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Såmark-Roth A, Cox DM, Rudolph D, Sarmiento LG, Carlsson BG, Egido JL, Golubev P, Heery J, Yakushev A, Åberg S, Albers HM, Albertsson M, Block M, Brand H, Calverley T, Cantemir R, Clark RM, Düllmann CE, Eberth J, Fahlander C, Forsberg U, Gates JM, Giacoppo F, Götz M, Götz S, Herzberg RD, Hrabar Y, Jäger E, Judson D, Khuyagbaatar J, Kindler B, Kojouharov I, Kratz JV, Krier J, Kurz N, Lens L, Ljungberg J, Lommel B, Louko J, Meyer CC, Mistry A, Mokry C, Papadakis P, Parr E, Pore JL, Ragnarsson I, Runke J, Schädel M, Schaffner H, Schausten B, Shaughnessy DA, Thörle-Pospiech P, Trautmann N, Uusitalo J. Spectroscopy along Flerovium Decay Chains: Discovery of ^{280}Ds and an Excited State in ^{282}Cn. Phys Rev Lett 2021; 126:032503. [PMID: 33543956 DOI: 10.1103/physrevlett.126.032503] [Citation(s) in RCA: 2] [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: 11/16/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
A nuclear spectroscopy experiment was conducted to study α-decay chains stemming from isotopes of flerovium (element Z=114). An upgraded TASISpec decay station was placed behind the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. The fusion-evaporation reactions ^{48}Ca+^{242}Pu and ^{48}Ca+^{244}Pu provided a total of 32 flerovium-candidate decay chains, of which two and eleven were firmly assigned to ^{286}Fl and ^{288}Fl, respectively. A prompt coincidence between a 9.60(1)-MeV α particle event and a 0.36(1)-MeV conversion electron marked the first observation of an excited state in an even-even isotope of the heaviest man-made elements, namely ^{282}Cn. Spectroscopy of ^{288}Fl decay chains fixed Q_{α}=10.06(1) MeV. In one case, a Q_{α}=9.46(1)-MeV decay from ^{284}Cn into ^{280}Ds was observed, with ^{280}Ds fissioning after only 518 μs. The impact of these findings, aggregated with existing data on decay chains of ^{286,288}Fl, on the size of an anticipated shell gap at proton number Z=114 is discussed in light of predictions from two beyond-mean-field calculations, which take into account triaxial deformation.
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Affiliation(s)
- A Såmark-Roth
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - D M Cox
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - D Rudolph
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - L G Sarmiento
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - B G Carlsson
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - J L Egido
- Departamento de Física Teórica and CIAFF, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - P Golubev
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - J Heery
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - A Yakushev
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - S Åberg
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - H M Albers
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - M Albertsson
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - M Block
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - H Brand
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - T Calverley
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - R Cantemir
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - R M Clark
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Ch E Düllmann
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Eberth
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - C Fahlander
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - U Forsberg
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - J M Gates
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - F Giacoppo
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Helmholtz Institute Mainz, 55099 Mainz, Germany
| | - M Götz
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - S Götz
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - R-D Herzberg
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - Y Hrabar
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - E Jäger
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - D Judson
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Khuyagbaatar
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Helmholtz Institute Mainz, 55099 Mainz, Germany
| | - B Kindler
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - I Kojouharov
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - J V Kratz
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Krier
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - N Kurz
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - L Lens
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Ljungberg
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - B Lommel
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - J Louko
- Department of Physics, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - C-C Meyer
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - A Mistry
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - C Mokry
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - P Papadakis
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - E Parr
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - J L Pore
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - I Ragnarsson
- Department of Physics, Lund University, 22100 Lund, Sweden
| | - J Runke
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - M Schädel
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - H Schaffner
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - B Schausten
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - D A Shaughnessy
- Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Thörle-Pospiech
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - N Trautmann
