Production of the Heaviest Elements 107 to 109, Limitations, and Prospects to go Beyond

  • P. Armbruster
Part of the Nato ASI Series book series (NSSB, volume 143)


In recent years isotopes of the elements 107 to 109 were discovered. Together with studies on the isotopes of the elements 104–106 it was established that beyond element 105 the main decay mode for isotopes with (N–Z) = (47–49) is α-decay. The trend of strongly increasing instability against spontaneous fission for the heaviest elements is broken. The isotope260, 106 has a partial halflife against spontaneous fission of about 7 ms, which is to be compared to a halflife of 8 ms for256, 104. The long α-chains detected allow to determine the absolute masses. Together with macroscopic mass values the shell correction energies are obtained. It is shown that the fission barrier for the (N–Z) = 48-isotopes of the heaviest elements stay constant at a value of about 6 MeV, in spite of vanishing macroscopic fission barriers. From an analysis of the mass values and the spontaneous fission halflives it follows, that the heaviest isotopes detected are protected against spontaneous fission by a single humped narrow fission barrier, which is due to shell corrections, e.g. the isotope260 106 is shell stabilized by 15 orders of magnitude in its halflife against spontaneous fission. Paskevich et al. and Møller et al. independently predict the nuclei to be deformed and to have a strong negative ß4 deformation (sausage-like). The isotopes investigated are shell stabilized isotopes of superheavy elements (SHE), in the sense that SHE are elements unstable within macroscopic models but stabilized by shell effects to halflives long enough to be detected still.


