71^{71}Ge als Quelle für die energiedispersive Röntgenfluoreszenzanalyse im Bereich 13 < Z < 30

Durch zahlreiche Beispiele wird gezeigt, daß eine durch Aktivierung in einem Forschungsreaktor herstellbare $^{71}$Ge-Quelle in Verbindung mit einem Si(Li)-Spektrometer ein für die analytische Untersuchung verschiedenster Proben vorzüglich geeignetes Röntgenfluoreszenzspektrometer bildet, das kompakt, vollautomatisierbar und transportabel ist und für die Bestimmung von Elementen zwischen Al und Zn eingesetzt werden kann. Die Empfindlichkeit und optimale Geometrie des Systems wurden untersucht

Reconstruction of individual cumulative radon exposures by low-level in vivo measurements and biokinetic modeling.

In vivo skull measurements of Pb-210 have been performed to assess the individual, chronic exposures of two persons living for 28 years in a house with a distinctly enhanced radon concentration of more than 10,000 Bq/m(3). A partial body counter consisting of 4 HPGe detectors, which were placed close to parietal positions of the head, was used in the study. The lower limit of detection of Pb-210 activity in the skeleton was found to be 40 Bq. Lead-210 activities of up to 152 Bq were found in the test persons, whereas no activity could be measured in an unexposed control person. The cumulative uptake of Pb-210 into the body was assessed for each single test person by using the ICRP respiratory tract and the biokinetic models. A fairly good agreement (within a factor of 2) between in vivo measurements and model was achieved for these two test persons. The technique used in the study may be a useful tool to evaluate assumptions, which have to be made for the reconstruction of individual, cumulative exposures to high radon concentrations

Study long-term radon progency in humans for retrospective evaluation of radon exposure 412 Springer.

An individual in vivo monitor using seven Germanium detectors with a total area of 24,000 mm^2 was prepared for ^210Pb skull measurements. System calibration with anthropomorphic head phantoms and a straightforward efficiency estimation yielded a minimum detectable activity (MDA) of 6.7 Bq and a lower limit of detection (LLD) of 14 Bq (CL: 95%). Two selected persons were measured for 1 h each to reconstruct their cumulative radon exposure. From the added pulse height spectrum a ^210Pb activity in the skull of 3.1±7.2 Bq (result with 95%-CL) was estimated, but clear conclusions on their radon exposure using a new metabolism model of lead in man could not be drawn. Further improvements in the selection of highly exposed persons as well as head calibration and Lackground reduction are necessary using this attempt for retrospective exposure reconstruction