- Department Chemie-Standort TRIGA, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Uusitalo
- Department of Physics, University of Jyväskylä, 40014 Jyväskylä, Finland
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Khuyagbaatar J, Yakushev A, Düllmann CE, Ackermann D, Andersson LL, Block M, Brand H, Cox DM, Even J, Forsberg U, Golubev P, Hartmann W, Herzberg RD, Heßberger FP, Hoffmann J, Hübner A, Jäger E, Jeppsson J, Kindler B, Kratz JV, Krier J, Kurz N, Lommel B, Maiti M, Minami S, Mistry AK, Mrosek CM, Pysmenetska I, Rudolph D, Sarmiento LG, Schaffner H, Schädel M, Schausten B, Steiner J, De Heidenreich TT, Uusitalo J, Wegrzecki M, Wiehl N, Yakusheva V. New Short-Lived Isotope ^{221}U and the Mass Surface Near N=126. Phys Rev Lett 2015; 115:242502. [PMID: 26705628 DOI: 10.1103/physrevlett.115.242502] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Indexed: 06/05/2023]
Abstract
Two short-lived isotopes ^{221}U and ^{222}U were produced as evaporation residues in the fusion reaction ^{50}Ti+^{176}Yb at the gas-filled recoil separator TASCA. An α decay with an energy of E_{α}=9.31(5) MeV and half-life T_{1/2}=4.7(7) μs was attributed to ^{222}U. The new isotope ^{221}U was identified in α-decay chains starting with E_{α}=9.71(5) MeV and T_{1/2}=0.66(14) μs leading to known daughters. Synthesis and detection of these unstable heavy nuclei and their descendants were achieved thanks to a fast data readout system. The evolution of the N=126 shell closure and its influence on the stability of uranium isotopes are discussed within the framework of α-decay reduced width.
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Affiliation(s)
- J Khuyagbaatar
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - A Yakushev
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - Ch E Düllmann
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - D Ackermann
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | | | - M Block
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - H Brand
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - D M Cox
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Even
- Helmholtz Institute Mainz, 55099 Mainz, Germany
| | | | | | - W Hartmann
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - R-D Herzberg
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - F P Heßberger
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - J Hoffmann
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - A Hübner
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - E Jäger
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | | | - B Kindler
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - J V Kratz
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Krier
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - N Kurz
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - B Lommel
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - M Maiti
- Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - S Minami
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - A K Mistry
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - Ch M Mrosek
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - I Pysmenetska
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | | | | | - H Schaffner
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - M Schädel
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - B Schausten
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - J Steiner
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | | | - J Uusitalo
- University of Jyväskylä, 40351 Jyväskylä, Finland
| | - M Wegrzecki
- The Institute of Electron Technology, 02-668 Warsaw, Poland
| | - N Wiehl
- Helmholtz Institute Mainz, 55099 Mainz, Germany
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - V Yakusheva
- Helmholtz Institute Mainz, 55099 Mainz, Germany
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Khuyagbaatar J, Yakushev A, Düllmann CE, Ackermann D, Andersson LL, Asai M, Block M, Boll RA, Brand H, Cox DM, Dasgupta M, Derkx X, Di Nitto A, Eberhardt K, Even J, Evers M, Fahlander C, Forsberg U, Gates JM, Gharibyan N, Golubev P, Gregorich KE, Hamilton JH, Hartmann W, Herzberg RD, Heßberger FP, Hinde DJ, Hoffmann J, Hollinger R, Hübner A, Jäger E, Kindler B, Kratz JV, Krier J, Kurz N, Laatiaoui M, Lahiri S, Lang R, Lommel B, Maiti M, Miernik K, Minami S, Mistry A, Mokry C, Nitsche H, Omtvedt JP, Pang GK, Papadakis P, Renisch D, Roberto J, Rudolph D, Runke J, Rykaczewski KP, Sarmiento LG, Schädel M, Schausten B, Semchenkov A, Shaughnessy DA, Steinegger P, Steiner J, Tereshatov EE, Thörle-Pospiech P, Tinschert K, Torres De Heidenreich T, Trautmann N, Türler A, Uusitalo J, Ward DE, Wegrzecki M, Wiehl N, Van Cleve SM, Yakusheva V. 48Ca+249Bk fusion reaction leading to element Z = 117: long-lived α-decaying 270Db and discovery of 266Lr. Phys Rev Lett 2014; 112:172501. [PMID: 24836239 DOI: 10.1103/physrevlett.112.172501] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Indexed: 06/03/2023]
Abstract
The superheavy element with atomic number Z=117 was produced as an evaporation residue in the (48)Ca+(249)Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allowed measuring decays of single atomic nuclei with half-lives between sub-μs and a few days. Two decay chains comprising seven α decays and a spontaneous fission each were identified and are assigned to the isotope (294)117 and its decay products. A hitherto unknown α-decay branch in (270)Db (Z = 105) was observed, which populated the new isotope (266)Lr (Z = 103). The identification of the long-lived (T(1/2) = 1.0(-0.4)(+1.9) h) α-emitter (270)Db marks an important step towards the observation of even more long-lived nuclei of superheavy elements located on an "island of stability."
