Detecting ultra-high-energy cosmic rays with prototypes of the Fluorescence detector Array of Single-pixel Telescopes (FAST) in both hemispheres

TL;DR

This paper reports on the development and testing of FAST prototypes in both hemispheres, demonstrating their potential for large-scale ultra-high-energy cosmic ray detection with improved efficiency and cost-effectiveness.

Contribution

It introduces the FAST prototype design, validates its observational capabilities, and discusses progress towards deploying a large-scale mini-array for UHECR detection.

Findings

Prototypes successfully detected UHECR-like events.

FAST design shows promise for cost-effective, large-scale deployment.

Ongoing developments aim to enhance detection efficiency.

Abstract

Ultra-high energy cosmic rays (UHECRs), whose energy are beyond $10^{18}~\mathrm{eV}$, are the most energetic particles we have ever detected. The latest results seem to indicate a heavier composition at the highest energies, complicating the search for their origins. Due to the limited number of UHECR events, we need to build an instrument with an order of magnitude larger effective-exposure to collect UHECRs in future decades. The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a proposed low-cost, easily deployable UHECR detector suitable for a future ground array. It is essential to validate the telescope design and autonomous observational techniques using prototypes located in both hemispheres. Here we report on the current status of observations, recent performance results of prototypes, and developments towards a future mini-array.