극저준위 액체섬광계수기와 파형분석법을 이용한 지하수 및 온천수중 $^{222}Rn$의 신속측정법
김창규;김철수;
A Rapid Method for the Measurement of $^{222}Rn$ in Groundwater and Hot Spring Water using Ultra Low-Level Liquid Scintillation Counter and Pulse Shape Analysis
Kim, Chang-Kyu;Kim, Cheol-Su;
ABSTRACT
For the determination of $^{222}Rn$ in water by a very simple and time saving liquid scintillation counting method that does not require any chemical separation, an optimum analytical condition has been investigated. The optimum pulse shape analysis(PSA) level for the measurement of $^{222}Rn$ using LKB 1220 Quantulus liquid scintillation counter was 110 for Optiphase HiSafe3 cocktail and 90 for toluene-based cocktail. The counting efficiencies of $^{222}Rn$ in the window covering u spectra using Optiphase HiSafe3 cocktail were 282.2% for glass vial and 271.6% for Teflon vial, whereas the counting efficiencies in toluene-based cocktail were 262.3% and 247.5% for glass and Teflon vials, respectively. The minimum detectable activity(MDA) in the u window for a 60-min measurement with a Teflon vial using Optiphase HiSafe3 cocktail was $0.30Bq/{iota}$. The analytical method studied from this work was also applied to the determination of $^{222}Rn$ in some groundwater and hot spring water samples.