質量数30-40,100領域の高スピン変形状態の研究

質量数30-40,100領域の高スピン

変形状態の研究

井手口 栄治

東大CNS

Outline

重イオンビームを用いて行ってきた高スピン状態の これまでの研究と今後の計画

• 質量数100領域の高スピン状態

– 107Inの高スピン状態の研究

• 質量数30－40領域の高スピン状態

– 40_{Caの高スピン状態}

• 今後の研究計画

– A～110領域の高スピン状態 – A～30-40領域の高スピン状態

Collaborators

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

質量数～100、Z～50領域の原子核

• 基底状態近傍は単一粒子励起 • 高スピン準位

– M1バンド πg_9/2-1⊗νg

7/2

– Multi particle-hole excitation – Intruder バンド

• πh_11/2の寄与（変形、高スピン）

• Smooth band termination

Æ 108_Sn, 109_{Sb, …}

In同位体での高スピン状態はあまり良く知られていない。 Z<50核(107_In)でπh

11/2 intruder orbitalの寄与は？

Experimental Setup

JUROGAM

43 Ge+BGO + RITU

Gas filled Ion Sep. +GREAT spectrometer

University of Jyväskylä

GREAT: Double sided Si strip Si PIN photodiode array Double sided planar Ge Segmented Clover Ge

Study of

107

In (Z=49, N=58)

Reaction : 52Cr(187MeV) + 58Ni(580+640μg/cm2)

B. Hadinia et al. PRC70, 064314(2004) 58_Ni(52_{Cr, 3p)}107_In 51 52 53 49 48 47 46 50 54 100 Sn 108 Xe109Xe110Xe 111Xe112Xe 107 I 108I 109I 110 I 111I 103 Te 104Te105 Te106Te107Te108Te 109 Te 110Te 102 Sb103Sb104 Sb105Sb106Sb107Sb108 Sb109Sb 100 In 101In 102In 103In 104In 105In 106 In 107In 98 In 99In 100 Cd101Cd102Cd103Cd104Cd105Cd106 Cd 97 Cd 98Cd 99 Cd 100 Ag101Ag102Ag103Ag104Ag105Ag 96 Ag 97Ag 98Ag 99Ag 100 Pd101Pd102Pd103Pd104Pd 95 Pd 96Pd 97 Pd 98Pd 99Pd 101 Sn102Sn103Sn104Sn105Sn106Sn 107 Sn108Sn 0.7 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%< ε + β 90%< ε + β99.9%≦ 10% 0 ε + β9%≦ ≦ 0.1% 10 ≦ε + β%≦ 99.9%< α 99.9%< p + α 0.1% α < 10%≦ 10% 9 α 0%≦≦ 90%< 99.9 α %≦

107

_{In level scheme}

S.K. Tandel et al.

A rotational band in

107

In

514 659 823 934 933 1053 1217 1386 1573 1786 (1972)

A conf. (+,+1/2) B conf.(+,-1/2) E conf.(-,-1/2)

J

(1)

,J

(2)

moment of inertia

Exp. and TRS calc.

ω I I d I dE J h h ⎥⎦ = ⎤ ⎢ ⎣ ⎡ = −1 2 2 ) 1 ( ) ( ) ( 2 ω d dI dI I E d J h h ⎥⎦ = ⎤ ⎢ ⎣ ⎡ = −1 2 2 2 ) 2 ( 1 ( ) Dynamical Kinematical

Collaborators

E. IdeguchiA_{, D. G. Sarantites}B_{, W. Reviol}B_{, C. J. Chiara}B_,

M. DevlinB, F. LermaB, R.V. F. JanssensC, M. P. CarpenterC, T. LauritsenC_{, C. J. Lister}C_{,P. Reiter}C_{,D. Seweryniak}C_,

C. BaktashD, A. Galindo-UribarriD, D. RudolphE, A. AxelssonF, M. WeiszflogF_{, D. R. LaFosse}G _{, J. N. Wilson}B _{, H. Madokoro}H

A. CNS, the University of Tokyo

B. Chemistry Department, Washington University C. Physics Division, Argonne National Laboratory D. Physics Division, Oak Ridge National Laboratory E. Department of Physics, Lund University

F. The Svedberg Laboratory and Department of Radiation Science, Uppsala University,

G. Department of Physics and Astronomy, SUNY-Stony Brook H. The Institute of Physical and Chemical Research (RIKEN)

High-spin

states

in

40

Ca

J.L. Wood et al, Phys. Rep. 215 (1992)101

SD band in

40

Ca

20_{Ne +} 28_{Si → 2α +} 40_Ca

ATLAS accelerator at ANL

Beam: 20_{Ne 84MeV (80MeV after Ta foil)}

Target: 0.45 mg/cm2 28_{Si on 1mg/cm}2 _Ta

Gammasphere (101Ge) + Microball (95 CsI(Tl)) ε(p)=60%, ε(α)=47%

known excited states of

40

Ca

J.L.Wood et al., Phy.Rep.215(1992)101

A:

