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Nuclear Physics in Storage Rings Yuri A. Litvinov Institute of Theoretical Physics (ITP), CAS, Beijing 10.06.2010 Max-Planck-Institut für Kernphysik, Heidelberg 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, ),( , )…] 6. Reactions in inverse kinematics [ 15 O( ) 19 Ne] 7. Experiments with isomeric beams 8. Experiments with polarized beams
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Beta-decay on the Chart of Nuclides p-process rp-process p-process fussion Astrophysical scenarios: high temperature = high degree of ionization r-process
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Half-life modifications G.T. Emery, Annu. Rev. Nucl. Sci. 22 (1972) 165: Effects of less than 1% Pressure, Temperature, Electromagnetic fields, Chemistry... Modification of the electron density at the nucleus Fundamental question: “Can we change the nuclear decay rate or it is a basic property ?!“
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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 57 Fe ions F. Attallah, et al., Phys. Rev. C55 (1997) 1665 Internal conversion in few-electron 125 Te 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)
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Two-body beta decay of stored and cooled highly- charged ions
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Fragment Separator FRS Production target Storage Ring ESR Heavy-Ion Synchrotron SIS Linear Accelerator UNILAC Production, storage and cooling of HCI at GSI
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ESR : E max = 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
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Electron Cooling momentum exchange with 'cold', collinear e- beam. The ions get the sharp velocity of the electrons, small size and divergence
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time SMS 4 particles with different m/q
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Sin( 1 ) Sin( 2 ) Sin( 3 ) Sin( 4 ) 11 22 33 44 time Fast Fourier Transform SMS
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SMS: Broad Band Frequency Spectra
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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
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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
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Half-Lives of Nuclear Isomers Neutral atom is 0.49(2) s laboratory frame Fully ionized atom is 11(1) s T 1/2 (fully ionized) T 1/2 (neutral) = 22(2) Yu.A. Litvinov, et al., PLB 573 (2003) 80-85
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Observation of 133m Sb isomeric state 17 s isomeric state in neutral 133 Sb Expected half-live of bare isomer: ~ 17 ms, t ~991 A new half-live domain for storage-ring experiments R IMS =200 000 B. Sun et al., PLB 688 (2010) 294
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Bound-State -decay
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187 Re 0 9.8 keV T ½ = 42 Gy; Q = 2.7 keV g.s. β-β- T ½ = 33 y 9.8 keV g.s. 187 Re 75+ βbβb Q = 62 keV F. Bosch et al., Phys. Rev. Lett. 77 (1996) 5190 Bound-State -decay of 187 Re E The 7 Nuclear Clocks for the Age of the Earth, the Solar System, the Galaxy, and the Universeclock T 1/2 [10 9 y] 40 K/ 40 Ar ( ) 1.3 238 U…Th… 206 Pb ( ) 4.5 232 Th…Ra… 208 Pb ( ) 14 176 Lu/ 176 Hf ( ) 30 187 Re/ 187 Os ( ) 42 87 Rb/ 87 Sr ( ) 50 147 Sm/ 143 Nd ( ) 100 Clayton (1964): a mother-daughter couple ( 187 Re/ 187 Os) is the “best” radioactive clock 5/2+ 1/2- 3/2-
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p process 160 164 162 161 163 164 166 Dy Ho Er r process s process 162 165 163 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 branchings caused by bound-state β decay M. Jung et al., Phys. Rev. Lett. 69 (1992) 2164 Bound-State -decay of 163 Dy T 1/2 = 48 days
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Bound-State -decay in 206,207 Tl λbλb λ = λ b +λ c +λ R bound/continuum branching ratio T. Ohtsubo et al., Phys. Rev. Lett. 95 (2005) 052501
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Next Step: Bound-State -decay of 205 Tl F. Bosch et al., GSI Proposal
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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
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Decay schemes H-like ions; g.s. → g.s.; no third particle
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EC in Hydrogen-like Ions Expectations: EC (H-like)/ EC (He-like) ≈ 0.5 EC (H-like)/ EC (He-like) = 1.49(8) Yu.A. Litvinov et al., Phys. Rev. Lett. 99 (2007) 262501 140 Pr EC (H-like)/ EC (He-like) = 1.44(6) 142 Pm N. Winckler et al., Phys. Lett. B579 (2009) 36
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Electron Capture in Helium-like Ions I = 1 S = 0 Gamow-Teller transition → EC I = 0 s = 1/2 F = 1 s = 1/2
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Electron Capture in Hydrogen-like Ions I = 1 s = 1/2 Gamow-Teller transition → EC I = 0 s = 1/2 F = I + s 3/2 1/2 F = 1/2 Z. Patyk et al., Phys. Rev. C 77 (2008) 014306
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S. Typel and L. Grigorenko Probability of EC Decay µ = +2.7812µ N Neutral 140 Pr: P = 2.381 Gamow-Teller transition → Electron Capture in Hydrogen-like Ions Z. Patyk H-like 140 Pr: P = 3 He-like 140 Pr: P = 2 Theory: The H-Like ion should really decay 20% faster than neutral atom! (2I+1)/(2F+1) Z. Patyk et al., Phys. Rev. C 77 (2008) 014306
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Next Step B.M. Dodsworth et al., Phys. Rev. 142 (1966) 638. µ ( 64 Cu) = −0.217(2) N
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Some speculations on the EC-decay of 7 Be A.V. Gruzinov, J.N. Bahcall, Astroph. J. 490 (1997) 437 Ionization of 7 Be in the Sun can be ~ 20-30 % (2I+1)/(2F 1 +1) Transition (F=1 F=1) is accelerated byi.e. by 8/3 of 7 Be in this state (2F 1 +1)/((2F 1 +1)+(2F 2 +1)) = 3/8 However, there are only
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Electron Capture in Hydrogen-like Ions F = I + s 4 3 5 4 Possibility to address the electron screening in beta decay under very clean conditions !
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Single-Particle Decay Spectroscopy
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Decay schemes H-like ions; g.s. → g.s.; no third particle
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