METHOD OF MEASURING RADON FLUX DENSITY FROM GROUND SURFACE BASED ON BETA- AND GAMMA-RADIATION Russian patent published in 2011 - IPC G01T1/16 

FIELD: physics.

SUBSTANCE: total number of pulses of beta- and gamma-radiation from radon decay products is measured, where the radon is inside the accumulation chamber of a beta- or gamma counter whose sensitive surface is placed such that beta-radiation of soil radionuclides does not fall on it, and the base of the accumulation chamber is closed by a filter which filters out thoron from the ground. Before measurement, the chamber is ventilated for not less than 15 minutes and background measurements are taken for a time t₁ not less than 5 minutes with the chamber open. The chamber is closed and for a period of time t₂ ranging from 40 to 80 minutes, the number of pulses of beta- and gamma-radiation is measured. Radon flux density is then determined using the expression , where q is radon flux density from the ground surface, Bq m^-2 s^-1; N is the measured total number of pulses over time t₂, pulses; N_f is the measured background value of the number of pulses over time t₁, pulses; ε is a compensation factor, pulses s^-1 Bq^-1; S is the surface area of the base of the accumulation chamber, m²; λ is the decay constant of radon, s^-1; t₁ is the time for measuring the background, s; t₂ is the time for accumulation of radon, s.

EFFECT: measuring radon flux density from the ground surface based on beta- and gamma-radiation which is suitable for use when conducting prolonged continuous measurements without participation of an operator.