The neutron sensitivity of the cerium-doped gadolinium aluminum gallium garnet (GAGG:Ce) has been determined for five different scintillator volumes. The good $\gamma $ ray detection performance of GAGG:Ce potentially results in a background signal that hides the low-lying neutron-capture $\gamma $ rays from de-excitation of ¹⁵⁶Gd and ¹⁵⁸Gd when the detector volume, and therefore the total $\gamma $ ray absorption, is large. We have investigated the competition between the detection of the neutron signature and discrimination of the background $\gamma $ rays. A significant improvement in the neutron response has been demonstrated with a reduction in the scintillator volume. The peak-to-background ratio of the key neutron signature increased with decreasing scintillator thickness to a maximum value of 14 ± 3 for 50 $\mu \text{m}$ . The limit of this correlation was not determined since the thinnest scintillator available (50 $\mu \text{m}$ ) is greater than the mean free path of a neutron in ¹⁵⁷Gd (15.54 ± 0.09 $\mu \text{m}$ ).

中文翻译：

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优化 GAGG:Ce 基热中子探测器的灵敏度

掺铈钆铝镓石榴石 (GAGG:Ce) 的中子敏感性已针对五种不同的闪烁体体积确定。好的 $\伽马$ GAGG:Ce 的射线检测性能可能会导致隐藏低位中子捕获的背景信号 $\伽马$ 来自¹⁵⁶ Gd 和¹⁵⁸ Gd去激发的射线，当探测器体积，因此总 $\伽马$ 射线吸收，大。我们研究了检测中子特征和识别背景之间的竞争 $\伽马$ 射线。随着闪烁体体积的减少，中子响应的显着改善已被证明。关键中子特征的峰背比随着闪烁体厚度的减小而增加，最大值为 14±3，时间为 50 $\mu \text{m}$ . 由于可用的最薄闪烁体（50 $\mu \text{m}$ ) 大于¹⁵⁷ Gd中子的平均自由程(15.54 ± 0.09 $\mu \text{m}$ ）。