Simulation of the simplest reactor model of the dynamics of runaway electron avalanches in thunderclouds

Relativistic electrons in strong large-scale thunderstorm electric fields can obtain more energy from acceleration by the electric field than they on average lose on interactions with air molecules. Such accelerating electrons are called runaway electrons. Runaway electrons can produce additional runaway electrons by Moller scattering on air molecules. In this way, runaway electrons multiply and form a relativistic runaway electron avalanche (RREA).

In strong electric fields, RREA can multiply by relativistic feedback. Infinite relativistic feedback makes avalanches self-sustaining and could hypothetically trigger a terrestrial gamma-ray burst (TGF). This report presents the results of modeling the simplest reactor - the model of the appearance of a TGF, consisting of two cells looking at each other, their comparison with theoretical calculations and previous models.  It was found that the considered model predicts lower requirements for the electric field for the appearance of TGF than the others.