X-ray Article Inspection Device Using Scattering Photon Ratios
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for inspecting dangerous goods, such as explosives, chemicals, and nuclear materials, face challenges in accurately distinguishing between materials based on atomic density and chemical elements, particularly failing to form precise three-dimensional images, which limits their detection sensitivity and accuracy.
Innovation Solution
The article inspection device employs a scattering detector array with collimators and shields to differentiate between pair production and Compton-effect scattering photons, forming a three-dimensional image by calculating the ratio of pair production effect annihilation photons to Compton-effect scattering photons, allowing for precise atomic number determination across sub-regions of the inspected article.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional x-ray transmission solution is used, then a two-dimensional image representing mass thickness information can be obtained, but it cannot discriminate between thinner high atomic number articles and thicker low atomic number articles, resulting in insufficient detection accuracy for nuclear materials
Solution Approach 1:
The patent segments the detection process into multiple measurement modes (transmission mode and scattering mode) that capture different physical interactions. By dividing the detection into these separate modes and combining their information, the system overcomes the limitation of single-mode detection that cannot provide sufficient material discrimination information.
Solution Approach 2:
The patent transitions from two-dimensional transmission imaging to three-dimensional scattering imaging by detecting photons scattered at specific angles. This adds a new dimensional aspect (scattering angle and spatial distribution) to the detection, enabling material discrimination based on scattering patterns rather than just transmission attenuation.
2Measurement precision
If conventional nuclear resonance fluorescence solution is used, then fingerprint information of atomic nucleus can be obtained, but the small energy spectrum width causes great number of scattering photons and background interference, resulting in poor detection sensitivity
Solution Approach 1:
The patent extracts and isolates the Compton scattering photons at specific scattering angles from the background radiation field. By using collimators to define specific detection angles and energy windows to select Compton scattering photons, the system separates the useful signal from the harmful background interference.
Solution Approach 2:
The patent uses Compton scattering as an intermediary process to obtain material information. Instead of directly detecting nuclear resonance fluorescence which is overwhelmed by background, the system detects Compton scattering photons that provide atomic number information through their scattering characteristics, serving as a mediator between the x-ray source and the detector.
3Measurement precision
If conventional neutron transmission solution is used, then sensitivity to low atomic number materials containing hydrogen can be improved, but it can only obtain integration information along the neutron transmission path, resulting in inability to detect nuclear materials hidden in the article
Solution Approach 1:
The patent implements three-dimensional imaging by detecting scattered photons from multiple angles and positions around the article. This spatial distribution information is obtained by arranging detectors in a three-dimensional configuration and tracking the angular and positional information of scattered photons, enabling localization of materials within the article.
4Measurement precision
If elements concentration analysis solution using neutrons is used, then different elements can be discriminated based on gamma rays induced by neutron reactions, but it can only be adapted to nuclides with large neutron reaction cross section, resulting in inability to detect nuclear elements with small neutron reaction cross section
Solution Approach 1:
The patent changes the detection parameter from neutron reaction cross section dependence to Compton scattering dependence. By using Compton scattering of x-rays, the system becomes sensitive to electron density and atomic number rather than neutron reaction cross sections, thereby expanding applicability to include nuclear elements with small neutron reaction cross sections.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances detection sensitivity and accuracy by providing a three-dimensional image of the article, enabling better discrimination between different materials and improving the ability to detect nuclear materials, while reducing interference from background photons.
Implementation Method 1
an x-ray source for generating x-rays having an energy greater than 1.022 MeV and transmitting the x-rays through the article
Implementation Method 2
detecting pair production effect annihilation photon count and Compton-effect scattering photon count from the article
Implementation Method 3
detecting pair production effect annihilation photon count and Compton-effect scattering photon count from the article
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention discloses an article inspection device, comprising: a x-ray machine, a collimation unit (4), a transmission detector array (10) and a scattering detector array (12). The scattering detector array comprising a plurality of same scattering detector modules arranged in a matrix of i-rows and j-columns. A transmission cross section (8) of the article (7) transmitted by the x-rays is divided into a plurality of same sub-regions arranged in a matrix of i-rows and j-columns. The plurality of scattering detector modules arranged in i-rows and j-columns correspond to the plurality of sub-regions arranged in i-rows and j-columns one by one for detecting pair production effect annihilation photons and Compton-effect scattering photons from the respective sub-regions. Obtaining atomic numbers of the respective sub-regions based on a ratio of the pair production effect annihilation photon count to the Compton-effect scattering photon count, so as to form a three-dimensional image of the article. In addition, the present invention further discloses an article inspection method.