Digital Radio Arrays for the Detection of Air Showers Initiated by Ultra-High-Energy Particles (Epiphany 2022)

TL;DR

Digital radio arrays are a promising, cost-effective method for detecting ultra-high-energy air showers, offering continuous operation and high accuracy, especially when combined with particle detectors.

Contribution

This paper reviews recent advancements in radio detection techniques and discusses the deployment and potential of large-scale radio arrays for cosmic-ray and neutrino research.

Findings

Radio arrays can measure air shower energy and depth with high accuracy.

Hybrid arrays improve mass composition determination of cosmic rays.

Several large-scale radio projects are underway or planned.

Abstract

Digital radio arrays have become an effective tool to measure air showers at energies around and above 100 PeV. Compared to optical techniques, the radio technique is not restricted to clear nights. Thanks to recent progress on computational analysis techniques, radio arrays can provide an equally accurate measurement of the energy and the depth of the shower maximum. Stand-alone radio arrays offer an economic way towards huge apertures, e.g., for the search for ultra-high-energy neutrinos, but still require technical demonstration on large scales. Hybrid arrays combining radio antennas and particle detectors have already started to contribute to cosmic-ray physics in the energy range of the presumed Galactic-to-extragalactic transition. In particular, the combination of radio and muon detectors can pave a path to unprecedented accuracy for the mass composition of cosmic rays. This proceeding reviews recent developments regarding the radio technique and highlights selected running and planned antennas arrays, such as GCOS, GRAND, the SKA, the AugerPrime Upgrade of the Pierre Auger Observatory, and IceCube-Gen2.