A comparative study of the radon-induced background in low-level gamma-ray spectrometers.

The radon-induced background of ten, high-resolution, germanium, gamma-ray spectrometers was analyzed. In the analysis the apparent activity was introduced, which is defined as the peak count rate normalized with respect to the emission probability and the detection probability. On the basis of its energy and time dependence, the contributions to the background count rates due to the radiation penetrating the shield and the radiation due to the contamination of the air with radon daughters were determined.