Laser isotope separation

The recent development of technology concerning the wide tunability and narrow spectral width of a laser has made it possible to enrich and separate only one of desired groups of isotopic species efficiently through the selective excitation by the laser. It is the purpose of this report to review the work on the isotope separation by means of lasers, which has been rapidly developed since 1970, and to point out the future direction with particular attention to the application of the separation process to isotopic species related to atomic energy materials including radioisotopes. The report consists of four chapters. Chapter I describes the social needs for the isotope separation and some advantages of the methods for laser isotope separation over the conventional ones. Chapter II presents some conditions which the atomic or molecular isotopes, to be enriched or separated, and the lasers to be used are required to possess. In addition, the relation between the isotope shift and the optical spectra in atoms and molecules is discussed. In Chapter III is reviewed the published laser isotope separation of uranium by photoionization, hydrogen and sulfur by molecular photodissociation, and chlorine by photochemical reaction. The principle, advantages and problems of these methods are also discussed according to a classification of the methods by the difference of separation processes after the selective laser-excitation of isotopic species. All the isotopic species published as what have been enriched or separated so far by the laser methods are tabulated. In Chapter IV it is pointed out that the laser methods are suitable for enrichment or separation of isotopes of the fuel of thermal nuclear fusion such as lithium and radioisotopes such as plutonium. As the result of the review, a few new methods for laser isotope separation are proposed. (auth.)