Measurements of Radon and Thoron Decay Products in Air. an Application of Lsc and Tld Methods

Liquid Scintillation Counting (LSC) is a measuring technique, broadly applied in environmental monitoring of different radionuclides. One of the possible applications of LSC is the measurement of radon and thoron progeny. There are certain advantages of this method, especially high counting efficiency for alpha and beta particles emitted by radon and thoron progeny. This advantage has been pointed out several years ago, when such methods were applied to calibration of portable monitors for radon progeny, especially due to the fact that in the case of radon progeny no standard atmosphere exists. Radon and thoron progeny might be collected on a filter, which after immersion in the liquid scintillator becomes transparent and can be counted without significant quenching. Therefore such a method can be stated as an absolute one and can be widely used for radon progeny monitoring. Both methods, LSC and TLD, can be used for calibration of decay product monitors. The LSC method has the advantage to be an absolute one, the TLD method to measure directly the (dose relevant) deposited energy.