The European Physical Journal A - Hadrons and Nuclei

, Volume 29, Issue 3, pp 281–287

Measurement of evaporation residue cross-sections of the reaction 30Si + 238U at subbarrier energies

  • K. Nishio
  • S. Hofmann
  • F. P. Heßberger
  • D. Ackermann
  • S. Antalic
  • V. F. Comas
  • Z. Gan
  • S. Heinz
  • J. A. Heredia
  • H. Ikezoe
  • J. Khuyagbaatar
  • B. Kindler
  • I. Kojouharov
  • P. Kuusiniemi
  • B. Lommel
  • R. Mann
  • M. Mazzocco
  • S. Mitsuoka
  • Y. Nagame
  • T. Ohtsuki
  • A. G. Popeko
  • S. Saro
  • H. J. Schött
  • B. Sulignano
  • A. Svirikhin
  • K. Tsukada
  • K. Tsuruta
  • A. V. Yeremin
Nuclear Structure and Reactions

Abstract.

The reaction 30Si + 238U → 268Sg* was studied at beam energies close to the Coulomb barrier. At a center-of-mass energy of Ec.m. = 144.0MeV for reactions at half thickness of the target we measured three decay chains of 263Sg produced by evaporation of five neutrons. The cross-section was ( 67+67-37) pb. At Ec.m. = 133.0MeV we measured three spontaneously fissioning nuclei which we assigned to the isotope 264Sg. The production cross-section was ( 10+10-6) pb and a half-life of ( 120+126-44) ms was determined. This half-life is a factor of twenty shorter than theoretical predictions. At Ec.m. = 128.0MeV an upper cross-section limit of 15pb was measured. The cross-section data reveal a strong influence of the orientation of the deformed target nucleus on the production yield. Compared to excitation functions measured for the lighter system 16O + 238U → 254Fm*, a reduction of the fusion probability was observed at low beam energies indicating increasing competition from quasifission processes.

PACS.

25.60.Pj Fusion reactions 23.60.+e α decay 25.85.Ca Spontaneous fission 27.90.+b 220 ⩽ A 

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Copyright information

© Società Italiana di Fisica and Springer-Verlag 2006

Authors and Affiliations

  • K. Nishio
    • 1
    • 2
  • S. Hofmann
    • 1
    • 3
  • F. P. Heßberger
    • 1
  • D. Ackermann
    • 1
  • S. Antalic
    • 4
  • V. F. Comas
    • 5
  • Z. Gan
    • 6
  • S. Heinz
    • 1
  • J. A. Heredia
    • 5
  • H. Ikezoe
    • 2
  • J. Khuyagbaatar
    • 1
    • 7
  • B. Kindler
    • 1
  • I. Kojouharov
    • 1
  • P. Kuusiniemi
    • 8
  • B. Lommel
    • 1
  • R. Mann
    • 1
  • M. Mazzocco
    • 1
  • S. Mitsuoka
    • 2
  • Y. Nagame
    • 2
  • T. Ohtsuki
    • 9
  • A. G. Popeko
    • 10
  • S. Saro
    • 4
  • H. J. Schött
    • 1
  • B. Sulignano
    • 1
    • 11
  • A. Svirikhin
    • 10
  • K. Tsukada
    • 2
  • K. Tsuruta
    • 2
  • A. V. Yeremin
    • 10
  1. 1.Gesellschaft für Schwerionenforschung mbHDarmstadtGermany
  2. 2.Japan Atomic Energy AgencyTokai, IbarakiJapan
  3. 3.Institut für KernphysikJohann Wolfgang Goethe-UniversitätFrankfurt am MainGermany
  4. 4.Department of Nuclear PhysicsComenius UniversityBratislavaSlovakia
  5. 5.Higher Institue of Technologies and Applied SciencesHabanaCuba
  6. 6.Institute of Modern PhysicsChinese Academy of SciencesLanzhouPRC
  7. 7.St. Petersburg State UniversityStari Petergof, St. PetersburgRussia
  8. 8.CUPPUniversity of OuluPyhäjärviFinland
  9. 9.Laboratory of Nuclear ScienceTohoku UniversitySendaiJapan
  10. 10.Flerov Laboratory of Nuclear ReactionsJINRDubnaRussia
  11. 11.Institut für KernchemieJohannes Gutenberg-Universität MainzMainzGermany

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