Tsuchiya H, Enoto T, Yamada S, Yuasa T, Kawaharada M, Kitaguchi T, Kokubun M, Kato H, Okano M, Nakamura S, Makishima K
Cosmic Radiation Laboratory, Riken, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan.
Phys Rev Lett. 2007 Oct 19;99(16):165002. doi: 10.1103/PhysRevLett.99.165002. Epub 2007 Oct 17.
A report is made on a comprehensive observation of a burstlike gamma-ray emission from thunderclouds on the Sea of Japan, during strong thunderstorms on 6 January 2007. The detected emission, lasting for approximately 40 sec, 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 the first clear evidence that strong electric fields in thunderclouds can continuously accelerate electrons beyond 10 MeV prior to lightning discharges.
本文报告了对2007年1月6日日本海强雷暴期间雷云爆发式伽马射线发射的综合观测情况。检测到的发射持续约40秒，先于云对地闪电放电。爆发光谱延伸至10兆电子伏特，可解释为由相对论电子产生的轫致辐射光子组成。此次地面观测首次明确证明，雷云中的强电场能够在闪电放电前持续将电子加速至超过10兆电子伏特。
