Application of LSC and TLD methods for the measurement of radon and thoron decay products in air.

Liquid scintillation counting (LSC) is a measuring technique, broadly applied in environmental monitoring. One of the possible applications of LSC is the measurement of radon and thoron progeny. Such a method can be stated as an absolute one. For long-term measurements, a different technique can be applied-monitors of potential alpha energy concentration (PAEC) with thermoluminescent detectors (TLDs). Such solution enables simultaneous measurements of PAEC and dust content. Moreover, the information which is stored in TLD chips is the energy of alpha particles and not the number of counted particles. Therefore, the readout of TL detector directly shows the potential alpha energy, with no dependence on equilibrium factor, etc. This technique, which had been used only for radon progeny measurements, was modified to allow simultaneous measurements of radon and thoron PAEC.