Modeling the mitigation of radon/thoron decay product activity concentration using unipolar ionizers

Ionizers have been shown to be effective in reducing the activity concentration of radon/thoron decay products in poorly ventilated environments. Studies have linked the role of unattached fraction and other associate factors with the resultant dose reduction. A mathematical model has been developed in this work to explain the ionizer effect on activity concentration. Parametric study of the model i.e. effect of variation of ventilation, ion current, particle radius etc. has been performed as a part of this work. The model parameters were selected using an experiment performed in our lab with thoron source. The model results matched well with the experimental reduction of ²¹²Pb activity concentration in presence of ionizers. (author)