Material Differentiation by Differential Computed Tomography

This paper presents the study on the feasibility of a differentiation of the individual materials using so called dual energy computed tomography. The individual pixels on tomogram are the results of X-ray attenuation penetrating through the sample from different angles of projections. Attenuation is caused by absorption and scattering of radiation. The contribution of these two main mechanisms is dependent on atomic number, electron density, and also the energy of the X-ray photons. The material characteristics may be quantitatively analyzed when the composition in to atomic number or density information is carried out. Therefore, two different X-ray spectra were used by application of filters. The principle of proposed method results in a numerical approach with the associated detector calibration. We tested first the method on the samples of known composition. From the results it was shown that we are able to obtain removal of “beam hardening ” and the estimation of material composition. For further more precise determination of materials, the proposed method will be used with the respect to detector acquisition improvement. [doi:10.2320/matertrans.I-M2011851