Results obtained with LEGe detectors applied for partial-body counting in the low-energy range (3-150 keV)

Due to a change in the field of duties, the Phoswich detector hitherto used for organ and partial-body scanning for measuring low-energy γ radiation and X-radiation had to be replaced by a modern detector system. A key application of the new system is detection and in vivo measurement of 210Pb in the human skeleton. This method of measuring 210Pb as a long-lived daughter product of radon is applied for retrospective assessment of radiation doses emanating from the radon decay chain, applied to former uranium miners (WISMUT) and members of the population living or having lived in houses with high radon concentrations. The bone activities to be expected from relevant exposures are only slightly above those of the normal 210Pb content in the bones (10-30 Bq), and the Phoswich detector system was not able to detect incorporated activity down to these low levels. The new system was also tested for its suitability and efficiency in detecting radionuclide depositions in body organs, particularly the actinides that are difficult to identify, in compliance with the relevant regulatory guide. (orig./CB)