blumenfeld

Subjects
Physics, Momentum, Nuclear physics, Nuclear and High Energy Physics, Fragment (computer graphics), Projectile, Nuclear Theory, Atomic physics, Nuclear Experiment, Projectile fragmentation, Ion
Abstract

Projectile fragmentation of 60 MeV A 14N ions has been studied by measuring isotopically separated fragments from A=3-13. The data are analysed within the Goldhaber model. The extracted reduced momentum widths sigma 0 are found to be nearly constant and close to values at relativistic energies.

Published
1990
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11. Disappearence of collective motion in very hot nuclei

Author

A. Gillibert, Paolo Piattelli, J.A. Scarpaci, Domenico Santonocito, Paolo Sapienza, Ph. Chomaz, J.H. Le Faou, R. Coniglione, Paolo Finocchiaro, R. Alba, C. Maiolino, C. Agodi, E. Migneco, G. Bellia, Y. Blumenfeld, K. Loukachine, Maria Colonna, J.C. Roynette, N. Alamanos, F. Auger, T. Suomijärvi, N. Frascaria, A. Del Zoppo, 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), 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, 010308 nuclear & particles physics, Nuclear Theory, Collective motion, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Interpretation (model theory), Nuclear physics, 0103 physical sciences, Incident energy, Atomic physics, Nuclear Experiment, 010306 general physics, Excitation
Abstract

Gamma-rays emitted from hot nuclei with mass around 115 and excitation energies above 300 MeV, formed in the 36 Ar + 98 Mo reaction at 37 A MeV, have been measured. A comparison with previous experiments at lower bombarding energies shows a decrease of the γ-yield with increasing incident energy. A tentative interpretation based on dynamical calculations is proposed.

Published
1998

12. Fast Particle Emission in Inelastic Channels of Heavy-Ion Collisions

Author

N. Frascaria, T. Suomijärvi, Y. Blumenfeld, Denis Lacroix, H. Laurent, I. Lhenry, J.R. Jongman, P. Roussel-Chomaz, Didier Beaumel, V. Pascalon-Rozier, A. van der Woude, J.C. Roynette, J. A. Scarpaci, and Ph. Chomaz

Subjects
Nuclear physics, Physics, Projectile, Nuclear Theory, Heavy ion, Inelastic scattering, Proton emission, Nuclear Experiment, Nucleon, Excitation, Communication channel, Ion
Abstract

Inelastic scattering of heavy ions has been extensively used to study the nuclear excitations. In particular the decay of giant resonances has been investigated to infer information on their microscopic structure1. In addition to the target excitation several processes are known to contribute to the inclusive inelastic spectrum. The quasi-elastic knock-out process is a major contribution in the inelastic scattering of protons and α-particle projectiles. For heavier ions this contribution is expected to be smaller but still persists. Proton emission coming from the knock-out process was clearly observed and was detected in the direction of the recoiling target nucleus. Another process contributing to the inclusive inelastic spectrum is the pick-up break-up process2. In this process the projectile picks up a nucleon from the target, leaving it in a 1-hole configuration. The ejectile will then break-up again and feed the inelastic channel. This process gives rise to a plateau spreading over a large energy interval centered slightly above the bombarding energy per nucleon, with a width determined by the specific decay characteristics of the system.

Published
1998
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13. Hard photon and energetic proton emission in heavy ion collisions at intermediate energy

Author

Y. Blumenfeld, N. Frascaria, J.P. Garron, A. Del Zoppo, G. Bellia, N. Alamanos, K. Loukachine, J.H. Le Faou, A. Gillibert, Paolo Sapienza, T. Suomijärvi, F. Auger, J.C. Roynette, Paolo Piattelli, Paolo Finocchiaro, R. Coniglione, C. Agodi, R. Alba, Ph. Chomaz, Domenico Santonocito, J.A. Scarpaci, A. Péghaire, C. Maiolino, E. Migneco, 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), 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, Photon, 010308 nuclear & particles physics, Nuclear Theory, Detector, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Nuclear physics, Intermediate energy, 0103 physical sciences, Physics::Accelerator Physics, Heavy ion, Proton emission, Atomic physics, Nuclear Experiment, 010306 general physics, Very Energetic, ComputingMilieux_MISCELLANEOUS
Abstract

The emission of hard photons and pre-equilibrium protons has been investigated in exclusive clusive experiments performed with MEDEA detector. The observation of the γ-proton anticorrelation indicate that the dominant production mechanism is the first chance neutron-proton collisions. Very energetic protons, with energy more than twice the kinematical limit for nucleon-nucleon collisions, have been observed in several reactions.

