Japan Geoscience Union Meeting 2014

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International Session (Oral)

Symbol U (Union) » Union

[U-02_28AM2] Particle Geophysics

Mon. Apr 28, 2014 11:00 AM - 12:42 PM 419 (4F)

Convener:*Hiroyuki Tanaka(Earthquake Research Institute, the University of Tokyo), Hiroko Watanabe(RCNS,Tohoku-U), Cristiano Bozza(U-Salerno), Dominique Gibert(IPGParis), William McDonough(U-Maryland), John Learned(U-Hawaii), Chair:Hiroyuki Tanaka(Earthquake Research Institute, the University of Tokyo)

11:45 AM - 11:54 AM

[U02-P07_PG] Upgrade plan of the KamLAND detector for improvement of sensitivity to geo-neutrino

3-min talk in an oral session

*Shuhei OBARA1 (1.RCNS, Tohoku University)

Keywords:geo-neutrino

Neutrino, which is a kind of elementary particles, interacts with other particles only via weak interaction. RCNS, Tohoku University, researches the neutrino science with the large neutrino detector, KamLAND. Measuring the geo-neutrinos that are produced in beta decays within the Earth′s interior, is only way to estimate the Earth′s radiogenic heats production and constrain composition models of the Earth. The KamLAND detector is marked by the ability to detect low energy electron-type anti-neutrinos. Radioactive isotopes, such as 238U and 232Th decay as follows, and produce the electron-type (anti-) neutrinos (geo-neutrino).238U➞ 206Pb+8 4He+6e-+6νbare+51.7[MeV]232Th➞ 208Pb+64He+4e-+4νbare+42.7[MeV]Geo-neutrino flux directly informs us the radiogenic heat generation. In fact, previously, the KamLAND experiment has given the result; the radiogenic heat production in the Earth′s interior by 238U and 232Th is estimated to be 20.1-9.1+9.1 TW through measuring the geo-neutrinos, and it is obviously smaller than the Earth′s total heat flow (44 ± 1TW). In order to improve the sensitivity of the KamLAND detector, the upgrade plans (KamLAND2 experiment) are in progress. Large light intensity liquid scintillator, light collection mirror, high quantum efficiency photomultiplier, imaging device, scintillation film, etc... In the KamLAND2 experiment, improving energy and vertex resolution are expected. Therefore it will be possible to observe geo-neutrinos with higher accuracy and statistics. This experimental improvement will have higher ability to discriminate between models and separate contributions from 238U and 232Th. The KamLAND2 will play a contribution to the geo physics in that way. In this presentation, future prospects and R&D are discussed.