Search

Your search keyword '"Ch. Fransen"' showing total 31 results
Start Over Author "Ch. Fransen" Publication Year Range Last 50 years
31 results on '"Ch. Fransen"'

1. Quadrupole and octupole collectivity in the semi-magic nucleus 80206Hg126

Author

L. Morrison, K. Hadyńska-Klȩk, Zs. Podolyák, L.P. Gaffney, M. Zielińska, B.A. Brown, H. Grawe, P.D. Stevenson, T. Berry, A. Boukhari, M. Brunet, R. Canavan, R. Catherall, J. Cederkäll, S.J. Colosimo, J.G. Cubiss, H. De Witte, D.T. Doherty, Ch. Fransen, G. Georgiev, E. Giannopoulos, M. Górska, H. Hess, L. Kaya, T. Kröll, N. Lalović, B. Marsh, Y. Martinez Palenzuela, G. O'Neill, J. Pakarinen, J.P. Ramos, P. Reiter, J.A. Rodriguez, D. Rosiak, S. Rothe, M. Rudigier, M. Siciliano, E.C. Simpson, J. Snall, P. Spagnoletti, S. Thiel, N. Warr, F. Wenander, and R. Zidarova

Subjects
Physics, QC1-999
Abstract

The first low-energy Coulomb-excitation measurement of the radioactive, semi-magic, two proton-hole nucleus 206Hg, was performed at CERN's recently-commissioned HIE-ISOLDE facility. Two γ rays depopulating low-lying states in 206Hg were observed. From the data, a reduced transition strength B(E2;21+→01+)=4.4(6) W.u. was determined, the first such value for an N=126 nucleus south of 208Pb, which is found to be slightly lower than that predicted by shell-model calculations. In addition, a collective octupole state was identified at an excitation energy of 2705 keV, for which a reduced B(E3) transition probability of 30−13+10 W.u. was extracted. These results are crucial for understanding both quadrupole and octupole collectivity in the vicinity of the heaviest doubly-magic nucleus 208Pb, and for benchmarking a number of theoretical approaches in this key region. This is of particular importance given the paucity of data on transition strengths in this region, which could be used, in principle, to test calculations relevant to the astrophysical r-process.

Published
2023
Full Text
View/download PDF

2. Study of the deformation-driving νd5/2 orbital in 6728Ni39 using one-neutron transfer reactions

Author

J. Diriken, N. Patronis, A.N. Andreyev, S. Antalic, V. Bildstein, A. Blazhev, I.G. Darby, H. De Witte, J. Eberth, J. Elseviers, V.N. Fedosseev, F. Flavigny, Ch. Fransen, G. Georgiev, R. Gernhauser, H. Hess, M. Huyse, J. Jolie, Th. Kröll, R. Krücken, R. Lutter, B.A. Marsh, T. Mertzimekis, D. Muecher, F. Nowacki, R. Orlandi, A. Pakou, R. Raabe, G. Randisi, P. Reiter, T. Roger, M. Seidlitz, M. Seliverstov, K. Sieja, C. Sotty, H. Tornqvist, J. Van De Walle, P. Van Duppen, D. Voulot, N. Warr, F. Wenander, and K. Wimmer

Subjects
Nuclear physics, One-nucleon transfer reactions, RIBs, Nuclear structure, Physics, QC1-999
Abstract

The νg9/2,d5/2,s1/2 orbitals are assumed to be responsible for the swift onset of collectivity observed in the region below 68Ni. Especially the single-particle energies and strengths of these orbitals are of importance. We studied such properties in the nearby 67Ni nucleus, by performing a (d,p)-experiment in inverse kinematics employing a post-accelerated radioactive ion beam (RIB) at the REX-ISOLDE facility. The experiment was performed at an energy of 2.95 MeV/u using a combination of the T-REX particle detectors, the Miniball γ-detection array and a newly-developed delayed-correlation technique as to investigate μs-isomers. Angular distributions of the ground state and multiple excited states in 67Ni were obtained and compared with DWBA cross-section calculations, leading to the identification of positive-parity states with substantial νg9/2 (1007 keV) and νd5/2 (2207 keV and 3277 keV) single-particle strengths up to an excitation energy of 5.8 MeV. 50% of the νd5/2 single-particle strength relative to the νg9/2-orbital is concentrated in and shared between the first two observed 5/2+ levels. A comparison with extended Shell Model calculations and equivalent (3He, d) studies in the region around 9040Zr50 highlights similarities for the strength of the negative-parity pf and positive-parity g9/2 state, but differences are observed for the d5/2 single-particle strength.

Published
2014
Full Text
View/download PDF

3. Erratum to 'Study of the deformation-driving νd5/2 orbital in 6728Ni39 using one-neutron transfer reactions' [Phys. Lett. B 736 (2014) 533–538]

Author

J. Diriken, N. Patronis, A.N. Andreyev, S. Antalic, V. Bildstein, A. Blazhev, I.G. Darby, H. De Witte, J. Eberth, J. Elseviers, V.N. Fedosseev, F. Flavigny, Ch. Fransen, G. Georgiev, R. Gernhauser, H. Hess, M. Huyse, J. Jolie, Th. Kröll, R. Krücken, R. Lutter, B.A. Marsh, T. Mertzimekis, D. Muecher, F. Nowacki, R. Orlandi, A. Pakou, R. Raabe, G. Randisi, P. Reiter, T. Roger, M. Seidlitz, M. Seliverstov, K. Sieja, C. Sotty, H. Tornqvist, J. Van De Walle, P. Van Duppen, D. Voulot, N. Warr, F. Wenander, and K. Wimmer

Subjects
Physics, QC1-999
Published
2015
Full Text
View/download PDF

4. Quadrupole deformation of Xe-130 measured in a Coulomb-excitation experiment

Author

J. Samorajczyk-Pyśk, E. Giannopoulos, R.L. Canavan, H. De Witte, L. Morrison, P. J. Napiorkowski, Ch. Fransen, A. Boukhari, M. Zielińska, Richard Catherall, Zs. Podolyák, J.P. Ramos, F. Wenander, D. T. Doherty, H. Hess, Liam Gaffney, D. Rosiak, S. Thiel, J. Snäll, L. Próchniak, P. Reiter, M. Brunet, P. Spagnoletti, M. Rudigier, J. Srebrny, M. Siciliano, Y. Martinez Palenzuela, J. G. Cubiss, K. Hadyńska-Klȩk, G. G. O'Neill, Janne Pakarinen, N. Lalović, B. A. Marsh, L. Kaya, Th. Kröll, Sebastian Rothe, Jose Rodriguez, S.J. Colosimo, T. Berry, Radostina Zidarova, N. Warr, 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, and Helsinki Institute of Physics

Subjects
Diagonal, Semiclassical physics, BEAM, Coulomb excitation, hiukkasfysiikka, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Structure, 114 Physical sciences, 01 natural sciences, sähkömagneettiset ilmiöt, nukleonit, symbols.namesake, Matrix (mathematics), NUCLEAR-DATA SHEETS, 0103 physical sciences, Phenomenological model, Nuclear Physics - Experiment, ddc:530, 010306 general physics, Physics, Science & Technology, 010308 nuclear & particles physics, nucleon distribution, Bohr model, Physics, Nuclear, electromagnetic transitions, STATES, SHAPES, Quadrupole, Physical Sciences, symbols, Atomic physics, ydinfysiikka, Hamiltonian (quantum mechanics)
Abstract

Physical review / C 102(5), 054304 (2020). doi:10.1103/PhysRevC.102.054304, Published by Inst., Woodbury, NY

