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 CS22892-052 (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 Pfeiffer et al. Shell quenching or fission or …? G. Martinez Pinedo et al.

Modifications of shell structure in neutron-rich nuclei How does the central potential change with neutron excess? What is the isospin dependence of the spin-orbit interaction? Spin-orbit coupling r V r V Valley of stability Neutron-rich nuclei

Lack of predictive power of mean-field models M. Bender, P.H. Heenen, P.G. Reinhard Rev. Mod. Phys. 75 (2003) 122 from RIA Whitepaper

What we can measure in the laboratory? Masses, Q-values Half-lives T1/2 Beta-delayed neutron emission probabilities Pn Evolution of single-particle structure and collectivity  probing of shell structure  working towards reliable theoretical models low-lying dipole strength important for e.g. (g,n)

Production of short-lived radioactive beams Isotope Separation On-Line 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 Diffusion out of thick target: depends on chemistry Slow process Fragments fly forward with beam velocity (30-90% c) Physical separation only - Fast separation

REX-ISOLDE From PS Booster 1.4 GeV MINIBALL

Gesellschaft für Schwerionenforschung (GSI) in Darmstadt Ion source Target Area Therapy UNILAC ESR Ion source (high Q) FRS Experimental hall 8-20% c (3-20 MeV/nucleon) N SIS Max. 90% c (2 GeV/nucleon)

Production of 100Sn and T1/2 of rp-process nuclei DE 124Xe beam E= 1 A.GeV TOF DE First production of 100Sn TUM T. Faestermann et al., EPJA 15 (2002) 185 A. Stolz et al.

FAIR: Facility for Antiproton and Ion Research Primary Beams 1012/s; 1.5-2 GeV/u; 238U28+ Factor 100-1000 over present in intensity Future Facility SIS 100/300 GSI today SIS 18 UNILAC ESR 100 m HESR Super FRS Secondary Beams Broad range of radioactive beams up to 1.5 - 2 GeV/u; up to factor 10 000 in intensity over present Antiprotons 3 - 30 GeV RESR CR Storage and Cooler Rings Radioactive beams e- - A and Antiproton-A collider NESR

Current experimental program Decay spectroscopy and T1/2: - 100Sn and vicinity (GSI, RIKEN) A~90 Ge,As,Se (ILL Grenoble) 128Pd and vicinity (GSI) below 208Pb (GSI) Coulomb excitation @ REX-ISOLDE N=40-50 Ni, Cu, Zn Cd, Xe, Ba around N=82 Probing evolution of shell structure knock-out and inelastic excitation: 55Ti, 73Cu (GSI) 42Si, 54Ca and vicinity (RIKEN) transfer reactions at REX-ISOLDE ~ 32Mg, ~ 68Ni

Reach of mass- and T1/2 measurements at FAIR Source: ILIMA collaboration Other future facilities: RIBF @ RIKEN HIE-ISOLDE @ CERN SPIRAL2 @ GANIL ISF @ 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