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Reactions of Synthesis and Decay Properties of Superheavy Elements
Yuri Oganessian
Flerov Laboratory of Nuclear ReactionsJoint Institute for Nuclear Research
141980 Dubna, Moscow region, Russia
HEAVIEST COMPOUND NUCLEI
Third International Workshop on Compound-Nuclear Reactions and Related Topics (CNR*11)
September 19-23, 2011, Prague, Czech Republic
110
120
100
90
80
70170
proton nuber
ne
utr
on
nu
mb
er
180 190110 120 130 140 150 160
92U / Tα = 4.5·109 a
82Pb / stable
Bi
Th
Macroscopic theory (charged liquid drop model)
TSF = 1.0·1016 a
102No / Tα ≈ 2 s. TSF ≈ 10-7 a
Z=106?
0 .900 .800 .70
E xp.
LDM
F iss ility P a ram ete r x
0
5
10
15
238U
255Fm
114 116
Fis
sion
Ba
rrie
r H
eig
ht
Bf /
Me
V
Fission Barriers
20
10
0
-10
-20
0 .70 0 .75 0 .80 0 .85 0 .90 0 .95
Lo
gT /
sS
FLDM
F iss ility P aram ete r x
114Z=112116
…and Half - Lives
R. Smolańczuk, Phys. Rev. C 56 (1997) 812
Predictions of the microscopic theoryPredictions of the microscopic theory
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
Neutron number
Pro
ton
n
um
be
r
100 110 120 130 140 150 160 170 180 190
120
110
100
90
80
70
New landsNew lands
New landsNew lands Microscopic theory-5 0 5 10 15 LogT1/2 s
1µs 1s 1h a 1 Ma
114
116
continent
Island ofStability
Peninsula
Sea of Instability
Отмель
106
Reaction of Synthesis
108
162
114
90
142126 146 184
Th U NW N N E
SW
W
Pb
Pu
peninsula
continent
shoal of deform ed
nuclei
island of stability
of superheavy nuclei
neutron num ber
pro
ton
nu
mb
er
Reactions of synthesis
Light ions
Neutron capture
Cold fusion
target from
“continent”
Act.+48Ca
target from“peninsula”
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
Compound nuclei excitation energy at the Coulomb barrier
-2-2
-3
-3
-6
-6
-5
-5
-7
-4
-4
-4
-14
120 130 160140 170150 180
80
90
100
110
120
190
SHE
actinides
deformednuclei
sphericalnuclei
Pbneutrons →
pro
ton
s
→
Reactions of SynthesisReactions of Synthesis
U
Pb Bi
Th
Neutron capture
Fusion of massive Ions with Pb-target
nuclei
Cold fusionSince 1975
Lightion fusionwith Act.-
nuclei Hot fusion
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
Cold fusion cross sections and fusion probabilityCold fusion cross sections and fusion probability
10-30
10-32
10-34
10-36
10-38
102 104 106 108 110 112 114 116 118
A tom ic num ber
Cro
ss s
ectio
ns
(cm
)2
208 209 48P b, B i + C a
Z n70 N i
64 F e
58 C r
54
T i
5010-30
10-32
10-34
10-36
10-38
102 104 106 108 110 112 114 116 118
A tom ic num ber
Cro
ss s
ectio
ns
(cm
)2
K . M orita et al., J. Phys. Soc. Jpn, (2004) 2593.
S. Hofm annRep. Prog. Phys., 61 (1998) 639
208 209 48P b, B i + C a
Z n70 N i
64 F e
58 C r
54
T i
50
150 200
100
10-2
10-4
10-6
10-8
C ou lom b repu ls ion
Fu
sion
pro
bab
ility
1 5010050
Z .Z / A +A1 21/3 1 /3
200 250 300
208 16P Ob +
48Ca
Zn70
Ni
64
Fe
58
Cr
54
Ti
50
1 event / year
SHE
Ex=12-15 MeVCold fusion Act.+48Ca
Z=112-118Z=112-118
Ex=40-45 MeVHot fusion
No
Rf
22Ne26M g34S (5n)
Db
Sg
Hs
Bh
Ds
10-30
10-32
10-34
10-36
10-38
4n
-cro
ss
sec
tio
n (
cm
)2
140 150
152 162
180160 170Neutron num ber
48Ca
112
114
116
114
116
118
120
184
σxn ~ (Γn / Γf)x;
х – number of neutrons
(Γn / Γf) ~ exp (Bf – Bn)
Bf = BfLD + ΔEShell
0
Cross sectionsCross sections
Yu.