Published
1998
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14. The giant dipole resonance in hot Sn nuclei

Author

J.C. Roynette, A. Gillibert, T. Suomijärvi, D. Pierroutsakou, F. Auger, N. Frascaria, J. L. Sida, N. Alamanos, I. Lhenry, P. R. S. Gomes, Institut de Physique Nucléaire d'Orsay (IPNO), 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
Nuclear reaction, Physics, Nuclear and High Energy Physics, Angular momentum, 010308 nuclear & particles physics, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Resonance (particle physics), Spectral line, Dipole, Excited state, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Saturation (chemistry), Excitation, Nuclear Physics
Abstract

We have studied the Giant Dipole Resonance (GDR) built on the excited states of 112Sn formed in the fusion of 19F with 93Nb. The excitation energy of the compound nucleus 112Sn was 130 and 152 MeV. High-energy γ-rays were detected in a 7-element BaF2 cluster and 4 NaI(Tl) scintillators. Coincidences with the evaporation residues detected in two parallel-plate avalanchecounters ensured that the γ-rays were associated with fusion events. In order to study the characteristics of the GDR, we have performed analyses of the γ-ray spectra within the statistical model, using a continuous evolution of the GDR centroid energy with the mass and the temperature of the emitting nucleus, and a nuclear temperature dependent level density parameter. The theoretical prescriptions concerning the evolution of the GDR width with excitation energy have been tested. We show that, in order to reproduce the γ-spectra, the increase of the width must be more rapid than the two theoretical predictions. The width has to reach large values, of the order of 15 to 20 MeV above 100 MeV of excitation energy. These values are greater than the saturation value of about 12 MeV which has been published following the analyses using constant parameters. On this condition, the shape of the spectra can be reproduced with or without a saturation of the width. It is therefore not possible to say if the increase of the width is due to angular momentum effects or to collisional effects.

Published
1996

15. The Giant Dipole Resonance Built on Highly Excited States

Author

Paolo Finocchiaro, M. Lamehi-Rachti, C. Agodi, N. Alamanos, N. Frascaria, J.C. Roynette, J.H. Le Faou, A. Del Zoppo, R. Liguori-Neto, Paolo Sapienza, J.P. Garron, G. Bellia, F. Auger, P. Piattelli, J. J. Gaardhøje, Domenico Santonocito, T. Suomijärvi, R. Alba, R. Coniglione, Y. Blumenfeld, E. Migneco, C. Maiolino, Ph. Chomaz, A. Gillibert, and J.A. Scarpaci

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Evaporation, Resonance, Charged particle, Dipole, Excited state, Yield (chemistry), Giant resonance, Physics::Accelerator Physics, Atomic physics, Nuclear Experiment, Excitation
Abstract

Gamma-rays emitted from hot nuclei of mass around 115 and excitation energies above 300 MeV, formed in the 36Ar + 90Zr at 27 MeV/u, 36Ar + 94Zr at 32 MeV/u and 36Ar + 98Mo at 37 MeV/u, have been measured with the MEDEA multidetector in coincidence with light charged particles and evaporation residues. The γ-ray yield from the decay of the Giant Dipole Resonance is independent of excitation energy and of bombarding energy.The best agreement with the data is obtained by assuming a cut-off the resonace γ-emission above an excitation energy of 250 MeV.

Published
1996
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16. Towards limiting temperatures in nuclei: the behavior of collective motion

Author

Philippe Chomaz, R. Alba, A. Gillibert, N. Alamanos, G.V. Russo, Paolo Piattelli, C. Maiolino, N. Frascaria, T. Suomijärvi, R. Coniglione, C. Agodi, G. Bellia, J. A. Scarpaci, R. Liguori-Neto, J.C. Roynette, F. Auger, Le Faou Jh, M. Lamehi-Rachti, Augusto Smerzi, J. J. Gaardhøje, E. Migneco, J.P. Garron, Y. Blumenfeld, Del Zoppo A, Domenico Santonocito, Paolo Sapienza, Paolo Finocchiaro, 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), 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
Nuclear reaction, Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Gamma ray, General Physics and Astronomy, Resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Electromagnetic radiation, Dipole, Giant resonance, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Excitation, 25.70.Ef, 24.30.Cz, 25.70.Gh
Abstract

