1. HEAVY ELEMENT RESEARCH AT THE FLNR (DUBNA)
Yuri Oganessian
Flerov Laboratory of Nuclear Reaction
Joint institute for Nuclear Research
The Fifth International Conference on Exotic Nuclei and Atomic Masses
ENAM′08 September 7-13, 2008, Ryn, Poland

2. Macroscopic theory (Liquid Drop Model)
Chart of nuclides
Macroscopic theory (Liquid Drop Model)
about 50 years ago…
Spontaneous
fission
TSF = 2·10-7 y
TSF = 1016 y
TSF < s
102No / Tα ≈ 2 s Th Bi
92U / Tα = 4.5·109 y
82Pb / stable

3. X Pb Chart of nuclides Nuclear shells (Shell model) 114
184
114
spherical
shells Pb X
spontaneous fission
162
108
deformed
shells
152
100
deformed
shells
spherical
126 82
spontaneous fission

4. New lands Microscopic theory New lands about 40 years ago… -5 5 10 15
Neutron number P r o t n u m b e
100
110
120
130
140
150
160
170
180
190 90 80 70
New lands
Microscopic theory
New lands -5 5 10 15
LogT1/2 s
1µs 1s 1h 1y
1My
about 40 years ago…
Island of
Stability
Shoal
Island of
Stability
shoal
Peninsula
Continent
Sea of Instability
peninsula
continent

5. Reactions of Synthesis
SHE
actinides
deformed
nuclei
spherical Pb
Fusion of massive
Ions with Pb-target
nuclei
Cold fusion
Since 1975
protons →
Light
ion fusion
with Act.-nuclei
Hot fusion
Neutron capture
neutrons →
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

6. Cold fusion cross sections and fusion probability
Act.+48Ca Z=
Ex=40-45 MeV
Hot fusion
Ex=12-15 MeV
Cold fusion
1 event / year
SHE

7. Cross sections
σxn ~ (Γn / Γf)x;
х – number of neutrons
(Γn / Γf) ~ exp (Bf – Bn)
Bf = BfLD + ΔEShell

8. Reactions of Synthesis
SHE
Cold fusion
protons →
Act.+48Ca
Neutron capture
Hot
fusion
actinides Pb
neutrons →
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

9. Reactions of Synthesis
Targets:
thickness
(mg/cm2)
Isotope
enrichment (%)
233U
238U
237Np
242Pu
Chemistry
244Pu
243Am
Chemistry
245Cm
248Cm
249Cf
Act. + 48Ca
Projectiles 48Ca
Energy:
MeV
Intensity:
pμA
Consumption:
0.5 mg/h
Beam dose:
( )∙1019

10. Experimental Setup Measured parameters: For recoils: energy TOF
Total detection efficiency:
for α-particles…………..83%
for SF-fragment…….~ 100%
for both fragments……..42%
Experimental Setup
Measured parameters:
For
recoils:
energy
TOF
positions
For decay
product:
time
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

11. 242Pu +48Ca, 3n Recoils R-α-α-..SF correlations Fission fragments
Yu. Oganessian J. Phys. G. 34 (2007) R165
Recoils
R-α-α-..SF
correlations
Fission fragments
242Pu +48Ca, 3n

12. Z=114

13. Alpha-particle spectra of SH-nuclei
242Pu(48Ca; 3n, 4n)287,286114
Alpha-particle spectra of SH-nuclei
245Cm(48Ca; 2n, 3n)291,290114
238U(48Ca; 3n, 4n)283,282112
249Cf(48Ca; 3n),294114
even-odd
even-even
Alpha particle energy (MeV)

14. Synthesis of Element 118
Yu. Oganessian et al., Phys. Rev C 74, (2006)
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

15. The identification of the atomic and mass numbers
of the nuclides was performed in several independent ways based on:
the mechanism of fusion reactions
excitation functions and cross bombardments ensuring variation
of the proton and neutron numbers in the compound nucleus;
production the same nuclei in different ways:
as evaporation residues
and
as -decay products of heavier nuclei;
the decay properties of the nuclei in the decay sequences:
half-lives Tα and -decay energies Qα of even-even
(and for many even-odd) isotopes;
the radiochemical identification of the nuclides: 268Db and
in correlated -decay chains.

