||Description of a Method for Measuring the Diffusion Coefficient of Thin Films to (222)Rn Using a Total Alpha Detector.
Mosley, R. B. ;
||Acurex Environmental Corp., Research Triangle Park, NC.;Environmental Protection Agency, Research Triangle Park, NC. National Risk Management Research Lab.
Alpha detection ;
Radon 222 ;
Diffusion coefficient ;
Thin films ;
Alpha dosimetry ;
Passive systems ;
Radionuclide migration ;
Radioecological concentration ;
Indoor air pollution ;
Air infiltration ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
The paper describes a method for using a total alpha detector to measure the diffusion coefficient of a thin film by monitoring the accumulation of radon that penetrates the film. It demonstrates that a virtual steady state condition exists in the thin film during the early stages of accumulation that allows reliable measurements of the diffusion coefficient without having to wait for the final conditions of equilibrium or having to analyze the complex transient solutions. In some cases, the final condition of equilibrium would require the measurement to last 3 or more weeks rather than 3 days.