Search

Your search keyword '"Neil Rowley"' showing total 30 results
Start Over Author "Neil Rowley" Topic [phys.nexp]physics [physics]/nuclear experiment [nucl-ex]
30 results on '"Neil Rowley"'

1. Isomeric states in 253No

Author

A. Minkova, O. Dorvaux, Louise Stuttge, Neil Rowley, Yu. Ts. Oganessian, A. Lopez-Martens, Sunniva Siem, A. Korichi, M. L. Chelnokov, D. Curien, André Larsen, A. P. Kabachenko, Alexey Belozerov, S. Sharo, B. Gall, A. I. Svirikhin, R. N. Sagaidak, K. Hauschild, V. A. Gorshkov, M. Rousseau, A. G. Popeko, Ch. Briançon, Francis Hanappe, V. I. Chepigin, Magne Guttormsen, O. N. Malyshev, Alexander Yeremin, Pierre Désesquelles, Ch. Theisen, N. U. H. Syed, F. Khalfallah, A. Shutov, 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), Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), financement du CNRS/IN2P3, du JINR, du Russian Foundation for Basic Research, des programmes de coopération JINR-Allemagne, JINR-Pologne et JINR-Slovaquie, du Norwegian Research Council, du Bulgarian National Foundation, GABRIELA, 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, noyaux lourds, 010308 nuclear & particles physics, Hadron, 21.10.-k 21.10.Tg 23.20.Lv 23.30.Nx, mesure de temps de vie, Parity (physics), Electron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, spectrosocpie gamma et électrons de conversion, Crystallography, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, Ground state
Abstract

6 pages; International audience; Isomeric states in 253No have been investigated by conversion-electron and gamma-ray spectroscopy with the GABRIELA detection system. The 31 micro second isomer reported more than 30 years ago is found to decay to the ground state of 253No by the emission of a 167 keV M2 transition. The spin and parity of this low-lying isomeric state are established to be 5/2+. The presence of another longer-lived isomeric state is also discussed.

Published
2007

2. Fusion-evaporation cross-sections for 48Ca + 154Sm near the Coulomb barrier

Author

Fernando Scarlassara, F. Haas, A. Gadea, Y. W. Wu, B. R. Behera, Suzana Szilner, I. M. Itkis, R. N. Sagaidak, S. Courtin, A. Yu. Chizhov, G. N. Kniajeva, A. M. Stefanini, S. Beghini, L. Corradi, E. M. Kozulin, A. Latina, V. M. Voskressensky, E. Fioretto, Neil Rowley, M. Trotta, N. A. Kondratiev, I. V. Pokrovskiy, G. Montagnoli, Institut de Recherches Subatomiques (IReS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Fusion, Range (particle radiation), Hadron, Evaporation, Nuclear fusion, Coulomb barrier, Prolate spheroid, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Deformation (engineering), Atomic physics, 25.70.-z - Low and intermediate energy heavy-ion reactions. 25.70.Jj - Fusion and fusion-fission reactions
Abstract

Measurements of fusion-evaporation cross-sections for the system 48Ca + 154Sm have been performed in the sub- and near-barrier energy range. Barrier-passing cross-sections have been obtained by adding recently measured capture-fission cross-sections at the same energies, and the barrier distribution for capture has been extracted. The data have been analyzed within a coupled-channel model, and a large subbarrier cross-section enhancement is observed, due to the ground-state prolate deformation of 154Sm. The 48Ca + 154Sm capture cross-sections are compared to existing data on 16O + 186W fusion, leading to the same CN, where a few higher-energy points have also been measured. The evaporation residue cross-sections for the two systems above the barrier indicate that complete fusion is inhibited for 48Ca + 154Sm by ≈ 40% in that energy region, with respect to 16O + 186W.

Published
2005

3. Nuclear physics with simple and multi-element detectors and with stable and radioactive beams

Author

Neil Rowley, 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 Heyd, Yvette

Subjects
Physics, Nuclear physics, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Physics::Instrumentation and Detectors, Detector, General Physics and Astronomy, Fusion barrier, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Multi element
Abstract

The phenomenon of fusion barrier distributions is discussed in the context of a problem already investigated in some detail with simple detection systems, but possessing avenues to studies with multi-detector arrays. The complementarity of research with simple and complex detectors, as well as with stable and radioactive beams, will be highlighted.

Published
2001

4. Structure and reactions at Coulomb-barrier energies

Author

Neil Rowley, Heyd, Yvette, Institut de Recherches Subatomiques (IReS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Work (thermodynamics), Fusion, Society, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Projectile, Evaporation, Coulomb barrier, Global, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Democracy, Knowledge, Complementarity (molecular biology), Atomic physics, Innovation, Nuclear Experiment, Spectroscopy
Abstract

This paper has three parts. In the first, it is thrown light about the economics of innovation departing from Schumpeter up to now. The main message is that innovation is a key issue to get economic wealth. But this is not without creating ups and downs in society using market economics and being liberal democracy. In the second, the global village's wealth at the long run is illuminated giving a world's legitimacy to the concern for innovation. In the third, a new knowledge policy is proposed. It is a way to capitalise on a wider spectrum of knowledge than today through market economics. Indeed, the new policy looks at the full set of knowledge a society from a given civilisation has at a certain moment of time. This seems to be more relevant when markets are open and civilisations encounter more than in the past. The new knowledge policy is a way to get new and more shared growth than in the past.

