Experimental investigation of geologically produced antineutrinos with KamLAND

• Published in: Nature Vol. 436; no. 7050; pp. 499 - 503
• Main Authors: Markoff, D. M, Koseki, Y, Freedman, S. J, Guillian, G, Yakushev, E, McKeown, R. D, Murayama, H, Owada, K, Keefer, G, Goldman, J, Kozlov, A, Vogel, P, Takeuchi, S, Gratta, G, Poon, A. W. P, Mitsui, T, Shirai, J, Mauger, C, Miletic, T, Lane, C. E, Tamae, K, Rojas, A, Learned, J. G, Leonard, D, Furuno, K, Busenitz, J, Ogawa, M, Luk, K.-B, Nakamura, K, Gando, Y, Fujikawa, B. K, Kamyshkov, Y, Tornow, W, Shimizu, I, Hsu, L, Horton-Smith, G. A, Berger, B. E, Nakamura, Y, Piepke, A, Batygov, M, Rohm, R. M, Decowski, M. P, Bugg, W, Motoki, M, Ichimura, K, Inoue, K, Tolich, N, Ricol, J.-S, O'Donnell, T, Ishii, K, Araki, T, Maeda, T, Dwyer, D. A, Svoboda, R, Koga, M, Steiner, H. M, Wendell, R, Gray, F, Pakvasa, S, Uchida, Y, Hatakeyama, S, Dieterle, B. D, Tada, K, Djurcic, Z, Lesko, K. T, Dazeley, S, Suekane, F, Heeger, K. M, Chen, M.-J, Tsuda, Y, Karwowski, H. J, Ikeda, H, Winslow, L. A, Detwiler, J, Efremenko, Y, Nakajima, K, Enomoto, S, Kishimoto, Y, Classen, T, Chan, Y. D, Matsuno, S, Maricic, J, Wang, Y.-F, Piquemal, F, Watanabe, H, Ogawa, H, Suzuki, A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 28.07.2005; Nature Publishing Group
• Subjects: Atoms & subatomic particles; Earth; Earth Sciences; Earth, ocean, space; Exact sciences and technology; Geophysics; High Energy Physics - Experiment; Isotope geochemistry; Isotope geochemistry. Geochronology; Physics; Radioactivity; Sciences of the Universe; Sensors; experimental studies; detection; heat production; thorium; radioactive decay; scintillations; concentration; radioactive isotopes; uranium; U-238; Th-232; radioactivity; experimental results; deep underground detector; potassium; geophysics; scintillation counter liquid; antineutrino p exclusive reaction; antineutrino/e; particle identification; charged current; KamLAND
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature03980

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.