Nuclear track detectors evaluation for radon activity concentration measurements

The Ionizing Radiation Metrology Laboratory (LMRI) from IFIN-HH has evaluated nuclear track detector responses to radon (²²²Rn). In order to perform the evaluation, a radon source was prepared using the standard system for the radon extraction from a solid ²²⁶Ra Pylon source with certified activity traceable to the NIST, USA. The solid state nuclear track detectors (SSNTDs) type TASTRACK PADC from TASL were exposed to radon in the radon chamber at the LMRI (1 m³ volume) together with the AlphaGuard DF2000 (AG) radon reference monitor. After exposure, the SSNTDs were placed and processed in a Clifton Digital bath with NaOH solution. After etching, an optical system (TASLImage) was used to determine the integrated exposure. The present analysis was made in order to develop a working procedure for the calibration of an SSNTD in a radon chamber. LMRI aims to extend the calibration services for customers with the nuclear track detectors calibration. The results for the radon activity concentration in air obtained with the SSNTDs were in good agreement (±10 %) with the values registered by the reference radon monitor.