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Affiliation(s)
- J Khuyagbaatar
- Helmholtz Institute Mainz, 55099 Mainz, Germany and GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - A Yakushev
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - Ch E Düllmann
- Helmholtz Institute Mainz, 55099 Mainz, Germany and GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany and Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - D Ackermann
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | | | - M Asai
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - M Block
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - R A Boll
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H Brand
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - D M Cox
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - M Dasgupta
- The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - X Derkx
- Helmholtz Institute Mainz, 55099 Mainz, Germany and Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - A Di Nitto
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - K Eberhardt
- Helmholtz Institute Mainz, 55099 Mainz, Germany and Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Even
- Helmholtz Institute Mainz, 55099 Mainz, Germany
| | - M Evers
- The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | | | | | - J M Gates
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - N Gharibyan
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | | | - K E Gregorich
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J H Hamilton
- Vanderbilt University, Nashville, Tennessee 37235, USA
| | - W Hartmann
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - R-D Herzberg
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - F P Heßberger
- Helmholtz Institute Mainz, 55099 Mainz, Germany and GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - D J Hinde
- The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - J Hoffmann
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - R Hollinger
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - A Hübner
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - E Jäger
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - B Kindler
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - J V Kratz
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Krier
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - N Kurz
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - M Laatiaoui
- Helmholtz Institute Mainz, 55099 Mainz, Germany
| | - S Lahiri
- Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - R Lang
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - B Lommel
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - M Maiti
- Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - K Miernik
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S Minami
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - A Mistry
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - C Mokry
- Helmholtz Institute Mainz, 55099 Mainz, Germany and Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - H Nitsche
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | | | - G K Pang
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Papadakis
- University of Liverpool, Liverpool L69 7ZE, United Kingdom and University of Jyväskylä, 40351 Jyväskylä, Finland
| | - D Renisch
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - J Roberto
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | | | - J Runke
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - K P Rykaczewski
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | | | - M Schädel
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany and Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - B Schausten
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | | | - D A Shaughnessy
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - P Steinegger
- Paul Scherrer Institute, 5232 Villigen, Switzerland and University of Bern, 3012 Bern, Switzerland
| | - J Steiner
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | - E E Tereshatov
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - P Thörle-Pospiech
- Helmholtz Institute Mainz, 55099 Mainz, Germany and Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - K Tinschert
- GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
| | | | - N Trautmann
- Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - A Türler
- Paul Scherrer Institute, 5232 Villigen, Switzerland and University of Bern, 3012 Bern, Switzerland
| | - J Uusitalo
- University of Jyväskylä, 40351 Jyväskylä, Finland
| | - D E Ward
- Lund University, 22100 Lund, Sweden
| | - M Wegrzecki
- Institute of Electron Technology, 02-668 Warsaw, Poland
| | - N Wiehl
- Helmholtz Institute Mainz, 55099 Mainz, Germany and Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - S M Van Cleve
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - V Yakusheva
- Helmholtz Institute Mainz, 55099 Mainz, Germany
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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 C, 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, Zielińska M. Shape coexistence in the neutron-deficient even-even (182-188)Hg isotopes studied via coulomb excitation. Phys Rev Lett 2014; 112:162701. [PMID: 24815644 DOI: 10.1103/physrevlett.112.162701] [Citation(s) in RCA: 5] [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: 11/08/2013] [Indexed: 06/03/2023]
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.
