1
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Auranen K, Briscoe AD, Ferreira LS, Grahn T, Greenlees PT, Herzáň A, Illana A, Joss DT, Joukainen H, Julin R, Jutila H, Leino M, Louko J, Luoma M, Maglione E, Ojala J, Page RD, Pakarinen J, Rahkila P, Romero J, Ruotsalainen P, Sandzelius M, Sarén J, Tolosa-Delgado A, Uusitalo J, Zimba G. Nanosecond-Scale Proton Emission from Strongly Oblate-Deformed ^{149}Lu. Phys Rev Lett 2022; 128:112501. [PMID: 35363028 DOI: 10.1103/physrevlett.128.112501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/02/2022] [Accepted: 02/22/2022] [Indexed: 06/14/2023]
Abstract
Using the fusion-evaporation reaction ^{96}Ru(^{58}Ni,p4n)^{149}Lu and the MARA vacuum-mode recoil separator, a new proton-emitting isotope ^{149}Lu has been identified. The measured decay Q value of 1920(20) keV is the highest measured for a ground-state proton decay, and it naturally leads to the shortest directly measured half-life of 450_{-100}^{+170} ns for a ground-state proton emitter. The decay rate is consistent with l_{p}=5 emission, suggesting a dominant πh_{11/2} component for the wave function of the proton-emitting state. Through nonadiabatic quasiparticle calculations it was concluded that ^{149}Lu is the most oblate deformed proton emitter observed to date.
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Affiliation(s)
- K Auranen
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - A D Briscoe
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - L S Ferreira
- Centro de Física e Engenharia de Materiais Avançados CeFEMA, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, P1049-001 Lisbon, Portugal
| | - T Grahn
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - P T Greenlees
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - A Herzáň
- Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava, Slovakia
| | - A Illana
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - D T Joss
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - H Joukainen
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - R Julin
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - H Jutila
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - M Leino
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - J Louko
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - M Luoma
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - E Maglione
- Centro de Física e Engenharia de Materiais Avançados CeFEMA, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, P1049-001 Lisbon, Portugal
| | - J Ojala
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - R D Page
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Pakarinen
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - P Rahkila
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - J Romero
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - P Ruotsalainen
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - M Sandzelius
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - J Sarén
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - A Tolosa-Delgado
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - J Uusitalo
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - G Zimba
- Accelerator Laboratory, Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
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2
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Carroll RJ, Podolyák Z, Berry T, Grawe H, Alexander T, Andreyev AN, Ansari S, Borge MJG, Brunet M, Creswell JR, Fraile LM, Fahlander C, Fynbo HOU, Gamba ER, Gelletly W, Gerst RB, Górska M, Gredley A, Greenlees PT, Harkness-Brennan LJ, Huyse M, Judge SM, Judson DS, Konki J, Kurcewicz J, Kuti I, Lalkovski S, Lazarus IH, Lică R, Lund M, Madurga M, Marginean N, Marginean R, Marroquin I, Mihai C, Mihai RE, Nácher E, Negret A, Nita C, Pascu S, Page RD, Patel Z, Perea A, Phrompao J, Piersa M, Pucknell V, Rahkila P, Rapisarda E, Regan PH, Rotaru F, Rudigier M, Shand CM, Shearman R, Stegemann S, Stora T, Sotty C, Tengblad O, Van Duppen P, Vedia V, Wadsworth R, Walker PM, Warr N, Wearing F, De Witte H. Competition between Allowed and First-Forbidden β Decay: The Case of ^{208}Hg→^{208}Tl. Phys Rev Lett 2020; 125:192501. [PMID: 33216605 DOI: 10.1103/physrevlett.125.192501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/21/2020] [Accepted: 10/07/2020] [Indexed: 06/11/2023]
Abstract
The β decay of ^{208}Hg into the one-proton hole, one neutron-particle _{81}^{208}Tl_{127} nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N>126, Z<82 quadrant of neutron-rich nuclei. While both negative and positive parity states with spin 0 and 1 are expected within the Q_{β} window, only three negative parity states are populated directly in the β decay. The data provide a unique test of the competition between allowed Gamow-Teller and Fermi, and first-forbidden β decays, essential for the understanding of the nucleosynthesis of heavy nuclei in the rapid neutron capture process. Furthermore, the observation of the parity changing 0^{+}→0^{-}β decay where the daughter state is core excited is unique, and can provide information on mesonic corrections of effective operators.