Published
1998

5. In-beam spectroscopy with intense ion beams: Evidence for a rotational structure in246Fm

Author

Daniel Cox, Neil Rowley, Rauno Julin, Andrej Herzan, A. Lopez-Martens, Ulrika Jakobsson, Pauli Peura, Paivi Nieminen, T. L. Khoo, Paul Greenlees, B. Sulignano, K. Hauschild, D. Seweryniak, Janne Pakarinen, Philippos Papadakis, S. Juutinen, T. Grahn, Steffen Ketelhut, F. P. Heßberger, F. Dechery, O. Dorvaux, Sami Rinta-Antila, E. Parr, J. Piot, Juha Uusitalo, Jan Sarén, Matti Leino, B. J. P. Gall, Juha Sorri, Peter B. Jones, C. Scholey, L.-L. Andersson, P. Ruotsalainen, G. Henning, R.-D. Herzberg, J. Rubert, M. Sandzelius, P. Rahkila, J. Ljungvall, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), ISOLDE, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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, ta114, 010308 nuclear & particles physics, 23.20.−g, 24.10.Eq, 21.10.Re, 27.90.+b, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Tracking (particle physics), 01 natural sciences, Recoil electron, Kokeellinen ydinfysiikka, Semiconductor detector, Ion, Recoil, Cardinal point, Nuclear magnetic resonance, 0103 physical sciences, Nuclear Physics - Experiment, Experimental nuclear physics, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy, Beam (structure)
Abstract

The rotational structure of ${}^{246}$Fm has been investigated using in-beam $\ensuremath{\gamma}$-ray spectroscopic techniques. The experiment was performed using the JUROGAMII germanium detector array coupled to the gas-filled recoil ion transport unit (RITU) and the gamma recoil electron alpha tagging (GREAT) focal plane detection system. Nuclei of ${}^{246}$Fm were produced using a 186 MeV beam of ${}^{40}$Ar impinging on a ${}^{208}$Pb target. The JUROGAMII array was fully instrumented with Tracking Numerical Treatment 2 Dubna (TNT2D) digital acquisition cards. The use of digital electronics and a rotating target allowed for unprecedented beam intensities of up to 71 particle-nanoamperes for prompt $\ensuremath{\gamma}$-ray spectroscopy at a level of approximately 11 nb. With all these major experimental advances a rotational band is observed in ${}^{246}$Fm.

Published
2012

6. Subbarrier fusion reactions with dissipative couplings

Author

Neil Rowley, S. Yusa, Kouichi Hagino, 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, Nuclear Theory, 010308 nuclear & particles physics, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear Theory (nucl-th), Condensed Matter::Superconductivity, 0103 physical sciences, Dissipative system, Rectangular potential barrier, Nuclear fusion, Atomic physics, 010306 general physics, Nuclear theory, Random matrix
Abstract

Using the random matrix model, we discuss the effect of couplings to non-collective states on the penetrability of a one dimensional potential barrier. We show that these non-collective excitations hinder the penetrability and thus smear the barrier distribution at energies above the barrier, while they do not affect significantly the penetrability at deep subbarrier energies. The energy dependence of the Q-value distribution obtained with this model is also discussed., 4 pages, 2 figures. A talk given at the 10th international conference on nucleus-nucleus collisions (NN2009), Aug. 16-21, 2009, Beijing, China

Published
2009

7. Capture barrier distributions: Some insights and details

Author

Neil Rowley, M. Trotta, N. Grar, Département Recherches Subatomiques (DRS-IPHC), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Projectile, Phonon, 0103 physical sciences, Quadrupole, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Atomic physics, 010306 general physics, Polarization (waves), 01 natural sciences, 24.10.Eq, 24.60.Dr, 25.60.Pj, 25.70.Jj
Abstract

The 'experimental barrier distribution' provides a parameter-free representation of experimental heavy-ion capture cross sections that highlights the effects of entrance-channel couplings. Its relation to the s-wave transmission is discussed, and in particular it is shown how the full capture cross section can be generated from an l=0 coupled-channels calculation. Furthermore, it is shown how this transmission can be simply exploited in calculations of quasifission and evaporation-residue cross sections. The system {sup 48}Ca+{sup 154}Sm is studied in detail. A calculation of the compound-nucleus spin distribution reveals a possible energy dependence of barrier weights due to polarization arising from target and projectile quadrupole phonon states; this effect also gives rise to an entrance-channel 'extra-push'.

Published
2007

8. Barrier distribution for a ‘superheavy' nucleus–-nucleus collision

Author

Robert Bark, S. M. Maliage, C. Theron, Matej Lipoglavšek, L.J. Mudau, Neil Rowley, J. J. Lawrie, E. A. Lawrie, Robert S. Lindsay, R. Neveling, S. M. Mullins, F. D. Smit, G. Sletten, O. M. Ndwandwe, S. V. Förtsch, S. S. Ntshangase, Département Recherches Subatomiques (DRS-IPHC), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear reaction, Nuclear and High Energy Physics, Nuclear Theory, 24.10.Eq, 25.70.Bc, 25.70.Jj, Deep-inelastic scattering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Cold fusion, 0103 physical sciences, medicine, Barrier distributions, 010306 general physics, Nuclear Experiment, Physics, Quasielastic scattering, Fusion, Quasi-fission, 010308 nuclear & particles physics, Deep inelastic scattering, medicine.anatomical_structure, Quasiparticle, Dissipative system, Superheavy-element creation, Atomic physics, Nucleus
Abstract

Large-angle quasielastic scattering has been studied in a high- Z 1 Z 2 nuclear reaction of the type leading to superheavy-element production by cold fusion. We show that despite the presence of strongly dissipative channels, and the complete absence of fusion, the notion of an external barrier distribution, determined by strong coupling to collective excitations of target and projectile, is still valid. Furthermore, our method allows us to deduce some properties of the deep-inelastic processes in this system.

