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001-es BibID:BIBFORM019350
Első szerző:Papp Zoltán (fizikus)
Cím:Measuring radon progeny and thoron progeny in air by absolute beta counting subsequent to grab sampling / Z. Papp, Z. Dezső
Megjegyzések:A new grab sampling method for the simultaneous determination of radon progeny and thoron progeny in air has been developed anddemonstrated by the first author of this paper a few years ago. The characteristics and capabilities of this method are discussed in the presentpaper in detail. The method is based on gross beta counting of filtered aerosol samples counted over successive time intervals using an end-window Geiger-Müller counter. The measured counting rate versus time curve is analyzed by fitting to it some linear combination of thetheoretical decay curves of the decay products with the knowledge of the counting efficiencies and some other quantities. Defined solid angleabsolute beta counting was used to evaluate the counting efficiencies for the decay products one by one. So, the method is an absolute one thatdoes not demand further calibration. The decay products of radon and thoron can be determined separately and simultaneously. The systematicerror of the results, deriving from the inaccurate evaluation of the counting efficiencies, is probably lower and can be estimated more surelythan that of the methods based on alpha counting. The method is highly sensitive: accurate results can be obtained for 214Pb, 214Bi, 212Pb,EEDC222 and EEDC220 even outdoors. However, the results for 218Po and 212Bi are much more inaccurate and 208Tl cannot be determined atall. The reliability of the determinations can be raised significantly using conditional computations based on the information obtainable fromsome theoretical considerations and models. The method can be used in a broad activity concentration range, equally in caves, mines, housesor outdoors. The above characteristics and capabilities of the method are demonstrated in this paper through the detailed presentation andanalysis of the results obtained for three samplings performed indoors in a house, in a cave, and outdoors, respectively. The known advantagesand drawbacks of the method are also surveyed in detail.
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Radon progeny
Thoron progeny
Grab sampling
Beta counting
Geiger Muller counter
Megjelenés:Radiation Measurements. - 41 : 5 (2006), p. 617-626. -
További szerzők:Dezső Zoltán (1947-) (fizikus)
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