Experimental study of the electric charge of a natural radioactive aerosol
Congress title :CFA 2007/2008 - 23ème Congrès Français sur les Aérosols
Congress location :Paris
Congress date :16/01/2008
The purpose of this paper is to describe an experimental setup used in the Aerosol Physics and Metrology Laboratory at IRSN to measure the electric charge apparent fraction of radon decay products. First, we show the mass-transport equations that present the evolution of the electric charge apparent fraction of 218Po in this device. Secondly, we present our experimental device (Zeleny tube) that is used to measure the electric charge apparent fraction of radon decay products depending on radon activity and on residence time. Experimental results concerning the electric charge apparent fraction are presented for parameters cited before. The preliminary experimental results are compared with results from the literature, such as the work of J. Malet (1997). The values obtained for the electric charge apparent fraction with two different dimensions of the Zeleny tube showed no effect of the radon activity for the same residence times. However, for the same activity concentration of 90 kBq/m3, the small electrode shows a significant difference for the electric charge apparent fraction of 218Po wich is more important for a longer residence time. Results require a numerical modelling (CASTEM 2000) that will allow us to compare the results of both Zeleny tube.