Published
2007

9. STRUCTURE OF BARRIER DISTRIBUTIONS: PROBING THE ROLE OF NEUTRON-TRANSFER CHANNELS

Author

A.J. Kordyasz, M. Kisieliński, Jerzy Jastrzębski, E. Piasecki, A. M. Stefanini, Manfred Mutterer, Ł. Świderski, Krzysztof Piasecki, K. Rusek, T. Krogulski, P. Russotto, M. Kowalczyk, Neil Rowley, Département Recherches Subatomiques (DRS-IPHC), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Large deformation, 010308 nuclear & particles physics, Projectile, Structure (category theory), General Physics and Astronomy, Deformation (meteorology), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Excited state, Transfer (computing), 0103 physical sciences, Neutron, Atomic physics, 010306 general physics
Abstract

In view of its large deformation, which should give rise to strong barrier structures, the 20 Ne projectile has been used to study the influence of neutron-transfer channels on the distribution of barrier heights. A previous experiment with a combination of projectiles 20,22 Ne suggested that the role of α-particle transfer channels is small. By an appropriate choice of targets (90 Zr and 92 Zr ), having very similar intrinsic structures (excited states and deformation parameters) but giving rise to different Q-values for neutron transfers, we highlight the role of these channels.

Published
2007

10. Multimodal Fission in Heavy-Ion Induced Reactions

Author

N. A. Kondratiev, Neil Rowley, I. V. Pokrovskiy, J. M. Iitkis, Francis Hanappe, Louise Stuttge, M. G. Iitkis, E. M. Kozulin, Ch. Schmitt, O. Dorvaux, V. Kinnard, A. A. Bogachev, Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), L.Corradi, D.Ackermann, E.Fioretto, A.Gadea, F.Haas, G.Pollarolo, F.Scarlassara, S.Szilner, and M.Trotta

Subjects
Cold fission, Cluster decay, Proton, nuclei with mass number 220 or higher, Chemistry, Fission, Neutron emission, Nuclear Theory, 020206 networking & telecommunications, 02 engineering and technology, Fission product yield, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 25.70.Jj, 27.90.+b, thorium, Nuclear physics, fission of plutonium, 0202 electrical engineering, electronic engineering, information engineering, Physics::Atomic and Molecular Clusters, heavy ion-nucleus reactions, 020201 artificial intelligence & image processing, Neutron, Nuclear Experiment, Excitation, protactinium
Abstract

Mass, energy and folding angle distributions of the fission fragments as well as multiplicities of neutron and gamma‐quanta emissions accompanying the fission process were measured for fission of 226Th, 227Pa and 234Pu compound nuclei produced in reactions with 18O and 26Mg projectiles over a wide energy range. Data were analyzed with respect to the presence of fission modes. Asymmetric fission was observed even at very high initial excitation for all the measured systems. The so‐called fission mode S1 (caused by the proton shell Z∼50 and neutron shell N∼82 in heavy fragment) was found to be dominant in asymmetric fission of 234Pu. Reactions with not full linear momentum transfer were observed in the folding spectra for all the measured systems.

Published
2006

11. GABRIELA : a new detector array for gamma-ray and conversion electron spectroscopy of transfermium elements

Author

O. N. Malyshev, A. G. Popeko, Francis Hanappe, K. Hauschild, Sonsoles Garcia-Santamaria, Louise Stuttge, Yu. Ts. Oganessian, A. Lopez-Martens, V. A. Gorshkov, Ch. Briançon, O. Dorvaux, A. I. Svirikhin, Alexander Yeremin, Neil Rowley, V. I. Chepigin, A. P. Kabachenko, M. L. Chelnokov, Alexey Belozerov, A. Shutov, A. Korichi, 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 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 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, Recoil separators, Nuclear and High Energy Physics, and conversion electron spectroscopy at recoil separators, Fission, Physics::Instrumentation and Detectors, Monte Carlo method, FOS: Physical sciences, Electron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Electron spectroscopy, GEANT Monte Carlo simulations, Nuclear physics, Recoil, 0103 physical sciences, gamma-ray, 23.60.+e, 27.80.+w, 29.30.Dn, 29.30.Kv, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation, Physics, Alpha, 010308 nuclear & particles physics, Detector, Gamma ray, Decay tagging spectrometer
Abstract

With the aid of the Geant4 Monte Carlo simulation package a new detection system has been designed for the focal plane of the recoil separator VASSILISSA situated at the Flerov Laboratory of Nuclear Reactions, JINR, Dubna. GABRIELA (Gamma Alpha Beta Recoil Investigations with the Electromagnetic Analyser VASSILISSA) has been optimised to detect the arrival of reaction products and their subsequent radioactive decays involving the emission of alpha- and beta-particles, fission fragments, gamma- and X-rays, and conversion electrons. The new detector system is described and the results of the first commissioning experiments are presented., 24 pages, Submitted to NIM A

Published
2006

12. The peculiarities of the production and decay of superheavy nuclei

Author

Marian Jandel, I. M. Itkis, M. G. Itkis, G. N. Knyazheva, S. Beghini, J. Kliman, E. M. Kozulin, Louise Stuttge, E. Fioretto, O. Dorvaux, Francis Hanappe, F. Scarlassara, R. N. Sagaidak, L. Corradi, M. Trotta, V. Bouchat, C. Schmitt, N. A. Kondratiev, B. R. Behera, A. A. Bogachev, G. Montagnoli, A. Latina, Thomas Materna, Neil Rowley, Suzana Szilner, A. M. Stefanini, E. V. Prokhorova, A. Ya. Rusanov, L. Krupa, Yu. Ts. Oganessian, I. V. Pokrovsky, Corradi, L., Szilner, S., Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), L.Corradi, D.Ackermann, E. Fioretto, A.Gadea, F.Haas, G.Pollarolo, F.Scarlassara, S.Szilner, and M.Trotta

