Simultaneous measurement of radon and thoron using Lucas scintillation cell

A method has been developed for the simultaneous estimation of radon and thoron in a mixed environment using the Lucas Scintillation Cell (LSC). The method requires two arbitrary counting periods and corresponding total disintegrations. The basis of the method involves formulation of simultaneous linear equations with two unknown variables. The unknown variables represent the radon and thoron activities in the cell. The coefficients of the equations are the integrated activities of radon, thoron and their alpha decay products per unit activities of the parent radionuclides. The method can be used to estimate the radon and thoron concentrations in a mixed environment accurately and quickly, as there is no need to delay the counting to achieve complete decay of thoron. The mathematical basis of the method along with few experimental results is presented in this paper. Results yielded, on comparison, good agreement with the Delay Count Method and Double Filter Sampling Technique. (author)