Published
2020
Full Text
View/download PDF

5. Firm spin and parity assignments for high-lying, low-spin levels in stable Si isotopes

Author

B. Löher, J. M. Keatings, J. Wilhelmy, N. A. Kelly, R. Gonzales, T. Beck, J. Kleemann, K. R. Mashtakov, Ronald Schwengner, V. Werner, M. Spieker, R. Chapman, M. D. Jones, Andreas Zilges, U. Friman-Gayer, O. Wieland, S. W. Yates, R. V. F. Janssens, J. Sinclair, Erin E. Peters, M. Müscher, D. Little, Werner Tornow, Dino A. Jaroszynski, O. Papst, P. Spagnoletti, Johann Isaak, Ch. Fransen, Krishichayan, Sean Finch, David O'Donnell, M. M. R. Chishti, E. Hoemann, M. Schilling, Giorgio Battaglia, S. Johnson, Marcus Scheck, and Deniz Savran

Subjects
Physics, Nuclear and High Energy Physics, Photon, Isotope, Silicon, 010308 nuclear & particles physics, Hadron, chemistry.chemical_element, Parity (physics), 01 natural sciences, Full width at half maximum, chemistry, 0103 physical sciences, Nuclear fusion, ddc:530, Isotopes of silicon, Atomic physics, 010306 general physics, QC
Abstract

The European physical journal / A 56(4), 105 (2020). doi:10.1140/epja/s10050-020-00118-8, Published by Springer, Heidelberg

Published
2020
Full Text
View/download PDF

6. Dealing with contaminants in Coulomb excitation of radioactive beams

Author

R. Canavan, J.P. Ramos, K. Hadyńska-Klȩk, Th. Kröll, B. A. Marsh, M. Zielińska, E. Giannopoulos, Edward Simpson, T. Berry, N. Warr, S.J. Colosimo, H. Grawe, L. Kaya, Sebastian Rothe, M. Brunet, Janne Pakarinen, D. T. Doherty, F. Wenander, P. Reiter, Liam Gaffney, P. Spagnoletti, J. G. Cubiss, A. Boukhari, S. Thiel, Richard Catherall, R. Zidarova, Ch. Fransen, Y. Martinez Palenzuela, M. Rudigier, N. Lalović, Zs. Podolyák, Jose Rodriguez, Herbert Hess, G. O'Neill, H. De Witte, M. Siciliano, L. Morrison, and D. Rosiak

Subjects
Physics, History, Large Hadron Collider, 010308 nuclear & particles physics, Coulomb excitation, Subtraction procedure, tutkimuslaitteet, Contamination, hiukkaskiihdyttimet, 01 natural sciences, Accelerators and Storage Rings, Computer Science Applications, Education, Nuclear physics, 0103 physical sciences, Physics::Accelerator Physics, Nuclear Physics - Experiment, 010306 general physics, Nuclear Experiment, ydinfysiikka, Beam (structure), Excitation, Radioactive beams
Abstract

Data analysis of the Coulomb excitation experiment of the exotic 206Hg nucleus, recently performed at CERN’s HIE-ISOLDE facility, needs to account for the contribution to target excitation due to the strongly-present beam contaminant 130Xe. In this paper, the contamination subtraction procedure is presented.

Published
2020

7. Population of lead isotopes in binary reactions using a Rb 94 radioactive beam

Author

Janne Pakarinen, G. de Angelis, P. Reiter, H. De Witte, Roberto Menegazzo, D. Mengoni, T. Marchi, P. Spagnoletti, P. Čolović, Zs. Podolyák, Liam Gaffney, J. G. Cubiss, A. Goasduff, E. Giannopoulos, M.L. Jurado-Gómez, A. Illana, Th. Kröll, Herbert Hess, G. Pollarolo, D. Testov, Suzana Szilner, F. Galtarossa, María José García Borge, J. J. Valiente-Dobón, Ch. Fransen, A. Boukhari, J. Snall, F. Recchia, T. Mijatović, L. Corradi, D. R. Napoli, N. Warr, G. Benzoni, D. Rosiak, R. Zidarova, S. Thiel, A. Boso, S. Ceruti, L. Kaya, E. Fioretto, G. G. O'Neill, European Commission, Science and Technology Facilities Council (UK), Croatian Science Foundation, Federal Ministry of Education and Research (Germany), Laboratoire de l'Accélérateur Linéaire (LAL), 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
Population, Nuclear Theory, Binary number, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Particle detector, Nuclear physics, nuclear reaction, transfer reaction, radioactive beam, 0103 physical sciences, Nuclear Reactions, Neutron, Nuclear Physics - Experiment, 010306 general physics, education, Nuclear Experiment, nuclear reactions, Physics, education.field_of_study, isotoopit, Science & Technology, Isotope, 010308 nuclear & particles physics, Physics, Nuclear, Physical Sciences, transfer reactions, Physics::Accelerator Physics, low and intermediate energy heavy-ion reactions, lyijy, models nad methods for nuclear reactions, Nucleon, ydinfysiikka, Beam (structure), Radioactive beam
Abstract

8 pags., 9 figs., We measured absolute cross sections for neutron transfer channels populated in the Rb-94 + Pb-208 binary reaction. Cross sections have been extracted identifying directly the lead isotopes with the high efficiency MINIBALL gamma-ray array coupled to a particle detector combined with a radioactive Rb-94 beam delivered at E-lab = 6.2 MeV/nucleon by the HIE-ISOLDE facility. We observed sizable cross sections in the neutron-rich mass region, where the heavy partner acquires neutrons. A fair agreement between the measured cross sections with those from GRAZING calculations gives confidence in the cross-section predictions of more neutron-rich nuclei produced via a larger number of transferred nucleons., This work was partly supported by the HORIZON 2020 ENSAR2 Grant Agreement no. 654002, and Marie Skłodowska-Curie COFUND (EU-CERN) grant agreement no. 665779, and by STFC (U.K.). This work has been supported in part by the Croatian Science Foundation under Project no. 7194 and in part under Project no. IP-2018-01- 1257, and the German BMBF under contract 05P18PKCIA + Verbundprojekt 05P2018

Published
2020
Full Text
View/download PDF

8. Electromagnetic properties of low-lying states in neutron-deficient Hg isotopes: Coulomb excitation of Hg-182, Hg-184, Hg-186 and Hg-188

Author

K Rezynkina, P. Marley, J. E. García-Ramos, Jan Diriken, N. Kesteloot, P. Reiter, L. M. Fraile, Mark Huyse, Kristiaan Heyde, R. D. Page, O. Ivanov, R. Gernhäuser, R. Krücken, Th. Kröll, A. C. Larsen, E. Rapisarda, Tuomas Grahn, Alick Deacon, N. Warr, A. Petts, AP Robinson, S. J. Freeman, P. J. Napiorkowski, P. Van Duppen, R-D Herzberg, Thomas Elias Cocolios, B. Bruyneel, Gry Merete Tveten, R. Orlandi, E. Piselli, Ch. Fransen, B. Bastin, Marcus Scheck, Conor Fitzpatrick, D. Voulot, Rauno Julin, Baharak Hadinia, L. Próchniak, J. Srebrny, Magne Guttormsen, Sunniva Siem, Liam Gaffney, J. L. Wood, H. Hess, Panu Rahkila, J. Van de Walle, P. A. Butler, J. F. Smith, K Singh Chakkal, D. G. Jenkins, Michaël Bender, Andreas Wiens, Andrei Andreyev, M. P. Carpenter, M. Hass, Pauli Peura, K Hadyńska-Klȩk, Janne Pakarinen, R. Lutter, Andreas Ekström, I. Stefanescu, P.-H. Heenen, Joakim Cederkäll, K. Geibel, A. Blazhev, M. Zielinska, K. Wrzosek-Lipska, E. Clément, N. Bree, N. Patronis, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire 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), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-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), 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 Helsinki Institute of Physics

