Separation of stable isotopes

A review is made of the present situation as regards the development of methods for separating stable isotopes of light elements (C,N,O,S), together with a discussion of the production of carbon, nitrogen and oxygen highly enriched in 13C, 15N and 18O respectively, and of nitrogen depleted in 15N. The special features and the technical-economic characteristics of the technological processes involved in obtaining isotopes are discussed, for example, chemical exchange and low-temperature distillation processes, which have become the ones used most widely on an industrial scale. Various tasks involved in intensifying these processes with a view to increasing further the scale of production of stable isotopes and making them substantially cheaper are considered, as well as various aspects of stable isotope separation based on the selective excitation of atoms and molecules by laser beams and in electric discharges. (author)