JpGU-AGU Joint Meeting 2020

講演情報

[E] ポスター発表

セッション記号 U (ユニオン) » ユニオン

[U-20] "Open Colloquium" Exploring the Earth's interior using cutting edge science and technology

コンビーナ:渡辺 寛子(東北大学ニュートリノ科学研究センター)、William F McDonough(Department of Earth Science and Research Center for Neutrino Science, Tohoku University, Sendai, Miyagi 980-8578, Japan)、上木 賢太(国立研究開発法人海洋研究開発機構)、荒木 英一郎(海洋研究開発機構)

[U20-P01] Study of Ocean Bottom Detector for observation of geo-neutrinos from mantle

*酒井 汰一1井上 邦雄1渡辺 寛子1william McDonough2,3上木 賢太4阿部 なつ江4櫻井 紀旭4許 正憲4荒木 英一郎4笠谷 貴史4吉田 弘4 (1.東北大学ニュートリノ科学研究センター、2.東北大学、3.メリーランド大学、4.国立研究開発法人海洋研究開発機構)

キーワード:地球ニュートリノ、マントル、固体地球科学

Observation of geo-neutrinos originating from radioactive isotopes in the Earth (238U,232Th, etc.) can be converted to the amount of radioactive isotopes and the heat generated by their decays which governs the Earth dynamics.
KamLAND experiment achieved world's first observation of geo-neutrinos in 2005. Improvement of observation accuracy allowed us to reach the level where we can obtain geoscientific knowledge. However, it is hard to obtain information on the mantle because 70% of neutrinos observed by detector currently operating or planned are derived from the crust (Figure 1).
Given that the oceanic crust is thinner than the continental crust and has lower densities of U and Th, Ocean Bottom Detector (OBD) makes it sensitive to geo-neutrinos originating from Earth's mantle. OBD is expected to provide transformative insights into the deep Earth.Unique feature of OBD is separation from the reactors which are the main background sources of continental detectors. In addition, this movable detector can observe at multiple points in the ocean.
Scientists at the University of Hawaii started to discuss the idea of observing the geo-neutrinos on the sea floor 15 years ago as the detector called "Hanohano"(Figure 2). Unfortunately, the idea has not been realized yet.
In 2019 joint research between Tohoku University and JAMSTEC was started to lead the comprehensive research relating to understanding the Earth's deep interior and realize OBD. We are currently working on the design of 10-ton prototype detector for the ultimate goal of a 10-50kt detector.
The prototype detector will demonstrate necessary technological developments and measure the environment which will be references for future detector design.
In this presentation, we will present results of detector design based on Monte Carlo simulation.