Long-term determination of airborne concentrations of unattached and attached radon progeny using stacked LR 115 detector with multi-step etching

We developed the theoretical basis for long-term determination of airborne concentrations of unattached and attached radon progeny. The work was separated into two parts. First, we showed that (stacked and multiply etched) LR 115 detectors could be used to determine airborne concentrations of the short-lived radon progeny, 218Po and 214Bi. The equilibrium factor F between radon and its progeny could then be determined through the use of the reduced equilibrium factor Fred. The airborne concentrations of 214Pb could then be determined. Second, we developed a method based on the airborne concentrations of 218Po, 214Pb and 214Bi to determine the parameters of the Jacobi room model, viz., the ventilation rate λv, aerosol attachment rate λa, deposition rate of unattached progeny λdu and the deposition rate of attached progeny λdu. With these parameters, the unattached fraction fp of the potential alpha energy concentration could also be determined. Knowledge of fp, together with F, would enable more accurate determination of the effective dose in the human lung.