The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of 238U and 232Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.
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Eguchi, K. et al. First results from KamLAND: Evidence for reactor antineutrino disappearance. Phys. Rev. Lett. 90, 021802 (2003)
Araki, T. et al. Measurement of neutrino oscillation with KamLAND: Evidence of spectral distortion. Phys. Rev. Lett. 94, 081801 (2005)
Eder, G. Terrestrial neutrinos. Nucl. Phys. 78, 657–662 (1966)
Marx, G. Geophysics by neutrinos. Czech. J. Phys. B 19, 1471–1479 (1969)
Avilez, C., Marx, G. & Fuentes, B. Earth as a source of antineutrinos. Phys. Rev. D 23, 1116–1117 (1981)
Krauss, L. M., Glashow, S. L. & Schramm, D. N. Antineutrino astronomy and geophysics. Nature 310, 191–198 (1984)
Kobayashi, M. & Fukao, Y. The Earth as an antineutrino star. Geophys. Res. Lett. 18, 633–636 (1991)
Raghavan, R. S. et al. Measuring the global radioactivity in the Earth by multidetector antineutrino spectroscopy. Phys. Rev. Lett. 80, 635–638 (1998)
Rothschild, C. G., Chen, M. C. & Calaprice, F. P. Antineutrino geophysics with liquid scintillator detectors. Geophys. Res. Lett. 25, 1083–1086 (1998)
Mantovani, F., Carmignani, L., Fiorentini, G. & Lissia, M. Antineutrinos from Earth: A reference model and its uncertainties. Phys. Rev. D 69, 013001 (2004)
Pollack, H. N., Hurter, S. J. & Johnson, J. R. Heat flow from the Earth's interior: analysis of the global data set. Rev. Geophys. 31, 267–280 (1993)
Hofmeister, A. M. & Criss, R. E. Earth's heat flux revised and linked to chemistry. Tectonophysics 395, 159–177 (2005)
McDonough, W. F. & Sun, S.-s. The composition of the Earth. Chem. Geol. 120, 223–253 (1995)
Jackson, M. J. & Pollack, H. N. On the sensitivity of parameterized convection to the rate of decay of internal heat sources. J. Geophys. Res. 89, 10103–10108 (1984)
Richter, F. M. Regionalized models for the thermal evolution of the Earth. Earth Planet. Sci. Lett. 68, 471–484 (1984)
Firestone, R. B. Table of Isotopes 8th edn (John Wiley, New York, 1996)
Behrens, H. & Jänecke, J. Landolt-Börnstein - Group I, Elementary Particles, Nuclei and Atoms Vol. 4 (Springer, Berlin, 1969)
McKeown, R. D. & Vogel, P. Neutrino masses and oscillations: triumphs and challenges. Phys. Rep. 394, 315–356 (2004)
Ahmed, S. N. et al. Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity. Phys. Rev. Lett. 92, 181301 (2004)
Wolfenstein, L. Neutrino oscillations in matter. Phys. Rev. D 17, 2369–2374 (1978)
Vogel, P. & Beacom, J. F. Angular distribution of neutron inverse beta decay, ν̄e + p → e+ + n. Phys. Rev. D 60, 053003 (1999)
Enomoto, S. Neutrino Geophysics and Observation of Geo-neutrinos at KamLAND. Thesis, Tohoku Univ. (2005); available at http://www.awa.tohoku.ac.jp/KamLAND/publications/Sanshiro_thesis.pdf
JENDL Japanese Evaluated Nuclear Data Library. http://www.ndc.tokai.jaeri.go.jp/jendl/jendl.html (2004).
Apostolakis, J. Geant—Detector description and simulation tool. http://www.asd.web.cern.ch/www.asd/geant/index.html (2003).
Walton, R. B., Clement, J. D. & Borlei, F. Interaction of neutrons with oxygen and a study of the C13(α,n)O16 reaction. Phys. Rev. 107, 1065–1075 (1957)
Kerr, G. W., Morris, J. M. & Risser, J. R. Energy levels of 17O from 13C(α,α0)13C and 13C(α,n)16O. Nucl. Phys. A 110, 637–656 (1968)
Kopeikin, V. I. et al. Inverse beta decay in a nonequilibrium antineutrino flux from a nuclear reactor. Phys. Atom. Nuclei 64, 849–854 (2001)
Rocholl, A. & Jochum, K. P. Th, U and other trace elements in carbonaceous chondrites: Implications for the terrestrial and solar-system Th/U ratios. Earth Planet. Sci. Lett. 117, 265–278 (1993)
Tolich, N. Experimental Study of Terrestrial Electron Anti-neutrinos with KamLAND Thesis, Stanford Univ. (2005); available at http://www.awa.tohoku.ac.jp/KamLAND/publications/Nikolai_thesis.pdf
KamLAND collaboration. Data release accompanying the 2nd KamLAND reactor result. http://www.awa.tohoku.ac.jp/KamLAND/datarelease/2ndresult.html (2005).
We thank E. Ohtani and N. Sleep for advice and guidance. The KamLAND experiment is supported by the COE program of the Japanese Ministry of Education, Culture, Sports, Science, and Technology, and by the United States Department of Energy. The reactor data were provided courtesy of the following associations in Japan: Hokkaido, Tohoku, Tokyo, Hokuriku, Chubu, Kansai, Chugoku, Shikoku and Kyushu Electric Power Companies, Japan Atomic Power Co. and Japan Nuclear Cycle Development Institute. Kamioka Mining and Smelting Company provided services for activity at the experimental site.
Reprints and permissions information is available at npg.nature.com/reprintsandpermissions. The authors declare no competing financial interests.
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Araki, T., Enomoto, S., Furuno, K. et al. Experimental investigation of geologically produced antineutrinos with KamLAND. Nature 436, 499–503 (2005). https://doi.org/10.1038/nature03980
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