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Affiliation(s)
- R J Carroll
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - Zs Podolyák
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt, Germany
| | - T Berry
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - H Grawe
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany
| | - T Alexander
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - A N Andreyev
- University of York, Dept Phys, North Yorkshire YO10 5DD, United Kingdom
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai-mura, Ibaraki 319-1195, Japan
| | - S Ansari
- Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - M J G Borge
- CERN, Physics Department, 1211 Geneva 23, Switzerland
| | - M Brunet
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - J R Creswell
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - L M Fraile
- Grupo de Física Nuclear & IPARCOS, Universidad Complutense de Madrid, CEI Moncloa, E-28040 Madrid, Spain
| | - C Fahlander
- Department of Physics, Lund University, S-22100 Lund, Sweden
| | - H O U Fynbo
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus, Denmark
| | - E R Gamba
- University of Brighton, Brighton BN2 4GJ, United Kingdom
| | - W Gelletly
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - R-B Gerst
- Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - M Górska
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany
| | - A Gredley
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - P T Greenlees
- University of Jyvaskyla, Department of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla, Finland
- Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - L J Harkness-Brennan
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - M Huyse
- KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, 3001 Leuven, Belgium
| | - S M Judge
- National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom
| | - D S Judson
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Konki
- University of Jyvaskyla, Department of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla, Finland
- Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - J Kurcewicz
- CERN, Physics Department, 1211 Geneva 23, Switzerland
| | - I Kuti
- Institute of Nuclear Research of the Hungarian Academy of Sciences, 4026 Debrecen, Hungary
| | - S Lalkovski
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - I H Lazarus
- STFC, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - R Lică
- CERN, Physics Department, 1211 Geneva 23, Switzerland
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - M Lund
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus, Denmark
| | - M Madurga
- CERN, Physics Department, 1211 Geneva 23, Switzerland
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - N Marginean
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - R Marginean
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - I Marroquin
- Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid, Spain
| | - C Mihai
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - R E Mihai
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - E Nácher
- Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid, Spain
| | - A Negret
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - C Nita
- University of Brighton, Brighton BN2 4GJ, United Kingdom
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - S Pascu
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - R D Page
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - Z Patel
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - A Perea
- Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid, Spain
| | - J Phrompao
- Department of Physics and Materials Science, Chiang Mai University, 50200 Chiang Mai, Thailand
| | - M Piersa
- Faculty of Physics, University of Warsaw, PL 02-093 Warsaw, Poland
| | - V Pucknell
- STFC, Daresbury Laboratory, Warrington WA4 4AD, United Kingdom
| | - P Rahkila
- University of Jyvaskyla, Department of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla, Finland
- Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - E Rapisarda
- CERN, Physics Department, 1211 Geneva 23, Switzerland
| | - P H Regan
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
- National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom
| | - F Rotaru
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - M Rudigier
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - C M Shand
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - R Shearman
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
- National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom
| | - S Stegemann
- Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - T Stora
- CERN, Physics Department, 1211 Geneva 23, Switzerland
| | - Ch Sotty
- KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, 3001 Leuven, Belgium
- Horea Hulubei National Institute for Physics and Nuclear Engineering, RO-077125 Bucharest, Romania
| | - O Tengblad
- Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid, Spain
| | - P Van Duppen
- KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, 3001 Leuven, Belgium
| | - V Vedia
- Grupo de Física Nuclear & IPARCOS, Universidad Complutense de Madrid, CEI Moncloa, E-28040 Madrid, Spain
| | - R Wadsworth
- University of York, Dept Phys, North Yorkshire YO10 5DD, United Kingdom
| | - P M Walker
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - N Warr
- Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - F Wearing
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - H De Witte
- KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, 3001 Leuven, Belgium
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3
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Kirsebom OS, Tengblad O, Lica R, Munch M, Riisager K, Fynbo HOU, Borge MJG, Madurga M, Marroquin I, Andreyev AN, Berry TA, Christensen ER, Fernández PD, Doherty DT, Van Duppen P, Fraile LM, Gallardo MC, Greenlees PT, Harkness-Brennan LJ, Hubbard N, Huyse M, Jensen JH, Johansson H, Jonson B, Judson DS, Konki J, Lazarus I, Lund MV, Marginean N, Marginean R, Perea A, Mihai C, Negret A, Page RD, Pucknell V, Rahkila P, Sorlin O, Sotty C, Swartz JA, Sørensen HB, Törnqvist H, Vedia V, Warr N, De Witte H. First Accurate Normalization of the β-delayed α Decay of ^{16}N and Implications for the ^{12}C(α,γ)^{16}O Astrophysical Reaction Rate. Phys Rev Lett 2018; 121:142701. [PMID: 30339438 DOI: 10.1103/physrevlett.121.142701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/22/2018] [Indexed: 06/08/2023]
Abstract
The ^{12}C(α,γ)^{16}O reaction plays a central role in astrophysics, but its cross section at energies relevant for astrophysical applications is only poorly constrained by laboratory data. The reduced α width, γ_{11}, of the bound 1^{-} level in ^{16}O is particularly important to determine the cross section. The magnitude of γ_{11} is determined via sub-Coulomb α-transfer reactions or the β-delayed α decay of ^{16}N, but the latter approach is presently hampered by the lack of sufficiently precise data on the β-decay branching ratios. Here we report improved branching ratios for the bound 1^{-} level [b_{β,11}=(5.02±0.10)×10^{-2}] and for β-delayed α emission [b_{βα}=(1.59±0.06)×10^{-5}]. Our value for b_{βα} is 33% larger than previously held, leading to a substantial increase in γ_{11}. Our revised value for γ_{11} is in good agreement with the value obtained in α-transfer studies and the weighted average of the two gives a robust and precise determination of γ_{11}, which provides significantly improved constraints on the ^{12}C(α,γ) cross section in the energy range relevant to hydrostatic He burning.
