Terrestrial gamma ray flashes with energies up to 100 MeV produced by nonequilibrium acceleration of electrons in lightning

摘要: [1] Using Monte Carlo models simulating energetic electrons in inhomogeneous electric field and the transport of photons Earth's atmosphere, we show that spectrum bremsstrahlung generated by nonequilibrium produced during stepping lightning leaders can deviate from typical relativistic runaway electron avalanches (RREA) developing weak homogeneous fields. This deviation is especially pronounced high-energy tail energy distribution for possessing high voltages (several hundreds megavolts) extremely fields around their tips. The photon obtained accurately reproduces recently discovered (up to 100 MeV) terrestrial gamma-ray flashes (TGFs). analysis provides first direct evidence TGFs are not over large distances thunderstorm