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04/21/23 1
Cuie Wu
School of Physics, Peking University
Neutron removal reactions of 17C
Cuie Wu et al., JPG31(2005)39
04/21/23 2
Outline
Introduction
Experiment
Result and analysis
Summary
04/21/23 3
1. Introduction
Features of the drip-line nuclei Short life, weak binding energy, halo, cluster structure, large interac
tion and reaction cross sections, narrow momentum distribution of
the core, …
Experiments
04/21/23 4
an excellent tool for getting spectroscopic i
nformation about states in exotic nuclei, su
ch as the Jπ of the ground state, the spectro
scopic factors for the halo states .
Neutron removal (knockout) of the neutron-rich nuclei
P (c + n) + T c + n + T
diffraction or elastic dissociation
c + X
stripping, or absorption, or inelastic dissociation
E. Sauvan et al., Phys. Rev. C 69 (2004) 044603
Z = 5 ~ 9 , A = 12 ~ 25
1. Introduction
04/21/23 5
Neutron-rich Carbon isotopes
Sn and S2n
17C
σR and σI
17C
1. Introduction
Reaction targetC
F2 F3
Primary beam22Ne (110A MeV)
Production targetBe
D2
BρF1
ΔE
TOF TOF ΔE
PPAC PlasticSSD Veto Plastic
Experimental setup (17C@79A MeV)
F0
E
NaIIC
D1
16,15,14,…C17C
17C,...
RIPS @ RIKEN
Particle identificationBefore reaction target : Bρ-TOF -ΔE
Z
ABp
1
TOF
2
2
Z
E
AZ
Z
After reaction target : TOF -ΔE - E
2 AE
1
TOF
2
2
Z
E Z
A
2. Experiment
04/21/23 7
E (channel)
14C15C
16C
17C
Particle identification at F3 with Z=6
TO
F (
ns)
2. Experiment
04/21/23 8
E* (arbitrary)
Cou
nts
16C
14C15C
17C
Target-in
Target-out
2. Experiment
04/21/23 9
in
x
xn NT
N
t
C1 17
Neutron removal cross sections
Summary of the experimental results for 17C + 12C at 79A MeV
16C
15C
14C
Fragments Neutron removal cross sections (mb)
30133 40
n
181161 n
3.Result and analysis
04/21/23 10
The ground state is a superposition
of the configurations from all states. J
c nljI
The few-body Glauber model analysis
3.Result and analysis
The total one-neutron removal cross sections is,
effnsp
nljccn
Glaubern SnljnljISCI , ,2
11
04/21/23 11
The few-body Glauber model calculation
Main component!
3.Result and analysis
04/21/23 12
one neutron-removal cross section for 17C
Closed: C target
Open: Be target
Experiments:
Calculations:
Solid: C target
Dotted: Be target
3.Result and analysis
04/21/23 13
The same few-body Glauber model predicts that if a nucleus (AZ) consists of a core (A-1Z) and a halo (1n), then,
The present work gives:
For 17C:If we use the reaction cross sections of 17C and 16C from [Cuie Wu et al., NPA739(2004)3] and [T. Zheng
et al., NPA709(2002)103], the right-hand side of the above equation is 113±33 mb.
mb181161 n
3.Result and analysis
04/21/23 14
We measured the one-neutron removal cross section of 17C on 12C target
at 79A MeV. The σ-1n was analyzed within the framework of the few-bod
y Glauber model and a good agreement was found.
The valence neutron of 17C is mainly in the d-orbital, which is in agreement w
ith the reaction cross section (C. Wu et al. NPA739(2004)3) and momentum di
stribution measurements (V. Maddalena et al. PRC63(2001)024613).
The calculation underestimate the data at higher energy while overestimate
the data at lower energy, the reason of which is yet to be understood.
Summary
The two- and three-neutron removal cross sections are reported for the first
time but not analyzed by lack of a suitable theory. We hope the development
of the theory.
4. Summary
04/21/23 15
Collaborators
Peking university, China Yanlin Ye, Dongxing Jiang, Hui Hua,
Tao Zheng, Zhihuan Li
RIKEN, Japan
Y. Yamguchi, A. Ozawa, I. Tanihata
04/21/23 16