Infrastructure for Detection of High-Energy Neutrinos

Time period: 2019-12-01 to 2019-12-31

Project leader: Olga Botner, Uppsala universitet

Funder: Swedish Research Council

Type of award: Research infrastructure

Total fundning: 7 958 000 SEK

The IceCube Neutrino Observatory at the South Pole is the world´s leading facility for the detection of high-energy neutrinos. Recent breakthroughs include the discovery of a flux of extraterrestrial high-energy neutrinos and the identification of the first likely source of such neutrinos. The infrastructure described here aims at upgrading the performance of IceCube by improving its pointing precision and extending its energy response both to lower energies (a few GeV) and to ultrahigh energies (into the EeV region). Given the wide energy range under consideration, and the different optimal techniques to detect low and high energy neutrinos, the infrastructure consists of two parts: a) A dense array of optical modules in the middle of the current IceCube array (the Deep Ice array), and b) A shallow/surface array of radio antennas. The Deep Ice array will lower the energy threshold of IceCube, allowing precise measurements of fundamental neutrino properties at energies down to 5 GeV. Through the deployment of new calibration devices, it will also provide an improved understanding of the optical properties of the ice. This can be incorporated into the analysis of existing and future data, leading to an improved pointing accuracy. The Radio Array will focus on exploring the ultrahigh-energy universe. The radio technique is a cost effective way to instrument sufficiently large volumes needed for the detection of EeV-neutrinos at the predicted flux level. A Swe­dish contribution to the Deep Ice Array would be timely, valuable and significantly increase the return on the initial investment. It would underscore Sweden’s influential role within IceCube and ensure Sweden’s standing in the future. In addition, we now have a unique opportunity to substantially contribute to the Radio Array by adding a crucial surface component. Activities related to procurement, verification and calibration would take place in Sweden.