@article{oai:repo.qst.go.jp:00045567,
 author = {Torii, Tatsuo and Sugita, Takeshi and Tanabe, Sachiko and Kimura, Yoshihisa and Kamogawa, Masashi and Yajima, Kazuaki and Yasuda, Hiroshi and 矢島 千秋 and 保田 浩志},
 issue = {13},
 journal = {Geophysical Research Letters},
 month = {Jul},
 note = {Fluctuations of energetic radiation were observed at the top of Mt.Fuji.  The largest event was gradual and lasted for about 20 minutes, attributing to high-energy gamma rays having a continuous energy spectrum up to 10 MeV or more.  Such fluctuations are possibly caused by the bremsstrahlung photons generated by the energetic electrons produced continuously with an intense electric field in the thundercloud.},
 pages = {L13804-1--L13804-4},
 title = {Gradual increase of energetic radiation in associated with thunderstorm activity at the top of Mt.Fuji},
 volume = {36},
 year = {2009}
}