Terrestrial gamma-ray flashes and neutron pulses from direct simulations of gigantic upward atmospheric discharge

Abstract

Gamma-ray pulses are calculated from 2D numerical simulations of upward atmospheric discharge in a self-consistent electric field using the multigroup approach to the kinetics of relativistic runaway electrons. Thecalculated numbers and spectra of γ-rays are consistent with the data on terrestrial γ-ray flashes observed aboard spacecraft. The calculated runaway electron flux is concentrated mainly within the domain of the blue jet fluorescence. This proves that exactly this domain is a source of the γ-ray flashes. One γ-ray flash generates ∼10 14 -10 15 photonuclear neutrons.