Subjects
Fission, 27.90.+b, 25.70.Jj, 25.70.Gh, 25.85.-w, Nuclear Theory, Transactinide element, magnesium, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], synthesis of superheavy nuclei, fusion-fission, quasi-fission, 01 natural sciences, 7. Clean energy, Nuclear physics, superheavy nuclei, nickel, iron, 0103 physical sciences, Nuclear fusion, fission, Neutron, titanium, 010306 general physics, Nuclear Experiment, Coalescence (physics), calcium, 010308 nuclear & particles physics, Chemistry, Observable, heavy ion fusion reactions, Atomic physics, Excitation, Radioactive decay
Abstract

The interest in the study of the fission process of superheavy nuclei mainly deals with the opportunity to obtain information about the cross-section of the compound nucleus (CN) formation at excitation energies E*\approx 15–30 MeV. It allows one to estimate the survival probability of the superheavy composite system after evaporation of 1–3 neutrons, i.e. in "cold" or "warm" fusion reactions. However, in order to solve this problem deeper understanding of the coalescence processes between colliding nuclei, the competition between fusion-fission and quasi-fission processes is needed. The characteristics of both processes, their manifestation in the experimental observables and the relative contribution to the capture cross-section in dependence on the excitation energies, reaction entrance channel etc were investigated for a wide range of target-projectile combinations. Results of the experiments devoted to the study of the fusion-fission and quasi-fission processes in the reactions of the formation of the superheavy nuclei with Z = 102–122 are presented. The heavy ions 26Mg, 48Ca, 50Ti, 58Fe and 64Ni were used as projectiles. The choice of the reactions with 48Ca and actinide-targets was inspired by the experiments on the production of the isotopes 283112, 289114 and 283116 in Dubna using the same reactions. The 50Ti, 58Fe and 64Ni projectiles were chosen since the corresponding projectile-target combinations lead to the synthesis of even heavier elements. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia) and the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) using the time-of-flight spectrometer of fission fragments CORSET. The role of the shell effects, the influence of the entrance channel asymmetry and the deformations of colliding nuclei on the mechanism of the fusion-fission and the competitive process of quasi-fission are discussed. The recent results on synthesis of superheavy nuclei and the perspectives of the "hot" fusion reaction for the production of superheavy nuclei are considered.

Published
2006

13. An extra push from entrance-channel effects

Author

Neil Rowley, N. Grar, Kouichi Hagino, Institut de Recherches Subatomiques (IReS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Nuclear Theory, Coulomb excitation, Fusion and fusion-fission reactions, Coulomb barrier, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 24.10.Eq, 25.70.Hi, 25.70.Jj, 25.70.De, Entrance channel, Nuclear Theory (nucl-th), Cross section (physics), Coupled channels, Transmission (telecommunications), Extra push, Quantum electrodynamics, Coulomb, Atomic physics, Nuclear Experiment (nucl-ex), Coulomb barrier distribution, Nuclear theory, Nuclear Experiment
Abstract

Symmetric heavy-ion collisions are known to display an `extra-push' effect. That is, the energy at which the s-wave transmission is 0.5 lies significantly higher than the nominal Coulomb barrier. Despite this, however, the capture cross section is still greatly enhanced below the uncoupled barrier. It is shown that this phenomenon can be simply explained in terms of entrance-channel effects which account for long-range Coulomb excitations., 9 pages, 4 ps figures, uses elsart.cls

Published
2005

14. Capture cross sections for very heavy systems

Author

L.J. Mudau, Robert Bark, F. D. Smith, J. J. Lawrie, Neil Rowley, S. M. Maliage, S. S. Ntshangase, C. Theron, G. Sletten, S. V. Förtsch, R. Neveling, O. M. Ndwandwe, E. Gueorguieva, S. M. Mullins, N. Grar, Département Recherches Subatomiques (DRS-IPHC), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear reaction, Physics, Excitation function, Nuclear and High Energy Physics, Unitarity, BARRIERS, 010308 nuclear & particles physics, Coulomb barrier, FRICTION, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Atomic and Molecular Physics, and Optics, Charged particle, Nuclear physics, Cross section (physics), Recoil, FUSION, 0103 physical sciences, 25.70.Gh - 24.10.Eq - 25.70.Jj, Atomic physics, ION REACTIONS, 010306 general physics, Nucleon, COUPLED-CHANNEL CODE
Abstract

In intermediate-mass systems, collective excitations of the target and projectile can greatly enhance the subbarrier capture cross section σ cap by giving rise to a distribution of Coulomb barriers. For such systems, capture essentially leads directly to fusion [formation of a compound nucleus (CN)], which then decays through the emission of light particles (neutrons, protons, and alpha particles). Thus, the evaporation-residue (ER) cross section is essentially equal to σ cap. For heavier systems, the experimental situation is significantly more complicated owing to the presence of quasifission (QF) (rapid separation into two fragments before the CN is formed) and by fusion-fission (FF) of the CN itself. Thus, three cross sections need to be measured in order to evaluate σ cap. Although the ER essentially recoil along the beam direction, QF and FF fragments are scattered to all angles and require the measurement of angular distributions in order to obtain the excitation function and barrier distribution for capture. Two other approaches to this problem exist. If QF is not important, one can still measure just the ER cross section and try to reconstruct the corresponding σ cap through use of an evaporation-model code that takes account of the FF degree of freedom. Some earlier results on σ cap obtained in this way will be reanalyzed with detailed coupled-channels calculations, and the “extra-push” phenomenon discussed. One may also try to obtain σ cap by exploiting unitarity, that is, by measuring instead the flux of particles corresponding to quasielastic (QE) scattering from the Coulomb barrier. Some new QE results obtained for the 86Kr + 208Pb system at iThemba LABS in South Africa will be presented.

