An improved trigger for Askaryan radio detectors

TL;DR

This paper systematically studies and optimizes trigger strategies for Askaryan radio detectors, demonstrating that bandwidth restriction and trigger scheme choice can significantly enhance sensitivity to high-energy neutrinos.

Contribution

It introduces an optimized trigger approach that improves detector sensitivity by over 50% through bandwidth restriction and compares trigger schemes for better performance.

Findings

Bandwidth restriction to 80-200 MHz improves sensitivity.

Different trigger schemes perform variably depending on detector dispersion.

Optimized triggers can significantly enhance neutrino detection without extra costs.

Abstract

High-energy neutrinos with energies above a few $10^{16}$eV can be measured efficiently with in-ice radio detectors which complement optical detectors such as IceCube at higher energies. Several pilot arrays explore the radio technology successfully in Antarctica. Because of the low flux and interaction cross-section of neutrinos it is vital to increase the sensitivity of the radio detector as much as possible. In this manuscript, different approaches to trigger on high-energy neutrinos are systematically studied and optimized. We find that the sensitivity can be improved substantially (by more than 50% between $10^{17}$eV and $10^{18}$eV) by simply restricting the bandwidth in the trigger to frequencies between 80 MHz and 200 MHz instead of the currently used 80 MHz to ~1 GHz bandwidth. We also compare different trigger schemes that are currently being used (a simple amplitude threshold, a high/low threshold trigger and a power-integration trigger) and find that the scheme that performs best depends on the dispersion of the detector. These findings inform the detector design of future Askaryan detectors and can be used to increase the sensitivity to high-energy neutrinos significantly without any additional costs. The findings also apply to the phased array trigger concept.