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Thomas Nilsson, CERN EP/IS

Thomas Nilsson, CERN EP/IS. Radioactive beams Rationale Production - separation CERN-ISOLDE Research on nuclei at the driplines Interdisciplinary uses of RIB REX-ISOLDE Outlook ISOLDE-RNB EURISOL. Exotic Nuclei and Radioactive Beams at Low Energy

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Thomas Nilsson, CERN EP/IS

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  1. Thomas Nilsson, CERN EP/IS • Radioactive beams • Rationale • Production - separation • CERN-ISOLDE • Research on nuclei at the driplines • Interdisciplinary uses of RIB • REX-ISOLDE • Outlook • ISOLDE-RNB • EURISOL Exotic Nuclei and Radioactive Beams at Low Energy EPS-12 Trends in Physics, Budapest August 29 2002

  2. Why study the atomic nucleus? • A few-body system of hadrons (neutrons and protons) with many remaining question marks • “Largest” system where strong and weak interaction are manifested • “Applications” • Astrophysics • Condensed matter • Energy • Medicine

  3. ? Nuclear chart N = Z

  4. Applied Physics Implanted Radioactive Probes, Tailored Isotopes for Diagnosis and Therapy Condensed matter physics and Life sciences Nuclear Physics Nuclear Decay Spectroscopy and Reactions Structure of Nuclei Exotic Decay Modes Fundamental Physics Direct Mass Measurements, Dedicated Decay Studies - WI CKM unitarity tests, search for b-n correlations, right-handed currents Atomic Physics Laser Spectroscopy and Direct Mass Measurements Radii, Moments, Nuclear Binding Energies Nuclear Astrophysics Dedicated Nuclear Decay/Reaction Studies Element Synthesis, Solar Processes Research with Radioactive Ion Beams f(N,Z)

  5. + spallation F r 2 0 1 1 GeV p fragmentation + + U 2 3 8 L i X 1 1 fission n + + p C s 1 4 3 Y RIB - Production reactions • Spallation • Fragmentation • Fission • n- (thermal or energetic), p-induced • Photofission (e-beam)

  6. Radioactive beams – production and separation

  7. In-flight production (e.g. FRS@GSI) 1 GeV/u U

  8. ISOL (e.g. ISOLDE@CERN)

  9. ISOL target

  10. Resonant LASER Ion Source

  11. Nuclear chart@ISOLDE

  12. RIB facilities worldwide

  13. Experimental Studies of Dripline Nuclei Elastic Scattering Spins Moments Reaction Cross Sections Masses Beta Decay Momentum Distributions Unbound Nuclei

  14. 7 106 s-1 3 101 s-1 1 104 s-1 8 104 s-1 3 107 s-1 Halo nuclei at ISOLDE

  15. Measurement of the Magnetic Moment of 11Be

  16. 11Be • The large radius of 11Be: halo structure or deformation? • I(11Be) = -1.682(3) N • Comparison to theoretical approaches • -1.5 N< I(11Be) < -1.6 N • for: strongsmall degrees of deformation • Result indicates a rather pure halo structure with hardly any additional deformation W. Geithner et al., PRL 83 (1999) 3793

  17. mass measurements of 11Li 450 400 Young93 Thibault75 (reaction) 350 (mass spec.) AME95 300 11Li two-neutron separation energy (keV) 250 Kobayashi91 (reaction) 200 Wouters88 150 (TOFI) 100 303±27keV r = /(2mS2n)1/2 D. Lunney

  18. RF magnet (22 T) 1 m ion counting slit 0.4 mm RF reference ion source B Mass measurement of 11Li at ISOLDE with MISTRAL AME: S2n = 303 ± 27 keV Mistral should achieve < 20 keV D. Lunney

  19. e- _ n Qbd = 3.004 –S2n MeV ½- 0.320 ½+ g 11Be T. Nilsson, G. Nyman, K. Riisager HFI 129(2000)67 Open delayed-particle channels in the 11Li beta decay 20.6 3/2- 11Li 17.916 9Li+d 15.721 8Li+t 10.59 8.82 8.982 8Be+3n 7.315 9Be+2n 0.504 0.320 (MeV) 10Be+n 11Be

  20. 11Li, charged particles 11Li 11Be* x+y 10Be (1n recoils) b E, Si DE, gas Tritons+deuterons

