The Magnetic Field Generated by a Critical Avalanche of Runaway Electrons

X-ray and gamma flares observed in the Earth's atmosphere during a thunderstorm are associated with the generation of runaway electrons in the atmospheric electric field. It is assumed that the main role in high-altitude discharges observed in a thunderstorm atmosphere is played by avalanches of runaway electrons initiated by cosmic rays. Using numerical calculations, in which the process of electron acceleration under the influence of a constant electrostatic force was simulated, the patterns of the evolution of avalanches of runaway electrons in air are investigated and the parameters of the critical avalanche of runaway electrons are determined.