Superallowed α Decay to Doubly Magic 100Sn

We report the first observation of the 108Xe→104Te→100Sn α-decay chain. The α emitters, 108Xe [Eα=4.4(2)  MeV, T1/2=58+106−23  μs] and 104Te [Eα=4.9(2)  MeV, T1/2<18  ns], decaying into doubly magic 100Sn were produced using a fusion-evaporation reaction 54Fe(58Ni,4n)108Xe, 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=Z parent nuclei may result in superallowed α decays with reduced α-decay wi…