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Affiliation(s)
- O S Kirsebom
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - O Tengblad
- Instituto de Estructura de la Materia, CSIC, E-28006 Madrid, Spain
| | - R Lica
- CERN, CH-1211 Geneva 23, Switzerland
- Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), RO-077125 Bucharest-Magurele, Romania
| | - M Munch
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - K Riisager
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - H O U Fynbo
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M J G Borge
- Instituto de Estructura de la Materia, CSIC, E-28006 Madrid, Spain
- CERN, CH-1211 Geneva 23, Switzerland
| | - M Madurga
- CERN, CH-1211 Geneva 23, Switzerland
| | - I Marroquin
- Instituto de Estructura de la Materia, CSIC, E-28006 Madrid, Spain
| | - A N Andreyev
- Department of Physics, University of York, York YO10 5DD, United Kingdom
- Advanced Science Research Centre (ASRC), Japan Atomic Energy Agency (JAEA), Tokai-mura, Ibaraki 319-1195, Japan
| | - T A Berry
- Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom
| | - E R Christensen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - P Díaz Fernández
- Department of Physics, Chalmers University of Technology, S-41296 Göteborg, Sweden
| | - D T Doherty
- Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - P Van Duppen
- KU Leuven, Instituut voor Kern- en Stralingsfysica, 3001 Leuven, Belgium
| | - L M Fraile
- Grupo de Física Nuclear, Universidad Complutense de Madrid, E-28040 Madrid, Spain
| | - M C Gallardo
- Grupo de Física Nuclear, Universidad Complutense de Madrid, E-28040 Madrid, Spain
| | - P T Greenlees
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - L J Harkness-Brennan
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - N Hubbard
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
- Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - M Huyse
- KU Leuven, Instituut voor Kern- en Stralingsfysica, 3001 Leuven, Belgium
| | - J H Jensen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - H Johansson
- Department of Physics, Chalmers University of Technology, S-41296 Göteborg, Sweden
| | - B Jonson
- Department of Physics, Chalmers University of Technology, S-41296 Göteborg, Sweden
| | - D S Judson
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Konki
- CERN, CH-1211 Geneva 23, Switzerland
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - I Lazarus
- STFC Daresbury, Daresbury, Warrington WA4 4AD, United Kingdom
| | - M V Lund
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - N Marginean
- Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), RO-077125 Bucharest-Magurele, Romania
| | - R Marginean
- Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), RO-077125 Bucharest-Magurele, Romania
| | - A Perea
- Instituto de Estructura de la Materia, CSIC, E-28006 Madrid, Spain
| | - C Mihai
- Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), RO-077125 Bucharest-Magurele, Romania
| | - A Negret
- Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), RO-077125 Bucharest-Magurele, Romania
| | - R D Page
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - V Pucknell
- STFC Daresbury, Daresbury, Warrington WA4 4AD, United Kingdom
| | - P Rahkila
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - O Sorlin
- CERN, CH-1211 Geneva 23, Switzerland
- GANIL, CEA/DSM-CNRS/IN2P3, Bvd Henri Becquerel, 14076 Caen, France
| | - C Sotty
- Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), RO-077125 Bucharest-Magurele, Romania
| | - J A Swartz
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - H B Sørensen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - H Törnqvist
- Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany
| | - V Vedia
- Grupo de Física Nuclear, Universidad Complutense de Madrid, E-28040 Madrid, Spain
| | - N Warr
- Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany
| | - H De Witte
- KU Leuven, Instituut voor Kern- en Stralingsfysica, 3001 Leuven, Belgium
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4
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Cederwall B, Doncel M, Aktas Ö, Ertoprak A, Liotta R, Qi C, Grahn T, Cullen DM, Hodge D, Giles M, Stolze S, Badran H, Braunroth T, Calverley T, Cox DM, Fang YD, Greenlees PT, Hilton J, Ideguchi E, Julin R, Juutinen S, Raju MK, Li H, Liu H, Matta S, Modamio V, Pakarinen J, Papadakis P, Partanen J, Petrache CM, Rahkila P, Ruotsalainen P, Sandzelius M, Sarén J, Scholey C, Sorri J, Subramaniam P, Taylor MJ, Uusitalo J, Valiente-Dobón JJ. Lifetime Measurements of Excited States in ^{172}Pt and the Variation of Quadrupole Transition Strength with Angular Momentum. Phys Rev Lett 2018; 121:022502. [PMID: 30085703 DOI: 10.1103/physrevlett.121.022502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 04/19/2018] [Indexed: 06/08/2023]
Abstract
Lifetimes of the first excited 2^{+} and 4^{+} states in the extremely neutron-deficient nuclide ^{172}Pt have been measured for the first time using the recoil-distance Doppler shift and recoil-decay tagging techniques. An unusually low value of the ratio B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+})=0.55(19) was found, similar to a handful of other such anomalous cases observed in the entire Segré chart. The observation adds to a cluster of a few extremely neutron-deficient nuclides of the heavy transition metals with neutron numbers N≈90-94 featuring the effect. No theoretical model calculations reported to date have been able to explain the anomalously low B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+}) ratios observed in these cases. Such low values cannot, e.g., be explained within the framework of the geometrical collective model or by algebraic approaches within the interacting boson model framework. It is proposed that the group of B(E2:4_{1}^{+}→2_{1}^{+})/B(E2:2_{1}^{+}→0_{gs}^{+}) ratios in the extremely neutron-deficient even-even W, Os, and Pt nuclei around neutron numbers N≈90-94 reveal a quantum phase transition from a seniority-conserving structure to a collective regime as a function of neutron number. Although a system governed by seniority symmetry is the only theoretical framework for which such an effect may naturally occur, the phenomenon is highly unexpected for these nuclei that are not situated near closed shells.