Gamma rays emitted from hot nuclei with mass around 115 and excitation energies between 350 and 500 MeV, formed in the [sup 36]Ar + [sup 90]Zr reaction at 27 MeV/nucleon have been measured. The [gamma]-ray yield from the decay of the giant dipole resonance in these nuclei remains constant over the excitation energy range studied. This quenching of the [gamma] multiplicity cannot be explained by a continuous increase with temperature of the width of the resonance. Better agreement with the data is obtained by assuming a cutoff of [gamma] emission from the resonance above an excitation energy of 250 MeV. The existing data do not show entrance channel effects.

Published
1994
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17. Neutron decay of the excitation-energy region up to 60 MeV excited by heavy-ion scattering.(II) $^{90}$Zr and $^{124}$Sn

Author

A.M. van den Berg, N. Alamanos, T. Suomaijärvi, J.A. Scarpaci, Sijtze Brandenburg, Nils Olsson, R. Turcotte, A. van der Woude, J.C. Roynette, J.A. Bordewijk, Y. Blumenfeld, Jan Blomgren, A. Gillibert, D. Chmielewska, Lars-Olof Nilsson, P. Roussel-Chomaz, F. Auger, N. Frascaria, Institut de Physique Nucléaire d'Orsay (IPNO), 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, Decay scheme, 010308 nuclear & particles physics, Scattering, Nuclear Theory, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Ion, Nuclear physics, Excited state, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Excitation
Abstract

The neutron decay of the continuum in Zr-90 and Sn-124, excited by inelastic scattering of 84A MeV O-17 ions in the range from 1.5 to 4.5-degrees, has been measured. Statistical decay was found to dominate the excitation-energy interval studied, up to about 50 MeV. In the excitation-energy interval from the neutron threshold up to about 35 MeV a distinct direct-decay component to the hole states in Zr-89 and Sn-123 was observed. In addition, a decay pattern resembling pre-equilibrium decay was observed for Zr-90. In the excitation energy spectrum of Zr-90 gated by low-energy (

Published
1994

18. Some recent results on neutron decay of $^{208}$Pb excited to energies in the 14 to 25 MeV range

Author

T. Suomijärvi, J. A. Scarpaci, N. Alamanos, Lars-Olof Nilsson, A. van der Woude, J.C. Roynette, F. Auger, Nils Olsson, J.A. Bordewijk, Sijtze Brandenburg, Y. Blumenfeld, N. Frascaria, A. Gillibert, D. Chmielewska, P. Roussel-Chomaz, A.M. van den Berg, R. Turcotte, Jan Blomgren, 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), and Damage and Repair in Cancer Development and Cancer Treatment (DARE)

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), 010308 nuclear & particles physics, GIANT MONOPOLE RESONANCE, Nuclear Theory, Resonance, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, DIPOLE, REGION, Nuclear physics, Dipole, Excited state, 0103 physical sciences, Neutron, High Energy Physics::Experiment, Atomic physics, 010306 general physics, Nuclear Experiment, Excitation
Abstract

First results of an 208 Pb( 17 0, 17 0'n) 207 Pb experiment at 84 MeV n , designed to study the neutron decay of the Giant Dipole Resonance and the region above, is presented. Direct decay up to an excitation energy of 25 MeV in 208 Pb has been observed. The direct decay branch in the GDR energy region is about 5%.

Published
1993

19. Excitation of giant resonances in $^{208}$Pb $^{120}$Sn $^{90}$Zr and $^{60}$Ni by 84 MeV/nucleon $^{17}$O ions

Author

A. Gillibert, J. Barrette, B. Fernandez, S. K. Mark, Y. Blumenfeld, A. van der Woude, P. Roussel-Chomaz, J.P. Garron, J. Gastebois, J. A. Scarpaci, J.C. Roynette, R. Liguori Neto, A. Miczaika, T. Suomijärvi, N. Frascaria, N. Alamanos, F. Auger, R. Turcotte, Roy A. Lacey, A.M. van den Berg, L. Rochais, D. Pierroutsakou, Institut de Physique Nucléaire d'Orsay (IPNO), 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
Nuclear reaction, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Isoscalar, Nuclear Theory, Resonance, Coulomb excitation, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, 0103 physical sciences, Quadrupole, Sum rule in quantum mechanics, Atomic physics, 010306 general physics, Excitation
Abstract

Elastic and inelastic scattering of 1435 MeV 17O ions on 208Pb, 120Sn, 90Zr and 60Ni have been measured. Hindrance in the excitation of the first 3− states is observed. Parameters of the isoscalar giant monopole and quadrupole resonances are obtained. The quadrupole resonance exhausts ∼ 55% of the energy-weighted sum rule while the observed monopole resonance corresponds to more than 100% of the sum rule. Strength is also observed at high excitation energy in all targets.