Published
2005

15. Charged particle feeding of hyperdeformed nuclei in the A=118-126 region

Author

A. Bürger, K. Juhasz, J.C. Lisle, Amrendra K. Singh, H. Hübel, A. Korichi, Benedicte Million, A. Neusser, O. Dakov, Gábor Kalinka, R. Moro, J. N. Wilson, J. Robin, Karin Lagergren, J. Gál, G. Sletten, L. Zolnai, P. Bednarczyk, F. Camera, A. Maj, M. Brekiesz, G. Rainovski, Th. Byrski, J. Styczen, Andreas Görgen, A. Al-Khatib, G.B. Hagemann, Nicolas Schunck, P. Bringel, B. M. Nyakó, Jozsef Molnar, S Siem, J Roccaz, Th. Dossing, C. Ronn Hansen, A. O. Evans, L. Piqeras, F. Azaiez, S. Odegard, János Timár, G. de Angelis, A. Lopez-Martens, E. Podsvirova, Zsolt Dombrádi, S. Leoni, D. Curien, Dóra Sohler, W. Gast, P. Fallon, K. Hauschild, H. Jäger, B. Herskind, M. Kmiecik, Alejandro Algora, Bo Cederwall, J. N. Scheurer, A. Bracco, N. Redon, O. Wieland, G. La Rana, G. Benzoni, S.B. Patel, C. M. Petrache, B. J. P. Gall, F. Khalfallah, P. Mason, D. Petrache, J. Dudek, Neil Rowley, R. M. Lieder, G. Duchêne, F. Hannachi, I. Y. Lee, A. Paleni, Kai Zuber, Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), 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 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), 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)-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, Angular momentum, 010308 nuclear & particles physics, Nuclear Theory, Rotational transition, Moment of inertia, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Condensed Matter Physics, 01 natural sciences, Atomic and Molecular Physics, and Optics, Charged particle, Spectral line, Nuclear physics, 0103 physical sciences, Nuclear fusion, Atomic physics, 010306 general physics, Nuclear Experiment, 21.10-Re, 21.60-Ev, Mathematical Physics
Abstract

International audience; A breakthrough was recently obtained in the analysis of the so-called Hyper-Long-HyperDeformed (HLHD) experiment made at the EUROBALL-IV γ-detector array (EB). The 64Ni + 64Ni ⇒ 128Ba* fusion reaction was studied at Ebeam = 255 and 261 MeV, reaching the highest angular momentum that the compound nuclei can accommodate. To date no discrete HD rotational bands have been identified. However, rotational patterns in the form of ridge-structures in three-dimensional (3D) rotational mapped spectra are identified with dynamic moments of inertia J(2) ranging from 71 to 1112 MeV-1 in 12 different nuclei selected by charged particle- and/or γ-gating. The four nuclei, 118Te, 124Cs, 125Cs and 124Xe found with moment of inertia J(2)≥100 2 MeV-1, are most likely hyperdeformed, the remaining nuclei with smaller values of J(2), are considered to be superdeformed, in qualitative agreement with recent theoretical calculations.

Published
2005

16. Absence of structure in the $^{20,22}$Ne + $^{118}$Sn quasi-elastic barrier distribution

Author

Neil Rowley, T. Czosnyka, T. Krogulski, P. Czosnyka, E. Piasecki, Ł. Świderski, A.J. Kordyasz, Jerzy Jastrzębski, M. Kisieliński, Wladyslaw Henryk Trzaska, Manfred Mutterer, Kouichi Hagino, M. Witecki, S. V. Khlebnikov, M. Kowalczyk, Krzysztof Piasecki, Département Recherches Subatomiques (DRS-IPHC), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Coupling, Nuclear reaction, Physics, Nuclear and High Energy Physics, Elastic Barrier, 010308 nuclear & particles physics, Scattering, 22Ne, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Coupled channels, Electric field, Quasi-elastic scattering, 0103 physical sciences, Isotopes of tin, 20Ne, 25.70.Bc, 25.70.Hi, 25.70.Jj, Deformation (engineering), Atomic physics, 010306 general physics, Nucleon, Coulomb barrier distribution
Abstract

Motivated by the extreme deformation parameters of the projectile, we have measured quasi-elastic scattering for 20 Ne + 118 Sn. In contrast to calculations based on known collective states, the experimental barrier distribution is structureless. A comparison with the system 22 Ne + 118 Sn shows that this smoothing is unlikely to be due to nucleon- or α -transfer channels, and is more likely to be due to coupling to many other weak channels.

Published
2005

17. E1 and E2 capture cross section and astrophysical reaction rate of the key reaction $^{12}C$($\alpha$,$\gamma$)$^{16}O$

Author

D. Le Du, M. Rousseau, J Kiener, A Coc, J.L. Weil, E. Galanopoulos, R. Meunier, F. Fleurot, Neil Rowley, E Krmpotic, C. Grama, D. Malcherek, M. Fey, G. Staudt, Tatischeff, C. Beck, J. W. Hammer, A Korichi, R. Kunz, M Assuncao, F Hammache, F Haas, J.J. Correia, Sotirios Harissopulos, S Courtin, Suzana Szilner, A. Lopez-Martens, P. Papka, T. Paradellis, C. Boukari-Pelissie, 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 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 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 physics, Reaction rate, Nuclear and High Energy Physics, Cross section (physics), Nucleosynthesis, 0103 physical sciences, Key (cryptography), Alpha (navigation), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 010303 astronomy & astrophysics, 01 natural sciences
Published
2004

