The Radar Echo Telescope for Cosmic Rays and Neutrinos

The Radar Echo Telescope is a proposed detector that aims to target neutrinos at energies at and above 10$^{16}$ eV, in an effort to extend the neutrino spectrum beyond the highest energy neutrinos detected to date. When a high-energy particle (like a neutrino) interacts in a dense material, it produces a relativistic cascade of charged particles, leaving an ionization trail behind. Radio waves can be transmitted toward---and reflected from---this ionization trail, to be detected by distant receivers. This radar echo method can be used to detect ultra high-energy neutrino interactions in the ice. As a pilot implementation, the Radar Echo Telescope for Cosmic Rays (RET-CR) aims to detect radar echoes from the ionized trail left in the ice as an ultra-high energy cosmic ray air shower core impacts the surface of a high-elevation ice sheet, creating a cascade in the ice. In this talk we will present the concept for RET-CR and discuss it as a pathfinder for the eventual Radar Echo Telescope for Neutrinos (RET-N), which seeks to detect neutrinos at energies of 10$^{16}$ eV and beyond.