RaDoM2: an improved radon dosimeter

A new dosimeter for radon progeny called RaDoM (Radon Dose Monitor) was recently developed at CERN. RaDoM is an active detector able to directly estimate the effective dose due to the radon progeny. The first version, which used the Timepix hybrid pixel detector, a system of filters and a pump, correctly assessed the effective dose in situations where the environmental conditions are characterized by a standard equilibrium factor, but showed low efficiency for low radon concentrations and in clean air environments. In this improved version, RaDoM2, the Timepix has been replaced by a silicon pin diode. This solution has allowed the optimization of the geometry, the pump flow rate and the associated electronics, improving the performance of RaDoM and substantially reducing its manufacturing costs. This paper describes the RaDoM2, its improved performance compared to RaDoM, the cloud and user interface, tests in a radon chamber and on-the-field measurements.