A Small Radioactive Source in a Large Media –Localization by Multi-detector Measurement.The Case of a Lung Counter

摘要

Considerable errors in the determination of radioactive contamination in lungs can beinduced if there is no homogeneous distribution, as assumed for the calibration. Modern lungcounter systems use several detectors, and the count rate ratios of the detectors can be used forlocalization of the radioactive contamination, enabling the use of correction algorithms. Thisgreatly reduces the errors in the determination of the activity. Further reduction of the errors canbe obtained by simultaneous analysis of several gamma lines (if several energies are emitted bythe radioisotope), and by optimizing the number and location of the detectors. This presentationdeals with the case of a point source of natural uranium in human lungs.