New Short-Lived Isotope 221U and the Mass Surface Near N=126

Research output: Contribution to journalArticle


Two short-lived isotopes 221U and 222U were produced as evaporation residues in the fusion reaction 50Ti+176Yb at the gas-filled recoil separator TASCA. An α decay with an energy of Eα=9.31(5)  MeV and half-life T1/2=4.7(7)  μs was attributed to 222U. The new isotope 221U was identified in α-decay chains starting with Eα=9.71(5)  MeV and T1/2=0.66(14)  μs leading to known daughters. Synthesis and detection of these unstable heavy nuclei and their descendants were achieved thanks to a fast data readout system. The evolution of the N=126 shell closure and its influence on the stability of uranium isotopes are discussed within the framework of α-decay reduced width.


  • J. Khuyagbaatar
  • A. Yakushev
  • Ch. E. Düllmann
  • D. Ackermann
  • L.-L. Andersson
  • M. Block
  • H. Brand
  • D. M. Cox
  • J. Even
  • W. Hartmann
  • R.-D. Herzberg
  • F. P. Heßberger
  • J. Hoffmann
  • A. Hübner
  • E. Jäger
  • J. Jeppsson
  • B. Kindler
  • J. V. Kratz
  • J. Krier
  • N. Kurz
  • B. Lommel
  • M. Maiti
  • S. Minami
  • A. K. Mistry
  • Ch. M. Mrosek
  • I. Pysmenetska
  • H. Schaffner
  • M. Schädel
  • B. Schausten
  • J. Steiner
  • T. Torres De Heidenreich
  • J. Uusitalo
  • M. Wegrzecki
  • N. Wiehl
  • V. Yakusheva
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Subatomic Physics


  • Heavy Elements, Shell Structure, Sampling Electronics
Original languageEnglish
Article number242502
Number of pages4
JournalPhysical Review Letters
Issue number24
Publication statusPublished - 2015
Publication categoryResearch

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Related research output

Såmark-Roth, A., Sarmiento, L. G., Rudolph, D., Ljungberg, J., Carlsson, B. G., Fahlander, C., Forsberg, U., Golubev, P., Ragnarsson, I., Ackermann, D., Andersson, L. L., Block, M., Brand, H., Cox, D. M., Di Nitto, A., Düllmann, C. E., Eberhardt, K., Even, J., Gates, J. M., Gerl, J. & 28 othersGregorich, K. E., Gross, C. J., Herzberg, R. D., Heßberger, F. P., Jäger, E., Khuyagbaatar, J., Kindler, B., Kojouharov, I., Kratz, J. V., Krier, J., Kurz, N., Lommel, B., Mistry, A., Mokry, C., Omtvedt, J. P., Papadakis, P., Runke, J., Rykaczewski, K., Schädel, M., Schaffner, H., Schausten, B., Thörle-Pospiech, P., Trautmann, N., Torres, T., Türler, A., Ward, A., Wiehl, N. & Yakushev, A., 2018 Oct 9, In : Physical Review C. 98, 4, 11 p., 044307.

Research output: Contribution to journalArticle

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Related projects

Dirk Rudolph, Claes Fahlander, Pavel Golubev, Luis Sarmiento Pico, Anton Såmark-Roth, Daniel Cox, Ulrika Forsberg, Christian Lorenz, Natasa Lalovic, Natasa Lalovic, Ulrika Forsberg, Jnaneswari Gellanki, Robert Hoischen, Emma Johansson, Lise-Lotte Andersson, Rickard du Rietz, Jörgen Ekman & Corina Andreoiu

Kungliga Fysiografiska Sällskapet i Lund, Swedish Research Council


Project: Research

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