Muon Tomography for Shielded Nuclear Material Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current detection systems for nuclear materials and threats, such as gamma and X-ray detectors, are limited by shielding effects, which reduce their effectiveness in detecting shielded nuclear materials and objects, and often require the use of artificial radiation, whereas cosmic ray imaging and sensing techniques can provide non-destructive inspection without radiation dose above the Earth's background.
Innovation Solution
The use of cosmic ray-produced muons and electrons for tomographic imaging and sensing, where the scattering of these particles is measured to detect high atomic mass materials like special nuclear materials (SNM) within a volume of interest, utilizing arrays of drift-tube sensors and signal processing to analyze the point of closest approach and scattering angles to identify potential objects and determine their likelihood of being threatening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gamma and X-ray detectors are used to detect nuclear materials, then detection capability is improved, but shielding effects reduce effectiveness and artificial radiation is required
Solution Approach 1:
The patent uses cosmic ray muons as an intermediary detection mechanism. Instead of using artificial gamma or X-ray sources that are blocked by shielding, the system employs naturally occurring cosmic ray muons that can penetrate through shielding materials. The muon scattering angle serves as an intermediary measurement that indirectly reveals the presence of nuclear materials behind shielding, overcoming the limitation of direct radiation detection.
2Object-affected harmful factors
If cosmic ray muons are used for detection, then shielding effects are overcome and non-destructive inspection is achieved, but measurement precision must be maintained
Solution Approach 1:
The patent replaces direct radiation measurement (mechanical/electromagnetic interaction) with scattering angle measurement. Instead of measuring the intensity of transmitted radiation which requires high precision to detect small changes, the system measures the scattering angle of muons, which provides a more robust signal that is less susceptible to noise and shielding effects, thereby maintaining measurement precision while achieving better penetration.
Solution Approach 2:
The patent changes the detection parameter from radiation intensity (used in gamma/X-ray detection) to scattering angle (used in muon detection). This parameter change allows the system to overcome shielding effects because scattering angle is less affected by attenuation, while maintaining detection accuracy through precise angular measurement and statistical analysis of multiple muon trajectories.
3Adaptability or versatility
If multiple detection instruments are used to identify different materials, then detection coverage is improved, but device complexity increases
Solution Approach 1:
The patent makes the cosmic ray muon detection system universal by demonstrating its ability to detect multiple types of materials (nuclear materials, dense metals, and other high-Z materials) using a single detection mechanism. The muon scattering technique serves multiple functions: it can identify nuclear materials, distinguish dense metals from ordinary materials, and provide tomographic imaging, eliminating the need for separate specialized detectors for each material type.
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 enables robust detection of nuclear materials and threats with reduced costs and increased effectiveness compared to traditional systems, providing a non-destructive inspection capable of identifying shielded nuclear materials without the need for separate instruments, and offering improved resolution and accuracy in identifying the presence and type of objects.
Implementation Method 1
Coulomb scattering from atomic nuclei in matter results in a very large number of small angle deflections of charged particles as they transit the matter
Implementation Method 2
Coulomb scattering from atomic nuclei in matter results in a very large number of small angle deflections of charged particles as they transit the matter
Data Source
AI summary
Techniques, systems, and devices are disclosed for analyzing a point of closest approach (PoCA) image of a volume of interest (VOI) comprising a set of recorded PoCA points from charged particle detector measurements to detect an object within the VOI. The VOI is partitioned into a set of equally-sized bins with each bin including a subset of the PoCA points. A bin metric is determined for each bin. A subset of the bins is selected based on the detected bin metric with the subset of bins being most likely to contain objects. A potential object for each selected bin is determined by determining a location and a size for the potential object based at least on the PoCAs inside the bin. A figure of merit (FOM) of the potential object is determined as a measure of the likelihood that the potential object is truly a threat object.