Simulation studies of diffusion-release and effusive-flow of short-lived radioactive isotopes

Simulation studies with computer models offer cost effective methods for designing targets and vapor transport systems at Isotope Separator On-Line (ISOL)-based radioactive ion beam facilities. A finite difference code, Diffuse II, was developed at the Oak Ridge National Laboratory (ORNL) for Studying diffusion-release of short-lived ion species from the three principal target geometries; results derived by use of the code are in close agreement with analytical solutions to Fick's second equation. A Monte-Carlo code, Effusion, was developed to address issues related to the design of fast vapor transport systems. Results, derived by the use of Effusion closely agree with experimental measurements. These codes and their applications are discussed in this article.