Subjects
Moments, Intruder, 01 natural sciences, MOMENTS, Nuclear Experiment, Physics, education.field_of_study, Yrast, Bohr model, LIFETIMES, ddc, Mean field theory, symbols, Física nuclear, Atomic physics, ydinfysiikka, Configuration, Nuclear and High Energy Physics, ELECTRIC-MONOPOLE TRANSITIONS, Population, Electric-monopole transitions, DEFORMED BANDS, Lifetimes, Coulomb excitation, NUCLEAR, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 114 Physical sciences, symbols.namesake, Isomerism, SHAPE COEXISTENCE, 0103 physical sciences, Nuclear fusion, Nuclear Physics - Experiment, Neutron, Nuclear, 010306 general physics, education, CONFIGURATION, Deformed bands, 010308 nuclear & particles physics, INTRUDER, Shape coexistence, 2207 Física Atómica y Nuclear, Decay, Physics and Astronomy, 13. Climate action, ISOMERISM, Interacting boson model, DECAY
Abstract

The neutron-deficient mercury isotopes serve as a classical example of shape coexistence, whereby at low energy near-degenerate nuclear states characterized by different shapes appear. The electromagnetic structure of even-mass 182-188 Hg isotopes was studied using safe-energy Coulomb excitation of neutron-deficient mercury beams delivered by the REX-ISOLDE facility at CERN. The population of $ 0^{+}_{1,2}$01,2+, $ 2^{+}_{1,2}$21,2+and $ 4^{+}_{1}$41+states was observed in all nuclei under study. Reduced E2 matrix elements coupling populated yrast and non-yrast states were extracted, including their relative signs. These are a sensitive probe of shape coexistence and may be used to validate nuclear models. The experimental results are discussed in terms of mixing of two different configurations and are compared with three different model calculations: the Beyond Mean Field model, the Interacting Boson Model with configuration mixing and the General Bohr Hamiltonian. Partial agreement with experiment was observed, hinting to missing ingredients in the theoretical descriptions. The neutron-deficient mercury isotopes serve as a classical example of shape coexistence, whereby at low energy near-degenerate nuclear states characterized by different shapes appear. The electromagnetic structure of even-mass 182-188 Hg isotopes was studied using safe-energy Coulomb excitation of neutron-deficient mercury beams delivered by the REX-ISOLDE facility at CERN. The population of $ 0^{+}_{1,2}$01,2+, $ 2^{+}_{1,2}$21,2+and $ 4^{+}_{1}$41+states was observed in all nuclei under study. Reduced E2 matrix elements coupling populated yrast and non-yrast states were extracted, including their relative signs. These are a sensitive probe of shape coexistence and may be used to validate nuclear models. The experimental results are discussed in terms of mixing of two different configurations and are compared with three different model calculations: the Beyond Mean Field model, the Interacting Boson Model with configuration mixing and the General Bohr Hamiltonian. Partial agreement with experiment was observed, hinting to missing ingredients in the theoretical descriptions. ispartof: The European Physical Journal A - Hadrons and Nuclei vol:55 issue:8 pages:130-130 status: published

Published
2019
Full Text
View/download PDF

9. Precise measurement of energies inSn115following the(n,γ)reaction

Author

Bastian Märkisch, T. Thomas, Ulli Köster, T. Rząca-Urban, Paolo Mutti, Ch. Fransen, Gary Simpson, C. Bernards, Michael Jentschel, W. Urban, and J. Jolie

Subjects
Physics, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, Binding energy, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Ground state, 01 natural sciences, 7. Clean energy, Energy (signal processing)
Abstract

The first measurement of $\ensuremath{\gamma}$ rays from the $^{114}\mathrm{Sn}(n,\ensuremath{\gamma})$ reaction using cold neutrons, performed with an array of Ge detectors at the PF1B facility of the Institute Laue-Langevin in Grenoble, has provided the most accurate energy, ${Q}_{\ensuremath{\beta}}=173(12)$ eV, of ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay of the $^{115}\mathrm{In}$ ground state to the first excited state in $^{115}\mathrm{Sn}$. This is the lowest of all such energies in the known nuclear landscape. The accuracy of the neutron binding energy of $^{115}\mathrm{Sn}$ and the mass of $^{114}\mathrm{Sn}$ have been improved.

Published
2016
Full Text
View/download PDF

10. Conceptual design and infrastructure for the installation of the first AGATA sub-array at LNL

Author

A. Triossi, D. Conventi, A. M. Stefanini, G. Montagnoli, D. Lersch, D. Bazzacco, S. Aydin, John Paul Strachan, B. Bruyneel, C. He, Agnese Giaz, S. Brambilla, S. Fantinel, Enrico Calore, E. Sahin, A. Bracco, B. Million, S. M. Lenzi, R. Peghin, A. Gottardo, L. Berti, G. Maron, Alessandro Zucchiatti, B. Birkenbach, E. Fioretto, Gheorghe Pascovici, V. Vandone, C. Fanin, M. Bellato, E. Legay, N. Blasi, J. Grebosz, F. Zocca, A. Gadea, E. Bissiato, C. A. Ur, O. Stezowski, Roberto Menegazzo, D. Mengoni, Alberto Pullia, E. Farnea, P.M. Jones, Joël Chavas, Roberto Isocrate, M. Nicoletto, Damiano Bortolato, N. Dosme, P. Reiter, G. Rampazzo, A. Corsi, S. Badoer, S. Coelli, Herbert Hess, R. Beunard, Francesco Lelli, F. Recchia, A. Cortesi, M. Ozille, F. C. L. Crespi, Th. Pissulla, J. Jolie, A. Colombo, J. Eberth, G. Salvato, D. R. Napoli, T. Habermann, E. Grodner, C. Boiano, Ch. Fransen, L. Costa, A. Austin, C. Veyssiere, Fernando Scarlassara, F. Tomasi, P. Cocconi, R. Nicolini, N. Toniolo, S. Leoni, A. Dewald, R. Venturelli, R. Griffiths, C. Michelagnoli, L. Corradi, D. Rosso, V. F. E. Pucknell, E. Viscione, F. Veronese, Stefano Riboldi, A. Capsoni, C. Rossi Alvarez, Oliver Wieland, J. Simpson, X. Grave, S. Lunardi, M. Turcato, D. Montanari, G. de Angelis, M. Pignanelli, G. Benzoni, P. Molini, A. Latina, M. Rigato, W. Rother, L. Ramina, F. Camera, J. J. Valiente-Dobón, M. Rebeschini, Andreas Wiens, O. Möller, M. Gulmini, Research Group: Information Management, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut de Physique Nucléaire d'Orsay (IPNO), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, AGATA, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Sabire Yazıcı Fen-Edebiyat Fakültesi, Triossi, Andrea -- 0000-0001-5140-9154, Montanari, Daniele -- 0000-0002-1980-7686, Gadea, Andres -- 0000-0002-4233-1970, Calore, Enrico -- 0000-0002-2301-3838, Napoli, Daniel Ricardo -- 0000-0002-8154-6958, Menegazzo, Roberto -- 0000-0002-3060-5276, Zucchiatti, Alessandro -- 0000-0002-3647-596X, Sahin, Eda -- 0000-0003-0683-5140, Jones, Pete -- 0000-0001-7480-6603, benzoni, giovanna -- 0000-0002-7938-0338, GOTTARDO, Andrea -- 0000-0002-0390-5767, Montagnoli, Giovanna -- 0000-0002-8944-1456, Recchia, Francesco -- 0000-0002-8428-0112, GIAZ, Agnese -- 0000-0002-2550-450X, Pullia, Alberto -- 0000-0002-6393-747X, Scarlassara, Fernando -- 0000-0002-4663-8216, Nicoletto, Marino -- 0000-0001-9301-0782, Lelli, Francesco -- 0000-0003-1900-9171, and Camera, Franco -- 0000-0003-1731-4834

