Abstract
Minimum detectable body radioactivity, the relation between the detection efficiency and source to detector distance, state of sources, dependence of detection limit to γ-ray energy and influence of the variation of background level are studied with a simple scintillation counter widely used in radiation facilities. The results show that most of γ-emitting nuclides of 0.1μCi are able to detect by a simple scintillation counter in the room without special shielding.
Effect of collimating shield of the detector to detection limit and the relation between the optimum counting condition and the background level, partition of counting time for sample and background are discussed.
