Quasimolecular structures and Cold Valleys in Formation and Decay of Heavy Elements

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Quasi-molecular structures and Cold Valleys
in Formation and Decay of Heavy Elements
Serban Misicu, NIPNE-HH, Bucharest
,
,

Walter Greiner, Institut für Theoretische Physik,
Frankfurt am Main
Kemer, 30 September 2003
Quasi-molecular pockets in the heavy-ion
potential Cluster Decay of actindes and
superheavies Orientation windows in fusion and
fission
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Heavy-Ion Potential
Double folding potential with g.s. 1-body
densities
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Heavy-Ion Potential
Double folding potential with g.s. 1-body
densities
Ground state one-body nuclear densities
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Heavy-Ion Potential
Double folding potential with g.s. 1-body
densities
Ground state one-body nuclear densities
M3YCoulomb effective N-N forces
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Heavy-Ion Potential
Double folding potential with g.s. 1-body
densities
Ground state one-body nuclear densities
M3YCoulomb effective N-N forces

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Heavy-Ion Potential
Double folding potential with g.s. 1-body
densities
Ground state one-body nuclear densities
M3YCoulomb effective N-N forces


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Heavy-Ion Potential
Double folding potential with g.s. 1-body
densities
Ground state one-body nuclear densities
M3YCoulomb effective N-N forces


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Heavy-Ion Potential
Double folding potential with g.s. 1-body
densities
Ground state one-body nuclear densities
M3YCoulomb effective N-N forces
Repulsive Core
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Orientation
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Orientation
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Orientation
Fixed Fission(Molecular) Axis
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Touching Configurations
(i) Pole-Pole(nose-to-nose)
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Touching Configurations
(i) Pole-Pole(nose-to-nose)
(ii) Pole-Equator(nose-to-bely)
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Touching Configurations
(i) Pole-Pole(nose-to-nose)
(ii) Pole-Equator(nose-to-bely)
(iii) Equator-Equator(belly-to-bely)
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Touching Configurations
(i) Pole-Pole(nose-to-nose)
(ii) Pole-Equator(nose-to-bely)
(iii) Equator-Equator(belly-to-bely)
(iv) Equator-Equator Twisted(crossed bellies)
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Driving Potential
- mass asymmetry
- charge asymmetry
Cold valleys
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Cluster Radioactivity

• The residual nuclei are found in the ground state
  or in a low-lying excited state.
• Emitters - preactinides and actinides.
  Daughters - nuclei around 208Pb.
  Clusters from C up to Si.
• Decay Rates

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Cluster Radioactivity

• The residual nuclei are found in the ground state
  or in a low-lying excited state.
• Emitters - preactinides and actinides.
  Daughters - nuclei around 208Pb.
  Clusters from C up to Si.
• Decay Rates

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Cluster Radioactivity

• The residual nuclei are found in the ground state
  or in a low-lying excited state.
• Emitters - preactinides and actinides.
  Daughters - nuclei around 208Pb.
  Clusters from C up to Si.
• Decay Rates

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Spectroscopic Factors(Cluster Preformation
Probabilities)
Blendowske-Walliser Empirical Law
Semimicroscopic Algebraic Cluster Model
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Life-time in CR and SF
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Cold Valley in Cluster Radioactivity
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Cluster Radioactivity in the Superheavy Island ?
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Cold Fission of 252Cf

• Fragments are emitted in their ground-states(no
  neutron emission)
• Low spins at scission
• High mass yields for light fragments in the range
  93 114 (heavy fragments in the range 138
  157(Gönnenwein-1996)

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Kalinin, 2001
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Capture Reactions with 48Ca Projectiles
FLNR-Dubna
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Capture Cross Sections

• Wong formula

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Coupling with Rotational Band States
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Barrier Distribution
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Effect of various Orientations
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Conclusions

• Cold valleys explain qualitatively the occurrence
  of cluster radioactivity in actinides
• Cold valleys explain the yields of neutronless
  spontaneous fission of 252Cf if hexadecupole
  deformations are taken into account and fragments
  are oriented pole-pole
• Cold valleys predicted in the past the best
  targets to be used with 48Ca projectiles in the
  synthesis reactions leading to superheavy
  elements
• Cold valleys seem to be a tool to explain the
  mass distribution of quasi-fission products in
  the synthesis of elements with Z112, 114 and 116
  using the equator-equator orientation for
  projectile and target