A liquid scintillator for a neutrino detector working at −50 degree
A liquid scintillator for a neutrino detector working at −50 degree
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用于工作温度≤50度的中微子探测器的液体闪烁体
DOI：
10.1016/j.nima.2021.165459
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Yuguang Xie
中科院分区：
文献类型：
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作者：
Zhangquan Xie;Jun Cao;Yayun Ding;Mengchao Liu;Xilei Sun;Wei Wang;Yuguang Xie
为台山反中微子天文台（TAO）的吨级中微子探测器研制了液体闪烁体（LS），采用硅光电倍增管（SiPMs）作为光传感器，测量反应堆反中微子能谱。为了将SiPM的暗噪声降低到可接受的水平，LS必须在−50 ° C或更低的温度下工作。研制了一种基于电荷耦合器件（CCD）的专用装置，用于低温恒温器中液体样品透明度的研究。我们发现LS中的水含量导致在低温下透明性降低，其可以通过鼓泡干燥氮气以除去水来固化。加入0.43g/L乙醇作为助溶剂，解决了PPO和bis-MSB低温溶解度下降的问题。最后，钆掺杂液体闪烁体（GdLS），在溶剂LAB中含有0.1% Gd（重量）、2 g/L PPO、1 mg/L bis-MSB和0.43 g/L乙醇，在−50 ℃下显示出良好的透明度和良好的光输出。
A liquid scintillator (LS) is developed for the Taishan Antineutrino Observatory (TAO), a ton-level neutrino detector to measure the reactor antineutrino spectrum with sub-percent energy resolution by adopting Silicon Photomultipliers (SiPMs) as photosensors. To reduce the dark noise of SiPMs to an acceptable level, the LS has to work at −50 ◦C or lower. A customized apparatus based on a charge-coupled device (CCD) is developed to study the liquid samples’ transparency in a cryostat. We find that the water content in LS results in transparency degradation at low temperatures, which can be cured by bubbling dry nitrogen to remove water. Adding 0.43 g/L ethanol as co-solvent cures the solubility decrease problem of the fluors PPO and bis-MSB at low.temperature. Finally, a Gadolinium-doped liquid scintillator (GdLS), with 0.1% Gd by weight, 2 g/L PPO, 1 mg/L bis-MSB, and 0.43 g/L ethanol in the solvent LAB, shows good transparency at −50 ◦C and also good light yield.