Presentation on theme: "Investigation of short-lived nuclei using RIBs Reiner Krücken Physik Department E12 Technische Universität München Maier-Leibniz-Laboratorium für Kern-"— Presentation transcript:
Investigation of short-lived nuclei using RIBs Reiner Krücken Physik Department E12 Technische Universität München Maier-Leibniz-Laboratorium für Kern- und Teilchenphysik der Ludwig-Maximilians-Universität München und der Technischen Universität München
Cycle of matter: Nucleosynthesis
Nuclear chart Example: r-process
r-Process abundance for metal poor stars element number abundance log(X/H)-12 CS (Sneden et al. 2003) solar r
Nuclei along the r-process K.L. Kratz Russbach 2006
r-process abundances not well described by current models G. Martinez Pinedo et al. Pfeiffer et al. Shell quenching or fission or …?
Modifications of shell structure in neutron-rich nuclei r V Valley of stability r V Neutron-rich nuclei Spin-orbit coupling How does the central potential change with neutron excess? What is the isospin dependence of the spin-orbit interaction?
Lack of predictive power of mean-field models from RIA Whitepaper M. Bender, P.H. Heenen, P.G. Reinhard Rev. Mod. Phys. 75 (2003) 122
What we can measure in the laboratory? Masses, Q-values Half-lives T 1/2 Beta-delayed neutron emission probabilities P n Evolution of single-particle structure and collectivity probing of shell structure working towards reliable theoretical models low-lying dipole strength important for e.g. (,n)
Production of short-lived radioactive beams Isotope Separation On-Line Diffusion out of thick target: - depends on chemistry -Slow process Fragments fly forward with beam velocity (30- 90% c) -Physical separation only - Fast separation Reaction of light projectile (p, d, n) on a heavy target - Spallation - Fission - Fragmentation Exotic nucleus produced in-flight as fragment of heavy beam -Fragmentation -Fission
1.4 GeV REX-ISOLDE MINIBALL From PS Booster
UNILAC SIS FRS ESR Target Area Therapy Ion source Max. 90% c (2 GeV/nucleon) Experimental hall 8-20% c (3-20 MeV/nucleon ) Ion source (high Q) N Gesellschaft für Schwerionenforschung (GSI) in Darmstadt
Production of 100 Sn and T 1/2 of rp-process nuclei E E TOF First production of 100 Sn 124 Xe beam E= 1 A.GeV TUM T. Faestermann et al., EPJA 15 (2002) 185 A. Stolz et al.
FAIR: Facility for Antiproton and Ion Research Primary Beams /s; GeV/u; 238 U 28+ Factor over present in intensity Secondary Beams Broad range of radioactive beams up to GeV/u; up to factor in intensity over present Antiprotons GeV Storage and Cooler Rings Radioactive beams e - - A and Antiproton-A collider 100 m UNILAC SIS 18 SIS 100/300 HESR Super FRS NESR CR RESR GSI today Future Facility ESR
Current experimental program Coulomb REX-ISOLDE - N=40-50 Ni, Cu, Zn - Cd, Xe, Ba around N=82 Decay spectroscopy and T 1/2 : Sn and vicinity (GSI, RIKEN) - A~90 Ge,As,Se (ILL Grenoble) Pd and vicinity (GSI) - below 208 Pb (GSI) Probing evolution of shell structure - knock-out and inelastic excitation: - 55 Ti, 73 Cu (GSI) - 42 Si, 54 Ca and vicinity (RIKEN) - transfer reactions at REX-ISOLDE - ~ 32 Mg, ~ 68 Ni
Reach of mass- and T 1/2 measurements at FAIR Source: ILIMA collaboration Other future facilities: RIKEN CERN GANIL MSU
Summary Properties of nuclei involved in nucleosynthesis are often not well known experimentally Theoretical models and extrapolations vary significantly lack of reliable predictions Current and future radioactive beam facilities allow for –Investigation of key nuclei to distinguish between theoretical models towards a unified nuclear theory –Direct measurement of properties of relevant nuclei Local groups (LS Krücken, LS Habs) involved in experiments and methodical developments New Professorship in Nuclear Astrophysics will strengthen local effort