Subjects
Nuclear and High Energy Physics, DANTE Heavy-ion Detector, Physics::Instrumentation and Detectors, HELENA multiplicity filter, 01 natural sciences, 7. Clean energy, Particle detector, Nuclear physics, PRISMA spectrometer, Conceptual design, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment, 010306 general physics, Gamma detection, Instrumentation, TRACE SI detector, Physics, Spectrometer, 010308 nuclear & particles physics, business.industry, Semiconductor detector, Cologne plunger, AGATA, DANTE heavy-ion-detector, business, Computer hardware
Abstract

WOS: 000295765100014, The first implementation of the AGATA spectrometer consisting of five triple germanium detector clusters has been installed at Laboratori Nazionali di Legnaro, INFN. This setup has two major goals, the first one is to validate the gamma-tracking concept and the second is to perform an experimental physics program using the stable beams delivered by the Tandem-PIAVE-ALPI accelerator complex. A large variety of physics topics will be addressed during this campaign, aiming to investigate both neutron and proton-rich nuclei. The setup has been designed to be coupled with the large-acceptance magnetic-spectrometer PRISMA. Therefore, the in-beam prompt gamma rays detected with AGATA will be measured in coincidence with the products of multinucleon-transfer and deep-inelastic reactions measured by PRISMA. Moreover, the setup is versatile enough to host ancillary detectors, including the heavy-ion detector DANTE, the gamma-ray detector array HELENA, the Cologne plunger for lifetime measurements and the Si-pad telescope TRACE. In this paper the design; characteristics and performance figures of the setup will be described.

Published
2011
Full Text
View/download PDF

11. Sub-nanosecond lifetime measurements using the Double Orange Spectrometer at the cologne 10MV Tandem accelerator

Author

L. Steinert, N. Braun, Gheorghe Pascovici, M. Rudigier, S. Thiel, G. Breuer, J. Jolie, N. Warr, S. Christen, C. Bernards, Ch. Fransen, T. Meersschaut, K. O. Zell, J.-M. Régis, Stefan Heinze, and T. Materna

Subjects
Physics, Nuclear and High Energy Physics, Electron spectrometer, Spectrometer, business.industry, Detector, Nanosecond, Scintillator, Electron spectroscopy, Nuclear physics, Optics, Beamline, Excited state, Nuclear Experiment, business, Instrumentation
Abstract

Conversion electron spectroscopy constitutes an important tool in nuclear structure physics. A high efficiency iron-free Orange type electron spectrometer with an energy resolution of 1–2% has been installed at a beam line of the Cologne 10 MV FN Tandem Van-de-Graaff accelerator for in-beam studies of conversion electrons. In combination with a γ -ray detector array, high efficiency e - – γ -coincidences can be performed. The newly developed very fast LaBr 3 ( Ce ) scintillator detector with an energy resolution of about 4% makes it also possible to use e - – γ -coincidences for lifetime measurements of nuclear excited states. A second iron-free Orange spectrometer can be connected to perform e - – e - -coincidences. Because of the higher efficiency and the better energy resolution, the use of the Double Orange Spectrometer for lifetime measurements is more powerful. Lifetimes down to 100 ps and even less can be determined with an accuracy of about 10 ps. The working principle of the Orange spectrometer and the setup of the Double Orange Spectrometer are described. The performances are illustrated by examples of in-beam experiments with a main focus on high precision lifetime measurements.

Published
2009
Full Text
View/download PDF

12. Collectivity in the light radon nuclei measured directly via Coulomb excitation

Author

D. Voulot, S. J. Freeman, P. Van Duppen, Liam Gaffney, J. F. Smith, M. Zielinska, Herbert Hess, R. Orlandi, Mark Huyse, Kathrin Wimmer, M. Seidlitz, Michaël Bender, P. Peura, N. Bree, Marcus Scheck, Alick Deacon, D. Muecher, K. Geibel, D. G. Jenkins, A P Robinson, R. Wadsworth, H. De Witte, Janne Pakarinen, A. Blazhev, P. Reiter, V. Kumar, Paul-Henri Heenen, Jan Diriken, Andreas Ekström, Douglas D. DiJulio, K. Singh, Ch. Fransen, Baharak Hadinia, J. Van de Walle, O. Ivanov, Tuomas Grahn, Fredrik Wenander, Th. Kroell, P. A. Butler, S. Martin-Haugh, Panu Rahkila, K. Wrzosek-Lipska, Joonas Konki, B. Bruyneel, U. Jakobsson, N. Kesteloot, Thomas Davinson, N. Warr, A. Petts, Thomas Elias Cocolios, M. Hass, Andrei Andreyev, Department of Chemistry [Cambridge, UK], University of Cambridge [UK] (CAM), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut du Cerveau et de la Moëlle Epinière = Brain and Spine Institute (ICM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), CSIR-National Institute of Oceanography, Gravitational-Wave Physics and Astronomy Center (GWPAC), California State University [Fullerton] (CSU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], and Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Population, FOS: Physical sciences, Coulomb excitation, shape coexistence, 01 natural sciences, 0103 physical sciences, Nuclear Physics - Experiment, Neutron, collectivity, Nuclear Experiment (nucl-ex), 010306 general physics, education, Spectroscopy, Nuclear Experiment, Physics, education.field_of_study, ta114, 010308 nuclear & particles physics, Gamma ray, radon, Physique atomique et nucléaire, 3. Good health, Radon, Excited state, Quadrupole, Atomic physics, Ground state
Abstract

Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z=82 and the neutron midshell at N=104. Purpose: Evidence for shape coexistence has been inferred from α-decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of Rn202 and Rn204 were studied by means of low-energy Coulomb excitation at the REX-ISOLDE in CERN. Results: The electric-quadrupole (E2) matrix element connecting the ground state and first excited 21+ state was extracted for both Rn202 and Rn204, corresponding to B(E2;21+→01+)=29-8+8 and 43-12+17 W.u. respectively. Additionally, E2 matrix elements connecting the 21+ state with the 41+ and 22+ states were determined in Rn202. No excited 0+ states were observed in the current data set, possibly owing to a limited population of second-order processes at the currently available beam energies. Conclusions: The results are discussed in terms of collectivity and the deformation of both nuclei studied is deduced to be weak, as expected from the low-lying level-energy schemes. Comparisons are also made to state-of-the-art beyond-mean-field model calculations and the magnitude of the transitional quadrupole moments are well reproduced., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2015
Full Text
View/download PDF

13. Experimental study of theNi66(d,p) Ni67one-neutron transfer reaction

Author

C. Sotty, D. Voulot, Th. Kröll, F. Wenander, R. Raabe, D. Muecher, V. Bildstein, V. N. Fedosseev, M. D. Seliverstov, B. A. Marsh, M. Seidlitz, Roman Gernhäuser, P. Reiter, T. Roger, Hans-Jurgen E. Hess, Kathrin Wimmer, A. Pakou, Georgi P. Georgiev, A. Blazhev, J. Van de Walle, F. Flavigny, Jan Diriken, Marc Huyse, A. N. Andreyev, J. Elseviers, N. Patronis, R. Lutter, J. Jolie, G. Randisi, P. Van Duppen, N. Warr, J. Eberth, H. Törnqvist, T. J. Mertzimekis, R. Orlandi, I. G. Darby, Ch. Fransen, S. Antalic, R. Krücken, and H. De Witte

