BACKSCATTER ENERGY ANALYSIS FOR CLASSIFICATION OF MATERIALS BASED ON POSITIONAL NON-COMMUTATIVITY

摘要

A system and methods for characterizing regions within, or on, an inspected object, wherein a lower-Z scattering material and a higher-Z material both lie along a common line of sight. The inspected object is scanned with penetrating radiation characterized by an energy distribution, and penetrating radiation scattered by the inspected object is detected in a manner that generates a first detector signal that distinguishes between materials of higher and lower effective atomic number under a first set of conditions with respect to the energy distribution of the penetrating radiation and a second detector signal that distinguishes between materials of higher and lower effective atomic number under a second set of conditions with respect to the energy distribution of the penetrating radiation. An image is generated, based on a function of the first detector signal and the second detector signal, while the first and the second detector signals are also combined to create a differential image, so as to allow distinction of higher-Z and lower-Z materials.