A Method for Measurement of Radon Activity Concentrations
Amos Ntarisa, Pabitra Aryal, H.J. Kim*
Kyungpook National University,
Department of Physics
Daegu, South Korea
Abstract
Radon is the most important source of ionizing radiation which poses human health risks. There are three naturally occurring radon isotopes which are Rn-222(radon), Rn-220(thoron) and Rn-219(actinon) with respect half-life of 3.8days, 56 seconds, and 4 seconds. They are formed on the alpha decay of their radium parents Ra-226, Ra-224 and Ra-223 which are members of decay series of U-238, Th-232 and U-235, respectively. The scientists and researchers are continuing designing and developing methods and techniques for measurements of Radon. We are developing a method which can be used to measure the activity concentrations of all three naturally occurring radon isotopes. To measure radon activity concentration we choose the isotope having short half-life from the decay chain. For example to measure Rn-222 activity we select out Po-214 in U-238 decay chain and we set the time difference from 2 μs to 656 μs. The lower limit of 2 μs is adopted to reject the short Bi-212→Po-212 coincidence in the Th-232 chain. This 2 μs is near about 7 half-lives of Po-212. The upper limit was set as 656 μs which is about four half-lives of Po-214. We will report on development of this method in which the analysis of the method will be presented and discussed.
Keywords: Radon; Activity Concentration;Radon Isotopes; Radon measurementss
Topic: Physics related sciences