An atmospheric electric field monitoring station for studying variations of cosmic ray flux at ground level during thunderstorms.

Abstract:

Cosmic rays are high energy particles reaching the Earth after crossing the interstellar space. Most cosmic rays originate from outside the solar system -only low-energy (< 10 GeV) particles come from the Sun. When such particles enter the terrestrial atmosphere, they interact with the atoms generating Extended Air Showers (EAS) of secondary particles.

Strong atmospheric electric fields cause such charged particles been accelerated/decelerated towards the ground or ionosphere enhancing/reducing the particle counting at the surface detectors. The accelerated secondary electrons can cause Relativistic Runaway Electron Avalanches (RREA) increasing the secondary flux at ground level detectors. On the other hand, strong electromagnetic pulses emitted by lightning generate unusual radiation events called ELVES (Emission of Light and Very Low-Frequency perturbations due to Electromagnetic Pulse Sources) at the ionosphere.

The lack of electric field monitoring networks inside cosmic ray observatories limits the understanding of the atmospheric electricity influence on the cosmic ray particles. In this work, we expose the preliminary results of the implementation of a weather station for monitoring the atmospheric electric field and lightning during thunderstorm episodes for studying its effect on the secondary particle flux. The lightning monitoring module is equipped with a 10-ns resolution triggering system synchronized by GPS allowing us to correlate the electric field transitory events with the particle detector counting rate.