A novel method to simulate radon exhalation rate with a solid Rn-222 source

Radon exhaled from rocks, building materials, and soil can be harmful to human health, so it is necessary to measure radon and its exhalation rate. In this paper, a novel method is proposed to simulate radon exhalation from different medium surface by using a solid Rn-222 source, and the radon exhalation rate can be adjusted by replacing radon accumulation chambers with different bottom areas. Firstly, an experiment was done to determine the activity of the Rn-222 source, and then the theoretical radon exhalation rate can be quickly calculated from the relationship between the radon source activity and the bottom area of the radon accumulation chamber. Three sets of comparative experiments were conducted using two radon accumulation chambers with different volumes, respectively. Comparing the average values obtained from the experiments with the calculated theoretical values, it can be obtained that the differences corresponding to the two radon accumulation chambers between the theoretical radon exhalation rates and the experimentally average values are all within 6%. Without replacing the radon source, the radon exhalation rate is inversely varies with the bottom area of the chamber. Therefore, the correctness of adjusting the radon exhalation rate by replacing radon accumulation chambers with different bottom areas to simulate radon exhalation from different media surfaces is verified. This method can be used to calibrate the radon exhalation measuring instruments.