Improved measurements of thoron (Rn-220) in natural waters

摘要

Thoron (Rn-220) in water measurements can be useful for prospecting for points of submarine groundwater discharge into surface waters. With a 56 s half-life any detection of thoron must mean that one is close to a source. To improve measurement sensitivity, the influence of airflow rates on both radon and thoron measurements have been investigated using a RAD7 detector. Based on lab experiments, 2.5 L min(-1) represents an optimum airflow rate for measuring both radon and thoron. Field data from a coastal zone demonstrates that use of an external air pump produced a thoron response 65% higher than a standard setup.