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear structure, 01 natural sciences, Atomic orbital, Excited state, 0103 physical sciences, Quadrupole, Neutron, Born approximation, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The quasi-SU(3) sequence of the positive parity $\ensuremath{\nu}{g}_{9/2},{d}_{5/2},{s}_{1/2}$ orbitals above the $N=40$ shell gap are assumed to induce strong quadrupole collectivity in the neutron-rich Fe $(Z=26)$ and Cr $(Z=24)$ isotopes below the nickel region. In this paper the position and strength of these single-particle orbitals are characterized in the neighborhood of $^{68}\mathrm{Ni} (Z=28,\phantom{\rule{0.16em}{0ex}}N=40)$ through the $^{66}\mathrm{Ni}(d,p)^{67}\mathrm{Ni}$ one-neutron transfer reaction at 2.95 MeV/nucleon in inverse kinematics, performed at the REX-ISOLDE facility in CERN. A combination of the Miniball $\ensuremath{\gamma}$-array and T-REX particle-detection setup was used and a delayed coincidence technique was employed to investigate the 13.3-$\ensuremath{\mu}\mathrm{s}$ isomer at 1007 keV in $^{67}\mathrm{Ni}$. Excited states up to an excitation energy of 5.8 MeV have been populated. Feeding of the $\ensuremath{\nu}{g}_{9/2}$ (1007 keV) and $\ensuremath{\nu}{d}_{5/2}$ (2207 keV and 3277 keV) positive-parity neutron states and negative parity $(\ensuremath{\nu}pf)$ states have been observed at low excitation energy. The extracted relative spectroscopic factors, based on a distorted-wave Born approximation analysis, show that the $\ensuremath{\nu}{d}_{5/2}$ single-particle strength is mostly split over these two excited states. The results are also compared to the distribution of the proton single-particle strength in the $^{90}\mathrm{Zr}$ region $(Z=40,N=50)$.

Published
2015
Full Text
View/download PDF

14. Erratum to 'Study of the deformation-driving νd5/2 orbital in 6728Ni39 using one-neutron transfer reactions' [Phys. Lett. B 736 (2014) 533–538]

Author

A. N. Andreyev, Marc Huyse, A. Blazhev, C. Sotty, Georgi P. Georgiev, P. Reiter, F. Nowacki, J. Jolie, D. Muecher, B. A. Marsh, Kamila Sieja, Jan Diriken, D. Voulot, V. N. Fedosseev, F. Wenander, J. Elseviers, J. Van de Walle, N. Patronis, M. D. Seliverstov, Herbert Hess, F. Flavigny, Kathrin Wimmer, V. Bildstein, G. Randisi, R. Orlandi, I. G. Darby, Ch. Fransen, S. Antalic, Roman Gernhäuser, M. Seidlitz, P. Van Duppen, R. Krücken, Th. Kröll, T. J. Mertzimekis, R. Lutter, J. Eberth, H. Törnqvist, T. Roger, H. De Witte, N. Warr, R. Raabe, and A. Pakou

Subjects
Physics, Nuclear and High Energy Physics, Condensed matter physics, Neutron, Deformation (meteorology), lcsh:Physics, lcsh:QC1-999
Published
2015
Full Text
View/download PDF

15. Low-energy Coulomb excitation of $^{62}$Fe and $^{62}$Mn following in-beam decay of $^{62}$Mn

Author

V. Bildstein, H. Hess, P. Reiter, Jan Diriken, Th. Kröll, Mark Huyse, Valentin Fedosseev, Douglas D. DiJulio, N. Bree, H. De Witte, I. G. Darby, Ch. Fransen, P. Van Duppen, K. Wrzosek-Lipska, B. Bastin, N. Warr, R. Lutter, N. Kesteloot, R. Gernhäuser, Fredrik Wenander, M. Seidlitz, A. Gustafsson, J. Van de Walle, D. Voulot, Liam Gaffney, Joakim Cederkäll, A. Blazhev, B. A. Marsh, Kathrin Wimmer, 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), CERN [Genève], 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, education.field_of_study, Population, Order (ring theory), FOS: Physical sciences, Charge (physics), Coulomb excitation, Trapping, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Ionization, Atomic physics, Nuclear Experiment (nucl-ex), education, Nuclear Experiment, Beam (structure), Excitation
Abstract

Sub-barrier Coulomb-excitation was performed on a mixed beam of $^{62}$Mn and $^{62}$Fe, following in-trap $\beta^{-}$ decay of $^{62}$Mn at REX-ISOLDE, CERN. The trapping and charge breeding times were varied in order to alter the composition of the beam, which was measured by means of an ionisation chamber at the zero-angle position of the Miniball array. A new transition was observed at 418~keV, which has been tentatively associated to a $(2^{+},3^{+})\rightarrow1^{+}_{g.s.}$ transition. This fixes the relative positions of the $\beta$-decaying $4^{+}$ and $1^{+}$ states in $^{62}$Mn for the first time. Population of the $2^{+}_{1}$ state was observed in $^{62}$Fe and the cross-section determined by normalisation to the $^{109}$Ag target excitation, confirming the $B(E2)$ value measured in recoil-distance lifetime experiments., Comment: 9 pages, 10 figures

Published
2015
Full Text
View/download PDF

16. Shape Coexistence in the Neutron-Deficient Even-EvenHg182−188Isotopes Studied via Coulomb Excitation

Author

N. Bree, K. Wrzosek-Lipska, A. Petts, A. Andreyev, B. Bastin, M. Bender, A. Blazhev, B. Bruyneel, P. A. Butler, J. Butterworth, M. P. Carpenter, J. Cederkäll, E. Clément, T. E. Cocolios, A. Deacon, J. Diriken, A. Ekström, C. Fitzpatrick, L. M. Fraile, Ch. Fransen, S. J. Freeman, L. P. Gaffney, J. E. García-Ramos, K. Geibel, R. Gernhäuser, T. Grahn, M. Guttormsen, B. Hadinia, K. Hadyńska-Kle¸k, M. Hass, P.-H. Heenen, R.-D. Herzberg, H. Hess, K. Heyde, M. Huyse, O. Ivanov, D. G. Jenkins, R. Julin, N. Kesteloot, Th. Kröll, R. Krücken, A. C. Larsen, R. Lutter, P. Marley, P. J. Napiorkowski, R. Orlandi, R. D. Page, J. Pakarinen, N. Patronis, P. J. Peura, E. Piselli, P. Rahkila, E. Rapisarda, P. Reiter, A. P. Robinson, M. Scheck, S. Siem, K. Singh Chakkal, J. F. Smith, J. Srebrny, I. Stefanescu, G. M. Tveten, P. Van Duppen, J. Van de Walle, D. Voulot, N. Warr, F. Wenander, A. Wiens, J. L. Wood, and M. Zielińska

Subjects
Physics, Mean field theory, Excited state, Quadrupole, General Physics and Astronomy, Neutron, Coulomb excitation, Atomic physics, Nucleon, Ground state, 7. Clean energy, Excitation
Abstract

Coulomb-excitation experiments to study electromagnetic properties of radioactive even-even Hg isotopes were performed with 2.85 MeV/nucleon mercury beams from REX-ISOLDE. Magnitudes and relative signs of the reduced E2 matrix elements that couple the ground state and low-lying excited states in Hg182-188 were extracted. Information on the deformation of the ground and the first excited 0(+) states was deduced using the quadrupole sum rules approach. Results show that the ground state is slightly deformed and of oblate nature, while a larger deformation for the excited 0(+) state was noted in Hg-182; 184. The results are compared to beyond mean field and interacting-boson based models and interpreted within a two-state mixing model. Partial agreement with the model calculations was obtained. The presence of two different structures in the light even-mass mercury isotopes that coexist at low excitation energy is firmly established.

