Mid-peripheral collisions : PLF* decayStep by stepFragments from the PLF*Comparison with a model : Classical N-Body DynamicsExperimental setupEvents with one heavy fragment from a PLF*One fragment : Isotropic componentOne fragment : reconstruction of the PLF*One fragment : temperaturesVelocity damping and excitation energyEvents with two fragments from a PLF*Two fragments : anisotropy of PLF* decayTwo fragments : relative velocitiesAsymmetry of the breakup : Sensitivity to vPLF*To summarize…Well-defined PLF* : ZPLF* and vPLF*Opening channelsAsymmetry and Coulomb barrierEnergy in the fragmentsA statistical picture : Viola systematicsEstimation of the temperatureSlide 22A law : energy conservation“Missing” energy : Q value?“Missing” energy : evaporation?Energy conservation : balanceA picture of the processTKE : width of the distributionConversion : Q + Coulomb to TKEConclusions : building a coherent pictureInfluence of the targetRatio of the standard fissionSummary & OutlooksCollaborationSpecials Thanks To …Mid-peripheral collisions : PLF* decayPTTLF*PLF*1 fragmentSylvie Hudan, Indiana UniversityvL > vHforwardvH > vLbackwardMore than 2 fragmentsStep by step1) Correlation Size - Velocity2) Experimental setup3) The simplest case : 1 heavy fragment4) Binary breakups : statistical vs. dynamical5) Summary & OutlookFragments from the PLF*ZMAXZ MAX-1Z MAX-2Z MAX-3«+Hierarchy of the velocity and of the angular distribution of the fragments as a fonction of their charge+»Ta+Au 33 MeV/AINDRA dataINDRA dataJ. Normand, J. Colin and D. CussolJ. Normand, J. Colin and D. CussolComparison with a model :Classical N-Body DynamicsD. Cussol, PRC65, 054614 (2002)«Asinthedata,theheaviestfragmentisthefastestandisalignedalongtheQPvelocity»Experimental setupMiniball/MiniwallBeamLASSA : Mass resolution up to Z=97  lab  58Ring Counter :Si (300 m) – CsI(Tl) (2cm)2.1  lab  4.21 unit Z resolutionMass deduced†114Cd+92Moat50A.MeV Detection of charged particles in 4Projectile48† : Modified EPAX K. Sümmerer et al., Phys. Rev. C42, 2546 (1990)Events with one heavy fragment from a PLF*PLFframeWell-defined emission from the PLF30ZPLF*46One fragment : Isotropic componentPLFframeIsotropic componentOther component(mid-rapidity, …)One fragment : reconstruction of the PLF*Fit of the isotropic componentAt  = 90, alpha particles  20% of non-statistical emissionMevap=6.97Zevap=10.6ZPLF+Zevap35+10.646(Zprojectile=48)One fragment : temperaturesData:slopetemperatureSimon:emissiontemperatureSimon* : A = 109 E*  500 MeV J = 0 hbar* : D. Durand, Nucl. Phys. A541, 266 (1992)Lower slope temperature for protons and alpha particlesVelocity damping and excitation energyStrong correlation between the multiplicity of evaporated particlesand the velocity dampingVelocity damping correlated to E* Strong correlation between the slope temperature and the velocity dampingEvents with two fragments from a PLF*PLF*ZHZLvL > vH, forwardZHZLvH > vL , backwardLH*PLFZZZ )f(ZAA*PLFL*PLFHA*PLFLLHH*PLFAvAvAvStatisticalbehavior  isotropy  vH>vLvL>vHTwo fragments : anisotropy of PLF* decay6NC10 Different charge splitsmore asymmetric split for the backward case Different alignments more alignment for the backward caseB. Davin et al., Phys. Rev. C65, 064614 (2002)Two fragments : relative velocities6NC10 Different relative velocities higher vrel for the backward case Dependence with the size for the backward caseB. Davin et al., Phys. Rev. C65, 064614 (2002)Asymmetry of the breakup :Sensitivity to vPLF*6NC10vprojectile = 9.45 cm/nsMore asymmetric Z distribution for the backward caseHigher asymmetry at high vPLF* (low E*,J)For all vPLF* , asymmetry for the backward case  An other degree of freedom?vL>vHvH>vLvPLF*9.28.98.38.6E*,Jx100x20x2x80x10x1B. Davin et al., Phys. Rev. C65, 064614 (2002)To summarize…The forward and backward cases are different :Forward emission is consistent with standard statistical emissionBackward emission is consistent with dynamical decay Different charge split  dynamical has higher asymmetryDifferent alignment  dynamical is more alignedDifferent relative velocity for the same ZL dynamical has higher vrelDifferent Z distribution for a given (E*,J)Well-defined PLF* : ZPLF* and vPLF*vL>vHvH>vLSame correlation expected if vPLF* and E* correlated PLF*PLF*vvσ More dissipation and fluctuations as ZPLF* decreasesFor a given size, less dissipation for the dynamical casedynamicalstatisticaldynamicalOpening channels Dynamical emission opens at higher vPLF* , i.e. lower E* Up to 10% of the cross-section in the 2 fragment decayvL>vHvH>vL1fragment(x0.1)Asymmetry and Coulomb barrierHigher asymmetry for the dynamical caseCoulomb barrier lowerDynamical case appears at lower E*35ZPLF*39LHLHZZZZηEnergy in the fragmentsMore kinetic energy in the 2 fragments for the dynamical caseFor a given vPLF*, difference of  20-30 MeVA statistical picture : Viola systematicsComparison statistical / Viola At large vPLF*, statistical  Viola  Deviation for low vPLF* Temperature ?Comparison dynamical / Viola  For all vPLF*, dynamical >>Viola  More compact shape needed for the dynamical case7.3AAZZ*0.755Viola1/321/3121Estimation of the temperatureT2CoulombTKE Measured Estimated (Viola systematic)Statistical case : vL > vHTemperatures between 0 and 10-12 MeVThese temperatures are consistent with T=7 MeV from the isotopes in LASSA (for 30  ZPLF*  46)To summarize…vPLF* as a good observable : Same correlation (vPLF*)-vPLF* for statistical and dynamical cases Dynamical case appears at higher vPLF* Coulomb barrier effect vPLF* (TKE)dynamical > (TKE)statistical by  20-30 MeVStatistical  Viola at high vPLF* and deviation with increasing vPLF*TemperatureDynamical case always underestimated by ViolaA law : energy conservationZHZLPLF*++E* , BEPLF*TKEH , BEHTKEL , BELTKEevap ,