Physics Potential of a Radio Surface Array at the South Pole (ARENA 2018)

A surface array of radio antennas will enhance the performance of the IceTop array and enable new, complementary science goals. First, the accuracy for cosmic-ray air showers will be increased since the radio array provides a calorimetric measurement of the electromagnetic component and is sensitive to the position of the shower maximum. This enhanced accuracy can be used to better measure the mass composition, to search for possible mass-dependent anisotropies in the arrival directions of cosmic rays, and for more thorough tests of hadronic interaction models. Second, the sensitivity of the radio array to inclined showers will increase the sky coverage for cosmic-ray measurements. Third, the radio array can be used to search for PeV photons from the Galactic Center. Since IceTop is planned to be enhanced by a scintillator array in the near future, a radio extension sharing the same infrastructure can be installed with minimal additional effort and excellent scientific prospects. The combination of ice-Cherenkov, scintillation, and radio detectors at IceCube will provide unprecedented accuracy for the study of highenergy Galactic cosmic rays.Comment: Proceedings of 8th ARENA 2018, to appear in EPJ Wo

Air Shower Detection by Arrays of Radio Antennas (ISVHECRI 2018)

Antenna arrays are beginning to make important contributions to high energy astroparticle physics supported by recent progress in the radio technique for air showers. This article provides an update to my more extensive review published in Prog. Part. Nucl. Phys. 93 (2017) 1 [arXiv: 1607.08781]. It focuses on current and planned radio arrays for atmospheric particle cascades, and briefly references to a number of evolving prototype experiments in other media, such as ice. While becoming a standard technique for cosmic-ray nuclei today, in future radio detection may drive the field for all type of primary messengers at PeV and EeV energies, including photons and neutrinos. In cosmic-ray physics accuracy becomes increasingly important in addition to high statistics. Various antenna arrays have demonstrated that they can compete in accuracy for the arrival direction, energy and position of the shower maximum with traditional techniques. The combination of antennas and particles detectors in one array is a straight forward way to push the total accuracy for high-energy cosmic rays for low additional cost. In particular the combination of radio and muon detectors will not only enhance the accuracy for the cosmic-ray mass composition, but also increase the gamma-hadron separation and facilitate the search for PeV and EeV photons. Finally, the radio technique can be scaled to large areas providing the huge apertures needed for ultra-high-energy neutrino astronomy.Comment: Proceedings of the 20th ISVHECRI 2018, Nagoya, Japan (to appear in EPJ WoC

Design and Expected Performance of the IceCube-Gen2 Surface Array and its Radio Component (ARENA2022)

IceCube-Gen2, the next generation of the IceCube Neutrino Observatory at the South Pole, will consist of three co-located arrays: a deep Optical Array and a more shallow and larger Radio Array for neutrino detection in the ice, and a Surface Array above the footprint of the Optical Array. The Surface Array will be comprised of hybrid stations featuring elevated radio antennas and scintillation detectors, following the design of a prototype station successfully operating at the South Pole since 2020. Besides providing a veto for neutrino detection, the Surface Array will make IceCube-Gen2 a unique laboratory for cosmic-ray air showers. Compared to the current IceCube detector with its IceTop surface array, the aperture for coincident air-shower measurements detected by both, the deep optical and surface arrays, will increase by about a factor of 30. In addition to particle physics questions, such as the production of PeV muons and neutrinos in prompt decays, these surface-deep coincidences will be used to target astrophysical questions of the most energetic Galactic cosmic rays. The combination of particle and radio measurements at the surface and high-energy muons measured in the ice promises unprecedented accuracy for the mass composition in the energy range of the presumed Galactic-to-extragalactic transition - complementing the multimessenger science case of IceCube-Gen2. This proceeding provides an overview of the IceCube-Gen2 Surface Array and, in particular, its radio component.Comment: Proceeding of ARENA 202

Status of air-shower measurements with sparse radio arrays

This proceeding gives a summary of the current status and open questions of the radio technique for cosmic-ray air showers, assuming that the reader is already familiar with the principles. It includes recent results of selected experiments not present at this conference, e.g., LOPES and TREND. Current radio arrays like AERA or Tunka-Rex have demonstrated that areas of several km2 can be instrumented for reasonable costs with antenna spacings of the order of 200m. For the energy of the primary particle such sparse antenna arrays can already compete in absolute accuracy with other precise techniques, like the detection of air-fluorescence or air-Cherenkov light. With further improvements in the antenna calibration, the radio detection might become even more accurate. For the atmospheric depth of the shower maximum, Xmax, currently only the dense array LOFAR features a precision similar to the fluorescence technique, but analysis methods for the radio measurement of Xmax are still under development. Moreover, the combination of radio and muon measurements is expected to increase the accuracy of the mass composition, and this around-the-clock recording is not limited to clear nights as are the light-detection methods. Consequently, radio antennas will be a valuable add-on for any air shower array targeting the energy range above 100 PeV