Radon daughter deposition on surfaces carrying alternating electric fields.

A theoretical model is proposed to explain the radon daughter deposition enhancements on surfaces subject to power frequency AC fields, recently reported by Henshaw et al. (1996). The effect of oscillatory contacts with the surface combined with turbulent diffusion is investigated within the framework of the convective-diffusion equation, through an approximation of the dividing surface. The fine and the course activity fractions are treated separately for flat-plate and wire-plane configurations. The results indicate maximum enhancement factors for 218Po in the range 1.7-3.3 for flat-plate and 5.2-15.5 for wire-plane configurations under typical indoor environmental conditions. While these compare favourably with the corresponding observed values, further analysis appears necessary to explain the greater enhancements observed in the case of 214Po.