Efficiency and spatial resolution of the CASCADE thermal neutron detector
Efficiency and spatial resolution of the CASCADE thermal neutron detector
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DOI：
10.1016/j.nima.2016.05.014
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发表时间：
2016-08
影响因子：
1.4
通讯作者：
M. Köhli;F. Allmendinger;W. Häussler;T. Schröder;M. Klein;M. Meven;U. Schmidt
中科院分区：
文献类型：
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作者：
M. Köhli;F. Allmendinger;W. Häussler;T. Schröder;M. Klein;M. Meven;U. Schmidt
我们报告的CASCADE项目的检测系统，这是专为中子自旋回波光谱的目的，并不断进一步发展和适应各种应用。它具有高速率热中子的2D空间分辨探测。CASCADE探测器由一堆涂有固体10 B的气体电子倍增器箔组成，这些箔既用作中子转换器，又用作标准计数气体环境中沉积的初级电离的放大器。这种多层设置有效地提高了检测效率，并且通过提取穿过堆叠的电荷的信号，可以识别转换层，从而允许精确确定飞行时间。通过光学对比度测定发现空间分辨率为σ=（1.39±0.05）mm，通过发散校正孔径测量发现空间分辨率为σ=（1.454±0.007）mm，这与模拟探测器模型一致。此外，这使得能够调查和描述非高斯分辨率函数。在HEiDi衍射仪上研究了绝对探测效率。对于目前雷塞达谱仪的一部分6层探测器，在0.6 μ m处测得的效率为7.8%，通过Monte Carlo模拟，对于1.8 μ m处的热中子和5.4 μ m处的热中子，效率分别为（21.0±1.5）%和（46.9±3.3）%。
We report on the CASCADE project–a detection system, which has been designed for the purposes of neutron Spin Echo spectroscopy and which is continuously further developed and adapted to various applications. It features 2D spatially resolved detection of thermal neutrons at high rates. The CASCADE detector is composed of a stack of solid 10 B coated Gas Electron Multiplier foils, which serve both as a neutron converter and as an amplifier for the primary ionization deposited in the standard counting gas environment. This multi-layer setup efficiently increases the detection efficiency and by extracting the signal of the charge traversing the stack the conversion layer can be identified allowing a precise determination of the time-of-flight. The spatial resolution is found by optical contrast determination to be σ=(1.39±0.05) mm and by divergence corrected aperture measurements σ=(1.454±0.007) mm, which is in agreement with the simulated detector model. Furthermore this enabled to investigate and describe the non-Gaussian resolution function. At the HEiDi diffractometer the absolute detection efficiency has been studied. At 0.6 Å for the 6 layer detector, which is currently part of the RESEDA spectrometer, an efficiency of 7.8% has been measured, which by means of Monte Carlo simulations translates to (21.0±1.5)% for thermal neutrons at 1.8 Å and (46.9±3.3)% at 5.4 Å.