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Affiliation(s)
- N Bree
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium
| | - K Wrzosek-Lipska
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and Heavy Ion Laboratory, University of Warsaw, PL-02-093 Warsaw, Poland
| | - A Petts
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - A Andreyev
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - B Bastin
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and GANIL CEA/DSM-CNRS/IN2P3, Boulevard H. Becquerel, F-14076 Caen, France
| | - M Bender
- Université Bordeaux, Centre d'Etudes Nucléaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan, France and CNRS/IN2P3, Centre d'Etudes Nucléaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan, France
| | - A Blazhev
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - B Bruyneel
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - P A Butler
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Butterworth
- Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - M P Carpenter
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Cederkäll
- Physics Department, University of Lund, Box 118, SE-221 00 Lund, Sweden and ISOLDE, CERN, CH-1211 Geneva 23, Switzerland
| | - E Clément
- GANIL CEA/DSM-CNRS/IN2P3, Boulevard H. Becquerel, F-14076 Caen, France and ISOLDE, CERN, CH-1211 Geneva 23, Switzerland
| | - T E Cocolios
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and ISOLDE, CERN, CH-1211 Geneva 23, Switzerland and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - A Deacon
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - J Diriken
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and Belgian Nuclear Research Centre SCK CEN, B-2400 Mol, Belgium
| | - A Ekström
- Physics Department, University of Lund, Box 118, SE-221 00 Lund, Sweden
| | - C Fitzpatrick
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - L M Fraile
- ISOLDE, CERN, CH-1211 Geneva 23, Switzerland and Grupo de Física Nuclear, Universidad Complutense de Madrit, 28040 Madrid, Spain
| | - Ch Fransen
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - S J Freeman
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - L P Gaffney
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J E García-Ramos
- Departamento de Física Aplicada, Universidad de Huelva, 21071 Huelva, Spain
| | - K Geibel
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - R Gernhäuser
- Physics Department E12, Technische Universität München, D-85748 Garching, Germany
| | - T Grahn
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland
| | - M Guttormsen
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - B Hadinia
- School of Engineering, University of the West of Scotland, Paisley PA1 2BE, United Kingdom and Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - K Hadyńska-Kle K
- Heavy Ion Laboratory, University of Warsaw, PL-02-093 Warsaw, Poland
| | - M Hass
- Department of Particle Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - P-H Heenen
- Physique Nucléaire Théorique, Université Libre de Bruxelles, B-1050 Bruxelles, Belgium
| | - R-D Herzberg
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - H Hess
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - K Heyde
- Department of Physics and Astronomy, Ghent University, B-9000 Gent, Belgium
| | - M Huyse
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium
| | - O Ivanov
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium
| | - D G Jenkins
- Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - R Julin
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - N Kesteloot
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and Belgian Nuclear Research Centre SCK CEN, B-2400 Mol, Belgium
| | - Th Kröll
- Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
| | - R Krücken
- Physics Department E12, Technische Universität München, D-85748 Garching, Germany
| | - A C Larsen
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - R Lutter
- Department of Physics, Ludwig Maximilian Universität München, 85748 Garching, Germany
| | - P Marley
- Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - P J Napiorkowski
- Heavy Ion Laboratory, University of Warsaw, PL-02-093 Warsaw, Poland
| | - R Orlandi
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and School of Engineering, University of the West of Scotland, Paisley PA1 2BE, United Kingdom
| | - R D Page
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Pakarinen
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland and Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland
| | - N Patronis
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and Department of Physics, The University of Ioannina, GR-45110 Ioannina, Greece
