Neutron Backscatter Inspection for Inaccessible Infrastructure Defects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current non-destructive inspection methods using neutron beams cannot effectively detect defects inside infrastructure like road surfaces and tunnel walls without placing a neutron detector on the inner side, as transmission images cannot be obtained due to the geometry of these structures.
Innovation Solution
A non-destructive inspection device that uses a pulse neutron beam to radiate the surface of an inspection target, detects scattered neutrons, and generates detection number data over time, allowing for the determination of defects without requiring a neutron detector on the inner side by analyzing the energy and timing of returned neutrons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a neutron detector is disposed on the inner side of the inspection target to obtain a transmission image, then the inspection precision is improved, but the ease of operation deteriorates due to the inability to access the inner side for infrastructure like road surfaces and tunnel walls
Solution Approach 1:
Instead of placing the detector on the opposite side of the inspection target (transmission mode), the patent inverts the detection approach by placing the detector on the same side as the neutron beam incidence (reflection mode). This allows inspection of infrastructure like road surfaces and tunnel walls where the inner side is inaccessible, while still detecting defects through neutron scattering signals from the defect locations.
2Measurement precision
If a transmission image method is used to inspect defects inside the inspection target, then the measurement precision is improved, but the device complexity increases due to the requirement of disposing detectors on both sides
Solution Approach 1:
The patent simplifies the device configuration by inverting from transmission mode (requiring detectors on both sides) to reflection mode (requiring detector on one side only). This reduces device complexity while maintaining defect detection capability through the use of scattered neutron detection and integrated value calculation.
3Productivity
If the detection time window is set to capture early returning neutrons, then the productivity is improved by reducing measurement time, but the measurement precision deteriorates due to inclusion of high-energy neutrons that do not indicate defects
Solution Approach 1:
The patent uses periodic action by dividing the neutron detection into time-gated intervals. It sets a specific time window that starts after the pulse neutron beam is radiated and ends before high-energy neutrons return, allowing selective detection of scattered neutrons from defects while excluding high-energy neutrons that do not indicate defects.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the time window parameters (start time and end time) based on the neutron flight time characteristics. This allows optimization of both productivity and measurement precision by setting the time window to capture defect-indicating neutrons while excluding high-energy neutrons.
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
Enables the detection of defects, such as water or cavities, inside infrastructure by differentiating between high-energy and low-energy neutron returns, determining their presence based on integrated values exceeding or falling below standard thresholds.
Implementation Method 1
a neutron detection device that detects scattered neutrons that are scattered in the inspection target and returned
Data Source
AI summary
A non-destructive inspection device 10 using backscattering of neutrons includes a neutron source 3 that radiates a pulse neutron beam to a surface 1a of an inspection target 1, a neutron detection device 5 that detects scattered neutrons scattered in the inspection target 1 and returned, and a measurement device 7 that measures the detection number of scattered and returned neutrons detected by the neutron detection device 5 and generates detection number data expressing the detection number with respect to time.