Experimental study on the effect of environmental parameters on Rn-220 exhalation rate.

Radon-220 is an important isotope of radon. Due to its short half-life, it is highly sensitive to changes in environmental parameters during its exhalation from the surface of the earth, which poses significant challenges for precise measurement and modeling. To study the influence of different environmental parameters on the diffusion rate of Rn-220 from the soil surface, this research used an indoor soil gas collection device to simulate process of Rn-220 exhalation. The RAD7 instrument was used to continuously monitor the changes in the concentration of Rn-220 on the soil surface, and at the same time, data on five environmental parameters such as air pressure, soil temperature and humidity, as well as environmental temperature and humidity were obtained and scientifically analyzed. The results showed that air pressure, environmental humidity, soil temperature, environmental temperature, and soil humidity exhibited different mechanisms and effects on Rn-220 exhalation rate. Air pressure showed an inhibitory effect on Rn-220 exhalation rate throughout the range; environmental humidity presented a three-stage dynamic change process of "decrease - increase - decrease" within the effective data range; soil temperature exhibits a dynamic equilibrium trend between thermodynamics and capillary water evaporation in the shallow layer area; environmental temperature showed a promoting effect throughout the overall range. This result provides a data science method for optimizing the Rn-220 measurement scheme and the measurement and prediction of short-lived radioactive gases.