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Radiation Protection Dosimetry 82:141-146 (1999)
© 1999 Oxford University Press
Modelling Radon Progeny Behaviour on Surfaces and Notes on the Radon Retrospective Dosimetry
The behaviour is modelled of short-lived radon progeny on surfaces of objects, taking into account their deposition and incorporation after alpha decay. It has been shown that the activity A7 of 210Po in superficial layers of an object is given by the equation A7 = (e1r1 + e4(r2 + r3))(1 - exp(-?5t)) where r1,2,3 are deposition fluxes of 218Po, 214Pb and 214Bi onto a surface (in atoms.m-2.s-1), respectively, e1 and e4 are incorporation efficiencies after alpha decay of 218Po and 214Po, and ?5 is the decay constant of 210Pb. This activity is functionally related to the total exposure to short lived radon progeny rather than radon. The theoretical case ei = 0.5 is also considered. Correction of A7 activity for the age of the object is also derived. The relationship between 210Po activity in the sub-surface layer and the average PAEC during the exposure of the object is also found using the Jacobi-Porstendörfer predictive model.