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.

► The radon-induced background of ten high-resolution gamma-ray spectrometers is presented.
► The correlation between the background and the outdoor temperature is described.
► The photon flux density normalized to unit of emission probability and efficiency is used.
► The locations of the contamination, inducing the background, are determined.
► The gain in the uncertainty of the background used for sample analysis is assessed.