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Exposure of Spectrometers and Dosimeters for Environmental Monitoring in the Radon Standard Chamber

27.01.2015

The major component of the natural radiation exposure of man is caused by radon and its progeny. Radon progeny may have a strong influence on the ambient dose equivalent rate. The direct influence of changing activity concentrations of radon-222 and its progeny in air on different spectrometer types, which may be used in environmental monitoring, was investigated in PTB's radon standard chamber (RSC). In the natural environment, the escaping of radon gas from the ground depends on ambient parameters such as temperature, air pressure and humidity. Due to the strong variability of the activity concentrations of radon and radon progeny, this influence on the measuring instruments should be known when a radiological early-warning system is operated.

In the RSC, different types of novel γ-spectrometers (LaBr3 and CeBr3 scintillation detectors as well as CdZnTe semiconductor detectors) were exposed under defined progeny atmospheres. The atmosphere is specified with respect to the activity concentrations of Rn-222, Po-218, Pb-214, Bi-214 and Po-214. In addition to spectrometers, dose rate measuring instruments were exposed in the same way in the RSC for systematic investigations to determine the direct influence of radioactive radon progeny on the measured dose rate.

These investigations were conducted under the auspices of the MetroERM project ("Metrology for radiological early warning networks in Europe"), which is carried out in the framework of EMRP, ENV57. Further information concerning this project is found in the separate report "Metrology for Radiological Early-Warning Systems in Europe".

Contact persons:
Opens window for sending emailH. Dombrowski, Department 6.3, Working Group 6.32
Opens window for sending emailP. Keßler, Department 6.3, Working Group 6.32
Opens window for sending emailA. Honig, Department 6.1, Working Group 6.13
Opens window for sending emailA. Röttger, Department 6.1, Working Group 6.13