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

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 Rotation Vibration

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

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  1. Study of high-spin states by using stable and unstable nuclear beams Eiji Ideguchi CNS, the University of Tokyo

  2. What can we learn in high-spin studies? • Variety of nuclear structure as a function of angular momentum • Single particle structure • Collective motion • Rotation • Vibration • Deformation • β、γdegree 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 9Be + 48Ca → 46Ar 46Ar 46Ar ΔE of SSD at F2 (MeV) RF - F2 Plastic TOF (ns) 46Ar beam intensity F2 : 7.3×105 cps F3 : 3.2×105 cps Purity : 90 % Low-energy 2ndary beams using RIPS 90% F1：Wedge degrader 221mg/cm2 ～ 5MeV/A 30MeV/A 2ndary target Ge array F2:Plastic 0.1mm Al rotatable degrader 46Ar 50MeV/A PPAC×２ X : 17 mm (s) Y : 8 mm (s) 2-6 A MeV F0：9Be target 1.0mm 48Ca 64MeV/A ～40pnA

  8. 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－F3PPACTOF 　　→　Beam Energy GRAPE(CNS Ge Array, position sensitive) GRAPE

  9. Gamma-ray spectra in 9Be(46Ar, xn)55-xTi reaction 1000 3000 0 4000 2000 g-ray energy [keV]

  10. 51Ti 52Ti 50Ti 1432 1051 1548 49Ti 1537 } } } 52Ti 51Ti 50Ti 49Ti Gamma-ray assignment Excitation function measurements

  11. total 50Ti 49Ti 51Ti 52Ti 1537 keV 1548 1537 1432 1051 1548 keV 1432 keV 49Ti 50Ti 51Ti 52Ti 1051 keV Excitation function

  12. 785 1537 or 965 or 785 or 1093 keV gated 965 1537 49Ti 1093 2370 1548 or 1117 or 523 or 232 or 803 keV gated 50Ti New transition in 49Ti γ-γ coincidence analysis → 2370 keV transition above (19/2)－state

  13. 761 New transition in 51Ti γ-γ coincidenceanalysis 761keV transition above (13/2,17/2) state

  14. 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

  15. High-spin studies of 107In

  16. Reaction : 52Cr(187MeV) + 58Ni(580+640μg/cm2) 112 110 111 Xe Xe Xe 109 108 Xe Xe 54 e + b 99.9%< 109 111 110 I 107 108 I I I I 53 e + b99.9% 90%< ≦ a < 10% 0.1% ≦ 108 107 106 Te 103 109 110 Te 104 Te Te Te Te 105 Te Te 52 e + b9% 10% 0 ≦ ≦ 102 109 103 Sb Sb 104 Sb 105 107 Sb 106 Sb Sb 108 Sb Sb a 0% 10% 9 51 ≦≦ 0.7 0.2 e + b% 0.1% 10 ≦ ≦ 101 102 106 103 104 100 Sn Sn 105 Sn 107 108 Sn Sn Sn Sn Sn Sn 50 a % 90%< 99.9 ≦ 0.1 33.5 1.1 20.9 105 101 103 In 102 104 106 99 100 98 107 In In In In In In In In In 49 a 99.9%< 3.1 8.7 4.3 59.6 46.1 97 98 105 Cd Cd 101 103 102 104 Cd 106 99 100 Cd Cd Cd Cd Cd Cd Cd 48 2.8 2.9 62.8 30.6 0.2 70.5 + a 99.9%< p 105 101 103 102 104 Ag 98 99 100 Ag Ag Ag Ag 96 97 Ag Ag Ag Ag Ag 47 21.5 13.6 1.0 3.8 101 103 102 104 99 98 100 95 Pd Pd 96 Pd Pd Pd 97 Pd Pd Pd Pd Pd 46 B. Hadinia et al. PRC70, 064314(2004) 1.1 11.9 58Ni(52Cr, 3p)107In Study of 107In (Z=49, N=58)

  17. 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

  18. 107In level scheme High-spin states Up to (33/2) at 6.976MeV S.K. Tandel et al. PRC58, 3738 (1998)

  19. 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

  20. Total Routhian Surface Calculation A conf. E. conf. Deformed minima with β2～0.2－0.3

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

  22. 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

  23. 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

  24. 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,

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