Thinned Silicon Neutron Detector with Inverted Radiator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional neutron detectors face challenges in accurately measuring low-energy neutrons due to reduced sensitivity and erroneous detection of gamma rays, particularly in the energy range of 0.5 MeV to 1 MeV, which is critical for health and safety management.
Innovation Solution
A neutron detector with a thinned Si semiconductor layer of 30 µm to 100 µm thickness, featuring a radiator with 10B or 6Li, and a configuration where the incident surface for neutrons is opposite to the conventional design, allowing for high sensitivity detection of neutrons in the 0.5 MeV to 1 MeV range without interference from gamma rays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a standard thickness Si semiconductor layer (about 400 μm) is used, then the detector can detect neutrons, but gamma rays cause erroneous detection and sensitivity for low energy neutrons is reduced
Solution Approach 1:
The patent applies parameter changes by reducing the Si semiconductor layer thickness from the conventional 400 μm to 30-100 μm. This parameter change allows low energy neutrons (0.5-1 MeV) to effectively reach the depletion layer while reducing gamma ray induced noise, thereby improving neutron detection accuracy and reducing gamma ray interference simultaneously.
2Measurement precision
If the Si semiconductor layer is thinned to 30 µm to 100 µm, then sensitivity for low energy neutrons improves, but the detector structure becomes more complex
Solution Approach 1:
The patent applies inversion by reversing the conventional detector configuration. Instead of placing the radiator on the incident neutron side with the depletion layer at the opposite side, the patent places the radiator on the opposite side from the incident neutron side, allowing neutrons to pass through to the depletion layer while enabling effective detection of low energy neutrons with thinned semiconductor layers.
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 detector effectively measures neutrons from thermal energies up to 15 MeV, ensuring accurate dose management in nuclear power plants, accelerator facilities, and medical treatments, with enhanced sensitivity and reduced gamma-ray interference.
Implementation Method 1
a radiator (8) which converts neutrons into charged particles (protons, alpha rays and tritons)
Implementation Method 2
The protons which injected into the element collide with Si atoms in the depletion layer and ionize Si, enabling the resulting charge to be detected
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A neutron detector having high sensitivity of detection for low energy neutrons is provided. The neutron detector 10 includes a detecting element including a Si semiconductor layer 2, a first electrode 1 formed on one main surface of the Si semiconductor layer 2 and a second electrode 4 formed on the other main surface of the Si semiconductor layer 2, in which the Si semiconductor layer 2 includes a P-type impurity region 2a in contact with the second electrode 4 and an N-type impurity region 2b in contact with the first electrode 1; and a radiator 8 arranged to face the first electrode 1. In addition, a personal dosemeter and a neutron fluence monitor including the same are provided.