Sorption and desorption of radioactive noble gases in polycarbonates

The remarkable ability of some polycarbonates to absorb noble gases makes them an useful tool for measurements of radioactive noble gases. In this paper the kinetic of sorption and desorption processes is theoretically and experimentally studied. A theoretical model is proposed that considers diffusion and radioactive decay. Experimental results for 85Kr, 133Xe and 222Rn are presented. They include experimental determination of the diffusion length of these radionuclides in polycarbonate and study of the time dependence of sorption and desorption processes. The experimental time dependence is in a very good agreement with the theoretical model. The conclusion is that the proposed model can be useful in practical applications.