JACOBI AND ANDRE 3808 TABLE 1. active equilibrium near ground level heights (see Table An experimental Calculated Deviation of Radioactive Equilibrium between Rn”? and Its Short-Lived Decay Products Activity Ratio the boundary layer of the radioactive equil 1.00 rium between Rn™ and Pb™ or Bi™ is possi by simultaneous measurements of Rn™with ion chamberorthe scintillation chamber met! and of Pb™ and Bi™ by the filter method. low turbulence (cases IWN and WNN) the deficiency is rather large near ground level b ut though in a rather undefined terrain, were m: by Jacobi et al. [1959]. The average Bi™/R ratio for 35 measurements at a height of 1 to meters—most of them during daytime—was to 0.5; radioactive equilibrium was found c during rather strong inversions at night anc the morming. Minimum values of about 0.2 0.3 were observed in the noon and afternoo: An exact proof of the theoretical results quires measurements of the Rn™ and fT (Bi™) profiles in the boundary layer during riods of rather constant atmospheric stabil Nuclide Ratio Pot4/Rn® Pb**/Rn2 + ms Bi?4 /Rn* 0.1 IWN 0.66 WNN 0.56 NNN 0.77 SSN 0.90 IWN 0.31 WNN 0.31 NNN 0.66 SSN 0.83 IWN 0.23 WNN 0.25 NNN 0.63 SSN 0.80 Height, m 1 10 0.98 0.85 0.88 0.938 0.73 0.54 0.76 0.85 0.62 0.45 0.7 0.82 1.00 0.99 0.95 0.96 0.99 0.82 0.84 0.88 0.97 0.73 0.80 0.84 100 few simultaneous measurements of this ki 1.00 1.00 0.98 1.00 0,99 0.94 Q.9L 1.00 0.88 0.90 0.88 decreases rapidly with increasing height. With But the theoretical results demonstrate the increasing turbulence the deviation from radio- sibility of obtaiming valuable information on 10" Specific activity (dps/cm’) wo Turbulence Case with Rn™ will be smal but will extend to grea 1). proof of the disturbance —— eee -_———— 10 owe ee wee ee ——— oo 16 1C lem 10cm Im 10m com 1km 10km 30kr Altitude Fig. 7. Vertical profiles of Pb™° and Po”, calculated with Ero = 1 Rn atom/cm* see and with the K profile NNN (parameter 7 = half-life of removal).