Calibration factor of track etch detectors at different temperatures of water

Abstract

Research was performed to determine track density as a function of radon exposure in water and exposure temperature for the track etch detectors Kodak LR II 5 Type 2 and CR-39. Films were submerged in water containing a known concentration of dissolved radon for graduated exposure times. Many different experimental techniques were conducted to confirm the detector's linear response. The results show that the track densities of track detectors LR II 5 Type 2 and CR-3 9 increase linearly with the increase of integrated radon exposures in water. The CR-39 etch detector is observed to be more sensitive to alpha particles than LR 115 Type 2 film. The exposure period ranged from 1 to 10 days. The linearity test was done at room temperature. The actual radon concentration in the water sample was determined by liquid scintillation counting. A calibration factor (tracks c@/kBq-hr L-1) is required to convert the detector response to a radon concentration estimate. The calibration factors for LR I 1 5 Type 2 etch detectors were derived from the observed track densities of each film and its corresponding integrated radon exposure in water held at different temperatures. The results indicates that the LR II 5 Type 2 calibration factor is strongly dependent on exposure temperature, as the temperature increases, so does the track density per integrated exposure time. The LR II 5 Type 2 results suggest that calibration factors as a function of water temperature should be determined for CR-39 and other track etch detector types.