Abstract

Tritium (³H or T) is the heaviest isotope of hydrogen. Unlike hydrogen or deuterium, T undergoes radioactive decay (B^–, ~ 12 yr half-life). Thus T compounds experience radiation damage at elevated tritium levels. Tritium is produced by cosmic rays in the higher atmosphere, and by neutron capture in lithium–aluminum alloy in nuclear fission reactors. Tritium can be purified by distillation, by thermal diffusion, by diffusion through palladium-silver-nickel membranes, or by chromatography on coated molecular sieves. Tritium is widely used as a tracer in molecular biology experiments. Tritium is a key element in nuclear fusion, in which energy is produced by the controlled fusion of tritium with deuterium.