Rechargeable Solid State Neutron Detector Using Chalcopyrite Crystal
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Solution Overview
Problem
Current solid state radiation detectors, particularly those for neutron detection, are not rechargeable and require replacement of active isotopes, and existing neutron indicators require post-exposure processing, lacking a simple visual indication of radiation levels.
Innovation Solution
A rechargeable solid state neutron detector using a chalcopyrite crystal, such as 6LiInSe2, which changes color with neutron exposure due to the 6Li(n, α) reaction, allowing for reversible indication and recharge through annealing, enabling a visible and reusable radiation detection device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid state radiation detectors use active isotopes for neutron detection, then detection capability is improved, but the active element is consumed and cannot be recharged
Solution Approach 1:
The patent changes the chemical parameter of the crystal by diffusing lithium atoms into the chalcopyrite crystal structure. This parameter change restores the lithium concentration that was depleted by neutron absorption, thereby recharging the detector's active element and enabling repeated use without replacing the entire device
Solution Approach 2:
The patent uses a lithium source as an intermediary substance to restore the active element. The lithium source diffuses lithium atoms through the crystal structure, acting as a mediator that replenishes the consumed lithium-6 isotope without requiring replacement of the detector itself
2Device complexity
If passive neutron indicators are used, then device simplicity is improved, but post-exposure processing is required for analysis
Solution Approach 1:
The patent utilizes color changes in the chalcopyrite crystal as a visual indicator of neutron exposure. The crystal changes color based on lithium concentration, providing immediate visual feedback about radiation levels without requiring post-exposure processing or analysis equipment
Solution Approach 2:
The crystal serves itself as both the detection medium and the indicator. The color change occurs automatically in response to neutron exposure, eliminating the need for external processing equipment or analysis steps that would otherwise be required
3Reliability
If the active isotope concentration is reduced through neutron absorption, then radiation detection function is improved, but the crystal requires replacement instead of recharging
Solution Approach 1:
The patent changes the concentration parameter of lithium in the crystal by controlled diffusion. This allows the lithium concentration to be adjusted and restored after neutron absorption, transforming the crystal from a single-use detector to a rechargeable system that can be reset and reused
Solution Approach 2:
The patent performs preliminary action by pre-positioning a lithium source in contact with the crystal before use. This lithium source is ready to diffuse and recharge the crystal when needed, eliminating the need for complex recharging equipment and simplifying the manufacturing process
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
The chalcopyrite crystal provides a reversible and visible indication of neutron radiation levels, allowing for a reusable detection system that can be recharged, addressing the limitations of existing detectors by offering a simple, visual, and rechargeable solution for neutron detection.
Implementation Method 1
Neutrons impinging on the 6Li in the crystal undergo a 6Li(n, α) reaction, which transforms the 6Li atom into a charged particle and tritium
Implementation Method 2
The visible spectrum of the chalcopyrite crystal is changed back from the modified color to the initial color by annealing the chalcopyrite crystal at an elevated temperature below a melting point of the chalcopyrite crystal over time
Data Source
AI summary
A radiation detection device, including: a support structure; and a chalcopyrite crystal coupled to the support structure; wherein, when the chalcopyrite crystal is exposed to radiation, a visible spectrum of the chalcopyrite crystal changes from an initial color to a modified color. The visible spectrum of the chalcopyrite crystal is changed back from the modified color to the initial color by annealing the chalcopyrite crystal at an elevated temperature below a melting point of the chalcopyrite crystal over time. The chalcopyrite crystal is optionally a 6LiInSe2 crystal. The radiation is comprised of neutrons that decrease the 6Li concentration of the chalcopyrite crystal via a 6Li(n,α) reaction. The initial color is yellow and the modified color is one of orange and red. The annealing temperature is between about 450 degrees C. and about 650 degrees C. and the annealing time is between about 12 hrs and about 36 hrs.