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Nuclear Physics in Storage Rings

Nuclear Physics in Storage Rings. Yuri A. Litvinov. 1. Broad band mass measurements 2. Beta decay of highly-charged ions 3. Nuclear magnetic moments 4. Nuclear reactions on thin targets 5. Capture reactions at low energies [(p, g ),( a , g )…]

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Nuclear Physics in Storage Rings

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  1. Nuclear Physics in Storage Rings Yuri A. Litvinov 1. Broad band mass measurements 2. Beta decay of highly-charged ions 3. Nuclear magnetic moments 4. Nuclear reactions on thin targets 5. Capture reactions at low energies [(p,g),(a,g)…] 6. Reactions in inverse kinematics [15O(a,g)19Ne] 7. Experiments with isomeric beams 8. Experiments with polarized beams Institute of Theoretical Physics (ITP), CAS, Beijing 10.06.2010 Max-Planck-Institut für Kernphysik, Heidelberg

  2. Beta-decay on the Chart of Nuclides r-process p-process rp-process νp-process Astrophysical scenarios: high temperature = high degree of ionization fussion

  3. Half-life modifications Fundamental question: “Can we change the nuclear decay rate or it is a basic property ?!“ Pressure, Temperature, Electromagnetic fields, Chemistry ... G.T. Emery, Annu. Rev. Nucl. Sci. 22 (1972) 165: Effects of less than 1% Modification of the electron density at the nucleus

  4. Highly-Charged Ions W.R. Phillips, et al., Phys. Rev. Lett. 62 (1989) 1025 W.R. Phillips, et al., Phys. Rev. A47 (1993) 3682 Internal conversion in few-electron 57Fe ions F. Attallah, et al., Phys. Rev. C55 (1997) 1665 Internal conversion in few-electron 125Te ions Half-life prolongations ranging from a few 10% up to 670% F.F. Karpeshin, et al., Phys. Rev. C53 (1996) 1640 M.R. Harston, et al., Nucl. Phys. A676 (2000) 143 New decay mode: Bound Internal Conversion (BIC)

  5. Two-body beta decay of stored and cooled highly-charged ions

  6. Production, storage and cooling of HCI at GSI Storage Ring ESR Linear Accelerator UNILAC Fragment Separator FRS Production target Heavy-Ion Synchrotron SIS

  7. ESR : Emax = 420 MeV/u, 10 Tm; e-, stochastic cooling ESR: B. Franzke, NIM B 24/25 (1987) 18 Stochastic cooling: F. Nolden et al., NIM B 532 (2004) 329 Electron cooling: M. Steck et al., NIM B 532 (2004) 357

  8. Electron Cooling momentum exchange with 'cold', collinear e- beam. The ions get the sharp velocity of the electrons, small size and divergence

  9. time SMS 4 particles with different m/q

  10. Sin(w1) Sin(w2) w4 w3 w2 w1 Sin(w3) time Sin(w4) SMS Fast Fourier Transform

  11. SMS: Broad Band Frequency Spectra

  12. Nuclear Decays of Stored Single Atoms Time-resolved SMS is a perfect tool to study dynamical processes in the ESR Nuclear electron capture, β+,β- and bound-β decays were observed

  13. Fully-Ionized Atoms John N. Bahcall, “Theory of Bound-State Beta Decay”, Phys. Rev. 124 (1961) 495 John N. Bahcall, “Beta Decay in Stellar Interiors”, Phys. Rev. 126 (1962) 1143 Koji Takahashi, Koichi Yokoi, “Nuclear Beta-Decays of Highly-Ionized Heavy Atoms in Stellar Interiors”, Nucl. Phys. A 404 (1983) 578 Koji Takahashi, Koichi Yokoi, “Beta-Decay Rates of Highly-Ionized Heavy Atoms in Stellar Interiors”, Atomic Data Nucl. Data Tables 36 (1987) 375

  14. laboratory frame T1/2 (fully ionized) T1/2 (neutral) Half-Lives of Nuclear Isomers Neutral atom is 0.49(2) s Fully ionized atom is 11(1) s = 22(2) Yu.A. Litvinov, et al., PLB 573 (2003) 80-85

