Physics of Atomic Nuclei

, Volume 63, Issue 10, pp 1679–1687

Synthesis of superheavy nuclei in 48Ca+244Pu interactions

  • Yu. Ts. Oganessian
  • V. K. Utyonkov
  • Yu. V. Lobanov
  • F. Sh. Abdullin
  • A. N. Polyakov
  • I. V. Shirokovsky
  • Yu. S. Tsyganov
  • G. G. Gulbekian
  • S. L. Bogomolov
  • B. N. Gikal
  • A. N. Mezentsev
  • S. Iliev
  • V. G. Subbotin
  • A. M. Sukhov
  • O. V. Ivanov
  • G. V. Buklanov
  • K. Subotic
  • M. G. Itkis
  • K. J. Moody
  • J. F. Wild
  • N. J. Stoyer
  • M. A. Stoyer
  • R. W. Lougheed
Nuclei Experiment

Abstract

This article reports the results of experiments aimed at producing hypothetical long-lived superheavy elements located near the spherical-shell closures with Z≥114 and N≥72. For the synthesis of superheavy nuclei, we used a combination of neutron-rich reaction partners, with a 244Pu target and a 48Ca projectile. The sensitivity of the present experiment exceeded by more than two orders of magnitude previous attempts at synthesizing superheavy nuclides in reactions of 48Ca projectiles with actinide targets. We observed new decay sequences of genetically linked alpha decays terminated by spontaneous fission. The high measured alpha-particle energies, together with the long decay times and spontaneous fission terminating the chains, offer evidence for the decay of nuclei with high atomic numbers. The decay properties of the synthesized nuclei are consistent with the consecutive alpha decays originating from the parent nuclides 288,289114, produced in the 3n-and 4n-evaporation channels with cross sections of about a picobarn. The present observations can be considered experimental evidence for the existence of the “island of stability” of superheavy elements and are discussed in terms of modern theoretical approaches.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    R. Smolańczuk, Phys. Rev. C 56, 812 (1997).ADSGoogle Scholar
  2. 2.
    P. Möller and J. R. Nix, J. Phys. G 20, 1681 (1994).ADSGoogle Scholar
  3. 3.
    S. Čwiok et al., Nucl. Phys. A 611, 211 (1996).ADSGoogle Scholar
  4. 4.
    Yu. A. Lazarev et al., Phys. Rev. Lett. 73, 624 (1994); 75, 1903 (1995); Phys. Rev. C 54, 620 (1996).CrossRefADSGoogle Scholar
  5. 5.
    S. Hofmann et al., Z. Phys. A 350, 277 (1995); GSI Nachrichten, No. GSI 02-95 (Darmstadt, 1995), p. 4; Z. Phys. A 350, 281 (1995); 354, 229 (1996).Google Scholar
  6. 6.
    A. Ghiorso et al., Phys. Rev. C 51, R2293 (1995).CrossRefADSGoogle Scholar
  7. 7.
    A. Türler et al., Phys. Rev. C 57, 1648 (1998).ADSGoogle Scholar
  8. 8.
    Yu. Ts. Oganessian, in Proceedings of the International Conference on Nuclear Physics at the Turn of the Millennium “Structure of Vacuum and Elementary Matter,” Wilderness, South Africa, 1996 (World Sci., Singapore, 1997), p. 11.Google Scholar
  9. 9.
    W. J. Swiatecki, Nucl. Phys. A 376, 275 (1982); J. P. Blocki, H. Feldmeier, and W. J. Swiatecki, Nucl. Phys. A 459, 145 (1986).ADSGoogle Scholar
  10. 10.
    E. K. Hulet et al., Phys. Rev. Lett. 39, 385 (1977); J. D. Illige et al., Phys. Lett. 78B, 209 (1978); R. J. Otto et al., J. Inorg. Nucl. Chem. 40, 589 (1978); A. Ghiorso et al., LBL Report, LBL 6575, 1977; Yu. Ts. Oganessian et al., Nucl. Phys. A 294, 213 (1978); P. Armbruster et al., Phys. Rev. Lett. 54, 406 (1985).CrossRefADSGoogle Scholar
  11. 11.
    R. Smolańczuk, J. Skalski, and A. Sobiczewski, in Proceedings of the International Workshop XXIV on Gross Properties of Nuclei and Nuclear Excitations “Extremes of Nuclear Structure,” Hirschegg, Austria, 1996 (GSI, Darmstadt, 1996), p. 35.Google Scholar
  12. 12.
    P. Möller, J. R. Nix, and K.-L. Kratz, At. Data Nucl. Data Tables 66, 131 (1997).ADSGoogle Scholar
  13. 13.
    W. D. Myers and W. J. Swiatecki, Nucl. Phys. A 601, 141 (1996).ADSGoogle Scholar
  14. 14.
    Yu. Ts. Oganessian et al., in Proceedings of the 4th International Conference on Dynamical Aspects of Nuclear Fission, Častá-Papiernička, Slovak Republic, 1998 (World Sci., Singapore, 2000), p. 334; Yu. A. Lazarev et al., in Proceedings of the International School-Seminar on Heavy Ion Physics, Dubna, Russia, 1993, JINR Report E7-93-274 (Dubna, 1993), Vol. II, p. 497.Google Scholar
  15. 15.
    Yu. A. Lazarev et al., JINR FLNR Scientific Report 1995–1996, E7-97-206 (Dubna, 1997), p. 30.Google Scholar
  16. 16.
    J. F. Wild et al., J. Alloys Compd. 213/214, 86 (1994).CrossRefADSGoogle Scholar
  17. 17.
    N. J. Stoyer et al., LLNL Preprint UCRL-JC-136927, 1999; submitted for publication in Elsevier Science.Google Scholar
  18. 18.
    V. B. Zlokazov, JINR Preprint No. E7-99-273 (Dubna, 1999); submitted for publication in Eur. Phys. J.Google Scholar
  19. 19.
    M. G. Itkis et al., Nuovo Cimento A 111, 783 (1998); private communication.ADSGoogle Scholar
  20. 20.
    Yu. Ts. Oganessian et al., Phys. Rev. Lett. 83, 3154 (1999).CrossRefADSGoogle Scholar
  21. 21.
    A. G. Demin et al., Z. Phys. A 315, 197 (1984); G. Münzenberg et al., Z. Phys. A 322, 227 (1985).Google Scholar
  22. 22.
    Yu. Ts. Oganessian et al., Z. Phys. A 319, 215 (1984); G. Münzenberg et al., Z. Phys. A 324, 489 (1986); F. P. Heßberger et al., in Proceedings of the Tours Symposium on Nuclear Physics III, Tours, France, 1997 (American Inst. Phys., New York, 1998), p. 3.Google Scholar
  23. 23.
    Table of Isotopes, Ed. by R. B. Firestone and V. S. Shirley (Wiley, New York, 1996, 8th ed.).Google Scholar
  24. 24.
    V. Ninov et al., Phys. Rev. Lett. 83, 1104 (1999).CrossRefADSGoogle Scholar
  25. 25.
    Yu. Ts. Oganessian et al., Eur. Phys. J. A 5, 63 (1999).CrossRefADSGoogle Scholar
  26. 26.
    R. N. Sagaidak, JINR FLNR Scientific Report 1997–1998 (Dubna, 2000) (in press).Google Scholar
  27. 27.
    S. Čwiok, W. Nazarewicz, and P. H. Heenen, Phys. Rev. Lett. 83, 1108 (1999).ADSGoogle Scholar
  28. 28.
    M. Bender, Phys. Rev. C 61, 031302 (2000).Google Scholar

