Prsentation PowerPoint

1

TDHF and beyond applied to nuclear reactions
C. Simenel, M. Bender CEA-SPhN, Saclay Ph. Chomaz
and G. de France GANIL, Caen T. Duguet MSU-NSCL,
E-Lansing (US)
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• Today's objectives
• Inelastic scattering
• Excitation of vibrational states
• Coulomb excitation of rotational states
• Fusion
• Charge equilibration
• Fusion probability with a deformed nucleus

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• TDHF code Paul Bonche (SPhT)
• History
• first application of TDHF
• to nuclear reaction
• P. Bonche et al., PRC 13, 1226 (1976)
• 3D with a full Skyrme force
• K.-H. Kim, T. Otsuka and P. Bonche,
• JPG 23, 1267 (1997)

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• I) Inelastic scattering
• A) vibration
• intrinsic frame of one nucleus
• time dependent
• external potential
• Q ? 1-body operator
• - monopole
• - quadrupole
• - dipole

x
z
y
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I) Inelastic scattering A)
vibration Observation of the response of an
excited 40Ca time evolution of 1-body
operators
Time (fm/c)
C. Simenel and Ph. Chomaz, PRC 68, 024302 (2003)
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• I) Inelastic scattering
• A) vibration
• Observation of the response
• of an excited 40Ca
• time evolution of 1-body operators

Time (fm/c)
C. Simenel and Ph. Chomaz, PRC 68, 024302 (2003)
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• I) Inelastic scattering
• A) vibration
• Observation of the response
• of an excited 40Ca
• time evolution of 1-body operators

C. Simenel and Ph. Chomaz, PRC 68, 024302 (2003)
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I) Inelastic scattering A) vibration Link
to the residual interaction
Time (fm/c)
C. Simenel and Ph. Chomaz, PRC 68, 024302 (2003)
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I) Inelastic scattering A) vibration Link
to the residual interaction
C. Simenel and Ph. Chomaz, PRC 68, 024302 (2003)
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I) Inelastic scattering B) rotation Long
range Coulomb excitation
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I) Inelastic scattering B) rotation Many
initial conditions (? orientations)
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I) Inelastic scattering B) rotation Many
initial conditions (? orientations)
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• I) Inelastic scattering
• B) rotation
• initial orientations
• ? ? reorientation
• - 24Mg 208Pb
• - ECM 112 MeV (?B)
• - head on collision

C. Simenel, P. Chomaz and G. de France, PRL 93,
102701 (2004)
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I) Inelastic scattering B)
rotation observables
? Beyond MF
?  improved  TDHF
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I) Inelastic scattering B)
rotation Excitation of the first 2 -
24Mg ( 208Pb) - ECM690 MeV
Semi-classical
P2(t?8)
c.m. scattering angle (deg.)
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I) Inelastic scattering B)
rotation Excitation of the first 2 -
24Mg ( 208Pb) - ECM690 MeV
Semi-classical
P2(t?8)
"improved" TDHF
c.m. scattering angle (deg.)
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I) Inelastic scattering B)
rotation Excitation of the first 2 -
24Mg ( 208Pb) - ECM690 MeV
Semi-classical
P2(t?8)
"improved" TDHF
Beyond Mean Field
c.m. scattering angle (deg.)
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• II) Fusion
• A) Charge equilibration
• N/Z asymmetric reaction
• non zero dipole moment
• QD ? Rprotons - Rneutrons
• at the touching
• oscillation of QD (GDR)
• during preequilibrium
• characteristics of QD(t)
• ? preequilibrium structure

QD
P. Bonche and N. Ngô, PLB 105, 17 (1981) E.
Suraud, M. Pi and P. Schuck, NPA 492, 204
(1989) Ph. Chomaz, M. Di Toro and A. Smerzi, NPA
563, 509 (1993) C. Simenel, P. Chomaz and G. de
France, PRL 86, 2971 (2001) V. Baran, D.M. Brink,
M. Colonna and M. Di Toro, PRL 87, 182501 (2001)
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• II) Fusion
• A) Charge equilibration
• N/Z asymmetric reaction
• 12Be (N/Z2) 28S (N/Z0.75) _at_ 0.5 MeV/u

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TDHF
28S 12Be?40Ca _at_ 0.5MeV/u
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• II) Fusion
• A) Charge equilibration
• density evolution
• ? prolate deformation
• dipole moment
• ? TGDRpreeq.gtTGDRCa
• (80fm/c)
• ?-spectrum ? Fourier of the
• acceleration of the charges
• (Jackson, Classical Electodynamics,
• Wiley NY 1962)
• ? lower EGDR

28S 12Be _at_ 0.5 MeV/u
40Ca
28S 12Be _at_ 0.5 MeV/u
? ? 0.14
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• II) Fusion
• A) Charge equilibration
• comparison of a N/Z
• symmetric and an
• N/Z asymmetric
• reaction
• statistical GDR
• ?-spectrum
• difference attributed
• to the preequilibrium
• GDR

FGDR (a.u.)
E? (MeV)
Flibotte et al. PRL 77, 1448 (1996)
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II) Fusion A) Charge equilibration differen
ce between both spectra
preliminary
FGDR (a.u.)
Statistical GDR
E? (MeV)
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• II) Fusion
• B) Fusion probability with
• a deformed nucleus
• 24Mg208Pb _at_ 94 MeV
• the fusion probability
• depends on the initial
• orientation

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• II) Fusion
• B) Fusion probability with
• a deformed nucleus
• Fusion probability
• - Isotropic distribution at
• D20fm blue line
• - Isotropic distribution at
• D220fm red points
• reduction of the fusion
• due to Coulomb excitation

Pfus
Pfus/P0
ECM (MeV)
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• Conclusions and perspectives
• Inelastic scattering
• Excitation of vibrational states ? residual
  interaction
• Coulomb excitation of rotational states
• ? need to go beyond the MF
• Fusion
• Charge equilibration ? predictive for
  experiments ?
• Excitation function with a deformed nucleus
• Need a good structure in the entrance channel
  (pairing)
• Extension to other mechanisms ?