Published
1993
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20. HIGH EXCITATION ENERGY STRUCTURES IN HEAVY ION COLLISIONS ON A208Pb TARGET

Author

J.C. Jacmart, A. Gamp, M. Buenerd, J.C. Roynette, Ph. Chomaz, D. Lebrun, W. von Oertzen, Y. Blumenfeld, J.P. Garron, N. Frascaria, W. Bohne, Ph Martin, 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 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
Spectrometer, Chemistry, Nuclear Theory, General Engineering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Spectral line, Time of flight, medicine.anatomical_structure, [PHYS.HIST]Physics [physics]/Physics archives, medicine, Physics::Accelerator Physics, Heavy ion, Atomic physics, Nuclear Experiment, Nucleus, Energy (signal processing), Excitation
Abstract

Energy spectra of fragments from the 36Ar +208Pb reaction at 11 MeV/n and 20Ne + 208Pb reaction at 30 MeV/n were measured using a time of flight spectrometer. Structures ranging up to 130 MeV excitation energy are observed in the inelastic spectra. These structures are shown to be due to an excitation of the208Pb target nucleus.

Published
1984
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21. Correlations between emerging alpha-particles and heavy ions in 32S+197 Au collisions

Author

N. Poffé, A. Gamp, H. Doubre, J.C. Jacmart, J. Wilczynski, J.C. Roynette, Institut de Physique Nucléaire d'Orsay (IPNO), 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, Field (physics), 010308 nuclear & particles physics, Projectile, Nuclear Theory, Alpha particle, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Ion, Nuclear physics, medicine.anatomical_structure, Coincident, 0103 physical sciences, Coulomb, medicine, Incident energy, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleus
Abstract

In-plane angular correlations between α-particles and projectile residue nuclei ( Z =5−22) emerging from 32 S+ 197 Au collisions have been measured at 373 MeV incident energy. In the combined Coulomb field of the projectile residue and the target nucleus coincident α-particles are strongly focused into a narrow cone. Model calculations indicate that α-emission originates from the region of the projectile which is facing the target nucleus during the collision.

Published
1978
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22. Réactions (p, 2p) À 156 MeV

Author

M. Riou, M. Arditi, J.C. Jacmart, J.C. Roynette, F. Mazloum, and C. Ruhla

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Scintillation, Spectrometer, Physics::Instrumentation and Detectors, Scattering, Nuclear Theory, Resolution (electron density), Spectral line, Nuclear physics, Physics::Accelerator Physics, Atomic physics, Nuclear Experiment
Abstract

Quasi-free proton-proton scattering at 6 Li, 7 Li and 9 Be has been studied at 156 MeV with an overall energy resolution of 2.1 MeV for 6 Li and 1.7 MeV for 7 Li and 9 Be. Two magnetic spectrometers, multi-channel scintillation detectors or spark chambers and an on-line computer were used. Summed energy spectra and angular correlations of the components of these spectra are given. The results suggests 1p + 2s configuration mixing for external protons in 6 Li and 7 Li. The (1s) −1 splitting is observed for both nuclei.

Published
1967
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23. Direct reactions induced by 14N on 12C AT 78MeV

Author

F. Pougheon, C. Stephan, M. Riou, J.C. Roynette, J.C. Jacmart, Miaoyuan Liu, C. Caverzasio, and W. von Oertzen

Subjects
Physics, Elastic scattering, Nuclear reaction, Nuclear and High Energy Physics, Nuclear Theory, Carbon-12, Coulomb barrier, Inelastic scattering, Ion, Nuclear physics, Isospin, Atomic physics, Nuclear Experiment, Nucleon
Abstract

Direct reactions induced by 14 N on 12 C at 78 MeV are studied. Angular distributions of the inelastic scattering and transfer of one and two nucleons have been measured. The DWBA analysis of the transfer based on the theory of Buttle and Goldfarb extended well above the Coulomb barrier has been performed. Using the Barshay and Temmer theorem, the isospin conservation in one-nucleon transfer reactions between heavy ions has been tested.

