International decay data evaluation project

Basic concepts of, and information from, radionuclide decay are used in many applications. Many of these applications require a knowledge of half-lives and radiation energies and emission probabilities. For over 50 years, people have compiled and evaluated measured data and combined these with theoretical results with the goal of obtaining the best values of these quantities. This has resulted in numerous sets of recommended values, many of which still have scientific, historical, or national reasons for existing. These sets show varying degrees of agreement and disagreement in the quoted values and varying time lags in incorporating new and improved experimental results. A new international group made up of six evaluators from four countries was formed in 1995 to carry out evaluations for radionuclides of importance in applications; it is expected that the results will become an authoritative and widely accepted set of decay data. This Decay Data Evaluation Project has selected nuclides to be evaluated, the methodology to be used, and a review and approval process.