The identification of element 108

The major problems in the investigation of the heaviest elements at the upper end of the periodic table are the small formation cross sections which are far below the nanobarn region and their short halflives of the order of milliseconds. The heaviest elements known up to now were I07 and I09. Two a-emitting odd-odd isotopes of these elements were identified by a-chains to known daughter isotopes /1,2/. Element I08 could not be observed so far /3,4/. Our aim was to produce element 108 by complete fusion of S'Fe with 2~ followed by evapora- tion of one neutron which leads to the odd mass isotope '6sI08. To allow an unambiguous identi- fication of the new element in case of its a-decay, we had also to investigate the unknown daughter isotope 2~I06.