Building and characterisation of a radon emanation source using a historical watch painted with radioluminescent paint containing radium

Abstract

Conducting experiments with 222Rn not always requires a radon emanation source trace- able to primary standards, often it is sufficient to use a well characterised radium source. In this work we present the building and characterisation of a radon emanation source using a watch with radioluminescent paint containing 226Ra. The source with 179±9 kBq 226Ra was characterised for different air flow rates between 0.05 L/min and 2 L/min. The mean radon emanation coefficient was 0.54 ± 0.19 while a dependence of radon emanation on relative air humidity was discovered.