Abstract
We report the first observation of the 108Xe → 104Te → 100Sn α-decay chain. The α emitters, 108Xe [Eα ¼ 4.4ð2Þ MeV, T1=2 ¼ 58þ106 −23 μs] and 104Te [Eα ¼ 4.9ð2Þ MeV, T1=2 < 18 ns], decaying into doubly magic 100Sn were produced using a fusion-evaporation reaction 54Feð58Ni; 4nÞ108Xe, and identified with a recoil mass separator and an implantation-decay correlation technique. This is the first time α radioactivity has been observed to a heavy self-conjugate nucleus. A previous benchmark for study of this fundamental decay mode has been the decay of 212Po into doubly magic 208Pb. Enhanced proton-neutron interactions in the N ¼ Z parent nuclei may result in superallowed α decays with reduced α-decay widths significantly greater than that for 212Po. From the decay chain, we deduce that the α-reduced width for 108Xe or 104Te is more than a factor of 5 larger than that for 212Po.