Fast measurement of radon concentration in water with Lucas cell

Abstract Fast method of measurement of radon concentration in water based on flushing (bubbling) water sample with air in closed loop with Lucas cell is presented. The main feature of the method is washing radon from large sample of water to small volume of air including the volume of Lucas cell, thanks to which high radon concentration in the air and considerable sensitivity of measurement is achieved. Estimated measuring sensitivity is S = 8.5 cpm/(Bq/dm3). Random error due to statistical fluctuations of count rate at radon concentration 1, 100, 10 000 Bq/dm3 is: 11, 1.1, 0.1% correspondingly at counting (measuring) time 10 min. Minimum detectable radon concentration in water for such counting time is 0.11 Bq/dm3.