Macroscopic Geo-Magnetic Radiation Model; Polarization effects and finite volume calculations

TL;DR

This paper develops a comprehensive macroscopic model for radio emissions from extensive air showers caused by ultra-high-energy cosmic rays, incorporating polarization, Cherenkov effects, and finite volume calculations to better understand the lateral distribution of signals.

Contribution

It introduces a novel macroscopic model that includes polarization effects and Cherenkov radiation, advancing the understanding of radio emission mechanisms in extensive air showers.

Findings

Inclusion of Cherenkov radiation up to 100 meters from the shower core.

Demonstration of polarization effects influencing the radio signal distribution.

Complex lateral distribution function dependent on observer orientation.

Abstract

An ultra-high-energy cosmic ray (UHECR) colliding with the Earth's atmosphere gives rise to an Extensive Air Shower (EAS). Due to different charge separation mechanisms within the thin shower front coherent electromagnetic radiation will be emitted within the radio frequency range. A small deviation of the index of refraction from unity will give rise to Cherenkov radiation up to distances of 100 meters from the shower core and therefore has to be included in a complete description of the radio emission from an EAS. Interference between the different radiation mechanisms, in combination with different polarization behavior will reflect in a lateral distribution function (LDF) depending on the orientation of the observer and a non-trivial fall-off of the radio signal as function of distance to the shower core.