The Radar Echo Telescope for Cosmic Rays

Abstract

The Radar Echo Telescope for Cosmic Rays (RET-CR) was deployed in May 2023. RET-CR aims to show the in-nature viability of the radar echo method to probe in-ice particle cascades induced by ultra high energy cosmic rays and neutrinos. The RET-CR surface system detects ultra-high-energy cosmic ray air showers impinging on the ice using conventional methods. The surface detector then triggers the in-ice component of RET-CR, that is subsequently used to search for a radar echo off of the in-ice continuation of an ultra high energy cosmic ray air shower. The two systems independently reconstruct the energy, arrival direction, and impact point of the particle cascade. Here we present RET-CR, its installation in Greenland, and the first operations and results of RET-CR.