New YAP:Ce scintillation detection for determination of 222Rn in water

Abstract A new detection unit for the determination of 222 Rn in water was developed. This paper describes the design and application of this detection unit. It consists of a YAP:Ce detector, 25 mm in diameter and 100 mm long, which is optically coupled with a photomultiplier tube and associated electronics. This configuration enables direct detection of alpha particles emitted by 222 Rn dissolved in water but it is also sensitive to gamma radiation. Calibration of the detection unit was carried out using gamma-rays of 137 Cs , 241 Am , 88 Y and 60 Co sources. Calibration for alpha rays was made using 241 Am alpha source. Peak interpretation of Rn spectra and a comparison of the measurements of different Rn activities in water are shown.