Neutron detector based on Particles of 6Li glass scintillator dispersed in organic lightguide matrix
Neutron detector based on Particles of 6Li glass scintillator dispersed in organic lightguide matrix
复制标题
基于分散在有机光导基质中的6Li玻璃闪烁体粒子的中子探测器
DOI：
10.1016/j.nima.2014.10.073
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发表时间：
2015
影响因子：
1.4
通讯作者：
M. T. Barker
中科院分区：
文献类型：
--
作者：
K. Ianakiev;M. Hehlen;M. Swinhoe;A. Favalli;M. Iliev;T. C. Lin;B. Bennett;M. T. Barker
当今大多数3 He替代中子探测器技术具有重叠的中子-伽马脉冲高度分布，这限制了它们的有用性和性能。不同的技术被用来减轻这个缺点，包括脉冲形状识别（PSD）或阈值设置，抑制所有的伽马射线以及大部分的中子。因此，当使用PSD时，计数率受到限制并且死区时间很高，并且由于高阈值而降低了对中子事件的检测效率。这是一个问题，在大多数应用中，中子-γ分离的3 He探测器已成为必要的。这一挑战对于中子符合和多重性测量来说尤其严峻，因为它们具有许多相互冲突的要求，例如高检测效率、短消亡时间、短死时间和高稳定性。6Li玻璃闪烁器具有优异的光输出和单峰分布，但由于它们的伽马敏感性，它们难以实现。通过在有机光导介质中嵌入小的玻璃颗粒来降低6Li玻璃衰减器的伽马灵敏度的想法首先由L.M.布林在60年代初，但据我们所知，从来没有减少到实践。我们提出了一个证明的原则探测器的设计和实验数据，开发这个概念的大面积中子探测器。这是通过使用多组分光学介质（6Li玻璃颗粒附着在玻璃支撑结构和矿物油光导上）实现的，该介质匹配折射率并最大限度地减少395 nm闪烁体光的吸收。探测器设计包括一个10英寸。双端读出长管，安装体积密度约3%的6Li玻璃颗粒。所提出的实验数据与各种中子和伽马源显示所需的宽的中子和伽马脉冲高度分布之间的差距，导致在一个真正的高原的计数特性类似的of 3 He探测器。
Most3He replacement neutron detector technologies today have overlapping neutron–gamma pulse-height distributions, which limits their usefulness and performance. Different techniques are used to mitigate this shortcoming, including Pulse Shape Discrimination (PSD) or threshold settings that suppress all gammas as well as much of the neutrons. As a result, count rates are limited and dead times are high when PSD is used, and the detection efficiency for neutron events is reduced due to the high threshold. This is a problem in most applications where the neutron–gamma separation of3He detectors had been essential. This challenge is especially severe for neutron coincidence and multiplicity measurements that have numerous conflicting requirements such as high detection efficiency, short die-away time, short dead time, and high stability.6Li-glass scintillators have excellent light output and a single peak distribution, but they are difficult to implement because of their gamma sensitivity. The idea of reducing the gamma sensitivity of6Li-glass scintillators by embedding small glass particles in an organic light-guide medium was first presented by L.M. Bollinger in the early 60s but, to the best of our knowledge, has never been reduced to practice. We present a proof of principle detector design and experimental data that develop this concept to a large-area neutron detector. This is achieved by using a multi-component optical medium (6Li glass particles attached to a glass supporting structure and a mineral oil light guide) which matches the indices of refraction and minimizes the absorption of the 395 nm scintillator light. The detector design comprises a 10 in. long tube with dual end readout with about 3% volume density of6Li glass particles installed. The presented experimental data with various neutron and gamma sources show the desired wide gap between the neutron and gamma pulse height distributions, resulting in a true plateau in the counting characteristics similar to that of3He detectors.