Element 117 discovered?

On 1 May 2014 a paper published in Phys. Rev. Lett by J. Khuyagbaatar and others states the superheavy element with atomic number Z = 117 (ununseptium) was produced as an evaporation residue in the 48Ca and 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 allows measurement of decays of single atomic nuclei with very short half-lives . Two decay chains comprising seven α-decays and a spontaneous fission each were identified and assigned to the isotope 294Uus (element 117) and its decay products.

This reinforces a paper published 5 April 2010 in Physical Review Letters by Yu. Ts. Oganessian and others claims the synthesis of a new element with atomic number 117. The abstract states “The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes 293117 and 294117 were produced in fusion reactions between 48Ca and 249Bk. Decay chains involving eleven new nuclei were identified by means of the Dubna Gas Filled Recoil Separator. The measured decay properties show a strong rise of stability for heavier isotopes with Z>=111, validating the concept of the long sought island of enhanced stability for super-heavy nuclei.” Read more: Physical Review Letters: element 117 preliminary publication

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