Photonuclear reactions triggered by lightning discharge

  title={Photonuclear reactions triggered by lightning discharge},
  author={Teruaki Enoto and Yuuki Wada and Yoshihiro Furuta and Kazuhiro Nakazawa and Takayuki Yuasa and Kazufumi Okuda and K. Makishima and Mitsuteru Sato and Yousuke Sato and Toshio Nakano and Daigo Umemoto and Harufumi Tsuchiya},
Lightning and thunderclouds are natural particle accelerators. Avalanches of relativistic runaway electrons, which develop in electric fields within thunderclouds, emit bremsstrahlung γ-rays. These γ-rays have been detected by ground-based observatories, by airborne detectors and as terrestrial γ-ray flashes from space. The energy of the γ-rays is sufficiently high that they can trigger atmospheric photonuclear reactions that produce neutrons and eventually positrons via β+ decay of the… 

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