Seven years of Tunka-Rex operation

TL;DR

Tunka-Rex, a cost-effective radio detector array in Siberia, has operated for seven years, demonstrating its capability to accurately reconstruct cosmic-ray air-shower parameters and cross-calibrate with other detection techniques, paving the way for future large-scale cosmic-ray and neutrino experiments.

Contribution

This paper provides a comprehensive overview of Tunka-Rex's seven-year operation, including its configuration, analysis improvements, and validation of radio detection techniques for cosmic-ray studies.

Findings

Tunka-Rex can reconstruct cosmic-ray energy and shower maximum with optical detector precision.

Radio detection allows cross-calibration between different cosmic-ray instruments.

The array's data and software are now publicly available for further research.

Abstract

The Tunka Radio Extension (Tunka-Rex) is a digital antenna array located in the Tunka Valley in Siberia, which measures the radio emission of cosmic-ray air-showers with energies up to EeV. Tunka-Rex is externally triggered by the Tunka-133 air-Cherenkov timing array (during nights) and by the Tunka-Grande array of particle detectors (remaining time). These three arrays comprise the cosmic-ray extension of the Tunka Advanced Instrument for cosmic rays and Gamma Astronomy (TAIGA). The configuration and analysis pipeline of Tunka-Rex have significantly changed over its runtime. Density of the antennas was tripled and the pipeline has become more developed forming now sophisticated piece of reconstruction software. During its lifecycle Tunka-Rex has demonstrated that a cost-effective and full duty-cycle radio detector can reconstruct the energy and shower maximum with a precision comparable to optical detectors. Moreover, it was shown that cosmic-ray instruments, that use different detection techniques and are placed in different locations, can be cross-calibrated via their radio extensions. These results show the prospects of application of the radio technique for future large-scale experiments for cosmic-ray and neutrino detection. For the time being Tunka-Rex has ceased active measurements and focuses on the data analysis and publication of corresponding software and data in an open-access data center with online analysis features. In this report we present the current status of the array and give an overview of the results achieved during these years as well as discuss upcoming improvements in instrumentation and data analysis, which can be applied for the future radio arrays.