JINR Director A.N. Sissakian announced: “The element number 117 of the Periodic Table of Elements was synthesized in the Flerov Laboratory of Nuclear Reactions (FLNR) of Joint Institute for Nuclear Research (JINR). Experiments (Leader Academician Yu.Oganessian) were held at the FLNR Accelerator of heavy ions in cooperation with the US National Laboratories of Oak Ridge and Livermore, with Vanderbilt University (USA), and also with the Scientific Research Institute of Atomic Reactors (Dimitrovgrad, Russia).

 

The synthesis of the new element was implemented in the reaction of accelerated 48Ca ions with the unique berkelium target of an artificial element 97 isotope – Berkelium-249, which has only 320 days physical half-life. Its production was held at the today’s most powerful atomic reactor HIFR in the US Oak Ridge National Laboratory. During a long (half a year) experiment 6 events of the “birth” of the new element were registered. The properties of a decay of an isotope of the 117th element and its daughter products – isotopes of elements 115, 113, 111, 109, 107 and 105 together with the isotopes of elements 112-116 and 118 synthesized in Dubna before – are the direct proof for the existence of the “Stability Island” of super-heavy nuclei.

 

The life time of new isotopes 115, 113 and 111, which is measured in seconds, allows research of the isotopes’ chemical properties with the existing express radio-chemical methods: the periodicity changing of the heaviest elements’ chemical properties is checked on the basis of the fundamental laws of quantum electrodynamics that describe electronic structure of super-heavy atoms. Similar experiments with the isotopes of elements 112 and 114 discovered earlier have been held in FLNR JINR in extensive collaboration with world leading radiochemical laboratories.

 

A scientific paper prepared by the authors of the discovery has been accepted for publication in the famous American journal «Physical Review Letters».