| | - P J Peura
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - E Piselli
- ISOLDE, CERN, CH-1211 Geneva 23, Switzerland
| | - P Rahkila
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - E Rapisarda
- ISOLDE, CERN, CH-1211 Geneva 23, Switzerland
| | - P Reiter
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - A P Robinson
- Department of Physics, University of York, York YO10 5DD, United Kingdom and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - M Scheck
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom and School of Engineering, University of the West of Scotland, Paisley PA1 2BE, United Kingdom and SUPA, Scottisch Universities Physics Alliance, Glasgow G12 8QQ, United Kingdom
| | - S Siem
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - K Singh Chakkal
- Department of Particle Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - J F Smith
- School of Engineering, University of the West of Scotland, Paisley PA1 2BE, United Kingdom
| | - J Srebrny
- Heavy Ion Laboratory, University of Warsaw, PL-02-093 Warsaw, Poland
| | - I Stefanescu
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium and Physics Department E12, Technische Universität München, D-85748 Garching, Germany
| | - G M Tveten
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - P Van Duppen
- KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium
| | | | - D Voulot
- ISOLDE, CERN, CH-1211 Geneva 23, Switzerland
| | - N Warr
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - F Wenander
- ISOLDE, CERN, CH-1211 Geneva 23, Switzerland
| | - A Wiens
- Institut für Kernphysik, Universität zu Köln, 50937 Köln, Germany
| | - J L Wood
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA
| | - M Zielińska
- Heavy Ion Laboratory, University of Warsaw, PL-02-093 Warsaw, Poland and IRFU/SPhN, CEA Saclay, F-91191 Gif-sur-Yvette, France
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5
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Rudolph D, Forsberg U, Golubev P, Sarmiento LG, Yakushev A, Andersson LL, Di Nitto A, Düllmann CE, Gates JM, Gregorich KE, Gross CJ, Heßberger FP, Herzberg RD, Khuyagbaatar J, Kratz JV, Rykaczewski K, Schädel M, Åberg S, Ackermann D, Block M, Brand H, Carlsson BG, Cox D, Derkx X, Eberhardt K, Even J, Fahlander C, Gerl J, Jäger E, Kindler B, Krier J, Kojouharov I, Kurz N, Lommel B, Mistry A, Mokry C, Nitsche H, Omtvedt JP, Papadakis P, Ragnarsson I, Runke J, Schaffner H, Schausten B, Thörle-Pospiech P, Torres T, Traut T, Trautmann N, Türler A, Ward A, Ward DE, Wiehl N. Spectroscopy of element 115 decay chains. Phys Rev Lett 2013; 111:112502. [PMID: 24074079 DOI: 10.1103/physrevlett.111.112502] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Indexed: 06/02/2023]
Abstract
A high-resolution α, x-ray, and γ-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum für Schwerionenforschung. Thirty correlated α-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z=115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z>112. Comprehensive Monte Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.
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6
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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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7
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Endres J, Litvinova E, Savran D, Butler PA, Harakeh MN, Harissopulos S, Herzberg RD, Krücken R, Lagoyannis A, Pietralla N, Ponomarev VY, Popescu L, Ring P, Scheck M, Sonnabend K, Stoica VI, Wörtche HJ, Zilges A. Isospin character of the pygmy dipole resonance in 124Sn. Phys Rev Lett 2010; 105:212503. [PMID: 21231295 DOI: 10.1103/physrevlett.105.212503] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Indexed: 05/30/2023]
Abstract
The pygmy dipole resonance has been studied in the proton-magic nucleus 124Sn with the (α, α'γ) coincidence method at Eα=136 MeV. The comparison with results of photon-scattering experiments reveals a splitting into two components with different structure: one group of states which is excited in (α, α'γ) as well as in (γ, γ') reactions and a group of states at higher energies which is only excited in (γ, γ') reactions. Calculations with the self-consistent relativistic quasiparticle time-blocking approximation and the quasiparticle phonon model are in qualitative agreement with the experimental results and predict a low-lying isoscalar component dominated by neutron-skin oscillations and a higher-lying more isovector component on the tail of the giant dipole resonance.
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Affiliation(s)
- J Endres
- Institut für Kernphysik, Universität zu Köln, Zülpicher Straße 77, D-50937 Köln, Germany.