Oga
ness
ian
2011
-2-2
-3
-3
-6
-6
-5
-5
-7
-4
-4
-4
-14
120 130 160140 170150 180
80
90
100
110
120
190
SHE
Pb
neutrons →
Cold fusionCold fusion
Act.+48CaAct.+48Ca
prot
ons
→
Reactions of SynthesisReactions of Synthesis
U
P b B i
T h
Neutron captureNeutron capture
HotfusionHot
fusion
Yu. Oganessian “Nuclei from Island of Stability of SHE” M-Lakes Conference Sept. 11-18, 2011, Poland
Targets from the n-rich isotopes of the elements
heavier than 238U
Intense ion beam of the rare isotope
- 48Са
DecaychainsDecaychains
184
244Pu, 248Cm +48Ca Z=116
114
112
110
Talk at the Meeting of RAS, Nov.,2000
170 μs
0.7 ms
114
11s
0.5 min
2.5 s
0.06 s
Yu.
Oga
ness
ian
201
1
Deformedshells
Sphericalshells
A/Z Setup Laboratory Publications
283112 SHIP GSI Darmstadt Eur. Phys. A32, 251 (2007)
283112 COLD PSI-FLNR (JINR) NATURE 447, 72 (2007)
286, 287114 BGS LRNL (Berkeley) P.R. Lett. 103, 132502 (2009)
288, 289114
292, 293116
TASCA
SHIP
GSI – Mainz
GSI Darmstadt
P.R. Lett. 104, 252701 (2010)
Eur. Phys. (to be published)
Confirmations 2007-2010
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
Odd-Z Superheavy Nuclei
Synthesis of Isotopes with Z =113, 115
and 117 in 2010
Experiments on the synthesis of element 115 in the reaction 243Am(48Ca, xn)291−x 115
Yu. Ts. Oganessian et al., PRC 69, 021601(R) (2004)
RAPID COMMUNICATIONS
spherical
deformed
Yu.
Oga
ness
ian
2011
Reaction: 249Bk + 48Ca → 297117* → 294-293117 + 3-4n
T1/2=320d
high neutron flux HFIR (ORNL)
Yu.
Oga
ness
ian
2010
high beam intensity of 48Ca-projectilesU-400 (JINR)
DGFRS
High efficiency of separation1 SH-atom/1012 products
Synthesis of Element 117
The Bk-249 was produced at ORNL (USA) by irradiation: of Cm and Am targets for approximately 250 days by thermal-neutron flux of
2.5 1015 n/cm²·s in the HFIR (High Flux Isotope Reactor).
Total dose:
4.3 1022 n/cm²
Yu.
Oga
ness
ian
2010
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
22.2 mg of Bk-249
Yu.
Oga
ness
ian
2010
50 Ci50 Ci
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
0 5 10 15 20 25 30 35 40 45 500
5
10
15
20
25
30
27 1 10 20 30 40 50
10
20
30
0
Bea
m c
urre
nt (
eA
)
1 p A
Yu.
Oga
ness
ian
2010
0 5 10 15 20 25 30 35 40 45 50268269270271272273274275276277278
27 1 10 20 30 50
+_0.
75 M
eV
A ugustJ uly Se p te m be r
Ene
rgy
(Me
V)
273
269
277
Tim e (d )
E* =39. 2 M eV
40
Beam dose: 2.4·1019
48C a-ions
ro ta ting entrancew indow
gas-filledcham ber
detec to rs ta tion
reco ils
pos ition sensitives trip de tecto rs
TO F -de tecto rs
“veto ” de tecto rs
22.50
S H reco il
s ide detec to rs
Dubna Gas-Filled Recoil SeparatorDubna Gas-Filled Recoil Separator
Transmission for: EVR 35-40%
target-like 10-4-10-7
projectile-like 10-15-10-17
Registration efficiency:
for α-particles 87%
for SF single fragment 100% two fragments ≈ 40%
beam48Ca
Experimental technique
target
Number of random sequences imitating such decay chain is:
3·10-11
5 events of decay of isotope
293117 were observed in this experiment
1 events of decay of odd-odd
isotope294117
and
Yu.
