Lightning as a natural source of synchrotron radiation of x-ray and gamma-ray photons.

Lightning is a source of x-ray and gamma radiation, one of the most powerful natural photon emissions on Earth. In the paper, based on recently published measurement data, we explain the experimental results and state that the observed high-energy radiation is generated by synchrotron and cyclotron radiation mechanisms. The existence of fast electromagnetic surface plasmon waves propagating along the lightning discharge channel at a speed close to the speed of light in a vacuum is shown. A physical model of the formation of a vortex current in a plasma channel of lightning discharges due to the anomalous Hall effect caused by the phenomenon of relativistic spin-orbit interaction is proposed. The spin properties of electrons become important at relativistic velocities, so the spin-orbit coupling manifests itself as an effective magnetic force acting on the electron's spin, leading to the formation of a vortex current in the absence of an external magnetic field. This allows us to consider the lightning discharge channel as a charged particle accelerator that generates microwave, x-ray, gamma, and radio frequency radiation with a current pulse moving along a spiral trajectory by synchrotron and cyclotron radiation mechanisms. The proposed theoretical model of the formation of plasmon-enhanced emission of high-energy photons is consistent with observations of lightning and spark discharges in the atmosphere.