地球中微子：来自地球深部的信使  

Geo-neutrino: Messenger from the Earth's interior

作　　者：韩然[1] 牛耀龄 李玉峰[3] 李志伟[4] 徐亚[5,6] 习宇飞[7] 高若菡 王安东[8] 曹俊[3] 赵亮[5,6] 何锦成[9] 冒鑫 Ran Han;Yaohng Nm;Yufeng Li;Zhiwei Li;Ya Xu;Yufei Xi;Ruohan Gao;Andong Wang;Jun Cao;Liang Zhao;Jincheng He;Xin Mao(Science and Technology on Reliability and Environmental Engineering Laboratory,Beijing Institute of Spacecraft Environment Engineering,Beijing 100094,China;School of Earth Sciences and Resources,China University ofGeosciences,Beijing 100083,China;Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Geodesy and Earth＇s Dynamics,Institute of Geodesy and Geophysics,Chinese Academy of Sciences,Wuhan 430077,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Institute of Earth Science,Chinese Academy of Sciences,Beijing 100029,China;Chinese Academy of Geological Sciences Shuiwen Geology Institute of Environment Geology,Shijiazhuang 050061,China;School of Earth Sciences,East China University of Techonology,Nanchang 330013,China;School of Nuclear Science and Engineering,North China Electric Power Llniversity,Beijing 102206,China)

机构地区：[1]北京卫星环境工程研究所,可靠性与环境工程技术重点实验室,北京100094 [2]中国地质大学地球科学与资源学院,北京100083 [3]中国科学院高能物理研究所,北京100049 [4]中国科学院测量与地球物理研究所,大地测量与地球动力学国家重点实验室,武汉430077 [5]中国科学院地质与地球物理研究所,北京100029 [6]中国科学院地球科学研究院,北京100029 [7]中国地质科学院水文地质环境地质研究所,石家庄050061 [8]东华理工大学地球科学学院,南昌330013 [9]华北电力大学核科学与工程学院,北京100026

出　　处：《科学通报》2018年第27期2853-2862,共10页Chinese Science Bulletin

基　　金：国家自然科学基金(11405056); 国家重点研发计划(2018YFA0404100)资助

摘　　要：中微子是构成物质世界最基本的单元之一,在自然界广泛存在.正在建设的江门中微子实验站(JUNO)是我国第二个大型国际领先的中微子实验站.地球中微子(geo-neutrino)是地球内部天然放射性元素(主要是^(238)U,^(232)Th和^(40)K三种同位素)衰变产生的反电子中微子.它们在衰变过程中也同时释放出大量热能,是驱动地球演化的主要地热能来源之一.地球中微子的通量和产生的热能成固定比例.因此,测量地球中微子的通量,可以获得放射性元素分布及其对地热能的贡献.江门中微子实验站的探测器质量为2万吨,运行一年所获取的地球中微子事例数达到400个以上,超过全球已有地球中微子探测器10年所探测事例的总和.江门中微子实验站周围500 km以内贡献50%以上的地球中微子事例数,利用地球科学手段可合理、有效估算实验站周围及邻区地壳的贡献,实验站测量总数减去地壳贡献,可得到地幔的贡献.因此,有效充分利用实验站可望帮助解决放射性元素衰变对地热能的贡献、测量Th/U比值和来自地幔的放射性地热等问题,并推动国内中微子地球科学研究的交叉领域发展.本文首先介绍了地球内部有关热量未解决的科学问题及地球中微子可能的贡献,其次介绍了地球中微子研究的国内外现状及精确地壳结构模型研究的重要意义,随后着重介绍了江门中微子实验的地球中微子探测潜力及其独特的地理位置和探测优势对地球科学研究的意义,最后给出总结和展望.For half a century we have established with considerable precision the Earth＇s heat flow to be（47±2） TW. However, it remains under debate what fraction of this power comes from Earth＇s primordial heat and what fraction comes from the radiogenic heat. This debate comes from the uncertainties on the composition of the Earth, the question of chemical layering in the mantle, the nature of mantle convection, the energy required to drive plate tectonics, and the power source of the geodynamo. The surface heat flux, as measured in boreholes, provides limited insights into the relative contributions of primordial versus radiogenic sources of the mantle＇s heat budget. Geoneutrinos are unique probes that bring direct information about the amount and distribution of heat producing elements in the crust and mantle. Cosmochemical, geochemical, and geodynamic compositional models of the Bulk Silicate Earth（BSE） predicted different mantle neutrino fluxes. The flux of geo-neutrinos at any point on the Earth＇s surface is a function of the abundances and distributions of radioactive elements within our planet. In 2005, the Kam LAND collaboration published the first experimental result about the geo-neutrino measurement, and then Borexino collaboration claimed the second. However the existing geo-neutrino detectors（Kam LAND and Borexino） have not accumulated enough geo-neutrino data to discriminate models that parameterize the mantle convection and identify hidden reservoirs in the mantle. The particle physics community is trying to take a bold advantage of the development of the JUNO（Jiangmen Underground Neutrino Observatory）. JUNO detector is a 20 kt liquid-scintillator, 20 times greater than Kam LAND detector and 60 times greater than Borexino detector. The new JUNO detector will collect a much larger number of geo-neutrino signals, and thus have the potential to inform the geological community about the Earth＇s total geo-neutrino flux and details of the contribution from the region surround the detect

关 键 词：地球中微子 放射性生热 Th/U比 地幔放射性地热能 江门中微子实验站 

分 类 号：P597.1[天文地球—地球化学]