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Affiliation(s)
- B Cederwall
- KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - M Doncel
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - Ö Aktas
- KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - A Ertoprak
- KTH Royal Institute of Technology, 10691 Stockholm, Sweden
- Department of Physics, Faculty of Science, Istanbul University, Vezneciler/Fatih, 34134 Istanbul, Turkey
| | - R Liotta
- KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - C Qi
- KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - T Grahn
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - D M Cullen
- Schuster Building, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - D Hodge
- Schuster Building, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - M Giles
- Schuster Building, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - S Stolze
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - H Badran
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - T Braunroth
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - T Calverley
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - D M Cox
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - Y D Fang
- Research Center for Nuclear Physics, Osaka University, JP-567-0047 Osaka, Japan
| | - P T Greenlees
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - J Hilton
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - E Ideguchi
- Research Center for Nuclear Physics, Osaka University, JP-567-0047 Osaka, Japan
| | - R Julin
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - S Juutinen
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - M Kumar Raju
- Research Center for Nuclear Physics, Osaka University, JP-567-0047 Osaka, Japan
| | - H Li
- Grand Accélérateur National dâIons Lourds (GANIL), CEA/DSMâCNRS/IN2P3, F-14076 Caen Cedex 5, France
| | - H Liu
- KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - S Matta
- KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - V Modamio
- Department of Physics, University of Oslo, NO-0316 Oslo, Norway
| | - J Pakarinen
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - P Papadakis
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - J Partanen
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - C M Petrache
- Centre de Sciences Nucléaires et Sciences de la Matière, CNRS/IN2P3, Université Paris-Saclay, 91405 Orsay, France
| | - P Rahkila
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - P Ruotsalainen
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - M Sandzelius
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - J Sarén
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - C Scholey
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - J Sorri
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
- Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy
| | - P Subramaniam
- KTH Royal Institute of Technology, 10691 Stockholm, Sweden
| | - M J Taylor
- Division of Cancer Sciences, School of Medical Sciences, The University of Manchester, Manchester, M13 9PL, United Kingdom
| | - J Uusitalo
- epartment of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - J J Valiente-Dobón
- Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy
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5
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David HM, Chen J, Seweryniak D, Kondev FG, Gates JM, Gregorich KE, Ahmad I, Albers M, Alcorta M, Back BB, Baartman B, Bertone PF, Bernstein LA, Campbell CM, Carpenter MP, Chiara CJ, Clark RM, Cromaz M, Doherty DT, Dracoulis GD, Esker NE, Fallon P, Gothe OR, Greene JP, Greenlees PT, Hartley DJ, Hauschild K, Hoffman CR, Hota SS, Janssens RVF, Khoo TL, Konki J, Kwarsick JT, Lauritsen T, Macchiavelli AO, Mudder PR, Nair C, Qiu Y, Rissanen J, Rogers AM, Ruotsalainen P, Savard G, Stolze S, Wiens A, Zhu S. Publisher's Note: Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in (254)Rf [Phys. Rev. Lett. 115, 132502 (2015)]. Phys Rev Lett 2015; 115:169902. [PMID: 26550909 DOI: 10.1103/physrevlett.115.169902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Indexed: 06/05/2023]
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6
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David HM, Chen J, Seweryniak D, Kondev FG, Gates JM, Gregorich KE, Ahmad I, Albers M, Alcorta M, Back BB, Baartman B, Bertone PF, Bernstein LA, Campbell CM, Carpenter MP, Chiara CJ, Clark RM, Cromaz M, Doherty DT, Dracoulis GD, Esker NE, Fallon P, Gothe OR, Greene JP, Greenlees PT, Hartley DJ, Hauschild K, Hoffman CR, Hota SS, Janssens RVF, Khoo TL, Konki J, Kwarsick JT, Lauritsen T, Macchiavelli AO, Mudder PR, Nair C, Qiu Y, Rissanen J, Rogers AM, Ruotsalainen P, Savard G, Stolze S, Wiens A, Zhu S. Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in ^{254}Rf. Phys Rev Lett 2015; 115:132502. [PMID: 26451549 DOI: 10.1103/physrevlett.115.132502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Indexed: 06/05/2023]
Abstract
Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73) μs have been discovered in the heavy ^{254}Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the K^{π}=8^{-}, ν^{2}(7/2^{+}[624],9/2^{-}[734]) two-quasineutron and the K^{π}=16^{+}, 8^{-}ν^{2}(7/2^{+}[624],9/2^{-}[734])⊗8^{-}π^{2}(7/2^{-}[514],9/2^{+}[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the ^{254}Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1) μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state.
