Speaker
Description
The polar ice sheets can serve as detection media for neutrinos with energies above 10 PeV. This detection can be achieved by observing Askaryan radiation or measuring in-ice radar echoes from the ionization trail left in the wake of the particle cascade. Ice-based radio neutrino detectors deploy antennas within or near the first 100-150 m of compacted snow, known as the firn layer, where the refractive index increases with depth. Firn density additionally fluctuates over time due to variable surface temperatures and melt events.
We present a simulation study quantifying the variability of in-ice radio signals due to evolving firn density. Glaciological simulations modeled changes in the refractive index profile at Summit Station in Greenland from 1980 to 2021. A radio source was simulated within the ice, and its signal was propagated over a 1 km distance, comparable to the attenuation length of ice. Amplitude fluctuations of signals traversing the firn can reach ~10% or greater. Understanding these effects is vital for accurate reconstruction of neutrino properties.
Additionally, we present preliminary measurements of ice properties and radio propagation at Summit Station as part of the Radar Echo Telescope 2024 summer deployment.