16. Confirmation Confirmation CHEMISTRY
4 evens
Confirmation
Confirmation
5 evens
3 evens
Dubna
Reaction:
242,244Pu + 48Ca - 287, ,4n
CHEMISTRY
16 evens
18 evens
22 evens

17. 226Ra 237Np 243Am 242Pu, 245Cm 244Pu, 248Cm 249Cf Decay chains 89
Sg/266
0.2 s
Hs/270
10 s
9.06 a
Decay
chains
237Np
249Cf
243Am
+ 48Ca
118
242Pu, 245Cm
36 nuclides 89
decay chains
was registered
244Pu, 248Cm
116
114
112

18. Spontaneous fission half lives
Actinides
Superheavy nuclei
Trans-actinides
break of α-decay
chains of SH-nuclei SF
hole!

19. Alpha-decay energies
Theory:
I. Muntian, Z. Patyk, A. Sobiczewski,
Acta Phys. Pol. B 34 (2003) 2073.
Experiment:
black – light ion induced reactions
blue – cold fusion
red – Act. + 48Ca reaction
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

20. Theory and Experiment 48Ca-induced reactions cold fusion deformed
shells
spherical
shells

21. available for chemical studies Act.+48Ca Pb+50Ti,…64Ni
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

22. It is my pleasure to convey my gratitude to my colleagues
For these investigations we used intense 48Ca beams, produced at the
heavy-ion cyclotron U-400 of the Flerov Laboratory of Nuclear Reactions
(FLNR, JINR, Dubna).
The experiments at the Recoil Separator were carried out in
collaboration with the Analytical and Radiochemical Division of the Lawrence
Livermore National Laboratory (LLNL, Livermore);
the experiments on the chemical identification of 268Db and
within the collaboration:
Paul Scherrer Institute (PSI, Villigen),
University of Bern,
FLNR (Dubna),
LLNL (Livermore),
Institute of Electronic Technology (IET,Warsaw) and
Dr. M. Hussonois from Institute of Nuclear Physics (IPN, Orsay).
It is my pleasure to convey my gratitude to my colleagues
and co-authors
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

23. Thanks for your attention
More information in topical review
published in:
the Journal of Physics G 34 (2007) R165-R242
Thanks for your attention

25. Atomic properties
Atomic properties Zn Ge Cd Sn Hg Pb

26. Chemical properties relativistic 12 14 Ca 20 Rn 86 Pu 94
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

27. Compound Hg(Au) and 112(Au) Compound Hg(Au) and 112(Au) Reaction:
R. Eichler et al., Nature 447 (2007) 72
Reaction:
242Pu(48Ca,3n)287114[0.5s]→α→283112[3.6s] Au
SiO2
Yu. Oganessian. HE-research at FLNR. ENAM’08, Sept.7-13, 2008, Ryn, Poland

28. Element 112 is a noble metal – like Hg
room temperature

29. Search for Element 120 The sensitivity of experiment
MMM
HFB
RMF
Search for Element 120
The sensitivity of experiment
corresponds to σ=0.4 pb
for detection of one event.

30. 292120 294118 Nuclear density of the SHE α Z=120, A=298-300
60 α-particles
+ 60 neutrons
292120
294118
was produced
in 249Cf+48Ca
reaction

31. Search for SHE
In Nature
108 y
105 y
1 y
1 d

32. β- Hs Pu U Th Pb β-
waiting
point

33. Calculated fission barrier heights
Extended Thomas-Fermi plus
Strutinsky integral method
A. Mamdouh et al.,
Nucl. Phys. A679 (2001) 337
Z=108
Cyclamen
1966
α-decay
β--decay EC SF

35. the counting rate 1 decay / year from a 1000-g metallic Os sample
corresponds to the ratio Hs/Os:
~ 7·10-16 g/g
or ~ g/g
in the Earth's crust
or in the meteorit’s
matter
Assuming for the SH-nuclide TSF = 109 years
Fréjus peak
in comparison with previous attempts
the sensitivity is increased by a factor ~ 109
Modane

37. R-process simulation
Courtesy: Gabriel Martinez-Pinedo

38. Th-U
SHE

39. Theory and Experiment 48Ca-induced reactions cold fusion deformed
nuclei
spherical

40. Search for Element 120 In symmetric fusion in symmetric fusion
1event
136Xe+136Xe → Hs+1n-3n
Testing in reaction:
176Yb+132Sn→ n

41. xn-channel cross sections
Excitation functions
xn-channel cross sections
from 242,244Pu+48Ca reactions
the maximum cross sections
for evaporation residues are
observed at the excitation
energy ~ 40 MeV (hot fusion).
Yu. Oganessian, Synthesis of the heaviest nuclei. Sept. 1-7, 2008, Zakopane, Poland