Published
2014
Full Text
View/download PDF

17. Lifetime measurements in neutron-rich63,65Co isotopes using the AGATA demonstrator

Author

A. Bracco, A. Dewald, D. R. Napoli, O. Stezowski, K. Geibel, G. Benzoni, O. Möller, B. Bruyneel, J. Chavas, Piotr Bednarczyk, Fernando Scarlassara, Kamila Sieja, Roberto Menegazzo, D. Mengoni, G. de Angelis, P. Reiter, E. Fioretto, Zs. Podolyák, Maria Doncel, T. Mijatović, S. Leoni, S. M. Lenzi, A. Bürger, V. Modamio, A. Nannini, Begoña Quintana, T. Habermann, M. N. Erduran, G. Pollarolo, F. C. L. Crespi, B. Birkenbach, Herbert Hess, Alberto Pullia, D. Rosso, L. Corradi, P. A. Söderström, A. M. Stefanini, B. Melon, M. D. Salsac, Suzana Szilner, E. Sahin, Alejandro Algora, Andreas Görgen, E. Farnea, Ch. Theisen, D. S. Judson, J. J. Valiente-Dobón, Rosanna Depalo, G. Montagnoli, B. Travers, B. Million, C. A. Ur, Ch. Fransen, F. Recchia, P. Desesquelles, A. Gottardo, N. Karkour, P. R. John, R.S. Kempley, A. Gadea, T. Hüyük, J. Jolie, A. Jungclaus, M. Hackstein, S. Lunardi, D. Montanari, D. Bazzacco, C. Michelagnoli, and W. Rother

Subjects
Physics, Nuclear and High Energy Physics, Isotope, 010308 nuclear & particles physics, SHELL model, Mass spectrometry, 7. Clean energy, 01 natural sciences, Nuclear physics, symbols.namesake, Recoil, 13. Climate action, 0103 physical sciences, symbols, AGATA, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Doppler effect, Beam (structure)
Abstract

Lifetimes of the low-lying (11/2-) states in 63,65Co have been measured employing the recoil distance doppler shift method (RDDS) with the AGATA γ-ray array and the PRISMA mass spectrometer. These nuclei were populated via a multinucleon transfer reaction by bombarding a 238U target with a beam of 64Ni. The experimental B(E2) reduced transition probabilities for 63,65Co are well reproduced by large-scale shell-model calculations that predict a constant trend of the B(E2) values up to the N=40 67Co isotope

Published
2013
Full Text
View/download PDF

18. Coulomb excitation of107In

Author

R. Lutter, Jan Diriken, M. Seidlitz, J. Iwanicki, Andreas Görgen, A. Blazhev, V. Bildstein, Gry Merete Tveten, Ch. Fransen, J. Van de Walle, Fredrik Wenander, Roman Gernhäuser, Jan Taprogge, P. Reiter, Herbert Hess, Thomas Davinson, Marcus Scheck, Morten Hjorth-Jensen, K. Geibel, Kathrin Wimmer, Andreas Ekström, M. Albers, D. Voulot, Sunniva Siem, Douglas D. DiJulio, Iain Darby, Joakim Cederkäll, Claes Fahlander, N. Warr, H. De Witte, and Kristiaan Heyde

Subjects
IONS, Physics, Nuclear and High Energy Physics, Large Hadron Collider, Isotope, ODD-MASS, SHELL model, Gamma ray, Semiclassical physics, Coulomb excitation, Ion, Physics and Astronomy, NUCLEAR-DATA SHEETS, STATES, SN-107, Physics::Accelerator Physics, UNIFIED DESCRIPTION, Atomic physics, Nuclear Experiment, DECAY
Abstract

The radioactive isotope 107In was studied using sub-barrier Coulomb excitation at the REX-ISOLDE facility at CERN. Two γ rays were observed during the experiment, corresponding to the low-lying 11/2+ and 3/2− states. The reduced transition probability of the 11/2+ state was determined with the semiclassical Coulomb excitation code GOSIA2. The result is discussed in comparison to large-scale shell-model calculations, previous unified-model calculations, and earlier Coulomb excitation measurements in the odd-mass In isotopes. ispartof: Physical Review C, Nuclear Physics vol:87 issue:1 status: published

Published
2013
Full Text
View/download PDF

19. Excitation strengths in109Sn: Single-neutron and collective excitations near100Sn

Author

M. Hjorth-Jensen, Joakim Cederkäll, R. Lutter, Claes Fahlander, Jan Diriken, K. Geibel, A. Blazhev, J. Iwanicki, Herbert Hess, T. Davinson, Roman Gernhaeuser, Douglas D. DiJulio, Andreas Görgen, Kathrin Wimmer, M. Albers, D. Voulot, P. Reiter, Iain Darby, Andreas Ekström, Vinzenz Bildstein, J. Van de Walle, M. Seidlitz, Sunniva Siem, Marcus Scheck, N. Warr, Gry Merete Tveten, Ch. Fransen, Jan Taprogge, Fredrik Wenander, and H. De Witte

Subjects
Physics, Nuclear and High Energy Physics, Large Hadron Collider, Isotope, Excited state, Quasiparticle, Physics::Accelerator Physics, Semiclassical physics, Neutron, Coulomb excitation, Atomic physics, Nuclear Experiment, Excitation
Abstract

A set of B(E2) values for the low-lying excited states in the radioactive isotope Sn-109 were deduced from a Coulomb excitation experiment. The 2.87-MeV/u radioactive beam was produced at the REX-ISOLDE facility at CERN and was incident on a secondary Ni-58 target. The B(E2) values were determined using the known 2(+) -> 0(+) reduced transition probability in Ni-58 as normalization with the semiclassical Coulomb excitation code GOSIA2. The transition probabilities are compared to shell-model calculations based on a realistic nucleon-nucleon interaction and the predictions of a simple core-excitation model. This measurement represents the first determination of multiple B(E2) values in a light Sn nucleus using the Coulomb excitation technique with low-energy radioactive beams. The results provide constraints for the single-neutron states relative to Sn-100 and also indicate the importance of both single-neutron and collective excitations in the light Sn isotopes. (Less)

Published
2012
Full Text
View/download PDF

20. Measurement of absolute E2 transition strengths in [sup 176]W: Signatures for a rapid shape change

Author

Ch. Fransen, A. Dewald, G. Friessner, M. Hackstein, J. Jolie, O. Möller, T. Pissulla, W. Rother, K.-O. Zell, Paraskevi Demetriou, Rauno Julin, and Sotirios Harissopulos

Subjects
Nuclear physics, Phase transition, Recoil, Critical point (thermodynamics), Chemistry, Nuclear Theory, Nuclear structure, Neutron, Atomic physics, Interacting boson model, Nuclear Experiment, Axial symmetry, Oxygen-16
Abstract

The X(5) symmetry describes nuclei at the critical point of the shape phase transition from axially deformed rotor nuclei to spherical vibrators. 150Nd, 152Sm, and 154Gd were the first nuclei where the predicted charateristics of the X(5) symmetry were observed. Later it was shown that also 176,178,180Os can be successfully described with the X(5) symmetry.In the close vicinity of shape phase transitions one expects strongly changing nuclear shapes. In the X(5) region around A = 150 this was observed for nuclei with different neutron numbers, whereas in the X(5) region around A = 180 this is to be expected for different proton numbers. The aim of the work presented here is the confirmation of a rapid shape change for nuclei close to 178Os. Besides the knowledge on the level scheme of the nuclei of interest, especially absolute E2 transition strengths are crucial for the interpretation of nuclear structure. Prolate deformation is expected for 176W. Thus we performed a recoil distance Doppler shift (RDDS) m...

