Zeitschrift für Physik A Atoms and Nuclei

, Volume 315, Issue 2, pp 145–158 | Cite as

Evidence for element 109 from one correlated decay sequence following the fusion of58Fe with209Bi

  • G. Münzenberg
  • W. Reisdorf
  • S. Hofmann
  • Y. K. Agarwal
  • F. P. Heßberger
  • K. Poppensieker
  • J. R. H. Schneider
  • W. F. W. Schneider
  • K. -H. Schmidt
  • H. -J. Schött
  • P. Armbruster
  • C. -C. Sahm
  • D. Vermeulen


An experiment to synthesize element 109 is presented. Decay patterns characteristic of complete fusion products were searched for in an irradiation of209Bi targets with58Fe projectiles at specific incident energies of 4.95, 5.05, and 5.15 MeV/u. A total dose of 7 ×1017 particles was obtained. The experimental method involves in-flight separation of forward peaked reaction products with a static-field velocity filter, their passage through a time-of-flight device and their final implantation into position sensitive solid state detectors to measure their kinetic energy, approximate mass and their time and position of incidence. The subsequent decay of the narrowly localised reaction products by cascades of alpha particles and/or spontaneous fission is also registered in terms of the energies and times of all the emitted particles. One outstanding decay sequence that started with the emission of two alpha particles within subsequent time intervals of 5 ms and 22 ms and ended with spontaneous fission after 13 s was found at 5.15 MeV/u. The first alpha particle had a kinetic energy of (11.10±0.04) MeV. A detailed analysis of all the alternative interpretations of this observation, such as a purely random correlation of signals, the decay of a product from a transfer reaction or of any of the various energetically possible evaporation residues, shows that the isotope with mass 266 of element 109, i.e. the one neutron evaporation channel after complete fusion, is the statistically most significant assignment. The outlook for new element synthesis is also briefly discussed.


