METHOD OF MEASURING DENSITY OF RADON AND THORON FLOW FROM SOIL SURFACE BY ALPHA-RADIATION Russian patent published in 2011 - IPC G01T1/00 

FIELD: physics.

SUBSTANCE: proposed method involves setting accumulation chamber accommodating semiconductor or scintillator alpha-detector. Note here that first measurement is carried out in between interval t1 varying from 6 to 6.1 minutes after accumulation start, while second measurement is performed in between interval _t2 varying from 40 to 60 minutes. Then, density of flow of radon q_Rn and thoron q_Tn "Бк" m^-2, s^-1 is defined by the expression , ,

where N_t1 is pulse count rate measured at t₁, min. After accumulation start, pulses; s^-1; Nt₂ is pulse count rate measured at t₂, min., after accumulation start, pulses, s^-1; K_Rn(t₂) is contribution of radon (²²²Rn) into total escape of alpha-particles from radon and products of is decay inside accumulation chamber at t₂ depending on t₂, relative units; φ is count factor that allows for counter efficiency and geometrical factor, pulses s^-1 "Бк"^-1; S is area of accumulation chamber base , m²; 6.3·10^-3 is factor to allows for contribution of radon (²²²Rn) into total escape of alpha-particles from radon and products of is decay inside accumulation chamber and accumulation of thoron and its radioactive decay for 6 minutes, s^-1.

EFFECT: simplified procedure.

1 dwg, 1 tbl