18. Shell effects in fission and quasi-fission of heavy and superheavy nuclei

Author

L. Krupa, J. A¨ysto¨, G. Montagnoli, Neil Rowley, S. Beghini, R. N. Sagaidak, Yu. Ts. Oganessian, E. M. Kozulin, I. V. Pokrovsky, M. Trotta, V. A. Rubchenya, Th. Materna, N. A. Kondratiev, A. M. Vinodkumar, S. Khlebnikov, G. N. Kniajeva, A. Latina, Valery Zagrebaev, A. M. Stefanini, Giorgio Giardina, F. Hanappe, Marian Jandel, I. M. Itkis, L. Stuttge, A. A. Bogachev, W. H. Trzaska, V.M. Voskressenski, E. V. Prokhorova, A. Ya. Rusanov, O. Dorvaux, A. Gadea, M. G. Itkis, J. Kliman, Suzana Szilner, D. N. Vakhtin, L. Corradi, Fernando Scarlassara, Heyd, Yvette, Institut de Recherches Subatomiques (IReS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Isotope, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Fission, Shell (structure), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Tandem accelerator, Entrance channel, Nuclear physics, heavy-ion reactions, ion-induced fission, model, Ca-48, Neutron, Atomic physics, National laboratory
Abstract

Results of the experiments aimed at the study of fission and quasi-fission processes in the reactions ^12C+^204Pb, ^48Ca-^144Sm, ^154Sm, ^168Er, ^208Pb, ^238U, ^244Pu, ^248Cm ; ^58Fe+^208Pb, ^244Pu, ^248Cm, and ^64Ni+^186W, ^242Pu are presented in the work. The choice of the above mentioned reactions was inspired by recent experiments on the production of the isotopes (283)112, (289)114 and (283)116 at Dubna [1], [2] using the same reactions. The Fe-58 and ^64Ni projectiles were chosen since the corresponding projectile-target combinations lead to the synthesis of even heavier elements. The experiments were carried out at the ^400U accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia), the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) and the Accelerator of the Laboratory of University of Jyvaskyla (JYFL, Finland) using the time-of-flight spectrometer of fission fragments CORSET[3] and the neutron multi-detector DEMON[4], [5]. The role of shell effects and the influence of the entrance channel on the mechanism of the compound nucleus fusion-fission and the competitive process of quasi-fission are discussed.

Published
2004

19. Fusion of $^{48}$Ca + $^{154}$Sm near the Coulomb barrier: enhancement vs. suppression

Author

F. Haas, E. Fioretto, S. Beghini, A. M. Stefanini, E. M. Kozulin, R. N. Sagaidak, M. Trotta, N. A. Kondratiev, Neil Rowley, Fernando Scarlassara, A. Yu. Chizhov, I. V. Pokrovsky, O. Dorvaux, Suzana Szilner, A. Gadea, I. M. Itkis, V. M. Voskressensky, G. Montagnoli, G. N. Kniajeva, L. Corradi, S. Courtin, 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 Heyd, Yvette

Subjects
Physics, Nuclear and High Energy Physics, Fusion, medicine.anatomical_structure, Fission, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], medicine, Coulomb barrier, Atomic physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Nucleus, heavy-ion reactions, fusion, fission, quasi-fission
Abstract

Fusion-evaporation and fusion-fission cross sections have been measured in the reaction 48 Ca+ 154 Sm from well below to well above the Coulomb barrier. The comparison of fusion cross sections for this reaction with previous data corresponding to 16 O+ 186 W, leading to the same compound nucleus 202 Pb * , puts in evidence an interesting competition between sub-barrier enhancement, due to the strong couplings related to the 154 Sm deformation, and above barrier suppression for the 48 Ca induced reaction. The fusion hindrance mechanism has been attributed to the strong quasi-fission component observed in the mass-energy distributions of fission fragments.

Published
2003

20. Fusion cross sections at deep subbarrier energies

Author

Kouichi Hagino, Neil Rowley, Mahananda Dasgupta, 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 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
Surface (mathematics), Physics, Excitation function, Nuclear and High Energy Physics, Fusion, Logarithm, Nuclear Theory, 010308 nuclear & particles physics, Coulomb barrier, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Computational physics, Nuclear Theory (nucl-th), 0103 physical sciences, Harmonic, Point (geometry), Atomic physics, 010306 general physics, Energy (signal processing)
Abstract

A recent publication reports that heavy-ion fusion cross sections at extreme subbarrier energies show a continuous change of their logarithmic slope with decreasing energy, resulting in a much steeper excitation function compared with theoretical predictions. We show that the energy dependence of this slope is partly due to the asymmetric shape of the Coulomb barrier, that is its deviation from a harmonic shape. We also point out that the large low-energy slope is consistent with the surprisingly large surface diffusenesses required to fit recent high-precision fusion data., 9 pages, 3 eps figures

Published
2003

21. Fusion suppression in mass-asymmetric reactions leading to Ra compound nuclei

Author

Suzana Szilner, L. Corradi, M. G. Itkis, Dieter Ackermann, Fernando Scarlassara, A. Latina, M. Trotta, A. M. Vinodkumar, S. Beghini, Louise Stuttge, V. M. Voskressensky, A. V. Yeremin, A. M. Stefanini, R. N. Sagaidak, I. V. Pokrovsky, A. Gadea, G. Montagnoli, I. M. Itkis, A. I. Svirikhin, G. N. Kniajeva, N. A. Kondratiev, Francis Hanappe, E. M. Kozulin, Neil Rowley, 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 Heyd, Yvette

Subjects
Physics, Nuclear and High Energy Physics, Fusion, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], 010308 nuclear & particles physics, Fission, 0103 physical sciences, Atomic physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, 01 natural sciences, Excitation
Abstract

Near-barrier excitation functions have been measured for evaporation-residue production and fission in the 12C + 204,206,208Pb and 48Ca + 168,170Er systems that lead to the compound nuclei 216,218,220Ra*. A Pronounced suppression of evaporation-residue production is observed for the more symmetric combinations, 48Ca + 168,170Er. We relate this to the significant quasifission components already observed for these systems.

