48Ca+249Bk Fusion Reaction Leading to Element Z=117: Long-Lived α-Decaying 270Db and Discovery of 266Lr

Research output: Contribution to journalArticle


The superheavy element with atomic number Z=117 was produced as an evaporation residue in the 48Ca+249Bk 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 270Db (Z=105) was observed, which populated the new isotope 266Lr (Z=103). The identification of the long-lived (T1/2=1.0+1.9−0.4  h) α-emitter 270Db marks an important step towards the observation of even more long-lived nuclei of superheavy elements located on an “island of stability.”


  • J. Khuyagbaatar
  • A. Yakushev
  • Ch. E. Düllmann
  • D. Ackermann
  • L.-L. Andersson
  • M. Asai
  • M. Block
  • R. A. Boll
  • H. Brand
  • D. M. Cox
  • M. Dasgupta
  • X. Derkx
  • A. Di Nitto
  • K. Eberhardt
  • J. Even
  • M. Evers
  • J. M. Gates
  • N. Gharibyan
  • K. E. Gregorich
  • J. H. Hamilton
  • W. Hartmann
  • R.-D. Herzberg
  • F. P. Heßberger
  • D. J. Hinde
  • J. Hoffmann
  • R. Hollinger
  • A. Hübner
  • E. Jäger
  • B. Kindler
  • J. V. Kratz
  • J. Krier
  • N. Kurz
  • M. Laatiaoui
  • S. Lahiri
  • R. Lang
  • B. Lommel
  • M. Maiti
  • K. Miernik
  • S. Minami
  • A. Mistry
  • C. Mokry
  • H. Nitsche
  • J. P. Omtvedt
  • G. K. Pang
  • P. Papadakis
  • D. Renisch
  • J. Roberto
  • J. Runke
  • K. P. Rykaczewski
  • M. Schädel
  • B. Schausten
  • A. Semchenkov
  • D. A. Shaughnessy
  • P. Steinegger
  • J. Steiner
  • E. E. Tereshatov
  • P. Thörle-Pospiech
  • K. Tinschert
  • T. Torres De Heidenreich
  • N. Trautmann
  • A. Türler
  • J. Uusitalo
  • D. E. Ward
  • M. Wegrzecki
  • N. Wiehl
  • S. M. Van Cleve
  • V. Yakusheva
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Subatomic Physics


  • superheavy elements, element 117, alpha-decay
Original languageEnglish
Article number172501
Number of pages4
JournalPhysical Review Letters
Issue number17
Publication statusPublished - 2014
Publication categoryResearch

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Related research output

Khuyagbaatar, J., Yakushev, A., Düllmann, C. E., Ackermann, D., Andersson, L. L., Asai, M., Block, M., Boll, R. A., Brand, H., Cox, D. M., Dasgupta, M., Derkx, X., Di Nitto, A., Eberhardt, K., Even, J., Evers, M., Fahlander, C., Forsberg, U., Gates, J. M., Gharibyan, N. & 52 othersP. Golubev, Gregorich, K. E., Hamilton, J. H., Hartmann, W., Herzberg, R. D., Heßberger, F. P., Hinde, D. J., Hoffmann, J., Hollinger, R., Hübner, A., Jäger, E., Kindler, B., Kratz, J. V., 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, J. P., Pang, G. K., Papadakis, P., Renisch, D., Roberto, J., D. Rudolph, Runke, J., Rykaczewski, K. P., L. G. Sarmiento, Schädel, M., Schausten, B., Semchenkov, A., Shaughnessy, D. A., Steinegger, P., Steiner, J., Tereshatov, E. E., Thörle-Pospiech, P., Tinschert, K., Torres De Heidenreich, T., Trautmann, N., Türler, A., Uusitalo, J., Ward, D. E., Wegrzecki, M., Wiehl, N., Van Cleve, S. M. & Yakusheva, V., 2019 May 7, In : Physical Review C. 99, 5, 16 p., 054306.

Research output: Contribution to journalArticle

Rudolph, D., Forsberg, U., Golubev, P., Sarmiento, L., Yakushev, A., Andersson, L-L., Di Nitto, A., Düllmann, C. E., Gates, J. M., Gregorich, K. E., Gross, C. J., Heßberger, F. P., Herzberg, R-D., Khuyagbaatar, J., Kratz, J. V., Rykaczewski, K., Schädel, M., Åberg, S., Ackermann, D., Block, M. & 31 othersBrand, H., Gillis Carlsson, Cox, D., Derkx, X., Eberhardt, K., Even, J., Claes Fahlander, Gerl, J., Jäger, E., Kindler, B., Krier, J., Kojouharov, I., Kurz, N., Lommel, B., Mistry, A., Mokry, C., Nitsche, H., Omtvedt, J. P., Papadakis, P., Ingemar Ragnarsson, Runke, J., Schaffner, H., Schausten, B., Thörle-Pospiech, P., Torres, T., Traut, T., Trautmann, N., Türler, A., Ward, A., Ward, D. & Wiehl, N., 2013, In : Physical Review Letters. 111, 11, 112502.

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