HR: 16:00h
AN: AE44A-01 INVITED    [Abstracts]
TI: Two Types of Energetic Radiation Observed in Winter Thunderstorms
AU: * Torii, T
EM: torii.tatsuo@jaea.go.jp
AF: Japan Atomic Energy Agency, 2-1 Shiraki, Tsuruga, 919-1279, Japan
AU: Sugita, T
EM: t.sugita@ibaraki.email.ne.jp
AF: Science System Lab. Inc., 1342-6 Sumiyoshi, Kasama, 309-1716, Japan
AU: Muraki, Y
EM: muraki@konan-u.ac.jp
AF: Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe, 658-8501, Japan
AB: The dose rate of the gamma-rays increases in association with the activities of the thunderstorm. They were observed on the ground in the winter season of Japan. To investigate the time profile of the radiations during the winter thunderstorms, four sets of the radiation detectors were prepared which consist of the long proportional counters. These detectors have different characteristics of the response for the energy of the incident particles by mounting different thick shielding covers. Those results were compared with the results measured at the same time by the environmental radiation monitors set up around a nuclear power facility. Electric field was also measured by using a field mill. As a result, the following two types of the radiation enhancements have been found during the winter thunderstorm activities; the gradual variation of photon intensity with energy of a few MeV, and the burst type of the radiation that is attributed to the injection of high energy photons with the energy over 10MeV.
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
SC: Atmospheric and Space Electricity [AE]
MN: 2007 Fall Meeting