Determination of ⁸⁵Kr by Liquid Scintillation

With a known activity of ⁸⁵Kr standardized by Anti-Compton γ spectrometer as working standards, and with a set of self-designed Kr collection and liquid scintillation sample preparation device, the radioactive measurement method of ⁸⁵Kr by liquid scintillation was established. Experimental results show that, under the condition of toluene used as solvent,PPO and POPOP used as solute, and 1.0 g silicone added into the liquid, Kr sample can be completely dissolved in 20 mL scintillation liquid and its activity can be determined without quenching correction. The absolute value of relative error less than 7% can be reached when ⁸⁵Kr activity is lower than 1 Bq in the sample. The sample stability is proved by compared with the counting of sample measurements in the interval 20 h. The device and method established can be applied to the measurement of environmental atmospheric ⁸⁵Kr activity concentration.