Published
2011
Full Text
View/download PDF

21. Nuclear structure analysis using the Orange Spectrometer

Author

J.-M. Régis, Gh. Pascovici, Th. Materna, S. Christen, T. Meersschout, C. Bernards, Ch. Fransen, A. Dewald, N. Braun, S. Heinze, S. Thiel, J. Jolie, Jan Jolie, Andreas Zilges, Nigel Warr, and Andrey Blazhev

Subjects
Beamline, Spectrometer, Chemistry, Analytical chemistry, Gamma spectroscopy, Electron, Atomic physics, Scintillator, Spectroscopy, Electron spectroscopy, Spectral line
Abstract

Recently, an Orange spectrometer, a focusing iron‐free magnetic spectrometer, has been installed at a beam line of the 10 MV Tandem accelerator of the IKP of the University of Cologne. The high efficiency of 15% of 4π for the detection of conversion electrons and the energy resolution of 1% makes the Orange spectrometer a powerful instrument. From the conversion electron spectrum, transition multipolarities can be determined using the so called K to L ratio. In combination with an array of germanium and lanthanum bromide detectors, e−‐γ‐coincidences can be performed to investigate the level scheme. Moreover, the very fast lanthanum bromide scintillator with an energy resolution of 3% allows e−‐γ lifetime measurements down to 0.3 ns. A second Orange spectrometer can be added to build the Double Orange Spectrometer for e−‐e−‐coincidences. It is indispensable for lifetime measurements of low intensity or nearby lying transitions as often occur in odd‐A and odd‐odd nuclei. The capabilities are illustrated wit...

Published
2009
Full Text
View/download PDF

22. Multiple host switching events shape the evolution of symbiotic palaemonid shrimps (Crustacea: Decapoda).

Author

Horká I, De Grave S, Fransen CH, Petrusek A, and Ďuriš Z

Subjects
Animals, DNA, Mitochondrial genetics, Evolution, Molecular, Genetic Markers, Host Specificity, Phylogeny, Sequence Analysis, DNA, Symbiosis, Palaemonidae physiology
Abstract

The majority of the almost 1,000 species of Palaemonidae, the most speciose family of caridean shrimp, largely live in symbioses with marine invertebrates of different phyla. These associations range from weak epibiosis to obligatory endosymbiosis and from restricted commensalism to semi-parasitism, with the specialisation to particular hosts likely playing a role in the diversification of this shrimp group. Our study elucidates the evolutionary history of symbiotic palaemonids based on a phylogenetic analysis of 87 species belonging to 43 genera from the Indo-West Pacific and the Atlantic using two nuclear and two mitochondrial markers. A complementary three-marker analysis including taxa from GenBank raises this number to 107 species from 48 genera. Seven larger clades were recovered in the molecular phylogeny; the basal-most one includes mostly free-living shrimp, albeit with a few symbiotic species. Ancestral state reconstruction revealed that free-living forms likely colonised cnidarian hosts initially, and switching between different host phyla occurred multiple times in palaemonid evolutionary history. In some cases this was likely facilitated by the availability of analogous microhabitats in unrelated but morphologically similar host groups. Host switching and adaptations to newly colonised host groups must have played an important role in the evolution of this diverse shrimp group.

Published
2016
Full Text
View/download PDF

23. Phylogenetic ecology of gall crabs (Cryptochiridae) as associates of mushroom corals (Fungiidae).

Author

van der Meij SE, Fransen CH, Pasman LR, and Hoeksema BW

Abstract

Coral-associated fauna is a relatively understudied topic. Hence, the nature of the relationship between an associated organism and its host is usually unknown. In the present study, the obligate associations between gall crabs (Decapoda: Cryptochiridae) and mushroom corals (Scleractinia: Fungiidae) are reviewed from a phylogenetic perspective. Based on field surveys, examination of museum material and a literature review, a total of 35 fungiid species have been found that act as hosts for four gall crab species. Fungiid-associated gall crabs appear to be more geographically widespread than previously known, with new records showing their occurrences from the Red Sea and western Indian Ocean all the way to the central Pacific Ocean. The obligate nature of the association between cryptochirids and their hosts makes them an ideal model taxon to test for possible cospeciation events. The congruence between their phylogenies was tested by using the program Jane 4.0, resulting in cospeciation and duplication events between the crabs and their host corals. The sharing of several closely related host coral species by the same gall crab species or genus may provide support to models indicating phylogenetic relationships within the Scleractinia.

Published
2015
Full Text
View/download PDF

24. Let's be pals again: major systematic changes in Palaemonidae (Crustacea: Decapoda).

Author

De Grave S, Fransen CH, and Page TJ

Abstract

In recent years the systematic position of genera in the shrimp families Gnathophyllidae and Hymenoceridae has been under debate, with phylogenetic studies suggesting the families are not real family level units. Here, we review the molecular evidence as well as the morphological characters used to distinguish both families, leading to the conclusion that neither family is valid. Further, we studied the structural details of the single morphological character which distinguishes the two subfamilies (Palaemoninae, Pontoniinae) in Palaemonidae, as well as their phylogenetic relationship. As the supposed character distinction plainly does not hold true and supported by the phylogenetic results, the recognition of subfamilies in Palaemonidae is not warranted. As a consequence, all three supra-generic taxa (Gnathophyllidae, Hymenoceridae, Pontoniinae) are thus herein formally synonymised with Palaemonidae.

Published
2015
Full Text
View/download PDF

25. Periclimenes macrorhynchia sp. nov., a new hydrozoan-associated pontoniine shrimp (Crustacea, Decapoda, Palaemonidae) from North East Kalimantan, Indonesia.

Author

Eilbracht J and Fransen CH

Subjects
Animal Structures anatomy & histology, Animal Structures growth & development, Animals, Body Size, Female, Hydrozoa physiology, Indonesia, Male, Organ Size, Palaemonidae anatomy & histology, Palaemonidae growth & development, Palaemonidae classification
Abstract

A new species of pontoniine shrimp belonging to the 'Periclimenes obscurus species group' is described from the Berau Islands, North East Kalimantan, Indonesia. Specimens were obtained from aglaopheniid hydrozoans of the genus Macrorhynchia. The new species is here described and figured. Its affinities with related species are discussed and a DNA-barcode is provided.

Published
2015
Full Text
View/download PDF

26. A second discovery of Diapontonia maranulus Bruce, 1986 (Crustacea: Decapoda: Palaemonidae) in the Caribbean.

Author

Fransen CH

Subjects
Animals, DNA, Mitochondrial, Female, Male, Netherlands Antilles, Palaemonidae genetics, Palaemonidae anatomy & histology, Palaemonidae classification
Abstract

A second discovery of the echinoid associated shrimp species Diapontonia maranulus Bruce, 1986 is recorded from deep water off Curaçao, Leeward Islands of the Dutch Caribbean. The material is compared with the type description and paratypic material as well as with material of closely related species. A mtDNA COI barcode was obtained from the material. The systematic position of the genus is discussed.

