In environment radiation measurement, calculation the correction factors are critical, especially for low energy measurement because of self-absorption phenomena. In this work the main purpose is to determination the self-absorption correction factors of lead-210 (210Pb) energy (46.5keV) in various environment samples (7 sediments, 5 soil) using an experimental method called Spike Method. The samples were collecting from different places in Syrian. They were prepared according to the laboratory producers starting from collecting, cleaning, drying, grounding, hemogenic and calculating the appearance density. Low-energy gamma spectroscopy HPGe was used for radiation analysis which available at the laboratories of the Protection and Safety Department - Syrian Atomic Energy Commission – Syria. The spike method depends on adding a quantity of a standard solution with a known activity which contains lead isotope 210Pb and added to the studied samples. Self-absorption correction factors (CF) calculated by the ratio of the count rate or activity of spiked and unspiked samples. The CF for sediment samples were between 29% to 54% and for soil samples, the CFs were between 38% to 56% recording correction higher than sediment samples. The results showed a relatively high self-absorption and CFs values because of the chemical composition changeable between the spiked and unspiked samples. For that, it is better to adopt other methods less expensive, give results faster, higher accuracy and do not make change in the chemical composition. The results were also showed the density factor is the most influential factor in self-absorption phenomena.

This study aimed to determine the self-absorption correction factors of lead-210 (210Pb) in various Syrian environment samples. Seven sediments, five soils, and four plant samples were analysed by Gamma Spectroscopy using simple and direct analysis method called Cutshall. The method is based on measuring the penetration of gamma which emitted from a standard source, prepared in the laboratory by deposition of QCYB40 Standard Solution on stainless steel disk. The source was placed on top of the studied sample and the reference air sample during the measurement. The purpose was to study the self-absorption inside each sample by calculation of its self-absorption factors without knowing its chemical composition. The self-absorption correction results for the sediment samples SE3, SE6 and SE8 ranged between 36% and 45%, and 34% to 42% for the soil samples S5 and S1, respectively. Also, for the four plant samples, it recorded variance range from 4% to 18%. This is due to the difference in the density of the G4 sample, which appeared to be very low. However, the self-absorption correction factors CF were set for the different environmental samples, and the results show that the density factor of the sample is not the only influent factor in the CF values for low energies measurement, the sample chemical composition (sample matrix) is also more effective in addition to the samples’ particle sizes.

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