Published
1970
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24. Réactions (p, 2p) À 156 MeV

Author

M. Arditi, C. Ruhla, R.A. Ricci, J.C. Roynette, J.C. Jacmart, H. Doubre, M. Riou, and Miaoyuan Liu

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Spectrometer, Scattering, Nuclear Theory, Binding energy, Resolution (electron density), Shell (structure), Physics::Accelerator Physics, Atomic physics, Nuclear Experiment, Spectral line
Abstract

Quasi-free proton-proton scattering at Ca and eight 1 f 7 2 shell nuclei has been studied at E p = 156 MeV with an overall energy resolution of 2.1 MeV, using two magnetic spectrometers. The 2 s 1 2 shell levels were detected in the summed energy spectra; some angular correlations were measured. The s 1 2 shell is shallow; the binding energies are 11–14 MeV. This implies that for these nuclei a gap of at least 20 MeV exists between the 2s, 1d and 1s, 1p regions.

Published
1967
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25. Forward angle measurements of 60 MeV/nucleonAr40peripheral interactions onPb208

Author

T. Suomijärvi, Y. Blumenfeld, B. Berthier, Didier Beaumel, J.C. Roynette, J. Barrette, N. Frascaria, Ph. Chomaz, J. Gastebois, J.C. Jacmart, B. Fernandez, J.P. Garron, and W. Mittig

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, Nuclear Theory, 01 natural sciences, Spectral line, Nuclear physics, Forward angle, Fragmentation (mass spectrometry), Electric field, 0103 physical sciences, Coulomb, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Velocity and angular distributions of projectile-like fragments were measured between theta/sub lab/ = 0/sup 0/ and 4/sup 0/ (inside the grazing angle) for the /sup 40/Ar+ /sup 208/Pb system at 60 MeV/nucleon using a magnetic spectrometer. Velocity spectra are similar to those obtained at larger angles, while the angular distributions, very forward peaked for light nuclei, tend to become flat for the heaviest fragments. The influence of the Coulomb and nuclear deflection of the fragments is discussed.

Published
1987
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26. A heavy-ion reaction leading to members of an isospin multiplet

Author

W. von Oertzen, J.C. Roynette, F. Pougheon, J.C. Jacmart, M. Riou, and Miaoyuan Liu

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle physics, High Energy Physics::Phenomenology, Nuclear Theory, Carbon-13, Carbon-12, Nuclear physics, Angular distribution, Isospin, Isospin multiplet, Heavy ion, Mirror nuclei, Nuclear Experiment
Abstract

A heavy-ion reaction leading to two members of the same isospin multiplet in the exit channel has been studied. The angular distribution is symmetric about 90°. This proves the “indentity” of mass 13 mirror nuclei, as seen from a nuclear reaction in which isospin is concerned.

Published
1969
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27. Angular evolution of peripheral heavy ion reactions at intermediate energies

Author

J.P. Garron, Ph. Chomaz, J.C. Roynette, D. Ardouin, Y. Blumenfeld, N. Frascaria, W. Mittig, J.C. Jacmart, Institut de Physique Nucléaire d'Orsay (IPNO), 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, Projectile, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Spectral line, Fragmentation (mass spectrometry), 0103 physical sciences, Heavy ion, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Energy spectra and angular distributions of projectile-like fragments have been measured in the vicinity of the grazing angle for the 40Ar + 40Ca and 40Ar + 208Pb reactions at 44 MeV/nucleon. Measurements of the 40Ar + 40Ca system at 27 MeV/nucleon and 20Ne + 208Pb reaction at 44 MeV/nucleon at one angle have also been performed. For fragments with charge and mass close to the projectile numerous deviations from the standard fragmentation model have been observed including rapidly changing shapes of the angular distributions with the fragment mass. Moreover the isotopic distributions and mean fragment velocities are strongly dependent on detection angle. A surface transfer reaction component dominant at the grazing angle can be separated from a second component which cannot be entirely accounted for by a simple fragmentation mechanism.

