heavy-ion radioactivity

Heavy-ion radioactivity is a rare type of radioactive decay observed in heavy atomic nuclei. It was first described in 1980 as a phenomenon intermediate between alpha decay and spontaneous fission. The initial observation occurred in 1984 when carbon-14 was emitted from radium-223. This process, like alpha decay, involves quantum-mechanical tunneling through a potential-energy barrier. Heavy-ion radioactivity is distinct from beta decay, which can sometimes lead to heavy-particle emission through a different mechanism involving excited nuclear states. Heavy ions themselves are particles with electric charge and a mass greater than a helium nucleus.12