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8
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Düllmann CE, Schädel M, Yakushev A, Türler A, Eberhardt K, Kratz JV, Ackermann D, Andersson LL, Block M, Brüchle W, Dvorak J, Essel HG, Ellison PA, Even J, Gates JM, Gorshkov A, Graeger R, Gregorich KE, Hartmann W, Herzberg RD, Hessberger FP, Hild D, Hübner A, Jäger E, Khuyagbaatar J, Kindler B, Krier J, Kurz N, Lahiri S, Liebe D, Lommel B, Maiti M, Nitsche H, Omtvedt JP, Parr E, Rudolph D, Runke J, Schausten B, Schimpf E, Semchenkov A, Steiner J, Thörle-Pospiech P, Uusitalo J, Wegrzecki M, Wiehl N. Production and decay of element 114: high cross sections and the new nucleus 277Hs. Phys Rev Lett 2010; 104:252701. [PMID: 20867370 DOI: 10.1103/physrevlett.104.252701] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Indexed: 05/29/2023]
Abstract
The fusion-evaporation reaction 244Pu(48Ca,3-4n){288,289}114 was studied at the new gas-filled recoil separator TASCA. Thirteen correlated decay chains were observed and assigned to the production and decay of {288,289}114. At a compound nucleus excitation energy of E{*}=39.8-43.9 MeV, the 4n evaporation channel cross section was 9.8{-3.1}{+3.9} pb. At E^{*}=36.1-39.5 MeV, that of the 3n evaporation channel was 8.0{-4.5}{+7.4} pb. In one of the 3n evaporation channel decay chains, a previously unobserved α branch in 281Ds was observed (probability to be of random origin from background: 0.1%). This α decay populated the new nucleus 277Hs, which decayed by spontaneous fission after a lifetime of 4.5 ms.
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Affiliation(s)
- Ch E Düllmann
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
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9
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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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10
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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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11
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Hurst AM, Butler PA, Jenkins DG, Delahaye P, Wenander F, Ames F, Barton CJ, Behrens T, Bürger A, Cederkäll J, Clément E, Czosnyka T, Davinson T, de Angelis G, Eberth J, Ekström A, Franchoo S, Georgiev G, Görgen A, Herzberg RD, Huyse M, Ivanov O, Iwanicki J, Jones GD, Kent P, Köster U, Kröll T, Krücken R, Larsen AC, Nespolo M, Pantea M, Paul ES, Petri M, Scheit H, Sieber T, Siem S, Smith JF, Steer A, Stefanescu I, Syed NUH, Van de Walle J, Van Duppen P, Wadsworth R, Warr N, Weisshaar D, Zielińska M. Measurement of the sign of the spectroscopic quadrupole moment for the 2(1)+ state in 70Se: no evidence for oblate shape. Phys Rev Lett 2007; 98:072501. [PMID: 17359019 DOI: 10.1103/physrevlett.98.072501] [Citation(s) in RCA: 2] [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: 08/17/2006] [Indexed: 05/14/2023]
Abstract
Using a method whereby molecular and atomic ions are independently selected, an isobarically pure beam of 70Se ions was postaccelerated to an energy of 206 MeV using REX-ISOLDE. Coulomb-excitation yields for states in the beam and target nuclei were deduced by recording deexcitation gamma rays in the highly segmented MINIBALL gamma-ray spectrometer in coincidence with scattered particles in a silicon detector. At these energies, the Coulomb-excitation yield for the first 2+ state is expected to be strongly sensitive to the sign of the spectroscopic quadrupole moment through the nuclear reorientation effect. Experimental evidence is presented here for a prolate shape for the first 2+ state in 70Se, reopening the question over whether there are, as reported earlier, deformed oblate shapes near to the ground state in the light selenium isotopes.
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Affiliation(s)
- A M Hurst
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
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12
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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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13
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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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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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Friedrichs H, Schlitt B, Margraf J, Lindenstruth S, Wesselborg C, Heil RD, Pitz HH, Kneissl U, Herzberg RD, Zilges A, Häger D, Müller G, Schumacher M. Evidence for enhanced electric dipole excitations in deformed rare earth nuclei near 2.5 MeV. Phys Rev C Nucl Phys 1992; 45:R892-R895. [PMID: 9967894 DOI: 10.1103/physrevc.45.r892] [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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