Production Cross Section Heavy Element Spontaneous Fission Superheavy Element Shell Correction 
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  1. 1.
    E. O. Fiset and J.R. Nix, Nucl.Phys. A193:647 (1972).ADSGoogle Scholar
  2. 2.
    K. Takahashi et al., At.Data and Nucl.Data Tables 12:101 (1973).ADSCrossRefGoogle Scholar
  3. 3.
    G. A. Leander et al., Proceedings of the 7th International Conf. on Atomic Masses and Fundamental Constants, AMCO-7, Darmstadt-Seeheim, p.466 (1984) and private communication.Google Scholar
  4. 4.
    W. D. Myers, W.J. Swiatecki, Nucl.Phys. 81:1 (1966).Google Scholar
  5. 5.
    S. G. Nilsson et al., Nucl.Phys. A131: l (1969).Google Scholar
  6. 6.
    Y. T. Oganessian, Lect.Notes Phys. 33:221 (1974).ADSCrossRefGoogle Scholar
  7. 7.
    P. Armbruster, Ann.Rev.of Nucl.and Part.Science 35:135 (1985).MathSciNetADSCrossRefGoogle Scholar
  8. 8.
    G. Münzenberg et al., Nucl.Instr.Meth. 161:65 (1979).CrossRefGoogle Scholar
  9. 9.
    Y. T. Oganessian et al., JETP Lett. 20:265 (1974).ADSGoogle Scholar
  10. 10.
    J. Randrup et al., Phys.Rev. C13:229 (1976).ADSGoogle Scholar
  11. 11.
    S. Hofmann et al., Nucl.Instr.Meth. 223:312 (1984).CrossRefGoogle Scholar
  12. 12.
    F. P. Heßberger et al., GSI Annual Report 1981, p.66 (1982); Z.Phys.Google Scholar
  13. 13.
    G. Münzenberg et al., Z.Phys. A300:107 (1981).ADSGoogle Scholar
  14. 14.
    G. Münzenberg et al., Z.Phys. A309:89 (1982).ADSGoogle Scholar
  15. 15.
    Y. T. Oganessian et al., Radiochemica Acta 37:113 (1984).Google Scholar
  16. 16.
    A. G. Demin et al., Z.Phys. A315:197 (1984).ADSGoogle Scholar
  17. 17.
    G. Münzenberg et al., Z.Phys. A317:235 (1984).ADSGoogle Scholar
  18. 18.
    Y. T. Oganessian et al., Z.Phys. A319:215 (1984).ADSGoogle Scholar
  19. 19.
    W. D. Myers, “Droplet Model of Atomic Nuclei,” IFI/Plenum,&New York (1973).Google Scholar
  20. 20.
    H. v. Groote et al., At.Data and Nucl.Data Tables 17:418 (1976).ADSCrossRefGoogle Scholar
  21. 21.
    P. A. Seeger and W.M. Howard, Nucl.Phys. A238:49 (1975).Google Scholar
  22. 22.
    S. Liran and N. Zeldes, At.Data and Nucl.Data Tables 17:431 (1976).ADSCrossRefGoogle Scholar
  23. 23.
    P. Møller and J. R. Nix, At.Data and Nucl.Data Tables 26:165 (1981).ADSCrossRefGoogle Scholar
  24. 24.
    P. Armbruster, “The Int. School of Physics ‘Enrico Fermi’,” Varenna (1984).Google Scholar
  25. 25.
    S. Cwiok et al., Nucl.Phys. A410:254 (1983).ADSGoogle Scholar
  26. 26.
    Y. T. Oganessian et al., JINR P 7-12054, Dubna (1978).Google Scholar
  27. 27.
    A. Ghiorso et al., Phys.Rev.Lett. 33:1490 (1974).ADSCrossRefGoogle Scholar
  28. 28.
    K. H. Schmidt et al., Z.Phys. A315:159 (1984).ADSGoogle Scholar
  29. 29.
    P. Armbruster et al., Phys.Rev.Lett. 54:406 (1985).ADSCrossRefGoogle Scholar
  30. 30.
    M. Dahlinger et al., Nucl.Phys. A376:94 (1982).ADSGoogle Scholar
  31. 31.
    F. P. Heßberger, Thesis, TH Darmstadt (1984).Google Scholar
  32. 32.
    S. Bjørnholm et al., Nucl.Phys. A391:471 (1982).ADSGoogle Scholar
  33. 33.
    G. Müzenberg et al., Z.Phys.Google Scholar
  34. 34.
    Y. T. Oganessian et al., Pis’ma Zh.Eksp.Theor.Fiz. 20:580 (1974).Google Scholar
  35. 35.
    Y. T. Oganessian et al., Nucl.Phys. A273:505 (1976).ADSGoogle Scholar
  36. 36.
    Y. T. Oganessian, “Int. School-Seminar on Heavy Ion Physics,” Alushta, JINR D7-83-644, p.55, Dubna (1983).Google Scholar
  37. 37.
    G. Münzenberg et al., Z.Phys. A315:145 (1984).ADSGoogle Scholar
  38. 38.
    H. Gäggeler et al., Z.Phys. A316:291 (1984).ADSGoogle Scholar
  39. 39.
    R. Bass, Nucl.Phys. A231:45 (1974).ADSGoogle Scholar
  40. 40.
    P. Armbruster, “Proc. Int. Conf. on Nuclear Physics,” Florence, Italy, P. Blasi and R. A. Ricci, eds., p.343, Bologna, Tipografia Compositori (1983).Google Scholar
  41. 41.
    R. Bass, “Proc. Symp. on Deep-Inelastic and Fusion Reactions with Heavy Ions,” Lect.Notes Phys. 117:281 (1980).ADSCrossRefGoogle Scholar
  42. 42.
    A. V. Ignatyuk et al., Sov.J.Nucl.Phys. 21:255 (1975).Google Scholar
  43. 43.
    K. H. Schmidt et al., Z.Phys. A308:215 (1982).ADSGoogle Scholar
  44. 44.
    A. S. Iljinov and E. A. Cherepanov, JINR P-7-84-68 Dubna (1984).Google Scholar
  45. 45.
    H. Delagrange et al., Phys.Rev.Lett. 39:867 (1977).ADSCrossRefGoogle Scholar
  46. 46.
    K. H. Schmidt et al., “Proc. Symp. Phys. Chem of Fission, Jülich 1979,” Vienna, IAEA:1 (1980).Google Scholar
  47. 47.
    C. C. Sahm et al., Nucl.Phys. A441:316 (1985).ADSGoogle Scholar
  48. 48.
    J. G. Keller, Thesis, TH Darmstadt (1984).Google Scholar
  49. 49.
    C. C. Sahm et al., Z.Phys. A319:113 (1984)ADSGoogle Scholar
  50. C.-C. Sahm, Thesis, TH Darmstadt (1984)Google Scholar

Copyright information

© Springer Science+Business Media New York 1986

Authors and Affiliations

  • P. Armbruster
    • 1
  1. 1.Gesellschaft für Schwerionenforschung mbHDarmstadtGermany

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