Light propagation in a neutron detector based on 6Li glass scintillator particles in an organic matrix
Light propagation in a neutron detector based on 6Li glass scintillator particles in an organic matrix
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基于有机基质中 6Li 玻璃闪烁体颗粒的中子探测器中的光传播
DOI：
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发表时间：
2018
影响因子：
3.2
通讯作者：
K. Ianakiev
中科院分区：
文献类型：
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作者：
M. Hehlen;B. Wiggins;A. Favalli;M. Iliev;K. Ianakiev
由有机基质中的 6Li 闪烁体颗粒组成的复合材料可以使热中子探测器具有出色的伽马射线背景抑制能力。通过这种复合材料传输闪烁光的效率对于探测器的性能至关重要。复合热中子探测器的光学射线追踪研究量化了闪烁光损失的各种来源，并确定了有利的光电倍增管 (PMT) 读出方案。该复合材料由有机基质内的闪烁体立方体组成，形状为直立圆柱体。圆柱体表面被光学反射器包围，光线由附着在圆柱体端面上的光电倍增管（PMT）检测。与复合材料直接接触的反射器导致闪烁光损失 53%。通过在复合材料和反射器之间创建空气间隙，允许一部分闪烁光通过全内反射传播，这种损失减少了 8 倍。用固体丙烯酸基质代替液体矿物油基质，光传输效率仅降低约 10%，有利于创建全固态器件。研究发现，光传播损耗与闪烁事件和光电倍增管之间沿圆柱主轴线的距离成指数关系。这使得 PMT 读出方案能够逐个事件地校正光传播损耗，并实现 4.0% 的能量分辨率，接近泊松极限性能。这些结果表明，复合材料可以使热中子探测器应用于广泛的核不扩散和安全保障应用。由有机基体中的 6Li 闪烁体颗粒组成的复合材料可以使热中子探测器具有出色的伽马射线背景抑制能力。通过这种复合材料传输闪烁光的效率对于探测器的性能至关重要。复合热中子探测器的光学射线追踪研究量化了闪烁光损失的各种来源，并确定了有利的光电倍增管 (PMT) 读出方案。该复合材料由有机基质内的闪烁体立方体组成，形状为直立圆柱体。圆柱体表面被光学反射器包围，光线由附着在圆柱体端面上的光电倍增管（PMT）检测。与复合材料直接接触的反射器导致闪烁光损失 53%。通过在复合材料和反射器之间创建空气间隙，允许一部分闪烁光通过全内反射传播，这种损失减少了 8 倍。更换液体矿机...
Composite materials consisting of 6Li scintillator particles in an organic matrix can enable thermal neutron detectors with excellent rejection of gamma-ray backgrounds. The efficiency of transporting scintillation light through such a composite is critical to the detector performance. This optical raytracing study of a composite thermal neutron detector quantifies the various sources of scintillation light loss and identifies favorable photomultiplier tube (PMT) readout schemes. The composite material consisted of scintillator cubes within an organic matrix shaped as a right cylinder. The cylinder surface was surrounded by an optical reflector, and the light was detected by PMTs attached to the cylinder end faces. A reflector in direct contact with the composite caused 53% loss of scintillation light. This loss was reduced 8-fold by creating an air gap between the composite and the reflector to allow a fraction of the scintillation light to propagate by total internal reflection. Replacing a liquid mineral oil matrix with a solid acrylic matrix decreased the light transport efficiency by only ∼10% for the benefit of creating an all-solid-state device. The light propagation loss was found to scale exponentially with the distance between the scintillation event and the PMT along the cylinder main axis. This enabled a PMT readout scheme that corrects for light propagation loss on an event-by-event basis and achieved a 4.0% energy resolution that approached Poisson-limited performance. These results demonstrate that composite materials can enable practical thermal neutron detectors for a wide range of nuclear non-proliferation and safeguard applications.Composite materials consisting of 6Li scintillator particles in an organic matrix can enable thermal neutron detectors with excellent rejection of gamma-ray backgrounds. The efficiency of transporting scintillation light through such a composite is critical to the detector performance. This optical raytracing study of a composite thermal neutron detector quantifies the various sources of scintillation light loss and identifies favorable photomultiplier tube (PMT) readout schemes. The composite material consisted of scintillator cubes within an organic matrix shaped as a right cylinder. The cylinder surface was surrounded by an optical reflector, and the light was detected by PMTs attached to the cylinder end faces. A reflector in direct contact with the composite caused 53% loss of scintillation light. This loss was reduced 8-fold by creating an air gap between the composite and the reflector to allow a fraction of the scintillation light to propagate by total internal reflection. Replacing a liquid miner...