Alpha Particle Complete Fusion Evaporation Residue Spontaneous Fission Velocity Filter 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    Bohr, N., Wheeler, J.A.: Phys. Rev.56, 426 (1939); Ericson, T.: Adv. Phys.9, 425 (1960)Google Scholar
  2. 2.
    Oganessian, Yu.Ts., Iljinov, A.S., Demin, A.G., Tretyakova, S.P.: Nucl. Phys. A239, 353 (1975)Google Scholar
  3. 3.
    Münzenberg, G., Armbruster, P., Faust, W., Güttner, K., Heßberger, F.P., Hofmann, S., Reisdorf, W., Sahm, C.-C., Schmidt, K.-H., Schött, H.-J., Thuma, B., Vermeulen, D.: Proc. Int. Conf. on Actinides 81, 223. New York: Pergamon Press 1982Google Scholar
  4. 4.
    Münzenberg, G., Hofmann, S., Heßberger, F.P., Reisdorf, W., Schmidt, K.-H., Schneider, J.R.H., Armbruster, P., Sahm, C.-C., Thuma, B.: Z. Phys. A — Atoms and Nuclei300, 107 (1981)Google Scholar
  5. 5.
    Münzenberg, G., Faust, W., Hofmann, S., Armbruster, P., Güttner, K., Ewald, H.: Nucl. Instrum. Methods161, 65 (1979)Google Scholar
  6. 6.
    Swiatecki, W.J.: Phys. Scr.24, 113 (1981); Nucl. Phys. A376, 275 (1982)Google Scholar
  7. 7.
    Bock, R., Chu, Y.T., Dakowski, M., Gobbi, A., Grosse, E., Olmi, A., Sann, H., Schwalm, D., Lynen, U., Müller, W., Bjørnholm, S., Esbensen, H., Wölfli, W., Morenzoni, E.: Nucl. Phys. A388, 334 (1982)Google Scholar
  8. 8.
    Gäggeler, H., Brüchle, W., Brügger, H., Schädel, M., Sümmerer, K., Wirth, G., Ghiorso, A., Gregorich, K.E., Lee, D., Moody, K.J., Seaborg, G.T., Welch, R.B., Wilmarth, P., Herrmann, G., Kratz, J.V., Trautmann, N., Hildebrand, N., Hickmann, U., Frink, C., Greulich, N., Hoffmann, D.C., Fowler, M., von Gunten, H.R.: XXI International Winter Meeting on Nuclear Physics, Bormio, Italy 1983, Università and Instituto Nazionale di Fisica Nuclear, Milano, Suppl. 30, 366 (1983)Google Scholar
  9. 9.
    Schmidt, K.-H., Armbruster, P., Heßberger, F.P., Münzenberg, G., Reisdorf, W., Sahm, C.-C., Vermeulen, D., Clerc, H.-G., Keller, J., Schulte, H.: Z. Phys. A — Atoms and Nuclei301, 21 (1981)Google Scholar
  10. 10.
    Münzenberg, G., Armbruster, P., Heßberger, F.P., Hofmann, S., Poppensieker, K., Reisdorf, W., Schneider, J.R.H., Schmidt, K.-H., Sahm, C.-C., Vermeulen, D.: Z. Phys. A — Atoms and Nuclei309, 89 (1982)Google Scholar
  11. 11.
    Marx, D., Nickel, F., Münzenberg, G., Güttner, K., Ewald, H., Faust, W., Hofmann, S., Schött, H.-J., Thalheimer, W.: Nucl. Instrum. Methods163, 15 (1979)Google Scholar
  12. 12.
    Hofmann, S., Münzenberg, G., Faust, W., Heßberger, F.P., Reisdorf, W., Schneider, J.R.H., Armbruster, P., Güttner, K., Thuma, B.: Proc. Int. Conf. on Nuclei far from Stability, Helsingør, Denmark, 190 (1981)Google Scholar
  13. 13.
    Northcliffe, L.C., Schilling, R.F.: Nucl. Data Tables7, 233 (1970)Google Scholar
  14. 14.
    Hoffmann, D.: Proceedings of the International Symposium on Physics and Chemistry of Fission, Jülich, 1979, IAEA Vienna 1980, Vol. II, 275, IAEA-Sm-241/F14Google Scholar
  15. 15.
    Faust, W., Münzenberg, G., Hofmann, S., Reisdorf, W., Schmidt, K.-H., Armbruster, P., Güttner, K.: Nucl. Instrum. Methods166, 397 (1979)Google Scholar
  16. 16.
    Reisdorf, W., Heßberger, F.P., Hildenbrand, K.D., Hofmann, S., Kratz, J.V., Münzenberg, G., Schlitt, K., Schmidt, K.-H., Schneider, J.R.H., Schneider, W.F.W., Sümmerer, K., Wirth, G.: (to be published)Google Scholar
  17. 17.
    Chestnut, R.P., Grasmück, B., Hadsell, R.N., Lebershausen, W., Lowski, J., Plappert, W., Richter, M., Rother, H.P., Siart, O., Steitz, M., Winkelmann, K.: EDAS (GOLDA+SATAN) User's Guide, GSI Darmstadt 1981Google Scholar
  18. 18.
    Liran, S., Zeldes, N.: The Hebrew University of Jerusalem, Int. Rep. (1976)Google Scholar
  19. 19.
    Möller, P., Nix, J.R.: At. Data Nucl. Data Tables26, 165 (1981)Google Scholar
  20. 20.
    Schmidt, K.-H., Pielenz, H., Sahm, C.-C., Clerc, H.-G.: (to be published)Google Scholar
  21. 21.
