ABSTRACT: Accurately measuring Rn-220 is crucial for evaluating natural radiation exposure. For the large volume of normal scintillation cell, the detection efficiencies for different energy of α particles decayed from Rn-222, Rn-220 and their progeny are varied. To address this, two systems of the low-pressure scintillation cell were designed to make the shortest range of α particles with minimum energy decayed from Rn-222 longer than the longest distance between any two points in the scintillation cell by reducing air pressure. Thus, the de...
