Study On The Humidity Influence In Electrostatic Collection Method For Radon

Electrostatic collection measure the radon conzentration by collecting the first radon daughter.But it is a free state metal atoms,about 90% with a positive charge.Polarization of water molecules can operate rapidly with the 218Po particle,then the 218Po particle become a neutral particle, thereby affecting the collection efficiency. So it must consider the impact of humidity when we use this method. Studying electrostatic collection of radon the effects of humidity can enhance measurement reliability of the results and increase their scope of using.This paper studied the method of electrostatic collection of radon measuring the progress of influencing factors, focusing on the humidity effect on the electrostatic collection of radon measurement method of the collection efficiency of particles 218Po were discussed: in the original electrostatic collection of radon measurement method based on the theoretical formula has been improved, and established the theoretical model for this paper; by using fluid dynamics software Fluent to the collection of rooms of different shapes to simulate the design of more rational collection room; the use of saturated salt solution method control the relative humidity in the experiments, obtained the collection efficiency under different relative humidity; article also come from the perspective of absolute humidity to study its relationship with the collection efficiency.Experimental results show that: for the same collection chamber, the relative humidity changes will not affect the determination of the saturation voltage of the collection, the relative humidity changes on the collection efficiency of remarkable, when it's more than 45% after this effect becomes unimportant, and that the collection efficiency tends to a constant. From the point of absolute humidity , when it is less than 5g/m3, the changes in collection efficiency is in evidence. when this value is greater than it, the collection efficiency tends to be constant. Finally compare the data obtained: When the relative humidity is greater than 45%, but the absolute humidity is less than 5g/m3 , the relative humidity affect is the dominant factor; when the relative humidity is less than 45%, absolute humidity is greater than 5g / m3 but smaller than 18 g / m3, the absolute humidity is the dominant factor.