2025年"核理安邦“联合博士生学术论坛

CJPL中宇宙线缪子通量和缪致中子产额测量

Not scheduled

1h

Location: 清华大学核能与新能源技术研究院

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Speaker

彬 张

Abstract

China Jinping Underground Laboratory (CJPL) is ideal for carrying out MeV-scale neutrino experiments and searching for neutrinoless double-beta-decay. To understand the cosmogenic background, we analyzed 820.28 days of the dataset from a one-ton prototype detector and measured the cosmic-ray muon flux to be (3.61±0.19stat.±0.10sys.)×10−10cm−2s−1. From the detected cosmic-ray muon events, we also measured the muon-induced neutron yield in liquid scintillation, which is (3.44±1.86stat.±0.76sys.)×10−4𝜇−1g−1cm2 at 340 GeV average energy of muons. In addition, we performed a survey of muon fluxes at different laboratory locations globally, considering both those situated under mountains and those down mine shafts. Under the same vertical overburden, the former is generally (4±2) times the latter due to the leakage through the mountain. Based on Jinping Mountain's terrain and the measurement in CJPL-I, we predicted cosmic-ray muons' energy and angle distributions and fluxes for the four halls at CJPL-II. We found the fluxes of Hall C and Hall D were about 2.3×10−10cm−2s−1 and 2.5×10−10cm−2s−1 respectively.

摘要

中国锦屏地下实验室（CJPL）是开展MeV尺度中微子实验和寻找无中微子双β衰变的理想场所。为了理解宇宙线本底，我们分析了一吨原型探测器820.28天的数据，测得宇宙线μ子通量为(3.61±0.19stat.±0.10sys.)×10−10cm−2s−1。从探测到的宇宙线μ子事件中，我们还测量了液体闪烁体中μ子诱发的中子产额，在μ子平均能量为340 GeV时，其值为(3.44±1.86stat.±0.76sys.)×10−4𝜇−1g−1cm2。此外，我们对全球不同实验室位置的μ子通量进行了研究，包括位于山下的实验室和矿井中的实验室。在相同的垂直覆盖层深度下，由于从山体侧面的泄漏，前者的μ子通量通常是后者的(4±2)倍。基于锦屏山的地形和CJPL-I的测量结果，我们预测了CJPL-II四个厅的宇宙线μ子能量、角度分布和通量。我们发现C厅和D厅的通量分别约为2.3×10−10cm−2s−1和2.5×10−10cm−2s−1。