Transcript 107Inの高スピン集団回転状態

Study of high-spin states
by using stable and unstable
nuclear beams
Eiji Ideguchi
CNS, the University of Tokyo
What can we learn in high-spin studies?



Variety of nuclear structure as a function of angular
momentum
Single particle structure
Collective motion



Deformation




Rotation
Vibration
β、γ degree of freedom
Super(2:1), Hyper(3:1) deformation  deformed shell gaps
Triaxial  Chirality, Wobbling  Next talk by Porf. Matsuzaki
Change of structure

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Collective  Single particle
Spherical  deformed
band termination
Studied High-Spin Nuclei
 Fusion evaporation,
Coulex, fission, βdecay
direct reactions were used
 Study of high-sin states is limited to proton-rich side
 High-spin states in neutron rich nuclei as well as
stable isotopes are not studied well
 Very proton-rich nuclei are not studied well
New detector system, new method (RI beam) is necessary
to expand the research to new region
High-Spin Studies

Study of high-spin states near 48Ca region
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RI-beam experiment at RIKEN, RIPS facility
Study of high-spin states in A～100 region

In-beam gamma-ray spectroscopy by using stable
isotope beam at JYFL
High-spin studies in neutron rich nuclei
Fusion reaction: effective to produce high-spin states
Stable isotope beam + Stable isotope target
→ High-spin states in proton-rich nuclei
High-spin study induced by RI beam
Fusion reaction:
RI beam + Stable isotope target
→ High-spin states in Stable | Neutron-rich nuclei
Study of
49-52Ti
(Z=22,N=27-30)
High-spin study of
most neutron-rich stable nuclei.
→ 48Ca and neighbors
deformed states at high spin
50Ti
(Z=22, N=28)
→ Deformed collective band
at high-spin
Deformation parameter b2
ΔE of SSD at F2 (MeV)
Low-energy 2ndary
beams using RIPS
F1：Wedge degrader
221mg/cm2
F2:Plastic 0.1mm
Al rotatable degrader
46Ar
50MeV/A
F0：9Be
48Ca
64MeV/A
～40pnA
target 1.0mm
+ 48Ca → 46Ar
46Ar
46Ar
90%
RF - F2 Plastic TOF (ns)
～ 5MeV/A
30MeV/A
9Be
46Ar
beam intensity
2ndary target F2 : 7.3×105 cps
Ge array
5
PPAC×２
X : 17 mm (s)
Y : 8 mm (s)
F3 : 3.2×10 cps
Purity : 90 %
2-6 A MeV
Setup around 2ndary target
Secondary target ：9Be 10μm (1.8mg/cm2) thick、10cmφ
Doppler correction:
2 PPACs before 2ndary target
→ Beam Image, incident angle on target
F2 Plastic－F3PPAC TOF
→ Beam Energy
GRAPE(CNS Ge Array, position sensitive)
GRAPE
Gamma-ray spectra in
9Be(46Ar, xn)55-xTi reaction
0
1000
3000
2000
g-ray energy [keV]
4000
Excitation function measurements
52Ti
51Ti
1051 1432 1548
}
51Ti
}
}
52Ti
50Ti
49Ti
Gamma-ray assignment
49Ti
1537
50Ti
Excitation function
total
51Ti
50Ti
49Ti
52Ti
1537 keV
1548 keV
1537
1548
1432
1051
1051 keV
49Ti
50Ti
51Ti
52Ti
1432 keV
New transition in
49Ti
γ-γ coincidence analysis
785
965
1537 or 965 or 785 or 1093 keV gated
1537
1093
2370
49Ti
1548 or 1117 or 523 or 232 or 803 keV gated
50Ti
→ 2370 keV transition
above (19/2)－ state
New transition in
51Ti
γ-γ coincidence
analysis
761
761keV transition
above (13/2,17/2) state
Comparison with Shell Model Calculations
ANTOINE
E. Caurier, shell model code ANOTINE,
IRES, Strasbourg 1989-2004
E. Caurier, F. Nowacki
Acta Phys. Pol. 30 (1999) 705
KB3G
High-spin studies of
107In
Study of
107In
(Z=49, N=58)
