X-ray inspection based on scatter detection

Abstract

Systems and methods for inspecting an object with a scanned beam of penetrating radiation are disclosed. Scattered radiation from the beam is detected, in either the backward or forward direction. Characteristic values of the backscattered radiation are compared to expected reference values to characterize the object. Additionally, penetrating radiation transmitted through the inspected object may be combined with scatter information. In certain embodiments, the inspected field of view is less than 0.1 steradians, and the detector is separate from the source of penetrating radiation and is disposed, with respect to the object, such as to subtend greater than 0.5 steradians in the field of view of the object.

Description

technical field [0001] The present invention generally relates to inspection systems based on remote detection of penetrating radiation scattered by an object under inspection. Background technique [0002] X-ray scattering can be applied to inspect people, vehicles, cargo or other objects of interest. The term "object" is used collectively herein to encompass any of the above. In systems employing X-ray scattering, the X-rays are formed into beams directed towards an object of interest. When the beam hits an object, an X-ray detector is used to capture the scattered X-rays, and various properties of the scattering object are determined either globally or relative to the pixel image of the object. [0003] The resolution of information obtained about an interrogated object or person depends on several factors, including the distance between the inspection system and the object and the magnitude and energy spectrum of the X-ray flux. In current systems, as the distance bet...

AI Technical Summary

Problems solved by technology

These low-energy X-rays are then greatly attenuated by the steel body of the vehicle, resulting in a greatly reduced amount of scattered X-rays being detected in the backscatter detector

This problem is often exacerbated because the scattered X-rays reaching the backscatter detector have passed through the intervening steel surface at an oblique angle, resulting in an effective thickness of the steel that is greater than the actual gauge of the steel

Images