Published
1986

28. Elastic and inelastic scattering of $^{86}$Kr on $^{208}$Pb at E$_{lab}$ = 43 MeV/nucleon

Author

B. Berthier, L. Kraus, J.C. Roynette, I. Linck, N. Frascaria, J. Gastebois, Ph. Chomaz, J.C. Jacmart, B. Fernandez, Y. Blumenfeld, W. Mittig, P. Roussel-Chomaz, J.P. Garron, J. Barrette, N. Alamanos, 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), 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 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, Isovector, 010308 nuclear & particles physics, Isoscalar, Nuclear Theory, Coulomb excitation, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Inelastic neutron scattering, Nuclear physics, Dipole, 0103 physical sciences, Quadrupole, Atomic physics, 010306 general physics, Nucleon
Abstract

Elastic and inelastic angular distributions of 43 MeV/nucleon 86 Kr on 208 Pb have been measured. Coulomb excitation of the low-lying collective states has a much smaller effect on the elastic angular distribution than observed at low bombarding energy. The inelastic angular distributions to the first 2 + states in 86 Kr and 208 Pb are well reproduced by coupled-channel calculations using adopted B (E2) values. Above E ∗ = 7 MeV the inelastic spectra are dominated by Coulomb excitation of the isovector giant dipole and isoscalar giant quadrupole resonances.

Published
1988
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29. On the time scale of $^{40}$Ca+$^{40}$Ca strongly damped reactions

Author

N. Frascaria, J.C. Jacmart, J.C. Roynette, H. Doubre, N. Poffé, M. Riou, Institut de Physique Nucléaire d'Orsay (IPNO), 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, Scattering, Component (thermodynamics), Fission, Nuclear Theory, Inelastic collision, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, medicine.anatomical_structure, 0103 physical sciences, medicine, Atomic number, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleus
Abstract

The time dependence of 40Ca+40Ca deep inelastic collisions is studied by means of the fragment change and mass distributions. Two time components are unfolded. The “fast” one exhibits all features of “quasi-fission”. The characteristics of the “slow” component cannot be distinguished from compound nucleus fission.

Published
1977

30. High excitation inelastic scattering induced by intermediate energy $^{40}$Ar beams

Author

J.C. Roynette, J.C. Jacmart, Y. Blumenfeld, Ph. Chomaz, J.P. Garron, N. Frascaria, W. Mittig, T. Suomijärvi, 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), 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 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)

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Resonance (particle physics), Giant resonance, Excited state, 0103 physical sciences, Quadrupole, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Excitation
Abstract

The inelastic channels of the 40Ar + 40Ca, 90Zn, 120Sn and 208Pb reactions at 44 MeV/nucleon and the 40Ar + 90Zr reaction at 33 MeV/nucleon were measured with a time-of-flight spectrometer in the vicinity of the respective grazing angles. In addition to the well known giant quadrupole resonance which is strongly excited, structures at higher excitation energies are observed in all the studied reactions. The existence and regular spacing of these structures are quantitatively confirmed by auto-correlation, cross correlation and Fourier analyses. The contributions to the spectra of transfer-evaporation reactions are calculated by Monte Carlo methods and are shown to reproduce the measured backgrounds. The excitation energies of the bumps are then shown to vary smoothly with target mass A as A − 1 3 . Interpretations of this phenomenon involving giant resonance and multiphonon excitations and multi-transfer reactions are discussed.

Published
1987
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31. High excitation energy structures in $^{208}$Pb

Author

W. Bohne, Ph Martin, W. von Oertzen, Y. Blumenfeld, J.C. Roynette, Ph. Chomaz, D. Lebrun, J.C. Jacmart, M. Buenerd, J.P. Garron, N. Frascaria, A. Gamp, 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 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, Nuclear and High Energy Physics, Spectrometer, 010308 nuclear & particles physics, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Spectral line, Time of flight, medicine.anatomical_structure, Giant resonance, 0103 physical sciences, medicine, Nuclear fusion, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleus, Excitation, Direct process
Abstract

Inelastic spectra from the36Ar+208Pb reaction at 11 MeV/n and20Ne+208Pb at 30 MeV/n have been measured with a time of flight spectrometer. Structures ranging up to 100 MeV excitation energy are observed together with previously known giant resonance excitations. Transfer-evaporation reactions are shown to contribute only to the background under the structures. These structures are interpreted in terms of an excitation of the target nucleus through a direct process.

