A combined approach to study the composition of 1-1000 PeV cosmic rays by EAS direct and reflected Cherenkov light detection

In this study, we propose an alternative approach to solving the CR composition problem using a newly designed detector that registers the Cherenkov light from extensive air showers (EAS). The new SPHERE-3 telescope will be lifted by an unmanned aerial vehicle above the snow surface to an altitude of up to 1.5 km. The telescope’s main detector will record an image of the EAS Cherenkov light reflected from the snow, while an additional detector will record an image of the angular distribution of the EAS Cherenkov light at the level of the telescope. Estimates show that observing both direct and reflected EAS Cherenkov light images will enable us to determine the direction and mass of the primary particle more accurately than existing ground-based detectors can.