Two-proton radioactivity studies with 45Fe and 48Ni
Résumé
In an experiment at the SISSI/LISE3 facility of GANIL, we have studied the decay of the two proton-rich nuclei 45Fe and 48Ni. We identified 30 implantations of 45Fe and observed for the second time four implantation events of 48Ni. In 17 cases, 45Fe decays by two-proton emission with a decay energy of 1.154(16) MeV and a half-life of T_1/2 = 1.6+0.5_-0.3 ms. The observation of 48Ni and of its decay allows us to deduce a half-life of T_1/2 = 2.1+2.1_-0.7 ms. One out of four decay events is completely compatible with two-proton radioactivity and may therefore indicate that 48Ni has a two-proton radioactivity branch. We discuss all information now available on two-proton radioactivity for 45Fe and 48Ni and compare it to theoretical models.