PRESENT STATUS AND FUTURE ASPECTS OF NUCLEAR-STRUCTURE CLOSE TO SN-100 - THE OSIRIS, NORDBALL-PEX AND EUROBALL COLLABORATIONS

The present status of experimental approach to Sn-100 in the spectrosc opy of excited states is landmarked by the T-z = 3/2 nuclei between (9 5)pd and In-101 and the T-z = 1 nuclei Pd-94 and Cd-98. The detection limits with Pre-EUROBALL gamma-arrays and ancillary detectors are belo w the 10(-5) level of the total fusion- evaporation residue cross sect ion. A large scale shell model analysis of the existing data reveals t he shell structure at Sn-100, which shows a remarkable similarity to N i-56. Evidence for an increasing proton-neutron interaction in approac hing the N = Z line is deduced from high spin isomers and spherical yr ast lines. The effective E2 operator for protons and neutrons and impl ications for a low lying particle-hole (ph) E2 excitation in Sn-100 ar e discussed.