Oga
ness
ian
2011
Yu.
Oga
ness
ian
2010
118
116
115
114
113
112
111
110
109
108
107
106
105
104
T1/2= 320d
249Bk +48Ca
117
48 new isotopes
6 new superheavy elements
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
Decay Properties
12.0
11 .0
10 .0
110
112
Z -even
T heory :
114
116
118
108
106
9.0
8.0
7.0260 270 280 2 09 300
A tom ic m ass num ber
Alp
ha d
eca
y en
erg
y (M
eV)
Z -even
E xp:
Yu.
Oga
ness
ian
2011
100
110
120
160 170 180 190Neutron num ber N
Pro
ton
nu
mbe
r Z
1 2 3 4 5 6 7 8
Bf (MeV)
P. Moller et al., Phys. Rev., C79, 064304 (2009)
Yu.
Oga
ness
ian
2011
deformed
▼110
113
▼▼
▼▼
▼▼ 108
cold fusion
▼▼▼
▼
▼
▼
Z=117
Z=112▼ spherical
▼
▼
▼
Calculated fission barrier heights
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
0.01
0.1
1
10
100
1000
10000
100000
105 110 115 120
Cold fusion
100
Total evaporation residues cross sections
(pb)
Atomic number
Cross sectionsCross sections
48Ca-inducedreactions
SHE
factor ~300
Yu.
Oga
ness
ian
201
1
100
110
120
160 170 180 190Neutron num ber N
Pro
ton
nu
mbe
r Z
1 2 3 4 5 6 7 8
Bf (MeV)
▼▼
▼
▼
Z=117
Z=112▼
▼
▼
Yu.
Oga
ness
ian
2011
spherical
deformed
alpha decayspontaneous fission
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
Trans-actinides
Superheavy nuclei
“critical” zones
-6
-8
-4
-2
0
2
4
6
8
10
12
14
16
18
Z=112
112
114110
106
106108
104
102
100
98 N 6=1 2
N 5=1 2N 84=1
140 145 150 155 160 165 170 175 180 185N eu tron num ber
Log
T
(s)
SF
TheorySpontaneous fission half-livesSpontaneous fission half-lives
Actinides
48Ca-induced reactions
155
Neutron num ber
Ha
lf-lif
e, T
(s
)
160 165 170 175
118
116
114
112
112
113
113110
110
111
111115
1801 0 -6
1 0 -4
1 0 -2
1 0 -4
1 0 0 1 s
1 m in
1 m s
102
Half-lives of nuclei with Z ≥ 110
Half-lives of nuclei with Z ≥ 110
Act. + 48Ca
N=162
available for chemical
studies
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
Yu.
Oga
ness
ian
2011
With Z >40% larger than that of Bi, the heaviest stable element, we see an impressive extension in nuclear survival.
Although SHN are at the limits of Coulomb stability,
• shell stabilization lowers ground-state energy,
• creates a fission barrier,
• and thereby enables SHN to exist.
The fundamentals of the modern theory for mass limits of nuclear matter were given experimental verification.
-2-2
-3
-3
-6
-5
-5
-7
-4
-4
-4
-14
SHE
U
Pb Bi
Th -2-2
-3
-3
-6
-5
-5
-7
-4
-4
-4
-14
120 130 160140 170150 18080
90
100
110
120
190
SHE
U
Pb Bi
Th
neutrons →
prot
ons
→
Nuclear structure and decay properties of the
SHNNuclear Physics
Chemical properties of the SHEChemistry
Search fornew shells
Nuclear theory
Search for SHE in Nature
Astrophysics
Electronic structure of SHE-atomsAtomic Physics
Yuri Oganessian “Heaviest Compound-Nuclei”(CNR*11) , September 19-23, 2011, Prague, Czech Republic
Z=117N=175
T1/2=100 ms
T1/2=1 ms
Z=118N=174
FLNR, JINR (Dubna) ORNL (Oak-Ridge, USA) LLNL (Livermore, USA)
RIAR (Dimitrovgrad, Russia)
Vanderbilt University (Nashville, USA)
Collaboration
Yu.
Oga
ness
ian
2010
Thank you
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