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

Total downloads

No data available

Related research output

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

Research output: Contribution to journalArticle

View all (1)

Related projects

Dirk Rudolph, Claes Fahlander, Pavel Golubev, Luis Sarmiento Pico, Daniel Cox, Yuliia Hrabar, Anton Såmark-Roth, 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

Swedish Research Council


Project: ResearchInternational collaboration

View all (1)