Sensitivity determination and optimisation of a cylindrical diffusion chamber, for radon measurements, with a CR39 detector

This paper deals with the determination of the sensitivity of the CR39 detector for radon measurements. The sensitivity was calculated by applying the Monte Carlo method for a detector in a diffusion cylindrical chamber with different radii and heights. The sensitivity is reduced as the chamber dimension decreased. certainty of radon concentration determination associated with the unknown radon progeny deposition on the inner chamber walls is discussed. This uncertainty can be almost completely avoided by using a chamber narrower than 1.25 cm and higher than 5 cm. Such design of the diffusion chamber can enable better and more accurate radon measurements to be achieved.