Study of high-spin states by using stable and unstable nuclear beamsEiji Ideguchi

CNS, the University of Tokyo

What can we learn in high-spin studies? Variety of nuclear structure as a function of angular m

omentum Single particle structure Collective motion

Rotation Vibration

Deformation 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 Collective Single particle band termination Spherical deformed

Studied High-Spin Nuclei

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

Fusion evaporation,　　 Coulex, fission, βdecay　　 direct reactions were used

High-Spin Studies

Study of high-spin states near 48Ca region 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 statesStable isotope beam + Stable isotope target

High-spin study induced by RI beam

Fusion reaction:RI beam + Stable isotope target

→ 　 High-spin states in Stable | Neutron-rich nuclei

→ 　 High-spin states in proton-rich nuclei

Study of 49-52Ti (Z=22,N=27-30)

Deformation parameter 2

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

Low-energy 2ndary beams using RIPS

RF - F2 Plastic TOF (ns)

ΔE

of

SS

D a

t F2

(MeV

)

46Ar 46Ar

9Be + 48Ca → 46Ar

2ndary targetGe array

F0 ： 9Be target 1.0mm

F2:Plastic 0.1mmAl rotatable degrader

F1 ： Wedge degrader221mg/cm2

30MeV/A～ 5MeV/A

PPAC× ２

46Ar beam intensityF2 : 7.3×105 cpsF3 : 3.2×105 cpsPurity : 90 %

X : 17 mm ()Y : 8 mm ()

2-6 A MeV

90%

46Ar50MeV/A

48Ca64MeV/A～ 40pnA

Setup around 2ndary targetSecondary 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 2000 3000 4000-ray energy [keV]

Excitation function measurements

15481051 1432

1537

52Ti51Ti

50Ti

49Ti

52Ti51Ti

}}

}

50Ti 49Ti

Gamma-ray assignment

Excitation function

1051 keV1432 keV

1537 keV

1548 keV

52Ti

51Ti50Ti 49Ti

total

105114321537 1548

52Ti51Ti50Ti49Ti

New transition in 49Ti

49Ti

50Ti

785965

10931537

2370

1537 or 965 or 785 or 1093 keV gated

1548 or 1117 or 523 or 232 or 803 keV gated

→ 2370 keV transition above (19/2) － state

γ-γ coincidence analysis

New transition in 51Ti

761

761keV transitionabove (13/2,17/2) state

γ-γ coincidence 　 analysis

Comparison with Shell Model Calculations

ANTOINEE. Caurier, shell model code ANOTINE,IRES, Strasbourg 1989-2004E. Caurier, F. NowackiActa 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)

B. Hadinia et al.PRC70, 064314(2004)

58Ni(52Cr, 3p)107In

51

52

53

49

48

47

46

50

54

100Sn

108Xe 109Xe110Xe 111Xe

112Xe

107I 108I109I 110I 111I

103Te 104Te 105Te106Te 107Te

108Te 109Te 110Te

102Sb 103Sb 104Sb 105Sb 106Sb107Sb 108Sb

109Sb

100In101 In 102In 103In 104In

105In 106In 107In98In 99In

100Cd101Cd 102Cd 103Cd 104Cd

105Cd 106Cd97Cd 98Cd 99Cd

100Ag101Ag 102Ag 103Ag 104Ag

105Ag96Ag 97Ag98Ag 99Ag

100Pd101Pd 102Pd 103Pd 104Pd95Pd 96Pd 97Pd

98Pd 99Pd

101Sn 102Sn 103Sn 104Sn 105Sn106Sn 107Sn 108Sn0.7 0.2

0.1 20.9 33.5 1.1

3.1 8.7 4.3 59.6 46.1

2.8 0.2 70.5 62.8 2.9 30.6

3.8 13.6 1.0 21.5

1.1 11.9

99.9%<

90%< ≦

10% 0 ≦ ≦

0.1% 10 ≦ ≦

99.9%<

99.9%< p

0.1% ≦

10% 9 ≦≦

90%< 99.9 ≦

Experimental Setup

JUROGAM　 43 Ge+BGO+ RITU　 Gas filled Ion Sep.+GREAT spectrometer

University of Jyväskylä

GREAT: Double sided Si stripSi PIN photodiode arrayDouble sided planar GeSegmented Clover Ge

107In level scheme

S.K. Tandel et al.PRC58, 3738 (1998)

High-spin states Up to (33/2) at 6.976MeV

A rotational band in 107In

514659823

934

933

1053

1217

1386

1573

1786

(1972)

Sum of 514,823,1053,1386,1573,1786 keV gate

Total Routhian Surface Calculation

Deformed minima with β2 ～ 0.2 －0.3

A conf. E. conf.

J(1), J(2) moment of inertia

SummaryRI-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 ℏ ω ～ 0.45Me

V

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 TokyoB. Department of Physics, Royal Institute of TechnologyC. Department of Physics, Osaka UniversityD. The Institute of Physical and Chemical Research (RIKEN)E. Department of Physics, Kyushu UniversityF. Department of Physics, the University of TokyoG. Department of Physics, Tohoku UniversityH. Institute of Physics, University of TsukubaI. 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, SwedenB. Department of Physics, University of Jyväskylä, FinlandC. CCLRC Daresbury Laboratory, UKD. Oliver Lodge Laboratory, University of Liverpool, UKE. Department of Physics, University of York, UKF. Department of Physics, Faculty of Science, Istanbul University,