Timepix3 detector for measuring radon decay products

The present work is focused on the characterization of a Timepix3 (TPX3) based test system for the identification of particles produced by the complex decay chain of $^{222}$Rn. The detector used is composed of a pixelated Cadmium Telluride (CdTe) semiconductor (500 μm thick) bump-bonded on an ASIC TPX3 chip. Measurements were carried out at the NIXT Laboratory (ENEA Frascati) using radioactive sources and exploiting the presence of natural radon gas by collecting its decay products on the sensor surface. Estimation of the radon gas risk is one of the most important problems in radiation protection and has stimulated further development of new advanced methods suitable for detecting this gas in confined environments. A study of the spatial uniformity and high energy calibration is also presented and an improved cluster analysis is introduced. The performance highlighted in this study will allow a detailed and faster analysis of the radon products and may have an important impact on the environmental radioprotection applications. This paper describes the application and use of this test system to identify the different decay signatures and follow the temporal evolution of the Radon decay chain.