Published
2014
Full Text
View/download PDF

27. Shape coexistence in the neutron-deficient even-even (182-188)Hg isotopes studied via coulomb excitation.

Author

Bree N, Wrzosek-Lipska K, Petts A, Andreyev A, Bastin B, Bender M, Blazhev A, Bruyneel B, Butler PA, Butterworth J, Carpenter MP, Cederkäll J, Clément E, Cocolios TE, Deacon A, Diriken J, Ekström A, Fitzpatrick C, Fraile LM, Fransen Ch, Freeman SJ, Gaffney LP, García-Ramos JE, Geibel K, Gernhäuser R, Grahn T, Guttormsen M, Hadinia B, Hadyńska-Kle K K, Hass M, Heenen PH, Herzberg RD, Hess H, Heyde K, Huyse M, Ivanov O, Jenkins DG, Julin R, Kesteloot N, Kröll T, Krücken R, Larsen AC, Lutter R, Marley P, Napiorkowski PJ, Orlandi R, Page RD, Pakarinen J, Patronis N, Peura PJ, Piselli E, Rahkila P, Rapisarda E, Reiter P, Robinson AP, Scheck M, Siem S, Singh Chakkal K, Smith JF, Srebrny J, Stefanescu I, Tveten GM, Van Duppen P, Van de Walle J, Voulot D, Warr N, Wenander F, Wiens A, Wood JL, and Zielińska M

Abstract

Coulomb-excitation experiments to study electromagnetic properties of radioactive even-even Hg isotopes were performed with 2.85  MeV/nucleon mercury beams from REX-ISOLDE. Magnitudes and relative signs of the reduced E2 matrix elements that couple the ground state and low-lying excited states in Hg182-188 were extracted. Information on the deformation of the ground and the first excited 0+ states was deduced using the quadrupole sum rules approach. Results show that the ground state is slightly deformed and of oblate nature, while a larger deformation for the excited 0+ state was noted in Hg182,184. The results are compared to beyond mean field and interacting-boson based models and interpreted within a two-state mixing model. Partial agreement with the model calculations was obtained. The presence of two different structures in the light even-mass mercury isotopes that coexist at low excitation energy is firmly established.

Published
2014
Full Text
View/download PDF

28. Hamodactylus macrophthalmus spec. nov., a new coral-associated pontoniine shrimp (Decapoda, Caridea, Palaemonidae) from Indonesia.

Author

Fransen CH and Rauch C

Subjects
Animals, Anthozoa, Ecosystem, Female, Indonesia, Palaemonidae genetics, Palaemonidae physiology, Phylogeny, Species Specificity, Animal Distribution physiology, Palaemonidae anatomy & histology, Palaemonidae classification
Abstract

A new coral-associated species of the genus Hamodactylus is described from Lembeh Strait, NE Sulawesi, Indonesia. The three other known species in the genus have been recorded in association with octocorals. The single ovigerous female specimen of the new species was collected from a scleractinian host. It can be easily separated from its congeners by the very long eyestalks and the chela of the second pereiopods having blunt tips of the fingers with tufts of long simple setae giving it an atyid-like appearance.

Published
2013
Full Text
View/download PDF

29. Caught in speciation? A new host for Conchodytes meleagrinae Peters, 1852 (Decapoda, Caridea, Palaemonidae).

Author

Fransen CH and Reijnen BT

Subjects
Animal Structures anatomy & histology, Animal Structures growth & development, Animals, Body Size, Female, Indonesia, Male, Palaemonidae anatomy & histology, Palaemonidae genetics, Palaemonidae growth & development, Phylogeny, Palaemonidae classification
Abstract

During fieldwork in 2009 at Ternate, Indonesia, a pair of a pontoniine shrimp species belonging to the genus Conchodytes was collected from a bivalve mollusk of the genus Spondylus. This constitutes the first record of a species of the genus Conchodytes associated with a spondylid host. The specimens can be distinguished from other known Conchodytes species based on both morphology and colour pattern. Its COI barcode however, strongly resembles those obtained from three specimens of C. meleagrinae and is nested in the C. meleagrinae clade of the reconstructed phylogeny. Based on morphology and colouration only the specimens associated with the Spondylus bivalve would have been described as a species new to science. The modest conflicting molecular data have lead the authors to fully describe and figure the Spondylus associated specimens and compare them with the Pinctada associated specimens. Based on the present information it is decided not to give the Spondylus associated specimens the status as a distinct species but regard them as host-related (colour)morph of Conchodytes meleagrinae.

Published
2013
Full Text
View/download PDF

30. A new species of the sponge-associated pontoniine shrimp genus Nippontonia Bruce & Bauer, 1997 (Decapoda, Caridea, Palaemonidae) from Sabah, Malaysia.

Author

Fransen CH

Subjects
Animal Distribution, Animal Structures anatomy & histology, Animal Structures growth & development, Animals, Body Size, Female, Malaysia, Male, Molecular Sequence Data, Organ Size, Palaemonidae anatomy & histology, Palaemonidae genetics, Palaemonidae growth & development, Phylogeny, Porifera growth & development, Palaemonidae classification
Abstract

A sponge-associated species of the genus Nippontonia new to science is described from Semporna, Sabah, Malaysia. The only other species in the genus is also known to be a sponge-dweller. The new species can be distinguished from its con- gener by a suite of characters mainly of the anterior appendages.

Published
2013
Full Text
View/download PDF

31. The magnitude of global marine species diversity.

Author

Appeltans W, Ahyong ST, Anderson G, Angel MV, Artois T, Bailly N, Bamber R, Barber A, Bartsch I, Berta A, Błażewicz-Paszkowycz M, Bock P, Boxshall G, Boyko CB, Brandão SN, Bray RA, Bruce NL, Cairns SD, Chan TY, Cheng L, Collins AG, Cribb T, Curini-Galletti M, Dahdouh-Guebas F, Davie PJ, Dawson MN, De Clerck O, Decock W, De Grave S, de Voogd NJ, Domning DP, Emig CC, Erséus C, Eschmeyer W, Fauchald K, Fautin DG, Feist SW, Fransen CH, Furuya H, Garcia-Alvarez O, Gerken S, Gibson D, Gittenberger A, Gofas S, Gómez-Daglio L, Gordon DP, Guiry MD, Hernandez F, Hoeksema BW, Hopcroft RR, Jaume D, Kirk P, Koedam N, Koenemann S, Kolb JB, Kristensen RM, Kroh A, Lambert G, Lazarus DB, Lemaitre R, Longshaw M, Lowry J, Macpherson E, Madin LP, Mah C, Mapstone G, McLaughlin PA, Mees J, Meland K, Messing CG, Mills CE, Molodtsova TN, Mooi R, Neuhaus B, Ng PK, Nielsen C, Norenburg J, Opresko DM, Osawa M, Paulay G, Perrin W, Pilger JF, Poore GC, Pugh P, Read GB, Reimer JD, Rius M, Rocha RM, Saiz-Salinas JI, Scarabino V, Schierwater B, Schmidt-Rhaesa A, Schnabel KE, Schotte M, Schuchert P, Schwabe E, Segers H, Self-Sullivan C, Shenkar N, Siegel V, Sterrer W, Stöhr S, Swalla B, Tasker ML, Thuesen EV, Timm T, Todaro MA, Turon X, Tyler S, Uetz P, van der Land J, Vanhoorne B, van Ofwegen LP, van Soest RW, Vanaverbeke J, Walker-Smith G, Walter TC, Warren A, Williams GC, Wilson SP, and Costello MJ

Subjects
Animals, Models, Statistical, Aquatic Organisms, Biodiversity, Databases, Factual
Abstract

Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered., Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000-72,000 species are collected but not yet described, and that 482,000-741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7-1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science., Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Published
2012
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results