Gadolinium-loaded liquid scintillator for high-precision measurements of antineutrino oscillations and the mixing angle, θ13
Gadolinium-loaded liquid scintillator for high-precision measurements of antineutrino oscillations and the mixing angle, θ13
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DOI：
10.1016/j.nima.2007.03.029
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发表时间：
2007-07
影响因子：
1.4
通讯作者：
M. Yeh;A. Garnov;R. Hahn
中科院分区：
文献类型：
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作者：
M. Yeh;A. Garnov;R. Hahn
使用多个相同的液体闪烁体(LS)探测器，在距离核反应堆0.1到2公里的距离内，有可能探测到反中微子振荡和测量未知的中微子混合角θ13的值。在LS中感兴趣的核反应是质子的逆β衰变反应，发射的瞬发正电子和延迟的中子俘获之间的符合标签提供了反中微子俘获的明显特征。由于Gd同位素的大(n，γ)截面(49,000谷仓的自然丰度Gd)和发射的∼8 MeV的γ射线，将Gd加载到LS中大大增强了中子俘获信号。我们已经在BNL开发了一种简单、一致和可重复的方法来合成高质量的Gd负载LS(Gd-LS)，使用pH控制的溶剂-溶剂萃取法。这种Gd-LS具有很长的衰减长度(>；15m)、高光输出(∼为假单面的90%)和长期稳定性(>；到目前为止为1.5年)。本文讨论了这种Gd-LS的制备方法和性能。
The use of multiple, identical liquid scintillator (LS) detectors at distances between 0.1 and 2km from a nuclear reactor has the potential to detect antineutrino oscillations and to measure the value of the unknown neutrino-mixing angle θ13. The nuclear reaction of interest in the LS is the inverse β-decay reaction on protons, with the coincidence tag between the emitted prompt positron and the delayed neutron-capture providing a clear signature of the antineutrino capture. The neutron-capture signal is greatly enhanced by loading gadolinium into the LS, because of the large (n, γ) cross-sections of the Gd isotopes (49,000 barns for natural abundance Gd), and the ∼8MeV of emitted γ-rays. We have developed procedures at BNL to synthesize high-quality Gd-loaded LS (Gd-LS) in a simplified, consistent, and reproducible way, using the method of pH-controlled, solvent–solvent extraction. This Gd-LS has long attenuation length (>15m), high-light output (∼90% of pseudocumene), and long-term stability (>1.5 years to date). The preparation and characteristics of this Gd-LS are discussed in this paper.