Synthesis of superheavy elements with Z =112-120 in hot fusion reactions
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1 Synthesis of superheavy elements with Z =112-120 in hot fusion reactions Wang Nan College of Physics, SZU Collaborators: S G Zhou, J Q Li, E G Zhao, W. Scheid Huzhou Apr. 13 th 2012
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Synthesis of superheavy elements with Z =112-120 in hot fusion reactions. Wang Nan College of Physics, SZU Collaborators: S G Zhou, J Q Li, E G Zhao, W. Scheid. Huzhou Apr. 13 th 2012. Contents. Introduction Formalism - PowerPoint PPT Presentation
Transcript of Synthesis of superheavy elements with Z =112-120 in hot fusion reactions
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Synthesis of superheavy elements with Z =112-120 in hot fusion reactions
Wang Nan
College of Physics, SZU
Collaborators: S G Zhou, J Q Li, E G Zhao, W. Scheid
Huzhou
Apr. 13th 2012
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Contents
Introduction
Formalism
Results and discussions
Summary
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Periodic Table for Chemistry Elements
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• Experimental achievements: Super-heavy elements up to Z=118 have been synthesized
experimentally.
Z=107-113: cold fusion, 208Pb/209Bi based reactions by evaporating 1 or 2 neutrons (Rev.Mod.Phys.72(2000)733, Rep.Prog.Phys.61(1998)639)
Z=112-118: 48Ca induced fusion reactions, 48Ca bombarding actinide targets
by evaporating 3-5 neutrons (J.Phys.G34(2007)R165, NPA787(2007)343c)
GSI: 107-112 Dubna: 112-118 Riken: 113 IMP: 259Db, 265Bh
Question: How many nucleons can stay together in nucleus?
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Theoretical models for SHN production
Macroscopic dynamical model
S. Bjornholm and W.J. Swiatecki, NPA 391 (1982) 471
Fluctuation-dissipation model
Aritomo et al. PRC 59 (1999) 796, Shen Int. J.Mod. E 17(2008)66 , Liu & Bao Phys.Rev.C 80(2009)034601
Nucleon collectivization model (Zagrebaev et al.PRC65(2001)014607)
Dinuclear system model
Adamian et al. NPA 618(1997) 176
Li, Wang et al. EPL 64 (2003) 750, Eur. Phys. J. A 24, 223 (2005) ， J. Phys. G32 (2006) 1143.
Feng et al., NPA 771 (2006) 50
Huang et al, PRC 84 (2011) 064619
Wang, Zhao, Scheid , Zhou 85,041601(R)(2012)
Other model
Wang et al 84, 061601(R) (2011)
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Evaporation residue cross section:
),(),(),()12(2
)( ........
2
.. JEWJEPJETJE
E mcsurmcCNmcJmc
mcER
Schematic picture of the formation of SHNDinuclear system (used to describe deep inelastic collisions of heavy systems): V.V. Volkov, Phys. Rep. 44(1978)93
TP
EN
CN
CF
capture
fusion
evaporation
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Capture of two colliding nuclei
J
mcmc
mcc JETJE
E ),()12(2
)( ....
2
..
dB
JJJR
BEJ
BfJET
Bmc
mc
)1()(2)(
2exp1
1)(),(
2
2
..
..
Transmission probability calculated from barrier distribution:
mm
mm
BBBB
N
BBBB
NBf
,exp1
,exp1
)(2
2
2
1
2/)(
2/)(
02
0
s
sm
BB
BBB
The value of 1 is 2-4 MeV less than the one of 2
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Formation of compound nucleus - Master equation
),()()],(),'()[(),,(
11'1'11
'1
11111tAPttAPdtAPdtW
dt
tEAdP
A
qfAAAAA
BGA
iiCN APP
0
)(
tVtHtH 0
tatattHKKK
K
0
tVtatatutVKK
KKKK
KK
KKKK
'
''
''
'
,,
Hamiltonian
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Dynamical Potential Energy Surface(Dyn-Pes)
Driving potential(Potential Energy Surface)
CNNCPES BrVrVABABV ),,(),,()()( 212121
2
120
222
20111
)(
)(
A
A
C
C
)1( /max
te
2
2,121211int 2
1),,(),,(),( i
iiNC CrVrVAE
Dynamical deformation satisfy
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Dynamical Potential Energy Surface(Dyn-Pes)
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Survival probability of excited compound nucleus
iifin
inx
iCNCNsur JEJE
JEJxEPJxEW
),(),(
),(),,(),,(
**
***
The thermal compound nucleus will decay by evaporating -ray, light particles and fission. The survival probabilities can be written as
2222
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21
1
3
4)(
GG
GE
EA
NZ
c
e
mcf
a
EBE
rotn
rot
dJEBEJE
RmsJE
1
02
2*
,),(
)12(),(
Vfor
VforVRinv
0
/1)(
2
6.1/ RKZZZV
f
rotf aEBE
rotf
rotff
ff EBE
dJEBE
JEJE
1
0 /2exp1
,
),(2
1),(
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Exp. Yu.Ts. Oganessian, et al., PRC 70 (2004) 064609
Capture and evaporation residue cross sections for Ca48+U238
Results and discussions
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Exp. Yu.Ts. Oganessian et al., PRC 70 (2004) 064609
Evaporation residue cross sections for Ca48+U238, Np237
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Exp. Yu.Ts. Oganessian et al., PRC 70 (2004) 064609
Evaporation residue cross sections for Ca48+Pu242, Pu244
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Exp. Yu.Ts. Oganessian et al., PRC 74.044602
Evaporation residue cross sections for Ca48+Am243, Cm248
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Exp. Yu.Ts. Oganessian et al., PRC 74.044602
Evaporation residue cross sections for Ca48+ Bk249, Cf249
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Exp. Yu.Ts. Oganessian et al., PRC 74.044602
Evaporation residue cross sections for Ca48+U-Cf
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About element Z=120
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Fusion probability for nuclei Z=120
Evp. cross sections for nuclei Z=120
Dash dot: Ti+Cf249 Solid: Cr+Cm248Dashed: Fe+Pu244
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Lifetime for some Cf isotopes
26 Evp. Cross sections for some Ti+ Cf isotope reactions
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About element Z=119
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Evp. Cross sections for Cr+ Am and Fe+Np reactions leading to nuclei with Z=119
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Lifetime for some Bk isotopes
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Evp. Cross sections for some Ti+ Bk isotope reactions
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Summary
Some evaporation residue cross sections for 112-118 are studied with dyn-pes DNS model . The calculated results are in good agreements with experimental
Several combinations for Z=119, 120 are calculated . Some reactions are suggested.
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Thanks谢谢
