Dependence of geosynchrotron radio emission on the energy and depth of maximum of cosmic ray showers

TL;DR

This study uses simulations to show that geosynchrotron radio signals from cosmic ray air showers can accurately determine the primary particle's energy and the shower maximum's depth, with minimal uncertainties.

Contribution

It demonstrates a method to infer cosmic ray energy and shower maximum depth from radio emission measurements, improving analysis precision.

Findings

Radio amplitude proportional to energy deposited in atmosphere

Radio amplitude ratio relates to depth of shower maximum

Uncertainties less than 3% for energy, 20 g/cm^2 for depth

Abstract

Based on CORSIKA and REAS2 simulations, we investigate the dependence of geosynchrotron radio emission from extensive air showers on the energy of the primary cosmic ray and the depth of the shower maximum. It is found that at a characteristic lateral distance, the amplitude of the bandpass-filtered radio signal is directly proportional to the energy deposited in the atmosphere by the electromagnetic cascade, with an RMS uncertainty due to shower-to-shower fluctuations of less than 3%. In addition, the ratio of this radio amplitude and that at a larger lateral distance is directly related to the atmospheric depth of the shower maximum, with an RMS uncertainty of ~15-20 g cm-2. By measuring these quantities, geosynchrotron radio emission from cosmic ray air showers can be used to infer the energy of the primary particle and the depth of the air shower maximum on a shower-to-shower basis.