Uranium-induced background of germanium gamma-ray spectrometers

The uranium-induced background in eight high-resolution gamma-ray spectrometers was analyzed in order to identify the locations of its sources. On the basis of the energy dependence of the peak count rates, normalized to units of emission probability and detection probability, the contributions of the molecular sieve and the beryllium window were extracted. Based on the uncertainties achieved the contribution of the detector shields could not be observed. However, some correlations between the construction of the detectors and the values of the parameters describing the energy dependence were observed and the uranium activity in the beryllium windows was assessed.

► Sources of uranium-induced background of gamma-ray spectrometers were located.
► Uranium contamination of the detector materials was found to induce the background.
► Molecular sieve and the beryllium window were identified as the strongest sources.
► No contribution of the shields to the uranium background could be determined.
► Uranium activity of the beryllium windows was assessed.