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Transfer reactions at ISOLDE: recent results and future plans

Transfer reactions at ISOLDE: recent results and future plans. Riccardo Raabe (IKS, K.U.Leuven). Seminar Grupo de Estructura de la Materia, Universidad de Huelva 09 Nov 2011. Overview. Introduction The structure of nuclei far from stability Transfer reactions as spectroscopic tool

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Transfer reactions at ISOLDE: recent results and future plans

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  1. Transfer reactions at ISOLDE:recent results and future plans Riccardo Raabe (IKS, K.U.Leuven) SeminarGrupo de Estructura de la Materia,Universidad de Huelva09 Nov 2011

  2. Overview • Introduction • The structure of nucleifar from stability • Transfer reactionsas spectroscopic tool • Available beams • REX-ISOLDE • Experimental setup • Advantages and problems • Some results • 11Be(d,p) • 30Mg(d,p) • 30Mg(t,p) • 66Ni(d,p) • 78Ni(d,p) • The future • HIE-ISOLDE • Instrumentation:magnets, active targets,a ring

  3. The structure of nuclei far from stability Evidence for stableconfigurations: Abundances Binding energy Energy of the first excited state What happensfar from stability?

  4. The NN interaction One-body SO potential: O. Sorlin, M.-G. Porquet, PPNP 61 (2008) 602 Tensor interactiononly if S=1 (parallel spins) T. Otsuka et al., PRL 95 (2005) 232502

  5. Transfer reactions as spectroscopic tool Measuring with RIBs Inverse kinematics Low intensity beams(“thick” targets) Detection ofbeam-like particle  spectrometertarget-like recoil  Si array-rays Ge array Problems Energy (angular) resolution Efficiency Background Q-values  position of levels Angular distribution spin and parities Cross sections (relative) spectroscopicfactors, ANCs

  6. REX: Radioactive beam EXperiment @ ISOLDE

  7. LINAC REXTRAP: Penning trapat 60 keV REXEBIS: charge breeding τ=10-100 ms, A/q <4.5efficiency up to 30% Separator: q/A resolution ≈150 LINAC: L = 10 m0.8 < Ebeam< 3.0 MeV/nucleon

  8. T-REX and Miniball Miniball 24 HPGe 6-fold segmented ε ≈ 7% @ 1.3 MeV T-REX V. Bildstein, K. Wimmer Resolution ≈5 deg ΔE-E for PID ε ≈ 60%

  9. Available ions RILIS Laser Ion Source Currently available Tested Feasible + isomeric beams(also post-accelerated)

  10. Transfer reactions at REX-ISOLDE 72Zn(t,p) 66Ni(t,p) 66Ni(d,p) 78Zn(d,p) 44Ar(t,p) 30Mg(t,p) 30Mg(d,p) 28Na(d,p) 11Be(d,p)

  11. Issues at 3 MeV/nucleon • Models • What are we measuring? • Absolute SF have little (or no) meaning Relative SF; ANCs • Coupling of channels  DWBA? • Angular distributionsnot characterized 66Ni(t,d) Calculation: T. Roger

  12. Issues at 3 MeV/nucleon • Models • What are we measuring? • Absolute SF have little (or no) meaning Relative SF; ANCs • Coupling of channels  DWBA? • Angular distributionsnot characterized • Experimentally • (Very) low-energy protons poor resolution use thick target and coincident -ray detection • Protons from fusion-evaporation (on C, Ti)No channel identification  energy has to be limited

  13. Coincident -ray detection …with Miniball Excellent resolution(necessary as density of states becomes important) but No gs-to-gs transfer Thick target  poor resolution for E proton Isomers!  slow coincidence setup

  14. Transfer reactions at REX-ISOLDE Katharina Nowak JytteElseviers 72Zn(t,p) 66Ni(t,p) Jan Diriken 66Ni(d,p) 78Zn(d,p) RiccardoOrlandi 44Ar(t,p) Kathrin Wimmer 30Mg(t,p) 30Mg(d,p) VinzenzBildstein 28Na(d,p) 11Be(d,p) Thorsten Kroell Jacob Johansen

  15. 11Be+d J. Johansen, K. Riisager Motivation: halo nucleus, N = 8, clusters… Goals: separation of states in 12Be,check spectroscopic factors of 0+ 1d3/2 2s1/2 8 1p1/2 1p3/2 1s1/2 ν

  16. 11Be+d J. Johansen, K. Riisager Motivation: halo nucleus, N = 8, clusters… Goals: separation of states in 12Be,check spectroscopic factors of 0+ 1d3/2 2s1/2 8 1p1/2 gammas 1p3/2 1s1/2 ν

  17. 11Be+d J. Johansen, K. Riisager 11Be(d,d’) 320 keV

  18. 11Be+d J. Johansen, K. Riisager 11Be(d,t) 2+ to 2+ 2+ 2− to 2+ 0+ 2+ to 0+

  19. 11Be+d J. Johansen, K. Riisager 11Be(d,p) 1‒ 0+2 2.24 MeVT1/2 = 300 ns S(0+1) = 0.29 2.1 MeV - ≈ 7000 cts 2.7 MeV - ≈ 3000 cts

