Nuclear Physics in Storage Rings Yuri A. Litvinov Institute of Theoretical Physics (ITP), CAS, Beijing 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
Beta-decay on the Chart of Nuclides p-process rp-process p-process fussion Astrophysical scenarios: high temperature = high degree of ionization r-process
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 ?!“
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)
Two-body beta decay of stored and cooled highly- charged ions
Fragment Separator FRS Production target Storage Ring ESR Heavy-Ion Synchrotron SIS Linear Accelerator UNILAC Production, storage and cooling of HCI at GSI
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
Electron Cooling momentum exchange with 'cold', collinear e- beam. The ions get the sharp velocity of the electrons, small size and divergence
time SMS 4 particles with different m/q
Sin( 1 ) Sin( 2 ) Sin( 3 ) Sin( 4 ) 11 22 33 44 time Fast Fourier Transform SMS
SMS: Broad Band Frequency Spectra
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
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
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
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 = B. Sun et al., PLB 688 (2010) 294
Bound-State -decay
187 Re 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 ( ) U…Th… 206 Pb ( ) Th…Ra… 208 Pb ( ) Lu/ 176 Hf ( ) Re/ 187 Os ( ) Rb/ 87 Sr ( ) 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-
p process Dy Ho Er r process s process 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
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)
Next Step: Bound-State -decay of 205 Tl F. Bosch et al., GSI Proposal
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
Decay schemes H-like ions; g.s. → g.s.; no third particle
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) Pr EC (H-like)/ EC (He-like) = 1.44(6) 142 Pm N. Winckler et al., Phys. Lett. B579 (2009) 36
Electron Capture in Helium-like Ions I = 1 S = 0 Gamow-Teller transition → EC I = 0 s = 1/2 F = 1 s = 1/2
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)
S. Typel and L. Grigorenko Probability of EC Decay µ = µ N Neutral 140 Pr: P = 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)
Next Step B.M. Dodsworth et al., Phys. Rev. 142 (1966) 638. µ ( 64 Cu) = −0.217(2) N
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 ~ % (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
Electron Capture in Hydrogen-like Ions F = I + s Possibility to address the electron screening in beta decay under very clean conditions !
Single-Particle Decay Spectroscopy
Decay schemes H-like ions; g.s. → g.s.; no third particle