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Affiliation(s)
- H M David
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Chen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J M Gates
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - K E Gregorich
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - I Ahmad
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Albers
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Alcorta
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - B B Back
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - B Baartman
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P F Bertone
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - L A Bernstein
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C M Campbell
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C J Chiara
- Argonne National Laboratory, Argonne, Illinois 60439, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - R M Clark
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M Cromaz
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - D T Doherty
- School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - G D Dracoulis
- Department of Nuclear Physics, R.S.P.E., Australian National University, Canberra A.C.T. 2601, Australia
| | - N E Esker
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Fallon
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - O R Gothe
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J P Greene
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P T Greenlees
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
| | - D J Hartley
- United States Naval Academy, Annapolis, Maryland 21402, USA
| | - K Hauschild
- CSNSM, IN2P3-CNRS, F-91405 Orsay Campus, France
| | - C R Hoffman
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S S Hota
- Department of Physics, University of Massachusetts, Lowell, Massachusetts 01854, USA
| | - R V F Janssens
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - T L Khoo
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Konki
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
| | - J T Kwarsick
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - T Lauritsen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A O Macchiavelli
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P R Mudder
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C Nair
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Y Qiu
- Department of Physics, University of Massachusetts, Lowell, Massachusetts 01854, USA
| | - J Rissanen
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A M Rogers
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P Ruotsalainen
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
| | - G Savard
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S Stolze
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
| | - A Wiens
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S Zhu
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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7
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Henning G, Khoo TL, Lopez-Martens A, Seweryniak D, Alcorta M, Asai M, Back BB, Bertone PF, Boilley D, Carpenter MP, Chiara CJ, Chowdhury P, Gall B, Greenlees PT, Gürdal G, Hauschild K, Heinz A, Hoffman CR, Janssens RVF, Karpov AV, Kay BP, Kondev FG, Lakshmi S, Lauritsen T, Lister CJ, McCutchan EA, Nair C, Piot J, Potterveld D, Reiter P, Rogers AM, Rowley N, Zhu S. Fission barrier of superheavy nuclei and persistence of shell effects at high spin: cases of 254No and 220Th. Phys Rev Lett 2014; 113:262505. [PMID: 25615317 DOI: 10.1103/physrevlett.113.262505] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Indexed: 06/04/2023]
Abstract
We report on the first measurement of the fission barrier height in a heavy shell-stabilized nucleus. The fission barrier height of 254No is measured to be Bf=6.0±0.5 MeV at spin 15ℏ and, by extrapolation, Bf=6.6±0.9 MeV at spin 0ℏ. This information is deduced from the measured distribution of entry points in the excitation energy versus spin plane. The same measurement is performed for 220Th and only a lower limit of the fission barrier height can be determined: Bf(I)>8 MeV. Comparisons with theoretical fission barriers test theories that predict properties of superheavy elements.
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Affiliation(s)
- Greg Henning
- CSNSM, IN2P3-CNRS, and Université Paris Sud, Bat. 104-108, F-91405 Orsay, France and Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - T L Khoo
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Lopez-Martens
- CSNSM, IN2P3-CNRS, and Université Paris Sud, Bat. 104-108, F-91405 Orsay, France
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Alcorta
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Asai
- Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195, Japan
| | - B B Back
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P F Bertone
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Boilley
- GANIL, CEA-DSM, and IN2P3-CNRS, B.P. 55027, F-14076 Caen Cedex, France and Université de Caen Basse-Normandie, F-14032 Caen Cedex, France
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C J Chiara
- Argonne National Laboratory, Argonne, Illinois 60439, USA and University of Maryland, College Park, Maryland 20742, USA
| | - P Chowdhury
- University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA
| | - B Gall
- Université de Strasbourg, IPHC, 23 rue du Loess, 67037 Strasbourg, France and CNRS, UMR7178, 67037 Strasbourg, France
| | - P T Greenlees
- Department of Physics, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - G Gürdal
- Argonne National Laboratory, Argonne, Illinois 60439, USA and DePaul University, Chicago, Illinois 60604, USA
| | - K Hauschild
- CSNSM, IN2P3-CNRS, and Université Paris Sud, Bat. 104-108, F-91405 Orsay, France
| | - A Heinz
- Fundamental Fysik, Chalmers Tekniska Hogskola, 412 96 Göteborg, Sweden and WNSL, Yale University, New Haven, Connecticut 06511, USA
| | - C R Hoffman
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - R V F Janssens
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A V Karpov
- Flerov Laboratory of Nuclear Reactions, JINR, Dubna, 141980, Russia
| | - B P Kay
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S Lakshmi
- University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA
| | - T Lauritsen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C J Lister
- University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA
| | - E A McCutchan
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C Nair
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Piot
- Université de Strasbourg, IPHC, 23 rue du Loess, 67037 Strasbourg, France and CNRS, UMR7178, 67037 Strasbourg, France
| | - D Potterveld
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P Reiter
- Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany
| | - A M Rogers
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - N Rowley
- IPN, CNRS/IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex, France
| | - S Zhu
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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8
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Henning G, Lopez-Martens A, Khoo T, Seweryniak D, Alcorta M, Asai M, Back BB, Bertone P, Boilley D, Carpenter MP, Chiara CJ, Chowdhury P, Gall B, Greenlees PT, Gurdal G, Hauschild K, Heinz A, Hoffman CR, Janssens RVF, Karpov AV, Kay BP, Kondev FG, Lakshmi S, Lauristen T, Lister CJ, McCutchan EA, Nair C, Piot J, Potterveld D, Reiter P, Rowley N, Rogers AM, Zhu S. Exploring the stability of super heavy elements: First Measurement of the Fission Barrier of254No. EPJ Web of Conferences 2014. [DOI: 10.1051/epjconf/20146602046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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9
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Carroll RJ, Page RD, Joss DT, Uusitalo J, Darby IG, Andgren K, Cederwall B, Eeckhaudt S, Grahn T, Gray-Jones C, Greenlees PT, Hadinia B, Jones PM, Julin R, Juutinen S, Leino M, Leppänen AP, Nyman M, O'Donnell D, Pakarinen J, Rahkila P, Sandzelius M, Sarén J, Scholey C, Seweryniak D, Simpson J. Blurring the boundaries: decays of multiparticle isomers at the proton drip line. Phys Rev Lett 2014; 112:092501. [PMID: 24655248 DOI: 10.1103/physrevlett.112.092501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Indexed: 06/03/2023]
Abstract
A multiparticle spin-trap isomer has been discovered in the proton-unbound nucleus (73)(158)Ta85 . The isomer mainly decays by γ-ray emission with a half-life of 6.1(1) μs. Analysis of the γ-ray data shows that the isomer lies 2668 keV above the known 9+ state and has a spin 10ℏ higher and negative parity. This 19- isomer also has an 8644(11) keV, 1.4(2)% α-decay branch that populates the 9+ state in (154)Lu. No proton-decay branch from the isomer was identified, despite the isomer being unbound to proton emission by 3261(14) keV. This remarkable stability against proton emission is compared with theoretical predictions, and the implications for the extent of observable nuclides are considered.