  20. Mapping the island of inversion Y. Utsuno et al.,PRC 60 (1999) 054315 14 As protons are removed from the πd5/2 orbital, the νd3/2 becomes more unbound  N = 20 gap reduction,new gap at N = 16intruder states appearingcollectivity, deformation 16 20 12 20 p3/2 f7/2 20 s1/2 d3/2 14 s1/2 ν d5/2 π

  21. 30Mg(d,p) V. Bildstein Island of inversion at Z = 12 Single particle structureof excited states in 31Mg 31Mg Elastic G. Neyens et al., PRL 94, 022501 (2005) F. Maréchal et al., PRC 72, 044314 (2005)

  22. 30Mg(d,p) V. Bildstein 170 keV Δℓ = 1  negative parity Cross section to gs and firstexcited state from total proton yield Comparison cross section to theory(Nilsson model)  info on deformation

  23. 30Mg(t,p) K. Wimmer et al., PRL 105 (2010) 252501 Y. Utsuno et al.,PRC 60 (1999) 054315 Looking for the spherical 0+ in 32Mg 30Mg(t,p)32Mgwave functions have large overlap 16 20 12 20

  24. 30Mg(t,p) K. Wimmer et al., PRL 105 (2010) 252501 Looking for the spherical 0+ in 32Mg 30Mg(t,p)32Mgwave functions have large overlap Tritium-implanted Ti foil3H 40 μg/cm2Activity 10 GBq 30Mg at 1.8 MeV/nucleon4.6x104pps

  25. 30Mg(t,p) K. Wimmer et al., PRL 105 (2010) 252501 Looking for the spherical 0+ in 32Mg Ground and excited state populated

  26. 30Mg(t,p) K. Wimmer et al., PRL 105 (2010) 252501 Looking for the spherical 0+ in 32Mg Ground and excited state populated both ΔL = 0

  27. 30Mg(t,p) K. Wimmer et al., PRL 105 (2010) 252501 Looking for the spherical 0+ in 32Mg -rays in coincidence:0+2 at 1058 keV 0+2 lower in energy and more long-living than expected Larger cross section than predicted Some (2p3/2)2 necessary

  28. 66Ni(d,p)J. Diriken The strange magicity of 68Ni Increased E* of the first 2+ state Local minimum of the B(E2) however No irregularities in the S2n  Check single-particle statesin neighbouring nuclei 1g7/2 2d5/2 50 1g9/2 2p1/2 40 1f5/2 2p3/2 28 ν

  29. 66Ni(d,p)J. Diriken Proton-gamma coincidences

  30. 66Ni(d,p)J. Diriken Proton-gamma coincidences Candidate for the νd5/2 state(across N=50)

  31. 78Zn(d,p) R. Orlandi Quenching of N = 50 What is the valueof the N=50 gap in 78Ni? 80Zn Van de Walle et al.Phys. Rev. Lett. 99 (2007) 142501 O. Sorlin, M.-G. PorquetProg. Part. Nucl. Phys. 61 (2008) 602

  32. 78Zn(d,p) R. Orlandi Coincident  rays (preliminary) 79Zn Calculations:K. Sieja (Strasbourg)

  33. The future: HIE-ISOLDE project manager: Y.Kadi (CERN) High Intensity:LINAC4 + new target stationsBeam quality improvement High Energy:up to 10 MeV/nucleonsuperconducting linac mid 2014 end 2015 end 2016

  34. HIE-ISOLDE Letters of Intent 13 LOIs on transfer @ 10 MeV/u Pb region accessible

  35. HIE-ISOLDE: Beam lines and Instrumentation slides: E. Siesling

  36. HIE-ISOLDE: Beam lines and Instrumentation slides: E. Siesling Spectrometer Miniball TSR Miniball Exp. station Actar-TPC / Helios HELIOS ACTAR-TPC

  37. HIE-ISOLDE: “Test” Storage Ring TSR at the Max-Planck Institute Heidelberg Physics cases: atomic physics,reactions for nuclear structure and astrophysics, decays… TSR@Hie-ISOLDE LoI Jan 2011 TDR in progressK. Blaum, Y. Litvinovand ≈100 collaborators Unique: storage ring at an ISOL facility

  38. Summary and perspectives • 3 MeV/nucleon: challenges on theory and experiment • -ray detection: very powerful to determine energies • Unique beams,combination of various reaction and decay techniques • The future • Increase in energy and intensity: HIE-ISOLDE • Instrumentation: • Upgrade T-REX, ACTAR-TPC, Helios • Spectrometer • Storage ring

  39. Time structure

  40. T-REX

  41. Issues at 3 MeV/nucleon calculations by N. Patronis 28 DWBA calculations 64Ni(d,p)65Nig 1.00 fm < r < 1.40 fm 0.50 fm < a < 0.75 fm 14 DWBA calculations 64Ni(d,p)65Ni 1.00 fm < r < 1.40 fm 0.50 fm < a < 0.75 fm Data:T.R. Anfinsen et alNPA 157 (1970) 561

  42. 221 keV: 3/2-[321], oblate Mixed, mainly 2p3/2 DL=1 P [312 3/2] 2p3/2 g.s.: 1/2+[200], prolate Mixed, mainly 2s1/2 DL=0 P 30Mg(d,p) V. Bildstein 221 keV: 3/2-[321], prolate 1f7/2 orbital DL=3 ~ 50 keV: 3/2+[202], prolate 1d3/2 orbital DL=2 P I. Hamamoto, PRC 76, 054319 (2007)

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