Coulomb Dissociation of 26 Ne
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Coulomb Dissociation of 26 Ne Nakamura-laboratory Kazuhiro Ishikawa 02M01020
description
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 - PowerPoint PPT Presentation
Transcript of Coulomb Dissociation of 26 Ne
Coulomb Dissociation of 26Ne
Nakamura-laboratory
Kazuhiro Ishikawa
02M01020
Contents
Motivation Introduction Experimental Setup Data Analysis Results and Discussions Conclusion
Motivation
Coulomb Dissociation Nuclear Breakup
Search for the Soft Dipole Resonance (SDR) in 26Ne
Breakup
Develop a method to distinguish two components
Introduction
RIPS
Neutron-rich nuclei
Giant Dipole Resonance (GDR) versusSoft Dipole Resonance (SDR)
stable nucleiE1 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)
PredictionLow Ex （ 8 MeV
26Ne)
In the case of 26Ne
Experimental MethodCoulomb DissociationUsing High Z
target
Cross section = photon number × B(E1)
Calculated by equivalent photon method
Experimental Setup
DALI
Experimental Setup
Reaction TargetPb: Coulomb DissociationAl : Nuclear Breakup
Data Analysis
Silicon
Strip Detector
Particle Identification Upstream of the Target
Pulse Height versus TOFΔE ～ Z2/v2=Z2TOF2
Particle Identification Downstream of the Target
ΔE=Z2/v2
Ekin=Av2/2 EkinΔE ～ AZ2 A: mass Z: charge
ΔE=ΔEX ＋ ΔEY
Ekin=E+ΔE
Mass Spectrum of Ne Fragments
AZ2 ～ ΔEE’kin=ΔE(E+ΔE/2)b (Z=10)b=0.75
Select specific mass Reaction Cross Section Angular Distribution
Neutron Tagged
Removal of beam contaminants
Selecting of Angle(1~6 degree)Selecting of Angle(1~6 degree)
Results and Discussions
Neutron Counter
Reaction Cross Section
Run 26Ne+pb
26Ne+Al
25Ne 119(2) 10(0.3)24Ne 211(3) 29(0.6)23Ne 167(3) 22(0.5)22Ne 197(3) 31(0.7)
Cross Section (mb)
ε ： εn~30%
PbPb
AlAl
Cross Section Ratio Ratio for 25Ne is high!
1. Coulomb dissociation for 25Ne2. Hindrance of σσ (Al)(Al) for 25Ne , 25Ne+Al→24Ne+n+x
%56)24(σ
)25(σ%34
)24(σ
)25(σ
pb
pb
Al
Al
(Al)/(Pb)
Angular Distribution of Ne Fragments
Two components are seen.
Al Pb
Estimation of the width by the fragmentation model
)2
exp(2
2
FE
ACd
dF
220
2
)1(
)1(
1
)(D
p
FF
p
FpF
pAA
AA
A
AAA
0 =87 MeV/c D =200~300 MeV/c
AP : Projectile massAF : Fragment mass
EF : Fragment energy
AP : Projectile massAF : Fragment mass
EF : Fragment energy
From Fermi motionFrom Fermi motion Target DeflectionTarget Deflection
Wide
Narrow
This result for wide is agreement with Goldhaber model.
σ ⊥(M
eV/c
)σ ⊥
(MeV
/c)
Al wide ＋Pb wide×
Al narrow ＊Pb narrow■
Al wide ＋Pb wide×
Al narrow ＊Pb narrow■
(Pb)(Al) DD
(Pb)(Al) DD
MeV/c 267(5)(Al)D σc262(5)MeV/(Pb)D
Conclusion
Electronics
for 25Ne Large Coulomb dissociation for the 26Ne+Pb→25Ne+n
reaction Angular distributions Two components
(narrow ,wide)
1. wide component : In agreement with fragmentation model (nuclear component)
2. narrow component : Further investigations are necessary (Coulomb component?)
(Al)/Pb)(
Special thanks toR332n 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 TechnologyB: Institut de Physique Nuclaire, Orsay, FranceC: University of Tokyo (CNS), Riken CampusD: Department of Physics, Rikkyo UniversityE: The Institute of Physics and Chemical Research (Riken)Nakamura-laboratoryTakashi Sugimoto, Nobuyuki Matsui, Masako Ohara, Takumi Nakabayashi, Yoshiko
Hashimoto