Copyright information

© MAIK "Nauka/Interperiodica" 2000

Authors and Affiliations

  • Yu. Ts. Oganessian
    • 1
  • V. K. Utyonkov
    • 1
  • Yu. V. Lobanov
    • 1
  • F. Sh. Abdullin
    • 1
  • A. N. Polyakov
    • 1
  • I. V. Shirokovsky
    • 1
  • Yu. S. Tsyganov
    • 1
  • G. G. Gulbekian
    • 1
  • S. L. Bogomolov
    • 1
  • B. N. Gikal
    • 1
  • A. N. Mezentsev
    • 1
  • S. Iliev
    • 1
  • V. G. Subbotin
    • 1
  • A. M. Sukhov
    • 1
  • O. V. Ivanov
    • 1
  • G. V. Buklanov
    • 1
  • K. Subotic
    • 1
  • M. G. Itkis
    • 1
  • K. J. Moody
    • 2
  • J. F. Wild
    • 2
  • N. J. Stoyer
    • 2
  • M. A. Stoyer
    • 2
  • R. W. Lougheed
    • 2
  1. 1.Joint Institute for Nuclear ResearchDubna, Moscow oblastRussia
  2. 2.Lawrence Livermore National LaboratoryUniversity of CaliforniaLivermoreUSA

Personalised recommendations