In situ, broadband measurement of the radio frequency attenuation length at Summit Station, Greenland

TL;DR

This study measures the radio frequency attenuation length in Greenland ice to improve neutrino detection techniques, revealing a linear frequency dependence and providing key parameters for future radio-based neutrino observatories.

Contribution

It presents the first in situ broadband measurement of radio frequency attenuation length at Summit Station, Greenland, with a detailed frequency dependence analysis.

Findings

Attenuation length averages 1154 meters at 145 MHz

Attenuation length decreases linearly with frequency

Results enhance understanding of ice as a neutrino detection medium

Abstract

Over the last 25 years, radiowave detection of neutrino-generated signals, using cold polar ice as the neutrino target, has emerged as perhaps the most promising technique for detection of extragalactic ultra-high energy neutrinos (corresponding to neutrino energies in excess of 0.01 Joules, or $10^{17}$ electron volts). During the summer of 2021 and in tandem with the initial deployment of the Radio Neutrino Observatory in Greenland (RNO-G), we conducted radioglaciological measurements at Summit Station, Greenland to refine our understanding of the ice target. We report the result of one such measurement, the radio-frequency electric field attenuation length $L_\alpha$. We find an approximately linear dependence of $L_\alpha$ on frequency with the best fit of the average field attenuation for the upper 1500 m of ice: $\langle L_\alpha \rangle = \big( (1154 \pm 121) - (0.81 \pm 0.14) (\nu/$MHz$)\big)$ m for frequencies $\nu \in [145 - 350]$ MHz.