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

Summary, in English

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.

• Author: J. Khuyagbaatar; A. Yakushev; Ch. E. Düllmann; D. Ackermann; L.-L. Andersson; M. Block; H. Brand; D. M. Cox; J. Even; Ulrika Forsberg; Pavel Golubev; 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; Dirk Rudolph; Luis Sarmiento; H. Schaffner; M. Schädel; B. Schausten; J. Steiner; T. Torres De Heidenreich; J. Uusitalo; M. Wegrzecki; N. Wiehl; V. Yakusheva
• Department/s: Nuclear physics
• Publishing year: 2015
• Language: English
• Publication/Series: Physical Review Letters
• Volume: 115
• Issue: 24
• Full text: - 379 kB; Download statistics
• Links: http://dx.doi.org/10.1103/PhysRevLett.115.242502
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Keywords: Heavy Elements; Shell Structure; Sampling Electronics
• Status: Published
• Project: Nuclear Structure at the Limits: Isotope-selective Spectroscopy
• Research group: Nuclear Structure
• ISBN/ISSN/Other: ISSN: 1079-7114