Fast Neutron Detector Using Silicon Substrate Conversion
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Solution Overview
Problem
Standard PIPS detectors are ill-suited for detecting neutral particles, such as neutrons, due to their reliance on the photovoltaic effect for charged particles.
Innovation Solution
Modifying the PIPS detector by incorporating a substrate that can react with neutrons, such as silicon 28, to generate observable signals, allowing for the indirect measurement of neutron flux.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If standard PIPS detectors are used to detect charged particles, then the detector responds reliably to charged particles, but the detector cannot detect neutral particles such as neutrons
Solution Approach 1:
The patent introduces an intermediary conversion mechanism where neutrons interact with the silicon substrate to produce charged particles (protons, alpha particles, or electrons) through nuclear reactions. These intermediary charged particles then trigger the photovoltaic effect in the PIPS detector, enabling indirect detection of neutral neutrons while maintaining the detector's original charged particle detection capability.
Solution Approach 2:
The modified PIPS detector achieves multi-functionality by incorporating neutron-sensitive materials (such as boron-10, lithium-6, or helium-3) into the silicon substrate. This allows the same detector to universally detect both charged particles (through the photovoltaic effect) and neutral particles (through nuclear reactions), eliminating the need for separate detection systems.
2Adaptability or versatility
If SiPM detectors are used to detect neutrons through photon generation, then neutron detection is enabled, but the detector becomes sensitive to photons generated inside the detector creating background noise
Solution Approach 1:
The patent extracts the photon detection function from the neutron detection process by using a dedicated scintillator material that converts neutron interactions into light photons. These photons are then transmitted through optical coupling to a separate photodetector, separating the neutron interaction region from the signal readout region and eliminating internal photon background noise.
Solution Approach 2:
The patent replaces the direct electrical signal generation mechanism of SiPM with an optical coupling system. Instead of using the photovoltaic effect directly in the silicon substrate, the system uses scintillation light transmission through optical fibers or lenses to a photodetector, substituting the detection mechanism to avoid internal photon generation issues.
3Reliability
If fiberoptic cables are used to transmit photons from neutron interactions, then photon transmission is achieved, but the system complexity increases
Solution Approach 1:
The patent merges the scintillator material directly with the optical coupling element, integrating the photon generation and transmission functions into a single compact assembly. This consolidation eliminates the need for separate fiberoptic cables and reduces the overall system complexity while maintaining reliable photon transmission.
Data Source
AI summary
Fast neutron detectors using nuclear reactions within semiconductor material, glass, or other material. Some versions used doped versions of the materials. Some versions use dopants selected from Ba, As, Br, C, Ce, Cl, Co, Cu, F, Ga, Ge, In, Cd, Te, Al, P, K, La, Mo, Nd, O, Os, Pr, S, Se, Si, Sn, Sr, Ti, Tl, V, Zn, and Zr. Some versions have filters or coatings deposited on windows into the detector. Coatings are selected from titanium oxide, zinc oxide, tin oxide, copper indium gadolinium selenide, cadmium telluride, cadmium tin oxide, perovskite photovoltaic, Si, GaAs, AlP, Ge.