Published
2003

22. Spin distributions at the Coulomb barrier in the $^{58}$Ni+$^{60}$Ni fusion reaction from gamma-ray multiplicity measurements

Author

Neil Rowley, P. Spolaore, Dieter Ackermann, Giuseppe Viesti, A. J. Boston, F. Haas, E. S. Paul, D. Bazzacco, S. Courtin, A. Lopez-Martens, C. Rossi-Alvarez, H. C. Scraggs, O. Stezowski, M. Cinausero, M. Rousseau, 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), 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, Fusion, Spins, 010308 nuclear & particles physics, Gamma ray, Coulomb barrier, Fusion barrier, Multiplicity (mathematics), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 0103 physical sciences, Nuclear fusion, Atomic physics, 010306 general physics
Abstract

Heavy-ion fusion barrier distributions are now routinely obtained directly from experimental data. Measurements of the total γ-ray multiplicity for the fusion channels of the 58 Ni + 60 Ni system, which has striking yet well understood barrier structures, confirm the theoretical predictions that very high spins can be populated at energies close to (and even below) the nominal Coulomb barrier. The mapping from multiplicities to spin populations shows that structures in the barrier distribution are still evident in the γ-ray results.

Published
2002

23. Nuclear fission at border lines

Author

A. A. Bogatchev, N. A. Kondratiev, L. Krupa, M. G. Itkis, I. V. Pokrovski, K. J. Moody, G. N. Kniajeva, Neil Rowley, J. Kliman, G. Giardina, E. V. Prokhorova, A. Ya. Rusanov, Th. Materna, I. V. Korzyukov, Marian Jandel, V. M. Voskresenski, F. Hanappe, Yu. Ts. Oganessian, E. M. Kozulin, I. M. Itkis, V. A. Ponomarenko, L. Stuttge, 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 Heyd, Yvette

Subjects
Nuclear physics, Physics, Nuclear fission, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear engineering, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Published
2002

24. INVESTIGATION OF NEUTRON AND GAMMA MULTIPLICITIES IN REACTIONS WITH HEAVY IONS LEADING TO THE PRODUCTION OF SUPERHEAVY NUCLEI CLOSE TO THE ISLAND OF STABILITY

Author

Marian Jandel, M. G. Itkis, I. V. Pokrovski, F. Hanappe, I. M. Itkis, Ch. Stodel, J. Kliman, G. N. Kniajeva, A. Yu. Chizhov, V. M. Voskresenski, I. V. Korzyukov, Alain Ninane, B. J. P. Gall, Z. Radivojevic, W. H. Trzaska, G. Giardina, P. Desesquelles, A. A. Bogatchev, J. M. Gauthier, O. Dorvaux, L. Krupa, Th. Materna, G. Chubarian, St. Grevy, Jean Péter, N. Amar, Neil Rowley, V. A. Rubchenya, Yu. Ts. Oganessian, E. M. Kozulin, V. A. Ponomarenko, Ch. Schmitt, E. V. Prokhorova, L. Stuttge, N. A. Kondratiev, 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), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de 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), Fazio G.Giardina G.Hanappe F.Imme G.Rowley N., Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Guesnon, Sandrine

Subjects
Nuclear physics, Physics, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], 010308 nuclear & particles physics, 0103 physical sciences, Neutron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Atomic physics, 010306 general physics, 01 natural sciences, Island of stability, Ion
Published
2002

25. Fusion-fission of superheavy nuclei at low excitation energies

Author

G. N. Kniajeva, Yu. Ts. Oganessian, E. M. Kozulin, V. A. Ponomarenko, Th. Materna, V. M. Voskresenski, Neil Rowley, N. A. Kondratiev, Marian Jandel, A. A. Bogatchev, K. J. Moody, M. G. Itkis, I. V. Pokrovski, J. Kliman, I. M. Itkis, F. Hanappe, G. Giardina, I. V. Korzyukov, L. Krupa, B. Benoit, E. V. Prokhorova, A. Ya. Rusanov, L. Stuttge, 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 Heyd, Yvette

Subjects
Nuclear physics, Physics, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Fusion fission, Atomic physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Excitation
Published
2000

26. Details of Nuclear Masses away from Stability: Pairing and Deformation effects

Author

Olivier Burglin, Neil Rowley, 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 Heyd, Yvette

Subjects
Physics, Nuclear and High Energy Physics, Isotope, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Hadron, General Physics and Astronomy, Fermi energy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], electronic codex, hypertext, tabularity, symbols.namesake, Classical mechanics, reading, Pairing, Neutron number, symbols, Hamiltonian (quantum mechanics), Spectroscopy, Open shell
Abstract

Exact many-body calculations have been performed in a large Nilsson-model basis using a two-body monopole-pairing force. The diagonalisations are reduced to a manageable size by exploiting the symmetry of the general pairing Hamiltonian and time-reversal invariance. The results have been successfully applied to a study of multi-quasiparticle states in the Hf-W region. An extension of this work, calculating nuclear masses, allows a comparison with the experimental neutron-pairing energiesP N. These have been studied in detail for the Kr isotopes. Two important conclusions emerge (i) the monopole-pairing term must be generalized to a state-dependent interaction; good results being obtained for a delta-function force (ii) the small nuclear deformations relevant to this mass region appear to vary smoothly, as given by laser spectroscopy experiments, rather than showing the fluctuations of microscopic-macroscopic calculations.

