EVIDENCE FOR THE ALPHA-DECAY OF I-108

A Residue Implantation Detection System has been used in conjunction with the Daresbury Recoil Mass Separator in a search for radioactivity from the unknown nuclides I108 and Te105. In the reaction of 260 MeV Ni-58 ions with a Fe-54 target two new decay lines at energies of 3.730+/-0.025 MeV and 3.885+/-0.025 MeV corresponding to cross sections of approximately 0.3-mu-b and 0.4-mu-b respectively were identified in the A = 108 region of the separator's focal plane. These decay lines are tentatively assigned to the alpha decays of I108. No evidence for a proton decay branch of this nuclide could be found. In a second reaction in which a Cr-50 target was bombarded with 230 MeV Ni-58 ions, no alpha decay peak from Te105 could be identified. Cross section dependent half life limits were determined from which corresponding Q-value limits were deduced.