    Heßberger, F.P., Münzenberg, G., Hofmann, S., Reisdorf, W., Schneider, J.R.H., Schmidt, K.-H., Schött, H.-J., Armbruster, P., Sahm, C.-C., Vermeulen, D., Thuma, B.: GSI Annual Report GSI 82-1, 66 (1982) and (to be published)Google Scholar
  22. 22.
    Randrup, J., Larsson, S.E., Möller, P., Nilsson, S.G., Pomorski, K., Sobiczewski, A.: Phys. Rev. C13, 229 (1976)Google Scholar
  23. 23.
    Dahlinger, M., Vermeulen, D., Schmidt, K.-H.: Nucl. Phys. A376, 94 (1982)Google Scholar
  24. 24.
    Habs, D., Kleve-Nebenius, H., Metag, V., Neumann, B., Specht, H.J.: Z. Phys. A — Atoms and Nuclei285, 53 (1978)Google Scholar
  25. 25.
    Gardés, D., Bimbot, R., Maison, J., de Reilhac, L., Rivet, M.F., Fleury, A., Hubert, F., Llabador, Y.: Phys. Rev. C18, No. 3, 1298 (1978)Google Scholar
  26. 26.
    Rehm, K.E., Essel, H., Sperr, P., Hartel, K., Kienle, P., Körner, H.-J., Segel, R.E., Wagner, W.: Nucl. Phys. A366, 477 (1981)Google Scholar
  27. 27.
    Viola, V.E., Jr., Mignerey, A.C., Breuer, H., Wolf, K.L., Glagola, B.G., Wilcke, W.W., Schröder, W.U., Huizenga, J.R., Hilscher, D., Birkelund, J.R.: Phys. Rev. C22, No. 1, 122 (1980)Google Scholar
  28. 28.
    Maripuu, S. (ed.): 1975 Mass Predictions, At. Data and Nucl. Data Tables17, Nos. 5–6, 476 (1976)Google Scholar
  29. 29.
    Lederer, C.M., Shirley, V.S., ed.: Table of Isotopes. New York: John Wiley & Sons 1978Google Scholar
  30. 30.
    Schmorak, M.R.: Nucl. Data Sheets32, 87 (1981); Nucl. Data Sheets34, 1 (1981)Google Scholar
  31. 31.
    Oganessian, Yu.Ts., Demin, A.G., Danilov, N.A., Flerov, G.N., Ivanov, M.P., Iljinov, A.S., Kolesnikov, N.N., Markov, B.N., Plotko, V.M., Tretyakova, S.P.: Nucl. Phys. A273, 505 (1976)Google Scholar
  32. 32.
    Takahashi, K., Yamada, M.: Prog. Theor. Phys.41, (No. 6) 1470 (1969)Google Scholar
  33. 33.
    Kolesnikov, N.N., Demin, A.G.: Int. Report Dubna P6-9421 (1975)Google Scholar
  34. 34.
    Rasmussen, J.O.: Phys. Rev.113, 1593 (1959)Google Scholar
  35. 35.
    Bemis, C.E.: Private communication 1983Google Scholar
  36. 36.
    Heßberger, F.P., Münzenberg, G., Hofmann, S., Reisdorf, W., Schmidt, K.-H., Schneider, J.R.H., Armbruster, P., Thuma, B., Vermeulen, D., Sahm, C.-C.: (in preparation)Google Scholar
  37. 37.
    Oganessian, Yu.Ts.: Private communication 1983Google Scholar
  38. 38.
    Swiatecki, W.J.: Phys. Rev.100, 937 (1955)Google Scholar
  39. 39.
    Metag, V.: Proceedings of the International Symposium on Physics and Chemistry of Fission, Jülich, 1979, IAEA Vienna 1980, Vol. I, 53, IAEA-SM-241/BeGoogle Scholar
  40. 40.
    Baran, A., Pomorski, K., Larsson, S.E., Möller, P., Nilsson, S.G., Randrup, J., Lukasiak, A., Sobiczewski, A.: Proceedings of the International Symposium on Physics and Chemistry of Fission, Jülich, 1979, Vienna 1980, Vol. I, 143, IAEA-Sm-241/B2Google Scholar
  41. 41.
    Randrup, J., Tsang, C.F., Möller, P., Nilsson, S.G., Larsson, S.E.: Nucl. Phys. A217, 221 (1973)Google Scholar
  42. 42.
    Münzenberg, G., Hofmann, S., Faust, W., Heßberger, F.P., Reisdorf, W., Schmidt, K.-H., Kitahara, T., Armbruster, P., Güttner, K., Thuma, B., Vermeulen, D.: Z. Phys. A — Atoms and Nuclei302, 7 (1981)Google Scholar
  43. 43.
    Myers, W.D., Swiatecki, W.J.: Nucl. Phys.81, 1 (1966)Google Scholar
  44. 44.
    Nilsson, S.G., Nix, J.R., Sobiczewski, A., Szymanski, Z., Wycech, S., Gustafson, G., Möller, P.: Nucl. Phys. A115, 545 (1968)Google Scholar

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • G. Münzenberg
    • 1
  • W. Reisdorf
    • 1
  • S. Hofmann
    • 1
  • Y. K. Agarwal
    • 1
  • F. P. Heßberger
    • 1
  • K. Poppensieker
    • 1
  • J. R. H. Schneider
    • 1
  • W. F. W. Schneider
    • 1
  • K. -H. Schmidt
    • 1
  • H. -J. Schött
    • 1
  • P. Armbruster
    • 1
  • C. -C. Sahm
    • 2
  • D. Vermeulen
    • 2
  1. 1.Gesellschaft für Schwerionenforschung mbHDarmstadtFederal Republic of Germany
  2. 2.Technische HochschuleDarmstadtFederal Republic of Germany

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