GRAND: status and perspectives

TL;DR

GRAND is a planned large-scale radio array aiming to detect ultra-high-energy neutrinos, cosmic rays, and gamma rays, with current prototypes testing its technology and paving the way for future deployment.

Contribution

This paper presents the GRAND concept, its scientific objectives, prototype status, initial measurements, and future perspectives for ultra-high-energy particle detection.

Findings

Prototype arrays have successfully tested detection principles.

Initial measurements demonstrate feasibility of GRAND technology.

Future deployment plans aim to enhance ultra-high-energy cosmic particle observations.

Abstract

GRAND (the Giant Radio Array for Neutrino Detection) is a proposed next-generation observatory of ultra-high-energy neutrinos, cosmic rays, and gamma rays of cosmic origin, with energies exceeding about 100 PeV. GRAND is envisioned as a collection of large-scale ground arrays of self-triggered radio antennas that target the radio emission from extensive air showers initiated by UHE particles. Three prototype arrays are in operation: GRAND@Nan\c{c}ay in France, GRAND@Auger in Argentina, and GRANDProto300 in China. They test the detection principle and technology of GRAND, in preparation for its next phase, consisting of two arrays of 10'000 antennas each, in the Northern and Southern hemispheres, to be deployed from 2030 on. We present the concept of GRAND, its science goals, the status of the prototypes, their first measurements, and the technical and scientific perspectives that these measurements open for the field.