Abstract: The influence of air intake system, scintillation chamber calibration, measuring time and other factors on ²²⁶Ra measurement in water by the emanation scintillation method is analyzed. Suggestions for optimization are further proposed as follows: simplifying the intake system and flushing the scintillation chamber and gas path with pure nitrogen; prolonging the sealing time of the standard source, so that the cumulative factor is greater than 0.9, which can improve the stability of the K value of the scintillation chamber; increasing the sample size and measuring time to improve the measurement accuracy, for samples with low radium content.

Key words: ²²⁶Ra, Emanation scintillation, Water, Scintillation chamber