Reaction : 52Cr(187MeV) + 58Ni(580+640μg/cm2)
108
54
Xe
107
53
103
52
Te
104
Te
105
Te
106
I
Te
109
Xe
108
107
I
Te
110
Xe
109
108
I
Te
111
110
109
102
49
48
47
B. Hadinia et al.
PRC70, 064314(2004)
46
Xe
I
Te
112
Xe
111
110
I
Te
109
Sb 103 Sb 104 Sb 105 Sb 106 Sb 107 Sb 108 Sb Sb
51
0.7 0.2
101
102
106
103
104
100
105
107
108
Sn Sn Sn Sn Sn Sn Sn Sn Sn
50
0.1
20.9 33.5 1.1
105
101
103
102
104
106
99
100
98
In
In In
In In
In 107 In
In
In
In
3.1 8.7 4.3 59.6 46.1
97
98
101
102
99
100
Cd Cd Cd Cd Cd Cd 103 Cd 104 Cd 105 Cd 106 Cd
2.8 0.2 70.5 62.8 2.9 30.6
105
101
103
102
104
98
99
100
96
97
Ag Ag Ag Ag Ag Ag Ag Ag Ag Ag
3.8 13.6 1.0 21.5
101
103
102
104
99
98
100
95
96
97
Pd Pd Pd Pd Pd Pd Pd Pd Pd Pd
1.1
11.9
58Ni(52Cr,
3p)107In
99.9%< e + b
90%< e + b99.9%
≦
a
<
10%
0.1% ≦
10% ≦
0 e + b9%
≦
10% ≦≦
9 a 0%
0.1% ≦
10e + b%
≦
%
90%< a
99.9
≦
99.9%< a
99.9%< p + a
Experimental Setup
University of Jyväskylä
JUROGAM
43 Ge+BGO
+ RITU
Gas filled Ion Sep.
+GREAT spectrometer
GREAT: Double sided Si strip
Si PIN photodiode array
Double sided planar Ge
Segmented Clover Ge
107In
level scheme
High-spin states
Up to (33/2) at 6.976MeV
S.K. Tandel et al.
PRC58, 3738 (1998)
A rotational band in 107In
(1972)
Sum of 514,823,1053,1386,1573,1786 keV gate
1786
1573
1386
1217
1053
934
933
823
659
514
Total Routhian Surface Calculation
A conf.
E. conf.
Deformed minima with β2～0.2－0.3
J(1), J(2) moment of inertia
Summary
RI-beam experiment
 Low-energy 46Ar beam was developed at RIPS
 In-beam γ-ray spectroscopy of 49-51Ti by 9Be+46Ar reaction
 Excitation function and γ-γ coincidence analysis
 New transitions in 49Ti and 51Ti
Stable isotope beam experiment
 In-beam γ-ray spectroscopy of 107In by using JUROGAM+RITU
 A rotational band in 107In
 TRS Calculation → （-,-1/2) ＝ πh11/2 contribution
 TRS Calc. could not reproduce band crossing at ℏω～0.45MeV
Collaborators (Study of
49-52Ti)
M.NiikuraA, M.LiuA, Y.ZhengA, C.IshidaB, T.FukuchiC, N.AoiD, H.BabaD,
N.HokoiwaE, Y.IchikawaF, H.IwasakiF, T.KoikeG, T.KomatsubaraH, T.KuboD,
M.KurokawaD, S.MichimasaD, K.MiyakawaH, K.MorimotoD, T.K.OnishiF,
T.OhnishiD, S.OtaA, A.OzawaH, S.ShimouraA, T.SudaD, D.SuzukiF,
H.SuzukiF, M.TamakiA, I.TanihataI, Y.WakabayashiA, K.YoshidaD,
B.CederwallB
A. CNS, the University of Tokyo
B. Department of Physics, Royal Institute of Technology
C. Department of Physics, Osaka University
D. The Institute of Physical and Chemical Research (RIKEN)
E. Department of Physics, Kyushu University
F. Department of Physics, the University of Tokyo
G. Department of Physics, Tohoku University
H. Institute of Physics, University of Tsukuba
I. Physics division, Argonne National Laboratory
Collaborators (Study of
107In)
B.CederwallA，E.GaniogluA，F，B.HadiniaA，K.LagergrenA，
T.BäckA，S.EeckhaudtB，T.GrahnB，P.GreenleesB，A.JohnsonA，
D.T.JossC，R.JulinB，S.JuutinenB，H.KettunenB，M.LeinoB，A.P.LeppanenB，P.NieminenB，M.NymanB，J.PakarinenB，
E.S.PaulD，P.RahkilaB，C.ScholeyB，J.UusitaloB，R.WadsworthE，
D.R.WisemanD，R.WyssA
A. Department of Physics, Royal Institute of Technology, Sweden
B. Department of Physics, University of Jyväskylä, Finland
C. CCLRC Daresbury Laboratory, UK
D. Oliver Lodge Laboratory, University of Liverpool, UK
E. Department of Physics, University of York, UK
F. Department of Physics, Faculty of Science, Istanbul University,