Limit Capabilities of Identifying Materials by High Dual- and Multi-Energy Methods

A method is considered for identifying materials in large-sized test objects by high dual- and multi-energy methods based on assessment of effective atomic number. An algorithm is presented for processing original images produced by dual- and multi-energy methods. The algorithm allows one to determine the effective atomic number of the material of the test object and its fragments. It is proved by a computational experiment that the ADC digit capacity and the mass thickness and effective atomic number of the test-object material have a significant effect on the quality of material identification. The necessity of prefiltering bremsstrahlung to ensure the prescribed identification quality for small thicknesses of fragments of studied objects is substantiated. An algorithm is provided for assessing the limit capabilities of the proposed method in material identification. The fundamental possibility of distinguishing between the following materials has been experimentally proved by numerical modeling: light organics (Z = 6); mineral materials (Z = 9); light metals (Z = 13); calcium (Z = 19); metals (Z = 26); heavy metals (Z > 50).