The European Spallation Source neutrino Super Beam Design Study

Abstract

The discovery of oscillations and the latest progress in neutrino physics will make possible to observe, for the first time, CP violation in the lepton sector, if it exists. This will help to understand the disappearance of antimatter in the Universe. To go further beyond the current knowledge, it is necessary to develop more and more powerful instruments, but also to combine skills by creating strong international networks between researchers. In this framework, the ESSvSB project proposes to use the proton linac of the European Spallation Source (ESS) currently in construction in Lund (Sweden) to produce a very intense neutrino Super Beam, in parallel with the spallation neutron production. The ESS linac is expected to be fully operational by 2023 delivering 5 MW average power, 2 GeV proton beam, with 2.86 ms long pulses at a rate of 14 Hz. By doubling the pulse rate, an average power of 10 MW can be obtained, providing at the same time 5 MW for the neutron facility and the 5 MW for the production of the neutrino beam. The primary proton beam-line completing the linac will consist of an accumulator ring to compress the beam pulses to 1.3 μs and a switchyard to distribute the protons onto the target station. The secondary beam-line producing neutrinos will consist of a four-horn/target station, a decay tunnel and a beam dump. A megaton scale Water Cherenkov neutrino detector will be located at a baseline of about 500 km in one of the existing mines in Sweden, to measure the neutrino oscillations.