Published
1984

32. Limiting temperatures for collective motion: The giant dipole resonance in very hot nuclei

Author

J.H. Le Faou, G. Bellia, Paolo Finocchiaro, T. Suomijärvi, C. Agodi, J.C. Roynette, K. Loukachine, Ph. Chomaz, R. Alba, R. Liguori-Neto, C. Maiolino, J.P. Garron, Y. Blumenfeld, J.A. Scarpaci, Domenico Santonocito, Paolo Piattelli, E. Migneco, Paolo Sapienza, R. Coniglione, A. Gillibert, M. Lamehi-Rachti, J. J. Gaardhøje, N. Alamanos, N. Frascaria, A. Del Zoppo, F. Auger, 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), 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 reaction, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Electromagnetic radiation, Resonance (particle physics), Charged particle, Dipole, Excited state, Giant resonance, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Excitation
Abstract

The study of the Giant Dipole Resonance (GDR) excited in hot nuclei allows to follow the evolution of collective motion with increasing nuclear temperature. A brief review of the characteristics of the GDR excited in nuclei with excitation energies up to ∼ 500 MeV is given. The results of recent experiments in which very hot nuclei have been studied with a nearly 4π detector are presented. Gamma-rays, light charged particles and evaporation residues emitted from hot nuclei of mass around 115 and excitation energies above 300 MeV, formed in the 36 Ar + 90 Zr at 27 MeV/u and 36 Ar + 98 Mo at 37 MeV/u reactions, have been measured with the MEDEA multidetector. The γ-ray yield from the decay of the Giant Dipole Resonance in these nuclei has been found to be independent of excitation energy and bombarding energy. The measured γ-ray spectra are compared with statistical calculations encompassing several recent theoretical models for the quenching of gamma-ray emission from the dipole resonance at very high temperatures. The best agreement with the data is obtained by assuming a cut-off of the resonance γ-emission above an excitation energy of 250 MeV.

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33. Hard photons and energetic protons as probes of the nuclear dynamics at intermediate energy

Author

A. Gillibert, Giacomo Vito Margagliotti, G. Bellia, J.C. Roynette, M. L. Fiandri, R. Alba, C. Agodi, R. Coniglione, A. Péghaire, Philippe Chomaz, Paolo Piattelli, P. G. Ventura, T. Suomijärvi, P. M. Milazzo, P. F. Mastinu, E. Migneco, Paolo Finocchiaro, G. Vannini, Nicola Colonna, Y. Blumenfeld, K. Loukachine, F. Gramegna, Laura Fabbietti, N. Alamanos, N. Frascaria, M. Bruno, Domenico Santonocito, A. Del Zoppo, Rinaldo Rui, F. Auger, A. Moroni, M. D'Agostino, Paolo Sapienza, Maria Colonna, I. Iori, J.A. Scarpaci, C. Maiolino, 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), A.A.V.V., Sapienza, P, Coniglione, R, Migneco, E, Agodi, C, Alba, R, Bellia, G, Colonna, M, Del Zoppo, A, Finocchiaro, P, Loukachine, K, Maiolino, C, Piattelli, P, Santonocito, D, Ventura, Pg, Colonna, N, Bruno, M, D'Agostino, M, Mastinu, Pf, Fiandri, Ml, Gramegna, F, Iori, I, Fabbietti, L, Moroni, A, Margagliotti, Giacomo, Milazzo, Pm, Rui, Rinaldo, Vannini, G, Blumenfeld, Y, Suomijarvi, T, Frascaria, N, Roynette, Jc, Scarpaci, Ja, Alamanos, N, Auger, F, Gillibert, A, Chomaz, P, Peghaire, A., 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, Photon, 010308 nuclear & particles physics, Scattering, Nuclear Theory, Detector, Fermi energy, HEAVY-ION COLLISIONS, MULTIELEMENT DETECTOR ARRAY, IMPACT PARAMETER, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, Intermediate energy, Nuclear dynamics, 0103 physical sciences, Impact parameter, Atomic physics, Nuclear Experiment, 010306 general physics, Anisotropy
Abstract

The emission of hard photons and pre-equilibrium protons has been investigated in exclusive experiments performed with MEDEA detector The observation of the gamma-proton anticorrelation indicates that the dominant production mechanism is the first-chance neutron-proton (np) collisions. The anisotropic angular distributions point out the presence of screening effects and are reminiscent of the free np scattering thus giving information of the space-time origin of the energetic protons. Protons, with energy more than twice the kinematical limit for nucleon-nucleon (NN) collisions, have been observed in several reactions around the Fermi energy.

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