Remote Explosive Detection via Rotatable Neutron Shield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current explosives detection technologies, such as Thermal Neutron Activation Analysis (TNAA), face challenges in detecting improvised explosive devices (IEDs) due to high false alarm rates and reduced detection rates in environments with nitrogen-rich materials, and lack the capability to effectively detect IEDs at a standoff distance, leading to increased inspection times and civilian casualties.
Innovation Solution
A portable detection apparatus using a thermal neutron beam generator, gamma ray detector, data collection modules, and a detection processing module, which directs a thermal neutron beam at a remote target, intercepts and processes gamma rays to determine the presence and location of explosive substances, minimizing background noise and improving signal-to-noise ratio through a bistatic orientation and independent rotatable neutron shields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Thermal Neutron Activation_analysis is used to detect explosives in nitrogen-rich environments, then detection capability is provided, but false alarm rate increases and detection rate decreases due to high background noise from nitrogen and silicon
Solution Approach 1:
The patent applies local quality by focusing the neutron beam on specific target areas and using energy-selective detection to isolate the 10.83 MeV gamma ray signal from nitrogen-14 against the background noise. The system selectively enhances the signal of interest while suppressing unrelated signals through spatial and spectral localization.
Solution Approach 2:
The patent extracts the harmful background noise components (gamma rays from silicon at 10.6 MeV and other nitrogen emissions) from the detection signal and removes them through energy discrimination. By extracting only the 10.83 MeV gamma rays associated with nitrogen-14 activation, the system eliminates interfering signals while preserving the explosive detection capability.
2Reliability
If detection is performed at close proximity to IEDs, then detection capability is achieved, but inspection time increases and standoff distance requirement cannot be met
Solution Approach 1:
The patent transitions from close-proximity detection to remote detection by utilizing the isotropic emission of gamma rays in all directions. This dimensional change in detection geometry allows the system to detect explosives at significant standoff distances while maintaining detection capability, thereby reducing inspection time and improving operational safety.
3Reliability
If conventional TNAA is used for landmine detection, then detection is provided, but signal-to-noise ratio decreases due to silicon gamma ray interference
Solution Approach 1:
The patent extracts and removes the interfering silicon gamma ray signal (10.6 MeV) from the detection spectrum through energy discrimination. By isolating and excluding this harmful signal component, the system restores the signal-to-noise ratio and enables accurate detection despite the presence of silicon-rich environments.
Solution Approach 2:
The patent changes the detection parameter from total gamma ray counting to energy-selective gamma ray detection at 10.83 MeV. This parameter change allows the system to distinguish between nitrogen-14 activation signals and silicon interference, thereby improving the signal-to-noise ratio in silicon-containing environments.
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 effective detection and location of IEDs at a standoff distance, reducing false alarms and increasing detection rates, thereby reducing civilian and friendly casualties and deterring IED attacks by improving the signal-to-noise ratio and allowing for safer routine patrols.
Implementation Method 1
explosives can be detected by bombarding them with thermal or slow neutrons of kinetic energy levels of approximately 0.026 eV, then detecting the resulting gamma rays
Implementation Method 2
Nitrogen-14, when bombarded by a thermal neutron, emits a strong gamma ray at 10.83 MeV
Implementation Method 3
detecting the resulting gamma rays
Data Source
AI summary
Apparatus and method for detecting and locating hidden explosive substances. The detection apparatus includes a thermal neutron beam generator, a gamma ray detector, data collection module and sensors, and a detection processing module. The thermal neutron beam generator includes a fast neutron source, a neutron moderator to slow the fast neutrons to thermal neutrons, and a rotatable neutron shield enclosing the generated thermal neutrons. The rotatable neutron shield has an aperture through which a thermal neutron beam is projected at a remote target. Gamma rays radiating from hidden explosives in the remote target are detected by the gamma ray detector, while the associated detection processing module spatially locates the target based at least in part on the position of the aperture in the rotatable neutron shield.