Cranked Relativistic Mean Field Calculation (preliminary results)

• Negative parity band :

→ odd number of particle in f_7/2 orbital

• Signature α= 0 band (A, B)

[200]1/2 α=－_{1/2 → [321]3/2 α=}－_{1/2 : conf.1} [200]1/2 α= +1/2 → [321]3/2 α= +1/2 : conf.2 • Signature α= 1 band (C) [200]1/2 α=－_{1/2 → [321]3/2 α= +1/2 : conf. 3} [200]1/2 α= +1/2 → [321]3/2 α=－1/2 : conf. 4 • π33υ32, π33υ34

・ Level scheme of 40_{Ca is extended to 17}－ _{at 23.5MeV}

・ Three negative parity bands in 40_Ca

・ Angular distribution → Spin assignments ・ Residual Doppler shift analysis

→ Qt(band A) = 0.90 ± 0.17eb, β₂ = 0.32 ± 0.06

Qt(band C) = 0.53 ± 0.13eb, β₂ = 0.20 ± 0.05

・ Cranked Relativistic Mean Field calculation in progress

今後の研究計画

• A～110領域の高スピン状態

– 高スピンの極限 – 変形の極限

• A～30-40領域の高スピン状態

– 未開拓のSD領域

A～110領域の高スピン状態の研究

Predicted New SD region

Cranked Strutinsky calculations Z=40～54、N=56～68

R.R.Chasman

Limit of deformation

1.89 1.89 1/A1/3 208_Pb 2:1 3:2 x : major-to-minor axis ratio x = 2 → 2:1deformation R = 1.2A1/3 fm

R.M.Clark et al., Phys. Rev. Lett. 87, 202502 (2001) eb x x ZR Q _2/3 2 2 2 0 10 1 5 2 − _{× −} = 89 . 1 5 / 2 2 0 = ZR Q

i

_13/2

intruder orbital

0.3 0.2 0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 5.0 5.5 6.0 2 Es.p. (h ) 50 82 1g9/2 1g7/2 2d5/2 1h11/2 2d3/2 3s1/2 3/2[301] 3/2 [541] 5/2[303] 5/2 [532] 1/2 [301] 1/2[301] 1/2 [550] 1/2 [440] 3/2 [431] 3/2 [431] 5/2 [422] 5/2[422] 7/2[413] 7/2[413] 9/2 [404] 1/2 [431] 1/2 [431] 3/2 [422] 3/2 [422] 5/2[413] 5/2 [413] 7/2[404] 7/2 [404] 7/2 [633] 1/2 [420] 1/2 [420] 3/2 [411] 3/2 [411] 3/2 [651] 5/2[402] 5/2 [642] 1/2_[550] 1/2 [550] 1/2[301] 1/2 [541] 3/2 [541] 3/2 [541] 3/2[301] 5/2 [532] 5/2 [532] 5/2 [303] 7/2 [523] _{7/2 [523]} 9/2[514] 9/2[514] 11/2 [505] 11/2 [505] 1/2 [411] 1/2 [411] 1/2 [660] 3/2 [402] 3/2 [651] 3/2 [411] 1/2[400] 1/2 [660] 1/2 [411] 1/2 [541] 1/2 [301] 3/2 [532] 5/2 [523] 7/2[514] 9/2 [505] 1/2 [66 0] 1/2 [40 0] 1/2 [651] 3/2 [651] 3/2 [40 2] 3/2 [64 2] 5/2 [642] 5/2 [40 2] 7/2 [633] 7/2 [404] 11/2 [615] 13/2 [606] 1/2 [530] 3/2 [521] 7/2 [50 3] 1/2 [770] 3/2 [76 1] 1/2 [640] i_13/2 proton Intruder Occupied in 108_Cd C-T. Lee et al., PRC 65, 041301 (2002)

A～110の高スピン原子核の生成

•

100

Ru:

96

Zr(

13

C, α5n)

•

106

Pd:

96

Zr(

13

C, 3n),

96

Zr(

18

O, α4n)

•

110

Cd:

96

Zr(

22

Ne, α4n)

•

114

Sn:

100

Mo(

22

Ne, α4n)

•

118

Te:

100

Mo(

22

Ne, 4n)

A～40領域の超変形状態の探索

• 40Ca I > 16ħ – Backbending around 20ħ? • 36_{S (Z=16, N=20),} 32_S(Z=N=16) • 40Ar (Z=18, N=22) – 36Ar (Z=18, N=18) • Ri beamを用いた高スピン分光 – 50_{Ti(Z=22,N=28),} 48_{Ca(Z=20,N=28)}