  21. 11Li 20.6 3/2- 18.15 11Li 17.9 Beta-strength function 9Li + d 15.7 8Li + t b- 2 11Li 8.90 BGT/MeV a+a+3n 1 7.32 7.91 a+6He+n 9Be + 2n 0 5 10 15 20 0.503 E(MeV) ½- 10Be + n ½+ 11Be M.J.G. Borge et al, PRC 55 (1997) R8 I.Mukha et al., PL B367 (1996) 65 M.J.G. Borge et al.. Nucl. Phys. A613 (1997) 199

  22. 14Be

  23. ISOLDE Physics programme 2001

  24. Systematics of the superallowed transitions I. S. Towner and J.C. Hardy,Proc. 5th Int. Symp. on Weak and Electromagnetic Interactions in Nuclei: WEIN'98, 14.-21.6.1998, Santa Fe, (1998) and this work (2001). Superallowed Fermi transitions Test of CVC (Conserved Vector Current) hypothesis

  25. CKM (Cabibbo-Kobayashi-Maskawa) matrix unitarity  unitarity is violated by 2.2s New physics or bad corrections? Test at extreme -> 74Rb … and later 62Ga

  26. MIS RAL 20 15 10 number of ions 5 0 270460 270465 270470 270475 270480 frequency (kHz) IS384 Complete spectroscopy on Fermi b-emitter 74Rb Results: 1) non-analog 0+ 0+ transition observed  estimate for the Coulomb mixing 2) mass of 74Rb (ISOLTRAP & MISTRAL) 3) mass of the daughter74Kr (ISOLTRAP) 2) & 3) QEC value 0+ <0.07% ISOLTRAP T1/2 = 64.9 ms!

  27. Condensed matter physics Radioactive ions as “spies” (PAC) in high-Tc superconductors… … or as dopants in semiconductors that change with time. M. Deicher, Europhysics News (2002) Vol. 33 No. 3

  28. Biomedical Research at ISOLDE • Example: samarium isotopes in vivo dosimetry by positron emission tomography (PET)   142-Sm (e, T1/2 = 72m)  142-Pm (b, T1/2 = 40s)   therapy  153-Sm (b, T1/2 = 47h)    Future tool? PET scan of a rabbit 60 min p.i. of ISOLDE produced 142-Sm in EDTMP solution

  29. IS393 - Nuclear properties in r-process vicinity

  30. Post-acceleration

  31. REX-ISOLDE

  32. Eex(10Li) = 1000 800 600 400 200 0 keV d(9Li,10Li*)p using REX-ISOLDE

  33. A second-generation RIB facility at CERN? – ISOLDE-RNB • Second generation RNB facility using the SPL as driver • <100 mA on « traditional » ISOL targets, >100 mA on converter • Post-acceleration to 100 MeV/u (cyclotron/LINAC) • Storage/re-cycler ring

  34. Ideas for exotic probes for RIB (RAMA@ECT*) • p-bar – antiprotonic atoms • Intersecting storage ring with 109 p-bar stored • Electron cooling on both rings • Multi turn injection • Merging reactions • m- – muonic atoms • Cyclotron trap (PSI) • Hydrogen layer (RIKEN-RAL) • Storage ring

  35. Conclusions • RIB are crucial in widening our understanding of the nuclear system when stretching the parameters • Low-energy RIBs with good beam quality is the optimal starting point for decay studies, laser physics, traps etc. • RIB overcome partly the fact that we now only have the stable and long-lived “ashes” of astrophysical processes • RIB and techniques used in the production and separation have important connections to other research fields • Large physics output obtained with “first-generation” RIB facilities – time to make a major step forward

  36. Acknowledgements • Collaborations: • IS304 (Mainz, Leuven, Montreal, CERN) • IS320 (Aarhus, CERN, Darmstadt, Gothenburg, Madrid, Orsay) • IS367 (Gothenburg , Aarhus, Madrid, CERN, Darmstadt, Örebro) • IS374 (Caen, Gothenburg , Aarhus, Madrid, Troitsk, Orsay, Mainz, CERN, Darmstadt) • IS376 (Gothenburg , Aarhus, Madrid, Stockholm, CERN, Darmstadt) • IS402 (Orsay, GSI, MSU, Munich, CERN, Sao Paulo)

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