Laboratory of Nuclear Reactions Joint Institute for Nuclear Research

Georgij Nikolaevich Flerov

1940 Discovery of spontaneous fission of uranium

1942-1950 Participation in Russian atomic project

1955 First beams of accelerated heavy ions

1956-57 Foundation of Laboratory of Nuclear Reactions (Dubna)

1962-1975 Synthesis of new elements: 103, 104, 105 (Dubnium), 106, 107.

Mendeleev’s Table (140 years ago)

Mendeleev’s Table

Nuclear Map

Abundance of the element in the Universe The 11 Greatest Unanswered Questions of Physics (National Research Council, NAS, USA, 2002):

1. What is dark matter? 2. What is dark energy? 3. How were the heavy elements from iron to uranium made? 4. Do neutrinos have mass? …

Strong neutron fluxes are expected in core-collapse supernova explosions or in the mergers of neutron stars.

Nucleosynthesis in Stars

Evolution of stars

Nucleosynthesis in Supernova

Nucleosynthesis in Supernova

Nucleosynthesis in stars

Hand-made chemical elements (reactors and nuclear explosion)

Rapid neutron capture in nuclear explosions

Synthesis of new elements (history)

In chase of new elements

США, Калифорния, Беркли: 1958 – 102(No), 1961 – 103(Lr), … Glenn Seaborg, Albert Ghiorso

СССР, Дубна: 1964 - 1975 – 102, 103, 104, 105 (Дубний), 106, 107 Г.Н. Флеров, Ю.Ц. Оганнесян

Германия, Дармштадт: 1989 - 2000 – 108, 109, 110, 111, 112 (?) P. Armbruster, G. Münzenberg , S. Hofmann

Япония, Токио: 2002 – 110, 111, 112, 2004 – 113 K. Morita

Франция, Нормандия, Каен: 2003 - … (?)

2000 – 114, 2002 – 116, 2003 – 113, 115, 118

Nuclear Map in 2000

Synthesis of superheavy elements (experiment)

Great progress in synthesis of superheavy nuclei within last 10 years

1 June 2011, International Union of Pure and Applied Chemistry (IUPAC) has recognized discovery of the elements 114 and 116 (proposed names are “Flerovium” and “Livermorium”)

Nuclear Map: Island of Stability

Superheavy Elements (Island of Stability)

Synthesis of new elements in fusion reactions

Why do nuclei not want to fuse ?

The problems

Which nuclei are to be fused ?

«cold» synthesis: 208Pb + 64Ni, 70Zn, … → 272110, 278112, … ( GSI, Germany )

«hot» synthesis: 238U, 244Pu, 248Cm, 249Cf + 48Ca → 286112, 292114 , 296116 , 297118

How to choose colliding energy ?

Synthesis of superheavy elements (cold and hot fusion)

Synthesis of superheavy elements (experiment)

Target made of 249Cf (half-life is 350 years)

Detection of SH nuclei and products of their decay

Beyond 48Ca: 50Ti and 54Cr induced fusion reactions

Probably these elements are the last ones which will be synthesized in the nearest future

Chemical properties of superheavy elements

Dmitriev et al., May 2006: Volatility and adsorption properties of 112 are the same as of mercury