Simulation study for an in-situ calibration system for the measurement of the snow accumulation and the index-of-refraction profile for radio neutrino detectors

Abstract

Sensitivity to ultra-high-energy neutrinos ($E>10^{17}$eV) can be obtained cost-efficiently by exploiting the Askaryan effect in ice, where a particle cascade induced by the neutrino interaction produces coherent radio emission that can be picked up by antennas. As the near-surface ice properties change rapidly within the upper $\mathcal{O}$(100m), a good understanding of the ice properties is required to reconstruct the neutrino properties. In particular, continuous monitoring of the snow accumulation (which changes the depth of the antennas) and the index-of-refraction $n(z)$ profile are crucial for an accurate determination of the neutrino's direction and energy. We present an in-situ calibration system that extends the radio detector station with two radio emitters to continuously monitor the firn properties within the upper 40m by measuring the time differences between direct and reflected (off the surface) signals (D'n'R). We determine the optimal positions of two transmitters at all three sites of current and future in-ice radio detectors: Greenland, Moore's Bay, and the South Pole. For the South Pole we find that the snow accumulation $\Delta h$ can be measured with a resolution of 3mm and the parameters of an exponential $n(z)$ profile $\alpha$ and $z_0$ with 0.04% and 0.14% precision respectively, which constitutes an improvement of more than a factor of 10 as compared to the inference of the $n(z)$ profile from density measurements. Additionally, as this technique is based on the measurement of the signal propagation times we are not bound to the conversion of density to index-of-refraction. We quantify the impact of these ice uncertainties on the reconstruction of the neutrino vertex, direction, and energy and find that the calibration device measures the ice properties to sufficient precision to have negligible influence.

arXiv commentReplaced with published version

References in corpus (24)

• The extragalactic optical-infrared background radiations, their time evolution and the cosmic photon-photon opacity
• The IceCube Neutrino Observatory: Instrumentation and Online Systems
• IceCube-Gen2: The Window to the Extreme Universe
• The IceCube high-energy starting event sample: Description and flux characterization with 7.5 years of data
• Improved Characterization of the Astrophysical Muon-Neutrino Flux with 9.5 Years of IceCube Data
• Performance of two Askaryan Radio Array stations and first results in the search for ultra-high energy neutrinos
• Design and Sensitivity of the Radio Neutrino Observatory in Greenland (RNO-G)
• The LPM effect for EeV hadronic showers in ice: implications for radio detection of neutrinos
• Calculation Methods for Radio Pulses from High Energy Showers
• NuRadioReco: A reconstruction framework for radio neutrino detectors
• Targeting ultra-high energy neutrinos with the ARIANNA experiment
• Measurements and Modeling of Near-Surface Radio Propagation in Glacial Ice and Implications for Neutrino Experiments
• Astrophysics Uniquely Enabled by Observations of High-Energy Cosmic Neutrinos
• NuRadioMC: Simulating the radio emission of neutrinos from interaction to detector
• Cosmic rays in galactic and extragalactic magnetic fields
• Observation of classically `forbidden' electromagnetic wave propagation and implications for neutrino detection
• Neutrino vertex reconstruction with in-ice radio detectors using surface reflections and implications for the neutrino energy resolution
• Modelling ice birefringence and oblique radio wave propagation for neutrino detection at the South Pole
• A low-threshold ultrahigh-energy neutrino search with the Askaryan Radio Array
• Probing the angular and polarization reconstruction of the ARIANNA detector at the South Pole
• Modeling in-ice radio propagation with parabolic equation methods
• Radio Detection of High Energy Neutrinos in Ice
• Impact of biaxial birefringence in polar ice at radio frequencies on signal polarizations in ultra-high energy neutrino detection
• First-principle calculation of birefringence effects for in-ice radio detection of neutrinos