A Radio Detector Array for Cosmic Neutrinos on the Ross Ice Shelf

ARIANNA (The Antarctic Ross Ice Shelf Antenna Neutrino Array) is a proposed large detector for ultrahigh energy (above 10¹⁷ eV) astrophysical neutrinos. It will instrument 900 km² of the 550 m thick Ross Ice Shelf (450 km³ total volume) with radio detectors, to study the origins of ultrahigh energy cosmic rays by searching for the neutrinos produced when these cosmic rays interact with the cosmic microwave background. Over 900 independently operating stations will detect the coherent radio Cherenkov emission produced when astrophysical neutrinos with energy above 10¹⁷ eV interact in the Antarctic Ross Ice Shelf. Each station will use 8 log periodic dipole antennas to look for short RF pulses, with the most important frequencies between 80 MHz and 1 GHz. By measuring the pulse polarization and frequency spectrum, the neutrino arrival direction can be determined. In one year of operation, the full array should observe a clear GZK neutrino signal, with different models predicting between 3 and 51 events, depending on the nuclear composition of the cosmic-rays and on the cosmic evolution of their sources.