  15. Observation of 133mSb isomeric state 17 s isomeric state in neutral 133Sb RIMS=200 000 Expected half-live of bare isomer: ~ 17 ms, t~991 A new half-live domain for storage-ring experiments B. Sun et al., PLB 688 (2010) 294

  16. Bound-State b-decay

  17. E 187Re75+ T½ = 33 y βb Q = 62 keV 9.8 keV g.s. β- 9.8 keV g.s. T½ = 42 Gy; Q = 2.7 keV Bound-State b-decay of 187Re The 7 Nuclear Clocks for the Age of the Earth, the Solar System, the Galaxy, and the Universe 187Re0 5/2+ 3/2- 1/2- Clayton (1964): a mother-daughter couple (187Re/187Os) is the “best” radioactive clock F. Bosch et al., Phys. Rev. Lett. 77 (1996) 5190

  18. p process 162 164 166 165 163 163 163 Er 164 160 161 162 Ho s process Dy r process Bound-State b-decay of 163Dy s process: slow neutron capture and β- decay near valley of β stability at kT = 30 keV; → high atomic charge state → bound-state β decay T1/2 = 48 days branchings caused by bound-state β decay M. Jung et al., Phys. Rev. Lett. 69 (1992) 2164

  19. Bound-State b-decay in 206,207Tl λ = λb+λc+λR λb bound/continuum branching ratio T. Ohtsubo et al., Phys. Rev. Lett. 95 (2005) 052501

  20. Next Step: Bound-State b-decay of 205Tl F. Bosch et al., GSI Proposal

  21. Hydrogen-Like Ions I. Iben et al., “The Effect of Be7 K-Capture on the Solar Neutrino Flux”, Ap. J. 150 (1967) 1001 L.M. Folan, V.I. Tsifrinovich, “Effects of the Hyperfine Interaction on Orbital Electron Capture”, Phys. Rev. Lett. 74 (1995) 499

  22. Decay schemes H-like ions; g.s. → g.s.; no third particle

  23. EC in Hydrogen-like Ions Expectations: lEC(H-like)/lEC(He-like) ≈ 0.5 142Pm 140Pr lEC(H-like)/lEC(He-like) = 1.49(8) lEC(H-like)/lEC(He-like) = 1.44(6) Yu.A. Litvinov et al., Phys. Rev. Lett. 99 (2007) 262501 N. Winckler et al., Phys. Lett. B579 (2009) 36

  24. Electron Capture in Helium-like Ions Gamow-Teller transition 1+ → 0+ s = 1/2 I = 0 I = 1 EC S = 0 s = 1/2 F = 1 F = 1

  25. Electron Capture in Hydrogen-like Ions Gamow-Teller transition 1+ → 0+ I = 0 I = 1 EC s = 1/2 s = 1/2 3/2 F = 1/2 F = I + s 1/2 Z. Patyk et al., Phys. Rev. C 77 (2008) 014306

  26. Electron Capture in Hydrogen-like Ions Gamow-Teller transition 1+ → 0+ S. Typel and L. Grigorenko µ = +2.7812µN Theory: The H-Like ion should really decay 20% faster than neutral atom! Z. Patyk Probability of EC Decay Neutral 140Pr: P = 2.381 (2I+1)/(2F+1) He-like 140Pr: P = 2 H-like 140Pr: P = 3 Z. Patyk et al., Phys. Rev. C 77 (2008) 014306

  27. Next Step B.M. Dodsworth et al., Phys. Rev. 142 (1966) 638. µ (64Cu) = −0.217(2) mN

  28. Some speculations on the EC-decay of 7Be A.V. Gruzinov, J.N. Bahcall, Astroph. J. 490 (1997) 437 Ionization of 7Be in the Sun can be ~ 20-30 % Transition (F=1F=1) is accelerated by (2I+1)/(2F1+1) i.e. by 8/3 However, there are only of 7Be in this state (2F1+1)/((2F1+1)+(2F2+1)) = 3/8

  29. Electron Capture in Hydrogen-like Ions 5 4 F = I + s F = I + s 3 4 Possibility to address the electron screening in beta decay under very clean conditions !

  30. Single-Particle Decay Spectroscopy

  31. Decay schemes H-like ions; g.s. → g.s.; no third particle

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