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Affiliation(s)
- R J Carroll
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - R D Page
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - D T Joss
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Uusitalo
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - I G Darby
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - K Andgren
- Department of Physics, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - B Cederwall
- Department of Physics, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - S Eeckhaudt
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - T Grahn
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - C Gray-Jones
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - P T Greenlees
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - B Hadinia
- Department of Physics, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - P M Jones
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - R Julin
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - S Juutinen
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - M Leino
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - A-P Leppänen
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - M Nyman
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - D O'Donnell
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom and STFC, Daresbury Laboratory, Daresbury, Warrington WA4 4AD, United Kingdom
| | - J Pakarinen
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - P Rahkila
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - M Sandzelius
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - J Sarén
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - C Scholey
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - D Seweryniak
- Argonne National Laboratory, Physics Division, Argonne, Illinois 60439, USA
| | - J Simpson
- STFC, Daresbury Laboratory, Daresbury, Warrington WA4 4AD, United Kingdom
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10
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Greenlees PT, Rubert J, Piot J, Gall BJP, Andersson LL, Asai M, Asfari Z, Cox DM, Dechery F, Dorvaux O, Grahn T, Hauschild K, Henning G, Herzan A, Herzberg RD, Heßberger FP, Jakobsson U, Jones P, Julin R, Juutinen S, Ketelhut S, Khoo TL, Leino M, Ljungvall J, Lopez-Martens A, Lozeva R, Nieminen P, Pakarinen J, Papadakis P, Parr E, Peura P, Rahkila P, Rinta-Antila S, Ruotsalainen P, Sandzelius M, Sarén J, Scholey C, Seweryniak D, Sorri J, Sulignano B, Theisen C, Uusitalo J, Venhart M. Shell-structure and pairing interaction in superheavy nuclei: rotational properties of the z=104 nucleus (256)rf. Phys Rev Lett 2012; 109:012501. [PMID: 23031099 DOI: 10.1103/physrevlett.109.012501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Indexed: 06/01/2023]
Abstract
The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin of 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of neighboring nuclei and it is shown that the kinematic and dynamic moments of inertia are sensitive to the underlying single-particle shell structure and the specific location of high-j orbitals. The moments of inertia therefore provide a sensitive test of shell structure and pairing in superheavy nuclei which is essential to ensure the validity of contemporary nuclear models in this mass region. The data obtained show that there is no deformed shell gap at Z=104, which is predicted in a number of current self-consistent mean-field models.
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Affiliation(s)
- P T Greenlees
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland.
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11
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Ketelhut S, Greenlees PT, Ackermann D, Antalic S, Clément E, Darby IG, Dorvaux O, Drouart A, Eeckhaudt S, Gall BJP, Görgen A, Grahn T, Gray-Jones C, Hauschild K, Herzberg RD, Hessberger FP, Jakobsson U, Jones GD, Jones P, Julin R, Juutinen S, Khoo TL, Korten W, Leino M, Leppänen AP, Ljungvall J, Moon S, Nyman M, Obertelli A, Pakarinen J, Parr E, Papadakis P, Peura P, Piot J, Pritchard A, Rahkila P, Rostron D, Ruotsalainen P, Sandzelius M, Sarén J, Scholey C, Sorri J, Steer A, Sulignano B, Theisen C, Uusitalo J, Venhart M, Zielinska M, Bender M, Heenen PH. Gamma-ray spectroscopy at the limits: first observation of rotational bands in 255Lr. Phys Rev Lett 2009; 102:212501. [PMID: 19519098 DOI: 10.1103/physrevlett.102.212501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Indexed: 05/27/2023]
Abstract
The rotational band structure of 255Lr has been investigated using advanced in-beam gamma-ray spectroscopic techniques. To date, 255Lr is the heaviest nucleus to be studied in this manner. One rotational band has been unambiguously observed and strong evidence for a second rotational structure was found. The structures are tentatively assigned to be based on the 1/2-[521] and 7/2-[514] Nilsson states, consistent with assignments from recently obtained alpha decay data. The experimental rotational band dynamic moment of inertia is used to test self-consistent mean-field calculations using the Skyrme SLy4 interaction and a density-dependent pairing force.
