Artificial radioactive element properties unknown	memory peg
	2004 Researchers from the Glenn T. Seaborg Institute, Berkeley, Calif., USA
	un-un-tri-um = 1-1-3-um

In experiments conducted at the JINR U400 cyclotron with the Dubna gas-filled separator between July 14 and Aug. 10, 2003, the team of scientists observed atomic decay patterns, or chains, that confirm the existence of element 115 and element 113. In these decay chains, element 113 is produced via the alpha decay of element 115.

The results have been accepted for publication in the Feb. 1, 2004 issue of Physical Review C.

Kosuke Morita and co-workers carried out an experiment on the synthesis of element 113. They published it in October 2004 in the Journal of the Physical Society of Japan. This is the abstract of their article:

The convincing candidate event of the isotope of the 113th element, ²⁷⁸113, and its daughter nuclei, ²⁷⁴111 and ²⁷⁰Mt, were observed, for the first time, in the ²⁰⁹Bi + ⁷⁰Zn reaction at a beam energy of 349.0 MeV with a total dose of 1.7 × 10¹⁹. Alpha decay energies and decay times of the candidates, ²⁷⁸113, ²⁷⁴111, and ²⁷⁰Mt, were (11.68 ± 0.04 MeV, 0.344 ms), (11.15 ± 0.07 MeV, 9.26 ms), and (10.03 ± 0.07 MeV, 7.16 ms), respectively. The production cross section of the isotope was deduced to be 55⁺¹⁵⁰_-45 fb (10^-39 cm²).

The element does not have a name yet, therefore the systematic IUPAC name is used (system explained at Ununoctium).

Further reading:

• Livermore Scientists Team With Russia To Discover Elements 113 and 115, Press Release 2 February 2004.
• Kosuke Morita et al., "Experiment on the Synthesis of Element 113 in the Reaction ²⁰⁹Bi(⁷⁰Zn,n)²⁷⁸113". Journal of the Physical Society of Japan 73, 10 (October 2004): 2593-2596 (Abstract)