REAS3: A revised implementation of the geosynchrotron model for radio emission from air showers

TL;DR

REAS3 improves radio emission simulations from air showers by including charge variation effects, leading to better agreement with observational data and enabling comprehensive modeling of geomagnetic and charge excess radiation.

Contribution

The paper introduces REAS3, a revised Monte Carlo code that incorporates end-point contributions for more accurate radio emission predictions from air showers.

Findings

Enhanced simulation accuracy with end-point contributions

Good agreement between REAS3 simulations and LOPES data

Simulation of both geomagnetic and charge excess radiation

Abstract

Over the past years, the freely available Monte Carlo-code REAS which simulates radio emission from air showers based on the geosynchrotron model, was used regularly for comparisons with data. However, it emerged that in the previous version of the code, emission due to the variation of the number of charged particles within an air shower was not taken into account. In the following article, we show the implementation of these emission contributions in REAS3 by the inclusion of ``end-point contributions'' and discuss the changes on the predictions of REAS obtained by this revision. The basis for describing radiation processes is an universal description which is gained by the use of the end-point formulation. Hence, not only pure geomagnetic radiation is simulated with REAS3 but also radiation due to the variation of the net charge excess in the air shower, independent of the Earth's magnetic field. Furthermore, we present a comparison of lateral distributions of LOPES data with REAS3-simulated distributions. The comparison shows a good argeement between both, data and REAS3 simulations.