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Affiliation(s)
- S Ketelhut
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland.
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12
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Sandzelius M, Hadinia B, Cederwall B, Andgren K, Ganioğlu E, Darby IG, Dimmock MR, Eeckhaudt S, Grahn T, Greenlees PT, Ideguchi E, Jones PM, Joss DT, Julin R, Juutinen S, Khaplanov A, Leino M, Nelson L, Niikura M, Nyman M, Page RD, Pakarinen J, Paul ES, Petri M, Rahkila P, Sarén J, Scholey C, Sorri J, Uusitalo J, Wadsworth R, Wyss R. Identification of excited states in the T(z) = 1 nucleus (110)Xe: evidence for enhanced collectivity near the N=Z=50 double shell closure. Phys Rev Lett 2007; 99:022501. [PMID: 17678215 DOI: 10.1103/physrevlett.99.022501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Indexed: 05/16/2023]
Abstract
Gamma-ray transitions have been identified for the first time in the extremely neutron-deficient (N=Z+2) nucleus (110)Xe, and the energies of the three lowest excited states in the ground-state band have been deduced. The results establish a breaking of the normal trend of increasing first excited 2(+) and 4(+) level energies as a function of the decreasing neutron number as the N=50 major shell gap is approached for the neutron-deficient Xe isotopes. This unusual feature is suggested to be an effect of enhanced collectivity, possibly arising from isoscalar n-p interactions becoming increasingly important close to the N=Z line.
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Affiliation(s)
- M Sandzelius
- Department of Physics, The Royal Institute of Technology, S-10691 Stockholm, Sweden
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13
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Chatillon A, Theisen C, Bouchez E, Butler PA, Clément E, Dorvaux O, Eeckhaudt S, Gall BJP, Görgen A, Grahn T, Greenlees PT, Herzberg RD, Hessberger F, Hürstel A, Jones GD, Jones P, Julin R, Juutinen S, Kettunen H, Khalfallah F, Korten W, Le Coz Y, Leino M, Leppänen AP, Nieminen P, Pakarinen J, Perkowski J, Rahkila P, Rousseau M, Scholey C, Uusitalo J, Wilson JN, Bonche P, Heenen PH. Observation of a rotational band in the odd-Z transfermium nucleus 101251Md. Phys Rev Lett 2007; 98:132503. [PMID: 17501196 DOI: 10.1103/physrevlett.98.132503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 12/18/2006] [Indexed: 05/15/2023]
Abstract
A rotational band has been unambiguously observed in an odd-proton transfermium nucleus for the first time. An in-beam gamma-ray spectroscopic study of 101/251Md has been performed using the gamma-ray array JUROGAM combined with the gas-filled separator RITU and the focal plane device GREAT. The experimental results, compared to Hartree-Fock-Bogolyubov calculations, lead to the interpretation that the rotational band is built on the [521]1/2(-) Nilsson state.
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Affiliation(s)
- A Chatillon
- Commissariat à l'Energie Atomique/SACLAY, DSM/DAPNIA/SPhN, F-91191 Gif-sur-Yvette Cedex, France.
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14
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Grahn T, Dewald A, Möller O, Julin R, Beausang CW, Christen S, Darby IG, Eeckhaudt S, Greenlees PT, Görgen A, Helariutta K, Jolie J, Jones P, Juutinen S, Kettunen H, Kröll T, Krücken R, Le Coz Y, Leino M, Leppänen AP, Maierbeck P, Meyer DA, Melon B, Nieminen P, Nyman M, Page RD, Pakarinen J, Petkov P, Rahkila P, Saha B, Sandzelius M, Sarén J, Scholey C, Uusitalo J. Collectivity and configuration mixing in 186,188Pb and 194Po. Phys Rev Lett 2006; 97:062501. [PMID: 17026165 DOI: 10.1103/physrevlett.97.062501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Indexed: 05/12/2023]
Abstract
Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |beta2|=0.29(5) and |beta2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.
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Affiliation(s)
- T Grahn
- Department of Physics, University of Jyväskylä, P. O. Box 35, FI-40014 Jyväskylä, Finland
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15
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Herzberg RD, Greenlees PT, Butler PA, Jones GD, Venhart M, Darby IG, Eeckhaudt S, Eskola K, Grahn T, Gray-Jones C, Hessberger FP, Jones P, Julin R, Juutinen S, Ketelhut S, Korten W, Leino M, Leppänen AP, Moon S, Nyman M, Page RD, Pakarinen J, Pritchard A, Rahkila P, Sarén J, Scholey C, Steer A, Sun Y, Theisen C, Uusitalo J. Nuclear isomers in superheavy elements as stepping stones towards the island of stability. Nature 2006; 442:896-9. [PMID: 16929293 DOI: 10.1038/nature05069] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Accepted: 07/11/2006] [Indexed: 11/09/2022]
Abstract
A long-standing prediction of nuclear models is the emergence of a region of long-lived, or even stable, superheavy elements beyond the actinides. These nuclei owe their enhanced stability to closed shells in the structure of both protons and neutrons. However, theoretical approaches to date do not yield consistent predictions of the precise limits of the 'island of stability'; experimental studies are therefore crucial. The bulk of experimental effort so far has been focused on the direct creation of superheavy elements in heavy ion fusion reactions, leading to the production of elements up to proton number Z = 118 (refs 4, 5). Recently, it has become possible to make detailed spectroscopic studies of nuclei beyond fermium (Z = 100), with the aim of understanding the underlying single-particle structure of superheavy elements. Here we report such a study of the nobelium isotope 254No, with 102 protons and 152 neutrons--the heaviest nucleus studied in this manner to date. We find three excited structures, two of which are isomeric (metastable). One of these structures is firmly assigned to a two-proton excitation. These states are highly significant as their location is sensitive to single-particle levels above the gap in shell energies predicted at Z = 114, and thus provide a microscopic benchmark for nuclear models of the superheavy elements.