Published
1997

27. Barrier distributions and scattering

Author

S. Beghini, J.H. He, Neil Rowley, J.R. Leigh, Mahananda Dasgupta, Dieter Ackermann, John Newton, G. Montagnoli, Heiko Timmers, J. C. Mein, Fernando Scarlassara, G.F. Segato, Clyde Morton, A. M. Stefanini, L. Corradi, David Hinde, 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 Heyd, Yvette

Subjects
Physics, Coupling, Normalization (statistics), Nuclear and High Energy Physics, Fusion, citizenship, 010308 nuclear & particles physics, Scattering, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Residual, 01 natural sciences, Molecular physics, design process, Distribution (mathematics), normalization, ICT, 0103 physical sciences, marketing, Sensitivity (control systems), 010306 general physics, Excitation, public policies
Abstract

The extraction of representations of the fusion barrier distribution from backward-angle, quasi-elastic, elastic and transfer excitation functions is discussed. Such excitation functions have been measured for , and projectiles incident on a variety of targets. The results are compared with representations obtained from fusion excitation functions. Varying in their sensitivity, all representations show evidence of the barrier structure. Differences between the scattering and the fusion representations can be related to the effects of coupling to residual, weak reaction channels.

Published
1997

28. Large-angle scattering and quasielastic barrier distributions

Author

Kouichi Hagino, Neil Rowley, 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 Heyd, Yvette

Subjects
Physics, Nuclear and High Energy Physics, Fusion, Quasielastic scattering, Nuclear Theory, 010308 nuclear & particles physics, Scattering, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], FOS: Physical sciences, Coulomb barrier, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Ion, Nuclear Theory (nucl-th), Distribution (mathematics), 0103 physical sciences, Quadrupole, Atomic physics, Nuclear Experiment, 010306 general physics, Nuclear theory
Abstract

We study in detail the barrier distributions extracted from large-angle quasi-elastic scattering of heavy ions at energies near the Coulomb barrier. Using a closed-form expression for scattering from a single barrier, we compare the quasi-elastic barrier distribution with the corresponding test function for fusion. We examine the isocentrifugal approximation in coupled-channels calculations of quasi-elastic scattering and find that for backward angles, it works well, justifying the concept of a barrier distribution for scattering processes. This method offers an interesting tool for investigating unstable nuclei. We illustrate this for the $^{32}$Mg + $^{208}$Pb reaction, where the quadrupole collectivity of the neutron-rich $^{32}$Mg remains to be clarified experimentally., Comment: 26 pages, 10 eps figures

Published
2004

29. Influence of entrance channel on fusion hindrance and quasi-fission

Author

S. Beghini, G. N. Kniazheva, A. Latina, E. M. Kozulin, F. Haas, M. Trotta, A. Gadea, R. N. Sagaidak, N. A. Kondratiev, F. Scarlassara, M. G. Itkis, B. R. Behera, L. Corradi, V. M. Voskressensky, Suzana Szilner, G. Montagnoli, A. Szanto de Toledo, P. R. S. Gomes, I. M. Itkis, E. Fioretto, A. Yu. Chizhov, S. Courtin, I. V. Pokrovsky, A. M. Stefanini, Neil Rowley, Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), A.J. Kreiner, O. Civitarese, C. Dorso, G. Garcia Bermudez, A.J. Pacheco, and N.N. Scoccola

Subjects
Nuclear reaction, 25.70.Jj, Fission, media_common.quotation_subject, Nuclear Theory, Transactinide element, Context (language use), 02 engineering and technology, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Asymmetry, Nuclear physics, 0202 electrical engineering, electronic engineering, information engineering, Physics::Atomic and Molecular Clusters, Nuclear fusion, fission, Nuclear Experiment, nuclear fusion, media_common, Physics, Fusion, Nuclear shell model, deformed nuclei, 020206 networking & telecommunications, nuclear mass, nuclear shell model, 020201 artificial intelligence & image processing
Abstract

International audience; Recent experimental data showing the interplay between fusion hindrance effects and the onset of the quasi-fission mechanism are presented. The aim of such investigations is understanding the role of entrance channel properties on the competing fusion-fission and quasi-fission processes, also in connection with the possible implications for superheavy element production. In this context, the role of mass asymmetry, nuclear deformation and shell effects is discussed.

30. Fusion hindrance and quasi-fission in heavy-ion induced reactions: disentangling the effect of different parameters

Author

A. Gadea, M. G. Itkis, P. R. S. Gomes, S. Beghini, M. Trotta, E. M. Kozulin, F. Haas, S. Courtin, N. A. Kondratiev, A. Latina, A. M. Stefanini, V. M. Voskressensky, I. V. Pokrovsky, Neil Rowley, I. M. Itkis, G. N. Kniajeva, B. R. Behera, A. Yu. Chizhov, R. N. Sagaidak, A. Szanto de Toledo, E. Fioretto, Suzana Szilner, F. Scarlassara, G. Montagnoli, L. Corradi, Département Recherches Subatomiques (DRS-IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), S.V. Harissopulos, P. Demetriou, and E. Julin

Subjects
Fusion, calcium, Fission, Chemistry, 25.70.Jj, 27.40.+z, Nuclear Theory, Evaporation, Carbon-12, Coulomb barrier, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Molecular physics, Ion, nuclei with mass number 39 to 58, heavy ion fusion reactions, fission, Heavy ion, Atomic physics, Nuclear Experiment, Oxygen-16
Abstract

Experimental results on the fusion inhibition effect near the Coulomb barrier due to the onset of the quasi-fission mechanism are presented. The investigation was focused on reactions induced by $^{48}$Ca projectiles on different heavy targets and comparing them to reactions induced by light ions such as $^{12}$C and $^{16}$O leading to the same compound nuclei. Cross sections and angular distributions of evaporation residues and fission fragments have been measured.

Catalog

Books, media, physical & digital resources
See catalog results