Identification of radon transfer velocity coefficient between liquid and gaseous phases

Radon transfer between a liquid phase and a gaseous phase is modelled by a Robin's condition (radon flux at the common interface is expressed as function of radon concentrations in the two phases). This condition involves two constants: Ostwald's coefficient (alpha) and the transfer velocity coefficient (beta). Assuming the value of alpha is known, a method is proposed to determinate the value of beta. by studying the radon transfer phenomenon at the laboratory scale. Knowing the initial radon concentrations, the experiment consists in measuring how long the radon flux passes through the common interface. In this stabilisation time radon transport is governed in each phase b diffusion and disintegration. Then, determination of beta is equivalent to solving an inverse problem formulated using measured data. A numerical procedure is developed to solve this problem.