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arXiv · 0708.2947

Detection of high-energy gamma rays from winter thunderclouds

H. Tsuchiya·T. Enoto·S. Yamada·T. Yuasa·M. Kawaharada·T. Kitaguchi·M. Kokubun·H. Kato·M. Okano·S. Nakamura·K. Makishima
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Abstract

A report is made on a comprehensive observation of a burst-like $γ$-ray emission from thunderclouds on the Sea of Japan, during strong thunderstorms on 2007 January 6. The detected emission, lasting for $\sim$40 seconds, preceded cloud-to-ground lightning discharges. The burst spectrum, extending to 10 MeV, can be interpreted as consisting of bremsstrahlung photons originating from relativistic electrons. This ground-based observation provides first clear evidence that strong electric fields in thunderclouds can continuously accelerate electrons beyond 10 MeV prior to lightning discharges.

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H. Tsuchiya, T. Enoto, S. Yamada, T. Yuasa, M. Kawaharada, T. Kitaguchi, M. Kokubun, H. Kato, M. Okano, S. Nakamura, K. Makishima. 2007-08-22. Detection of high-energy gamma rays from winter thunderclouds. https://doi.org/10.1103/physrevlett.99.165002

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