Collaborative Research: 2016-2019 Development of the Askaryan Radio Array Ultra-High Energy Neutrino Detector at the South Pole

University Of Maryland, College Park, College Park MD

Investigators

Abstract

Ultra-high-energy neutrinos are unique astrophysical messengers that interact weakly with intervening matter and can therefore be used to probe the distant universe. A small but theoretically observable flux of these ultra-high-energy neutrinos is expected to be produced by the interaction between high-energy "cosmic ray" charged particles and cosmic microwave background photons as the cosmic rays travel through the Universe. Observing these cosmogenic neutrinos would allow physicists to begin to study physics at energies beyond the standard models. The large volume of radio transparent ice covering the geographic South Pole in Antarctica has hosted several pioneering efforts to detect these high energies neutrinos using a radio Cherenkov "Askaryan effect." The Askaryan effect describes the process by which ultra-high-energy neutrinos traversing the dense polar ice generate observable radio waves. The Askaryan Radio Array (ARA), located at the South Pole Station, was designed to exploit this phenomenon to first detect and ultimately study these ultra-high-energy neutrinos. This award provides funding to deploy two more ARA stations to the existing suite of three stations, and to continue observations. The award will support the involvement of students, including undergraduate students, who will be engaged in on-site activities at the South Pole. It will also support outreach efforts including activities with QuarkNet. ARA is designed to be implemented in phases. During the initial phase the ARA project deployed a testbed and three full stations that used equipment designed and built for the co-located IceCube Neutrino Observatory. With this award the project will deploy two more stations and continue observations with all stations to demonstrate the technology, accumulate knowledge about radio frequency properties of the upper layers of the ice sheet at South Pole, and develop reliable hardware and software for deployable in-ice stations in the future.