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Affiliation(s)
- R-D Herzberg
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK.
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16
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Reiter P, Khoo TL, Ahmad I, Afanasjev AV, Heinz A, Lauritsen T, Lister CJ, Seweryniak D, Bhattacharyya P, Butler PA, Carpenter MP, Chewter AJ, Cizewski JA, Davids CN, Greene JP, Greenlees PT, Helariutta K, Herzberg RD, Janssens RVF, Jones GD, Julin R, Kankaanpää H, Kettunen H, Kondev FG, Kuusiniemi P, Leino M, Siem S, Sonzogni AA, Uusitalo J, Wiedenhöver I. Structure of the odd-A, shell-stabilized nucleus 253/102No. Phys Rev Lett 2005; 95:032501. [PMID: 16090736 DOI: 10.1103/physrevlett.95.032501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Indexed: 05/03/2023]
Abstract
In-beam gamma-ray spectroscopic measurements have been made on 253/102No. A single rotational band was identified up to a probable spin of 39/2planck, which is assigned to the 7/2(+)[624] Nilsson configuration. The bandhead energy and the moment of inertia provide discriminating tests of contemporary models of the heaviest nuclei. Novel methods were required to interpret the sparse data set associated with cross sections of around 50 nb. These methods included comparisons of experimental and simulated spectra, as well as testing for evidence of a rotational band in the gammagamma matrix.
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Affiliation(s)
- P Reiter
- Institut für Kernphysik, Universität zu Köln, Zülpicher Str 77, 50937 Köln, Germany
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17
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Butler PA, Humphreys RD, Greenlees PT, Herzberg RD, Jenkins DG, Jones GD, Kankaanpää H, Kettunen H, Rahkila P, Scholey C, Uusitalo J, Amzal N, Bastin JE, Brew PMT, Eskola K, Gerl J, Hammond NJ, Hauschild K, Helariutta K, Hessberger FP, Hürstel A, Jones PM, Julin R, Juutinen S, Keenan A, Khoo TL, Korten W, Kuusiniemi P, Le Coz Y, Leino M, Leppänen AP, Muikku M, Nieminen P, Ødegård SW, Page T, Pakarinen J, Reiter P, Sletten G, Theisen C, Wollersheim HJ. Conversion electron cascades in 254(102)No. Phys Rev Lett 2002; 89:202501. [PMID: 12443472 DOI: 10.1103/physrevlett.89.202501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2002] [Indexed: 05/24/2023]
Abstract
The spectrum of prompt conversion electrons emitted by excited 254No nuclei has been measured, revealing discrete lines arising from transitions within the ground state band. A striking feature is a broad distribution that peaks near 100 keV and comprises high multiplicity electron cascades, probably originating from M1 transitions within rotational bands built on high K states.
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Affiliation(s)
- P A Butler
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
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18
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Reiter P, Khoo TL, Lauritsen T, Lister CJ, Seweryniak D, Sonzogni AA, Ahmad I, Amzal N, Bhattacharyya P, Butler PA, Carpenter MP, Chewter AJ, Cizewski JA, Davids CN, Ding KY, Fotiades N, Greene JP, Greenlees PT, Heinz A, Henning WF, Herzberg R, Janssens RV, Jones GD, Kondev FG, Korten W, Leino M. Entry distribution, fission barrier, and formation mechanism of 254102No. Phys Rev Lett 2000; 84:3542-3545. [PMID: 11019141 DOI: 10.1103/physrevlett.84.3542] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2000] [Indexed: 05/23/2023]
Abstract
The entry distribution in angular momentum and excitation energy for the formation of 254No has been measured after the 208Pb(48Ca,2n) reaction at 215 and 219 MeV. This nucleus is populated up to spin 22Planck's over 2pi and excitation energy greater, similar6 MeV above the yrast line, with the half-maximum points of the energy distributions at approximately 5 MeV for spins between 12Planck's over 2pi and 22Planck's over 2pi. This suggests that the fission barrier is greater, similar5 MeV and that the shell-correction energy persists to high spin.
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Affiliation(s)
- P Reiter
- Argonne National Laboratory, Argonne, Illinois 60439 and Ludwig-Maximilians-Universitat, Am Coulombwall 1, D-85748 Garching, Germany
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19
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Helariutta K, Enqvist T, Jones P, Julin R, Juutinen S, Jämsen P, Kankaanpää H, Kuusiniemi P, Leino M, Muikku M, Piiparinen M, Savelius A, Trzaska WH, Törmänen S, Uusitalo J, Allatt RG, Butler PA, Greenlees PT, Page RD. First observation of excited states in 192Po. Phys Rev C Nucl Phys 1996; 54:R2799-R2801. [PMID: 9971716 DOI: 10.1103/physrevc.54.r2799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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