Abstract
Recently, a technique using an imaging plate (IP) is applied for the 90Sr concentration determination. However, this IP technique has some difficulties on the determination of absolute values. A difficulty is found in manufacturing the standard source with some kinds of form, though the thickness of the tooth which can be obtained is various. On be half of manufacturing various standard sources, we propose the IP technique combined with self-absorption correction in sample calculated using MCNP Monte Carlo code.At first, the validity of the calculation method was examined through an experiment using standard sources. The standard sources consist of the mixture of paraffin, the powders of extracted tooth dentin from a Techa River area resident and standard bone. They were used for preparation of the pellets melted into aluminum block, with 37.6, 20.9,10.8 Bq/g of 90Sr. Calculated energy deposit in imaging plate (MeV/mm2) was compared with measured signal (PSL/mm2) with respect to their radial distributions, i.e. for various radius of tallies. Experimental and calculated data are in good agreement, which suggests the validity of the calculation method used in the present study. Second, the proposed method is tested on the determination of 90Sr concentration in the tooth of the mammal (cow) offered from Mayak, the first nuclear plant in former Soviet Union. As a result, it was found that the accuracy of 90Sr determination can be improved by the present method.
