PLANS TO IDENTIFY HEAVY-ELEMENTS PRODUCED IN REACTIONS WITH CROSS-SECTIONS OF 1-PB AND BELOW

Reactions for the production of heavy elements have been extensively studied since universal heavy ion accelerators became available. New separation and detection systems have been developed, leading to the identification of the new elements (107)Ns, (108)Hs and (109)Mt. Based on the results obtained, estimates for the production of still heavier elements are given. These extrapolations demand enough experimental sensitivity to measure nuclei produced in reactions of cross-section 1 pb. Similar sensitivity is necessary to measure small decay branches of already known nuclei, to investigate fine structure and to search for new, more neutron-deficient or neutron-rich isotopes. Their stability is determined by details of the nuclear shell structure. Measured data on the reaction processes and the decay properties of the nuclei produced are the bases for a better physical understanding of the formation and stability of the heaviest nuclei. Experimental developments are described aiming at identifying nuclei and their radioactive decays on a cross-section level of 1 pb.