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

Summary, in English

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.”

• Author: 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; Claes Fahlander; Ulrika Forsberg; J. M. Gates; N. Gharibyan; Pavel Golubev; 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; Dirk Rudolph; J. Runke; K. P. Rykaczewski; Luis Sarmiento; 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
• Department/s: Nuclear physics
• Publishing year: 2014
• Language: English
• Publication/Series: Physical Review Letters
• Volume: 112
• Issue: 17
• Full text: - 549 kB; Download statistics
• Links: http://link.aps.org/doi/10.1103/PhysRevLett.112.172501; http://dx.doi.org/10.1103/PhysRevLett.112.172501
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Keywords: superheavy elements; element 117; alpha-decay
• Status: Published
• Project: Nuclear Structure at the Limits: Isotope-selective Spectroscopy
• Research group: Nuclear Structure
• ISBN/ISSN/Other: ISSN: 1079-7114