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Coulomb Dissociation of 26 Ne. Nakamura-laboratory Kazuhiro Ishikawa 02M01020. Contents. Motivation Introduction Experimental Setup Data Analysis Results and Discussions Conclusion. Motivation. Search for the Soft Dipole Resonance (SDR) in 26 Ne. Coulomb Dissociation
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CoulombDissociation of 26Ne Nakamura-laboratory Kazuhiro Ishikawa 02M01020
Contents • Motivation • Introduction • Experimental Setup • Data Analysis • Results and Discussions • Conclusion
Motivation Search for the Soft Dipole Resonance (SDR) in 26Ne Coulomb Dissociation Nuclear Breakup Breakup Develop a method to distinguish two components
Introduction RIPS
Giant Dipole Resonance (GDR) versusSoft Dipole Resonance (SDR) stable nuclei E1 strength is almost exhausted by Giant Dipole Resonance (GDR). Ex=80A-1/3 MeV(~20 MeV 20Ne) unstable nuclei low lying E1 strength Soft Dipole Resonance (SDR) Prediction Low Ex( 8 MeV 26Ne)
Experimental MethodCoulomb Dissociation Using High Z target Calculated by equivalent photon method Cross section = photon number × B(E1)
Experimental Setup DALI
Experimental Setup Reaction Target Pb: Coulomb Dissociation Al : Nuclear Breakup
Data Analysis Silicon Strip Detector
Particle Identification Upstream of the Target Pulse Height versus TOF ΔE~Z2/v2=Z2TOF2
Particle Identification Downstream of the Target ΔE=ΔEX+ΔEY Ekin=E+ΔE ΔE=Z2/v2 EkinΔE~AZ2 A: mass Z: charge Ekin=Av2/2
Mass Spectrum of Ne Fragments AZ2~ΔEE’kin=ΔE(E+ΔE/2)b (Z=10) b=0.75 Removal of beam contaminants Selecting of Angle(1~6 degree) Neutron Tagged Select specific massReaction Cross Section Angular Distribution
Results and Discussions Neutron Counter
Reaction Cross Section Cross Section (mb) Pb Al ε:εn~30%
Cross Section Ratio Ratio for 25Ne is high! Coulomb dissociation for 25Ne Hindrance of σ(Al) for 25Ne , 25Ne+Al→24Ne+n+x
Angular Distribution of Ne Fragments Al Pb Wide and Narrow Two components are seen.
Estimation of the width by the fragmentation model AP : Projectile mass AF : Fragment mass EF : Fragment energy From Fermi motion Target Deflection =87 MeV/c =200~300 MeV/c
Al wide+ Pb wide× Al narrow* Pb narrow■ σ⊥(MeV/c) This result for wide is agreement with Goldhaber model. Wide Narrow
Conclusion Electronics
for 25Ne Large Coulomb dissociation for the 26Ne+Pb→25Ne+n reaction Angular distributions Two components (narrow ,wide) • wide component : In agreement with fragmentation model (nuclear component) • narrow component : Further investigations are necessary (Coulomb component?)
Special thanks to R332n Collaborators Julien GibelinB, Koichi YoshidaE, Takashi NakamuraA, Dider BeaumelB, Nori AoiE, Hidetada BabaD, Yorick BlumefeldB, Zoltan ElekesE, Naoki FukudaE, Tomoko GomiD, Yosuke KondoA, Akito SaitoD, Yositeru SatoA, Eri TakeshitaD, Satoshi TakeuchiE, Takashi TeranisiC, Yasuhiro ToganoD, Victor LimaB, Yoshiyuki YanagisawaE, Attukalathil Mayyan VinodkumarA, Toshiyuki KuboE, Tohru MotobayashiE A: Department of Physics. Tokyo Institute of Technology B: Institut de Physique Nuclaire, Orsay, France C: University of Tokyo (CNS), Riken Campus D: Department of Physics, Rikkyo University E: The Institute of Physics and Chemical Research (Riken) Nakamura-laboratory Takashi Sugimoto, Nobuyuki Matsui, Masako Ohara, Takumi Nakabayashi, Yoshiko Hashimoto